HomeMy WebLinkAboutAttachment #11_Public Comments
ATTACHMENT 11
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Subject:
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Ms Kikuchi:
Myra & Rick <myrickwenzel@gmail.com>
Tuesday, March 02, 2021 8:20AM
Noriko Kikuchi
Case No. 3.4215 MAJ
Mesa0bjection1.pdf; Mesa0bjection2.pdf; Mesa0bjection3.pdf
Attached please find our 3 page timely filed objection to the above referenced.
E.W.Rick Wenzel
1
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March 1 ~ 2021
Noriko Kikuchi
Department of Planning Services
City of Palm Springs
3200 E. Tabquitz Canyon Way
Palm Springs, CA 92262
Dear Ms Kikuchi:
320 W. El Camino Way
Palm Springs, CA 92264
(760) 778·2842
In respo~ to your letter of February 18, 2021, my wife and I file this objection to the Proposed
New Hillside Single-Family Residence on Vacant Parcel (Lot 4) Immediately Adjacent to 294
West Crestview Drive (APN:SI3·361...024).
Location to Proposed Construction.
Our house is the last house on the north side of West El Camino Way at tbe mouth of the
Canyon/Wash. Our property extends into the Canyon/Wash and is adjacent to the subject Lot 4
which extends from the ridge at West Crestview Drive down the Canyon/Wash waU to the
bottom.
Area Bacground.
The proposed construction is in The Mesa neighborhood of Palm Springs which consists of
approximately 180 homes at the base of the San Jacinto Mountains. The area was created in the
1930s and was envisioned as a quaint and private community. AJthough some oftbe private
aspect of the vision bas not been realized, the quaintness has. Moreover, The Mesa is the
personification of eclectic with atchitecrural styles going from Spanish-style and adobe to the
Mid-Centuty modem styles of Donald Wexler and the "simple yet stunning Alexander home on
El C3ltlino at Mesa''.
To say that The Mesa bas a unique charm and character would be an understatemenL
Against that backdrop, we present our objections to the proposed application.
1
RECEIVED
MAR 0 2 2021
PLANNI G SERVICES
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t. The Projected Contttuetion Is Excessively BulkY fgr the Site.
The project consists of a 2889 SF house, 776 SF attached garage, pool and spa. The project
encompasses 4S 15 SF of a 15,173 lot with the ridge portion of the lot of insufficient area to
support the entire structure thereby requiring the use of ailspace for the back of the structure to be
supported by piers into \he Canyon/Wash wall.
When the dimensions of 8 house exceed the dimensions of the lot on which jt is to sit, that is the
definition of excessive and bulky.
Therefore, the appUcation must be denied.
2. The Natural agd Existina= i;ontours of the Canyon/Wash are Spoiled.
Because the structure is of excessive bulk and scale requiring supporting piers to be impJanted in
the wall of the Canyon/Wash, those supporting piers spoU the natural and existing contours of the
Canyon/Wash thereby introducing unnatural features -i.e., concrete piers, in an otherwise natural
setting,
Therefore, the application must be denied.
3. The Project is Incompatible with the Desip of the Existin& Architeeture.
The Mesa is an eclectic mix of architectural styles with that mix no more evident than in the
surrounding homes on the ridge. The massive, overbearing design of the project would negatively
dominate those homes and conflict with the charm and character of the Mesa neighborhood.
Therefore, the application must be denied.
4. The Canyon is a Natural Watenhecl Necessitatinc an Absenq o[ Obstruction
The area in question is at the base of the San Jacinto Mountains. It is the natural recipient of
runoff .from the mountains and is the common outlet for any resulting outflow.
That outflow was never more pronounced than on V aJentines Day 2019. The JUDOff that ensued
on that day came down the mountain. duougb the Canyon/Wash and down West El Camino Way
to Mesa Drive and South Palm Canyon Drive. It can only be described as 8 raging torrent of water
that would take no prisonefl. To liken it to the roaring rapids of the American River in
Sacramento would not be an injustice to the American River,
That event alone, even if it ~only occasionally, requires the use of ultimate restraint when
considering projects which impact areas susceptible of doing great harm.
2
RECEIVED
MAR 0 2 2021
PLAN lNG SERVICES
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The implantation of concrete piers in the walls of a natural watershed creates an obstruction of
unknown effect with the possibility of doing great harm.
Therefore, the application must be denied.
Conclusion.
Whether the proposed construction is viewed from an environmental or aesthetic viewpoint, the
question is whether it wiU enhance or detract. From OW' vantage point, the answer is cJear. The
project must not be approved.
Thank you.
3
RECEIVED
MAR 0 2 2021
PLANNING SERVICES
COMMENTS ON PROPOSED NEW HILLSIDE SINGLE FAMILY RESIDENCES
VACANT PARCELS 4 AND 5 ADJACENT TO 294 W CRESTVIEW
• Developer bought 5 lots as part of one parcel
• Although he has filed plans for just 2 houses, it is clear he intends to build out all 5, thus
it makes sense to take into account the near future use of all 5 of this HILLSIDE LOT
DEVELOPMENT .
• These lots are part of the wash and two parcels are in a small area that overlooks the
wash. These parcels are proposed to be build on the wash
• There have been no environmental, seismic or community studies submitted on how this
proposed housing development will affect the area
• The 2 eastern most lots, which include lot 4 { proposed 4500SF house , swimming pool ,
deck etc) overlap with a FEMA FLOOD ZONE, which starts toward the bottom of the
wash and, bounded by W Crestview and El Camino, extends toward Mesa Drive This is
shown on a Riverside County property website .
• There needs to be a Natural Hazard Report confirming that the wash is a flood zone
were these parcels are located
• The lots are all located in a wash which serves as rainfall runoff drainage during times of
heavy rain , a phenomenon occurring with more frequency as a result of climate change.
Last active runoff through this wash/canyon was during the storm 2/14/2019. Other
flooding has occurred on almost a yearly basis.
• The proposed houses , at 4500 and 3500 SF are much larger than all other houses in
the immediate neighborhood defined by upper W Crestview, Ridge Road and El Camino
• West Crestview Road is only 20' wide at the building sites. City ordinance for new
hillside development mandates 36' curb to curb width.
• Architecturally no effort has been made to be harmonious with the existing homes .
Proposed houses are large white rectangles that make no effort to integrate into the
topography as well
• There is no street parking and almost no off street parking at the site and in a radius
around the site to accommodate the construction machinery and all the work trucks that
will be required by the construction crews and tradespeople
• The building process will severely restrict access of emergency and delivery vehicles,
raising public safety concerns.
• The Mesa neighborhood is a quite and peaceful area that many walk with their dogs
• Part of The Mesa's charm is the local residents that meet up during these outings.
• There are no sidewalks, so the narrow streets are shared by the pedestrians and cars
RECEIVED
MAR 0 2 2021
PLA ~NG S~J--lV iC E S
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From:Beck, Carly@Wildlife
To:Planning; Noriko Kikuchi
Cc:Thomas, Alicia L; Noelle Ronan (noelle_ronan@fws.gov); Pert, Heather@Wildlife
Subject:CDFW Comments for the City of Palm Springs Planning Case Numbers 3.4215 MAJ, Case 3.4216 MAJ, and Case
3.4273DP
Date:Tuesday, January 25, 2022 6:58:07 PM
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Hello,
The California Department of Fish and Wildlife (CDFW) is providing comments on Case 3.4215 MAJ,
Case 3.4216 MAJ, and Case 3.4273DP scheduled to go before the City of Palm Springs Planning
Commission, Public Hearing on January 26th, 2022. The City of Palm Springs is located within the
boundaries and is a permittee to the Coachella Valley Multiple Species Habitat Conservation Plan
(MSHCP). Case 3.4273DP occurs within or directly adjacent to the Santa Rosa and San Jacinto
Mountains Conservation Area described in the MSHCP. All three projects contain fish and wildlife
resources that are subject to Fish and Game Code section 1600 et seq. and have potential impacts to
the fully protected Peninsular bighorn sheep.
CDFW issued Natural Community Conservation Plan Approval and Take Authorization for Coachella
Valley MSHCP per Section 2800, et seq., of the California Fish and Game Code on September 9, 2008.
The MSHCP establishes a multiple species conservation program to minimize and mitigate habitat
loss and provides for the incidental take of covered species in association with activities covered
under the permit. Compliance with approved habitat plans, such as the MSHCP, is discussed in
CEQA. Specifically, Section 15125(d) of the CEQA Guidelines requires that the CEQA document
discuss any inconsistencies between a proposed project and applicable general plans and regional
plans, including habitat conservation plans and natural community conservation plans. An
assessment of the impacts to the MSHCP as a result of a proposed project is necessary to address
CEQA requirements.
The proposed project, Case 3.4273DP, is within or directly adjacent to the MSHCP conservation area
and is subject to the provisions and policies of the MSHCP. In order to be considered a covered
activity, Permittees need to demonstrate that proposed actions are consistent with the MSHCP, the
Permits, and the Implementing Agreement. CDFW recommends that the City of Palm Springs consult
with the Coachella Valley Conservation Commission on Case 3.4273DP to ensure proper
implementation of the MSHCP. If the project boundaries are within the Santa Rosa and San Jacinto
Mountains Conservation Area a Joint Project Review may be required for the project. This process is
outline within the Implementation Agreement Section 11.2.4 and within the MSHCP Section 6.6.1.1.
If the project is not within but adjacent to the Santa Rosa and San Jacinto Mountains Conservation
Area then the City of Palm Springs should condition the project to implement the Land Use
Adjacency Guidelines set forth in Section 4.5 and, if necessary, the species objectives for Peninsular
bighorn sheep Section 9.8.4 of the MSHCP.
Additionally, CDFW was informed that the City of Palm Springs staff gave instruction during a public
hearing that citizens could place water out for Peninsular bighorn sheep. CDFW is providing the
following information for City Staff as guidance regarding Peninsular bighorn sheep. Peninsular
bighorn sheep is an endangered and fully protected species. The best way for the public to support
the recovery of Peninsular bighorn is by observing them from afar, respect sheep habitat by leaving
no trace, and removing unnatural attractants within the adjacent urban environment. Providing food
and or a water source for Peninsular bighorn sheep is considered as an attractant. Feeding or
providing water to Peninsular bighorn sheep, classified as non-game, is a violation of the California
Code of Regulations, Title 14, subdivision 251.1 and is punishable by a fine or of a misdemeanor, as it
disrupts the normal behavioral patterns of Peninsular bighorn sheep, especially in desert habitats,
and is considered harassment. For your convenience the California Code of Regulations, Title 14,
subdivision 251.1 is provided below.
Cal. Code Regs., tit. 14, § 251.1Harassment of Animals.
Except as otherwise authorized in these regulations or in the Fish and Game Code, no
person shall harass, herd or drive any game or nongame bird or mammal or furbearing
mammal. For the purposes of this section, harass is defined as an intentional act which
disrupts an animal's normal behavior patterns, which includes, but is not limited to,
breeding, feeding or sheltering. This section does not apply to a landowner or tenant
who drives or herds birds or mammals for the purpose of preventing damage to private
or public property, including aquaculture and agriculture crops.
Lastly, all three projects appear to have streams subject to Fish and Game Code section 1600 et seq.
Depending on how the Project is designed and constructed, it is likely that the project’s applicant will
need to notify CDFW per Fish and Game Code section 1602. Fish and Game Code section 1602
requires an entity to notify CDFW prior to commencing any activity that could substantially divert or
obstruct the natural flow; change or use any material from the bed, channel or bank of any river,
stream, or lake; or deposit debris, waste or other materials that could pass into any river, stream or
lake. This includes ephemeral streams, desert washes, and watercourses with a subsurface flow.
Upon receipt of a complete notification, CDFW determines if the proposed Project activities may
substantially adversely affect existing fish and wildlife resources and whether a Lake and Streambed
Alteration (LSA) Agreement is required. CDFW’s issuance of an LSA Agreement is a “project” subject
to CEQA (see Pub. Resources Code § 21065). To facilitate issuance of an LSA Agreement, if
necessary, a CEQA document should fully identify the potential impacts to the stream, or riparian
resources, and provide adequate avoidance, mitigation, and monitoring and reporting
commitments.
CDFW would like to request the status of MSHCP implementation and any conditions of approval
that have been assigned to the above projects. Should you have any questions please contact me at
Carly.Beck@wildlife.ca.gov.
Sincerely,
Carly Beck
Senior Environmental Scientist (Specialist)
Inland Deserts Region
California Department of Fish and Wildlife
3602 Inland Empire Blvd., Suite C-220
Ontario, CA 91764
951-218-2940
From:Miranda, Salomon@DWR
To:Amanda Ross; Noriko Kikuchi; Rick Minjares
Cc:Trushinski, Brian (brian.j.trushinski@fema.dhs.gov); Soule, Kelly@DWR; Duncan, Anntonette@DWR; Tam Sing, Garret@DWR; Marquez, Maria@DWR
Subject:310 & 322 Crestview Drive, Palm Springs
Date:Wednesday, February 16, 2022 4:48:00 PM
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Hi Amanda,
Let me again thank you for the insightful conversation last Monday and for the opportunity to comment on the proposed structures located at 310 and
322 Crestview Drive, Palm Springs, CA, and the plans for future development in the 3 empty lots (APNs: 513-352-022, 513-352-020, and 513-352-021)
located north of 310 and 322 Crestview Drive, and bounded by Ridge Rd. to the north and El Camino Way to the south (see Fig. 4).
After our conversation, I conducted a research on the subject matter as it relates to the National Flood Insurance Program and the City’s Flood Damage
Prevention Ordinance (Chapter 8.68 of the City’s Municipal Code), which covers all development standards within the Federal Emergency Management
Agency’s special flood hazard areas for the City of Palm Springs. During my investigation I met with City of Palm Springs’ staff to go over the proposed
project and development permit process. After my meeting with the City, it is fair to say that there is no evidence that the other 3 empty lots (APNs:
513-352-022, 513-352-020, and 513-352-021) shown in Fig. 4 are being part of any future development – no permit application for these lots exists at
this time. Therefore, the focus of my investigation was on the proposed structures located at 310 & 322 Crestview Drive only.
Here are my findings:
Address: 310 Crestview Dr. (APN 513-361-024)
FEMA’s Flood Insurance Rate Map (FIRM) number: 06065C1566G
FIRM Effective Date: 8/28/2008
Flood Hazard Designation: the northeast portion of this lot is located in FEMA’s Zone AO- Depth 1-ft flood hazard designation (see Fig. 2, and 3
below)
Zone AO Definition:
Areas subject to inundation by 1-percent-annual-chance shallow flooding (usually sheet flow on sloping terrain) where average depths are
between one and three feet. Average flood depths derived from detailed hydraulic analyses are shown in this zone. Mandatory flood
insurance purchase requirements and floodplain management standards apply.
Some Zone AO have been designated in areas with high flood velocities such as alluvial fans and washes. Communities are encouraged to
adopt more restrictive requirements for these areas.
Drainage: During our conversation we discussed drainage and potential flow path obstructions this structure might cause. As you already know,
the City is already seeking, from the developer, a hydrology/hydraulic analysis to address any adverse impacts. The City is also conditioning the
building to conform with its drainage policies.
Site Plan and Setbacks (Fig. 5-6):
Special flood hazard area boundary extends nearly 42.2-feet from the lot’s north boundary line.
foundation of the proposed structure is more than 56-feet from the lot’s north boundary line (nearly 14-ft away from the special flood
hazard area).
contour elevations (Fig. 5) show a difference of +10-feet between the foundation and the bottom of the tributary.
Conclusion: based on my research, I conclude that if the structure is built as proposed, then it’ll be outside the FEMA’s special flood hazard
area.
Fig1. Lot boundary
Fig. 2: FEMA’s Map Service Center https://msc.fema.gov/portal/search?AddressQuery=310%20crestview%20rd.%20palm%20springs%2C%20ca
Fig. 3: ArcGIS – special flood hazard area and lot overlay
Fig. 4: APNs: 513-352-022, 513-352-020, and 513-352-021
Fig. 5: 310 Crestview Dr. Site Plan
Fig. 6: SFHA is about 42.2 feet from the lot boundary.
ADDRESS: 322 Crestview Rd (APN 513-361-003)
Conclusion: lot is outside the FEMA’s special flood hazard area.
Salomon Miranda, P.E., MS, ManagerWater Management BranchSouthern Region OfficeCA Department of Water Resources770 Fairmont Avenue, Suite 200Glendale, California 91203818.549.2347
STRUMWASSER & WOOCHER LLP
ATTORNEYS AT LAW
MICHAEL J. STRUMWASSER 10940 WILSHIRE BOULEVARD, SUITE 2000 TELEPHONE: (310) 576-1233
BRYCE A. GEE LOS ANGELES, CALIFORNIA 90024 FACSIMILE: (310) 319-0156
BEVERLY GROSSMAN PALMER WWW.STRUMWOOCH.COM
DALE K. LARSON
CAROLINE C. CHIAPPETTI FREDRIC D. WOOCHER
JULIA G. MICHEL † ANDREA SHERIDAN ORDIN
SALVADOR E. PÉREZ SENIOR COUNSEL
† Also admitted to practice in Washington
February 22, 2022
Via email to planning@palmsprings.ca.gov
Planning Commission
City of Palm Springs
3200 East Tahquitz Canyon Way
Palm Springs, CA 92262
Re: February 23, 2022 Agenda Items 3A and 3B: 310 and 322 West Crestview Drive
To the Honorable Planning Commission:
This firm writes on behalf of member of The Mesa Neighborhood Organization, the
official neighborhood association of The Mesa neighborhood, a hillside community of nearly
200 homes occupied by full and part time residents of Palm Springs. The Mesa Neighborhood
Organization is concerned that the proposed residential construction at 310 and 322 West
Crestview Drive (“the projects”) are being improperly exempted from review under the
California Environmental Quality Act (“CEQA”). The proposal to build these two houses must
be considered along with applicant’s publicly stated intention to build homes on two additional
parcels also owned by the applicant. Moreover, special circumstances apply to the construction
of two new homes in this area bordering on large expanses of undeveloped hillside that make the
application of the CEQA exemption improper. Lastly, flood control concerns must be fully
studied and addressed prior to approval of these projects to ensure that flooding is not an issue
for either the future residents, or for existing homeowners that could be adversely implicated by
alterations in natural flood and drainage patterns. These two proposed projects should be
considered along with the other foreseeable development on these five lots and a full
environmental analysis should be conducted prior to approval of any of the houses.
The Projects Are Proposed for Steeply Sloping Lots, and 322 West Crestview Contains
Structural Walls on Slopes Greater than 30 Percent
The two projects listed in Agenda Items 3A and 3B are the development of single-family
homes on steeply sloped hillside parcels. The single-family home structure at 310 West
Crestview is proposed at 3,278 square feet; at 322 West Crestview the proposal is for a 3,344
square foot home.
Neither structure complies with the zoning code requirements. The structure at 310 West
Crestview requires an increase in maximum allowable building height (from 12-18 feet to 23.6
Planning Commission
February 22, 2022
Page 2
feet) and a front yard setback reduction (from 25 feet to 10 feet). The structure at 322 West
Crestview also requests a height increase (from 12-18 feet to 25.8 feet) and a reduced front yard
setback (from 25 feet to 10 feet).
The staff report notes that for the 322 West Crestview property, “the structural walls will
be located in the area which is more than 30% in slope. Considering the area, support structures
that minimize their impact on the natural hillside topography are highly desired. A condition of
approval is proposed to revise the design and improve conformance with this finding.”
The Palm Springs Municipal Code contains specific hillside development standards
regarding slope. While these standards apply initially to the permissible density of a site
development, they also make clear that slopes over 30 percent are inappropriate locations for
building. Municipal Code section 93.13.00 C3 explains that areas with a slope greater than 30
percent shall not be included in the allowable area for density calculation, and such area “shall be
retained as open space.” The standards further requires that the City must “insure permanent
retention of the open space,” by recording a covenant on it.
Of course, The Mesa subdivision long pre-dates these hillside standards, but that does not
mean that the standards should be ignored when approving these specific developments. The
staff recommendation includes a condition of approval for the 322 site to require “review and
approval by the ARC” for the proposed structural wall. These issues should not be deferred for
future review; the applicant should be required to submit a satisfactory proposal at the time of
project approval.
The Projects Are Part of a Larger Development Proposal of this Applicant
While each address is listed as a separate approval and agenda item, there is no mistaking
that these two residences are being considered in tandem. For instance, the presentation of mass
and scale and the visual simulations of the residences are included together for each item. The
applicant and staff recognize that the structures must be considered together to fully and properly
evaluate the aesthetic and other impacts of the proposed construction in this sensitive and historic
residential area.
It is therefore critical for the Planning Commission to be aware that these properties on
Crestview are not the only properties on which this applicant intends to develop homes in the
foreseeable future. As the applicant’s representative owner Eric Krut made abundantly clear
during the July 20, 2021 Architectural Review Committee (“ARC”) meeting, the ownership
owns five lots that are adjacent to each other. As Mr. Krut stated:
“In so much as density affects the residential aspect, we are willing to make a one
time offer of reducing the density of this entire project from five lots to four lots.
We will combine the remaining three lots into two lots. This of course is a
considerable loss of value and of eventual profit, but in the hopes of minimizing
time and expense of this process, which has been significant, since the last
meeting . . . I wanted to make that clear to the neighbors listening, and so much as
it might affect the perception of this project by the Committee, of our willingness
to reduce the density by twenty percent.”
Planning Commission
February 22, 2022
Page 3
The parameters of the “one time offer” were not made express, but what is clear is that
either two or three additional homes to the two that are before the Planning Commission will be
requested by this same applicant, in the foreseeable future. The fact that two or three other
homes will be developed by the same applicant in the same vicinity is a relevant consideration
for the Planning Commission that has not been addressed by the staff’s analysis.
A member of the ARC raised this issue, noting that previously the ARC had viewed the
project as only two homes and now it was clearly a larger project. The applicant did not refute
this conclusion, stating:
“I own five lots, and I’m willing to go from five lots to four lots. The construction
will certainly impact the neighborhood via noise and road disturbance, of course.
I heard that loud and clear at our first neighborhood meeting, and I’m responding
to it, in a very positive and a very costly way. If that’s not appreciated, that’s fine,
and we’re fine staying with five lots. It’s certainly a more profitable project for
me ultimately. But I thought that was a grand concession, in the large scheme of
things.”1
The Planning Commission must therefore consider not only the impacts of constructing
the two homes on West Crestview, but the full impact of the acknowledged development project
to construct homes on the three other lots owned by this applicant along El Camino Way and
Ridge Road.
CEQA Obligation to Review Full Impacts of Proposed Development Plan
It has been black letter law nearly since CEQA was enacted by the Legislature that
review of a project’s environmental impact requires examination of the environmental impacts of
the proposed project and all reasonably foreseeable related development. (See Bozung v. Local
Agency Formation Com. (1975) 13 Cal.3d 263, 283-284 [CEQA mandates “that environmental
consideration do not become submerged by chopping a large project into many little ones – each
with a minimal potential impact on the environment – which cumulatively may have disastrous
consequences.”].) In that case, a request that included “only ‘those properties anticipated to be
developed in the near future’ indicate[d] that at some point [the developer] intend[ed] to develop
a further part or all of its holdings.” (Id., p. 284.) In Arviv Enterprises, Inc. v. South Valley Area
Planning Comm. (2002) 101 Cal.App.4th 1333, the court considered an applicant who had
serially proposed two house construction projects, multiple times, attempting to mask that the
developer planned to construct 21 homes in total, and agreed that the City’s determination to
require an environmental impact report was appropriate. (Id., p. 1346.)
Even if it were only the two homes that would be developed (and that is not the case), the
impacts of construction of both homes must be considered, together. While the reports on each
1 The July 20, 2021 ARC meeting video may be viewed at
https://www.youtube.com/watch?v=iT2V9Mkde9U&list=PLS_Hi1VCi766sgDTtvZDe9XtXzQu
mg317&index=81. These comments appear between 33:30 and 36:30.
Planning Commission
February 22, 2022
Page 4
item include images and some discussion of the other home, there is no discussion of ways to
reduce impacts of construction by either staging construction or ensuring that combined noise
impacts will not significantly disturb sensitive receptors like the federally listed endangered
species, the Peninsular bighorn sheep. At a minimum, the City must consider the cumulative
impacts of the construction of these two homes at the same or similar times, as the approvals
expire in two years.
The City has required environmental review for a similar project in the recent past. In
2018 the City prepared a mitigated negative declaration for a request to subdivide a 1.7 acre
parcel into two lots for the creation of single-family zoned lots. (See
https://www.palmspringsca.gov/home/showdocument?id=58339.) Like the instant proposal,
those lots were steep hillside lots. A difference is that that these lots were subdivided long ago,
but the environmental impacts of that subdivision were never assessed pursuant to CEQA.
Of course, as set forth above, the applicant has admitted in a public hearing that he fully
intends to develop at least two, if not three, additional homes on his property. The subdivision
here was created in the 1920s or 30s, well before today’s environmental concerns were known
and considered. So while a legal subdivision is no longer required, that does not mean that the
environmental impacts of the further development of that subdivision can be ignored. A
proposal to develop four or five homes on these hillside properties would certainly not be exempt
from environmental review; the Planning Commission should not turn a blind eye to the admitted
plans to develop the remainder of the parcels.
The Full Residential Project Does Not Satisfy the Categorical Exemption
The proposed resolutions note that the two structures are exempt under CEQA Guidelines
section 15303(a), which is a categorical exemption from CEQA review for “[o]ne single-family
residence . . . in urbanized areas, up to three single-family residences may be constructed or
converted under this exemption.” CEQA defines “urbanized area” as “a central city or group of
contiguous cities with a population of 50,000 or more, together with adjacent densely populated
areas having a population density of at least 1,000 persons per square mile.” (CEQA Guidelines
§ 15387.)
Exemptions to CEQA are narrowly construed and “[e]xemption categories are not to be
expanded beyond the reasonable scope of their statutory language.” (Mountain Lion Foundation
v. Fish & Game Com. (1976) 16 Cal.4th 105, 125.) While the contours of what constitutes an
“urbanized area” may be subject to debate, the project location is most certainly not densely
populated or anything like an urban core. More importantly, the project, including the homes
that are planned for development on the other parcels, exceed the three single-family home limit
on the categorical exemption. Because the scope of exemptions must be strictly construed, and
because CEQA forbids “chopping a single project into smaller bits,” the full scope of the
potential (and admitted) development plan must be included when evaluating the propriety of
this categorical exemption. The categorical exemption is improper and should not be relied
upon.
Planning Commission
February 22, 2022
Page 5
Categorical Exemption is Additionally Improper Due to Exceptions to the Exemption,
Unusual Circumstances, and Cumulative Impacts
Even if the categorical exemption for single-family homes could be properly applied to
the project and the other residences planned for the adjacent sites, unusual circumstances make
the application of the exemption improper.
CEQA Guidelines section 15300.2(s) provides that “[a] categorical exemption shall not
be used for an activity where there is a reasonable possibility that the activity will have a
significant effect on the environment due to unusual circumstances.” The Supreme Court has
explained that “[a] party invoking the exception may establish an unusual circumstance without
evidence of an environmental effect, by showing that the project has some feature that
distinguishes it from others in the exempt case, such as its size or location. In such a case, to
render the exception applicable, the party need only a show a reasonable possibility of a
significant effect due to that unusual circumstance.” (Berkeley Hillside Preservation v. City of
Berkeley (2015) 60 Cal.4th 1086, 1105.) The determination of whether there is a “reasonable
possibility” of a significant environmental effect is determined by application of the “fair
argument” standard. (Id. at p. 1115.) The “fair argument” standard has been characterized as
setting a “low threshold requirement for initial preparation of an EIR and reflect[ing] a
preference for resolving doubts in favor of environmental review when the question is whether
any such review is warranted. [Citations.]” (Sierra Club v. County of Sonoma (1992) 6
Cal.App.4th 1307, 1316-1317.)
Here, there is substantial evidence that the project presents unusual circumstances that are
not typically present for newly constructed single-family homes. And there is more than a “fair
argument” that these unusual circumstances may lead to a significant environmental impact.
Unusual Circumstance: Peninsular Bighorn Sheep Habitat
The project is proposed for construction on hillside property, very close to the edge of the
mountainous portion of Palm Springs that is known habitat for the federally endangered
Peninsular bighorn sheep. The location of these properties in an area that is known to serve as a
grazing and foraging ground for an endangered species is a characteristic that distinguishes these
homes from a typical single-family home. That this area is home to bighorn sheep can be
established by the testimony of residents who have observed them. Below are photos and videos
by residents taken in the immediate vicinity of the parcels slated for future development, just
north of the two lots listed in the agenda items. This evidence makes clear that bighorn sheep
utilize the area in the immediate vicinity of the proposed development.
Planning Commission
February 22, 2022
Page 6
From Ring camera at 356 Ridge Rd. Right click and open in browser to play video.
January 2021, wash behind W. Crestview
Planning Commission
February 22, 2022
Page 7
From 355 Ridge Road
From 355 Ridge Road
Planning Commission
February 22, 2022
Page 8
Right click and open in browser to play video.
Because the bighorn sheep constitute an “unusual circumstance” from the typical single-
family home site, the next step is to consider whether the record supports a “fair argument” that a
significant impact on the bighorn sheep is a reasonable probable consequence of construction of
the project.
CEQA Guidelines Appendix G, the Environmental Checklist Form, provides a tool for
local governments to utilize to determine whether a project may have a potentially significant
environmental impact. One factor is whether a project will “have a substantial adverse effect,
either directly or through habitat modifications, on any species identified as a candidate,
sensitive, or special status species in local or regional plans, policies, or regulations, or by the
California Department of Fish and Game or U.S. Fish and Wildlife Service?”
The Peninsular bighorn sheep were listed as an endangered species by the U.S. Fish and
Wildlife Service in 1998, and the federal government revised its “critical habitat” for Peninsular
bighorn sheep in 2007-2009. The 2007 proposed rulemaking that sought comment on proposed
critical habitat designations sets forth some of the key characteristics and challenges to this
endangered species.2 These sheep occupy moderate to steep open slopes, canyons and washes,
ranging from 300 to 4,600 feet in elevation. (Exhibit 1, p. 2.) “A wide range of forage resources
and vegetation associations are required by this subspecies to meet annual and drought-related
variations in forage quality and availability. . . Valley floors, rolling hills, and alluvial fans and
2 The entire October 10, 2007 Federal Register Notice (72 FR 57740) is included as Exhibit 1 to
this letter.
Planning Commission
February 22, 2022
Page 9
washes with productive soils provide seasonal vegetations and water resources important to the
Peninsular bighorn sheep, especially for ewes during the reproductive season.” (Ibid.) In 2006,
it was estimated that there were only 21 sheep in the San Jacinto Mountains near Palm Springs.
(Ibid.) Today, the Bighorn Institute estimates that there are roughly 85 sheep, so the population
has increased but still remains endangered.
The species is particularly threatened by habitat loss due to construction and
development. The U.S. Fish and Wildlife Service noted that “[h]abitat loss (especially in canyon
bottoms), degradation, and fragmentation associated with the proliferation of residential and
commercial development, roads and highways, water projects, and vehicular and pedestrian
recreational uses threaten the Peninsular bighorn sheep throughout its range. (Id. at p. 6.)
Moreover, “[d]evelopment adjacent to and within Peninsular bighorn sheep habitat affects the
quality and quantity of lower elevation habitat and associated vegetation, alluvial fans, and water
sources.” (Id. at p. 7.) The critical habitat designation rulemaking specifically identified lands in
Palm Springs as losing significant habitat in the form of low elevation alluvial fans and washes
that “provided important sources of nutrients to ewes when they are rearing their lambs.” (Ibid.)
The U.S. Fish and Wildlife Service also published a “Recovery Plan for Bighorn Sheep in
the Peninsular Ranges, California,” in 2000.3 The Recovery Plan lays out in detail some of the
specific challenges for bighorn sheep, including particularly pregnant and nursing ewes. “Failure
to acquire sufficient nutrients during the last two months of gestation and during nursing can
adversely affect the survival of newborn ungulates.” (Exhibit 2, p. 8.) “An important
consideration in the conservation of Peninsular bighorn sheep is their behavioral response to
humans and human activity. Bighorn have been considered a wilderness animal because they do
not thrive in contact with human development. . . . Though the effect of human activity in
bighorn habitat is not always obvious, human presence or activity in many cases has been found
to detrimentally alter normal behavioral and habitat use patterns.” (Id., p. 14.) A study of captive
bighorn in 1999 found few lambs born that year survived, and noted that during the lambing
season that year, “captive bighorn were observed fleeing from the feeding area in response to
construction noise from nearby development projects on multiple occasions. . . . Stress resulting
from human disturbance may have played a role in predisposing captive lambs to disease.” (Id.,
p. 19.) “Habitat loss is a leading cause of current species extinctions and endangerment. It
represents a particularly serios threat to Peninsular bighorn sheep because they live in a narrow
band of lower elevation habitat that represents some of the most desirable real estate in the
California desert and is being developed at a rapid pace.” (Id. at p. 38.)
Based upon these scientific studies, there is more than a “fair argument” that construction
of two to five homes in an area frequented by the endangered bighorn sheep could have a
substantially adverse effect, either directly or by habitat modification, on the bighorn sheep. The
habitat in the wash at the rear of the two West Crestview properties is utilized by bighorn sheep,
who will likely be deterred from visiting these sites during periods of noisy construction. These
kind of disturbances are documented to be particularly detrimental to pregnant or nursing ewes
and their lambs. Analysis of the potential impacts on this sensitive species is required and
3 The full Recovery Plan is included as Exhibit 2 to this letter.
Planning Commission
February 22, 2022
Page 10
mitigation measures must be imposed to prevent any impacts. For this reason, review under
CEQA is required prior to the approval of the projects on West Crestview along with the related
adjacent future development.
Unusual Circumstance: Hydrology and Flood Issues
The project’s location presents an additional unusual circumstance: its location in and
immediately adjacent to a mapped 100-year floodplain. The map below, while not encompassing
the full jurisdiction, shows that the location of a residential development within and next to a
mapped flood hazard area is unusual within the City of Palm Springs. The light blue areas on the
map are the mapped Special Flood Hazard Areas. Because most homes are not located in these
areas, the location of the 310 and 322 West Crestview parcels in the floodplain is an unusual
circumstance for purposes of the exceptions to the single family residential exemption.
CEQA Guidelines Appendix G includes multiple questions relevant to the proximity of
housing in or near a floodplain, demonstrating that there is a reasonable possibility that
construction on the West Crestview properties will have a significant environmental impact.
Planning Commission
February 22, 2022
Page 11
Appendix G asks whether the project will “[p]lace housing within a 100-year flood hazard area
as mapped on a federal Flood Hazard Boundary or Flood Insurance Rate Map or other flood
hazard delineation map?” or “[p]lace within a 100-year flood hazard area structures which would
impede or redirect flood flows?” Similarly, Appendix G also queries whether the project would
“[s]ubstantially alter the existing drainage pattern of the site or area . . . in a manner which would
result in flooding on- or off-site?”
In spite of the obvious risk to the safety of life and structures associated with floodplains,
the proposed approval defers full study to a later time, an issue discussed in further detail below.
Without specifying the measures taken to address the proximity of the floodplain to these
projects, there is a reasonable possibility that the project’s location in and near the mapped
floodplain will lead to significant environmental impacts, making reliance on the exemption
improper.
Environmental Resource Exception
CEQA Guidelines section 15300.2(a) provides that the Class 3 exemption for single-
family homes may not be applied “where the project may impact on an environmental resource
of hazardous or critical concern where designated, precisely mapped, and officially adopted
pursuant to law by federal, state, or local agencies.” In Salmon Protection & Watershed Network
v. County of Marin (2004) 125 Cal.App.4th 1098, the court held that construction of only one
single-family home was not exempt from CEQA because the home site was adjacent to a
protected anadromous fish stream within a stream conservation area. (Id., pp. 1106-1107.)
Moreover, relying on project conditions or mitigation measures in order to state that the project
had no environmental impact was an improper basis for a CEQA exemption. (Id., pp. 1107-
1108.)
The Peninsular bighorn sheep is, as discussed above, a specific environmental resource
that has been designated as an endangered species. The species is known to occupy the area
where the proposed projects are to be constructed.
In addition, as discussed in more detail below, at least a portion of the project is slated to
be constructed in the mapped flood hazard area, which is a hazardous resource that is precisely
mapped, meeting the specific terms of the above quoted exception. The project cannot rely on
the Class 3 exemption because of the location of these residences adjacent and within the
mapped flood hazard area.
Cumulative Impact: Future Development
CEQA Guidelines section 15300.2(b) prohibits reliance on an exemption when “the
cumulative impact of successive projects of the same type in the same place, over time is
significant.” While it is most appropriate to consider the construction of the five lots that
applicant owns and has clearly stated an intent to develop as part of the singular project to be
evaluated by the City, at a minimum the cumulative impact of the construction of these four or
five homes would render reliance on the exemption improper. Particularly where construction
impacts are so disturbing to a sensitive endangered species like the bighorn sheep, the
Planning Commission
February 22, 2022
Page 12
cumulative impacts of successive construction must be addressed, and the use of an exemption is
improper.
Flooding and Hydrology Must Be Fully Addressed Prior to Approval
There can be no doubt that the two West Crestview properties are located just beyond the
demarcation line where floodplain studies have not yet extended. The images below are of flood
waters rushing down El Camino Way downstream of the demarcation line, in the special flood
hazard area, illustrating the significant quantity of flood water that moves through this area
directly downhill from the proposed homes.
Planning Commission
February 22, 2022
Page 13
Planning Commission
February 22, 2022
Page 14
The image below is taken from FEMA’s Flood Map Service Center, searching for 310
West Crestview by address.
As the image above demonstrates, the official mapped flood hazard abruptly stops at the “limit of
study” right on the 310 West Crestview parcel. Utilizing the mapping tool, it is possible to
measure the depth of the official mapped flood hazard area onto that parcel, below.
Planning Commission
February 22, 2022
Page 15
The flood hazard area extends 42.2 feet into the site. However, the plans for the
residence on 310 West Crestview show only a 41 foot setback in this very same area.
Planning Commission
February 22, 2022
Page 16
The proposed project on 310 West Crestview requests construction directly in the area of
special flood hazard pursuant to Palm Springs Municipal Code section 8.68.060 and 8.68.070.
Projects proposed in the special flood hazard area require an “area of special flood hazard
development permit” before “any construction or other development . . . within any area of
special flood hazard.” (PSMC, § 8.68.150.) The permit requirements are numerous and detailed.
Instead of requiring compliance with these conditions prior to approval, the proposed
conditions of approval require the submission of a hydrology study in the future. This condition
notes that the hydrology study may require redesign or changes to the layout of the proposed
project. Given the general emphasis placed on the design and appearance of the structure in this
process, it is unacceptable that the approval can be finalized prior to the completion of a review
process for a project located in the flood hazard area, where that review may result in changes to
the project’s layout and appearance.
Moreover, under the circumstances where the “line of study” terminates prior to reaching
the 322 West Crestview parcel, the Municipal Code authorizes the City Engineer to require
additional study. Section 8.68.070 provides the “basis for establishing the areas of special flood
hazard,” and notes that the FEMA map “is the minimum area of applicability of this chapter, and
may be supplemented by studies for other areas.” Clearly, the flood hazard does not commence
abruptly at the line of study, and if new development is proposed on 322 West Crestview, and
likely to be proposed on the applicant’s properties off of El Camino Way, additional study
should be required prior to proceeding.
CONCLUSION
Members of The Mesa Neighborhood Organization respectfully request that the Planning
Commission deny the requested Major Architectural Modification and Administrative Minor
Modification applications so that the whole of the planned development in these locations can be
comprehensively evaluated as required by CEQA. In addition, compliance with the City’s
special flood hazard rules is required prior to the finalization of development plans for these
sites.
Yours truly,
Beverly Grossman Palmer
Exhibit 1
57740 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
RIN 1018–AV09
Endangered and Threatened Wildlife
and Plants; Designation of Critical
Habitat for the Peninsular Bighorn
Sheep (Ovis canadensis nelsoni) and
Proposed Taxonomic Revision
AGENCY: Fish and Wildlife Service,
Interior.
ACTION: Proposed rule.
SUMMARY: We, the U.S. Fish and
Wildlife Service (Service), propose to
revise currently designated critical
habitat for the Peninsular bighorn sheep
(Ovis canadensis nelsoni) under the
Endangered Species Act of 1973, as
amended (Act). In total, approximately
384,410 acres (ac) (155,564 hectares
(ha)) of land in Riverside, San Diego,
and Imperial counties, California, fall
within the boundaries of the proposed
revised critical habitat designation. Of
the area proposed as revised critical
habitat, approximately 4,512 ac (1,826
ha) of land are Tribal; 93,720 ac (37,927
ha) are Federal; 249,840 ac (101,107 ha)
are State; 35,824 ac (14,497 ha) are
private; and 514 ac (208 ha) are local.
We are proposing to exclude from the
final designation, under section 4(b)(2)
of the Act, approximately 4,512 ac
(1,826 ha) of Agua Caliente Band of
Cahuilla Indians Tribal land. We are
also evaluating and considering the
possible exclusion of approximately
19,211 ac (7,774 ha) of private land
covered under the draft Coachella
Valley Multiple Species Habitat
Conservation Plan. Further, we are
acknowledging a taxonomic change to
the species and are proposing a
taxonomic revision of the listed entity
from distinct population segment (DPS)
of species Ovis canadensis, to DPS of
subspecies Ovis canadensis nelsoni.
DATES: We will accept comments from
all interested parties until December 10,
2007. We must receive requests for
public hearings, in writing, at the
address shown in the ADDRESSES section
by November 26, 2007.
ADDRESSES: If you wish to comment on
this proposed rule, you may submit
your comments and materials
concerning by any one of several
methods:
1. By mail or hand-delivery to: Jim
Bartel, Field Supervisor, U.S. Fish and
Wildlife Service, Carlsbad Fish and
Wildlife Office, 6010 Hidden Valley
Road, Carlsbad, CA 92011.
2. By electronic mail (e-mail) to:
fw8cfwocomments@fws.gov. Please see
the Public Comments Solicited section
below for other information about
electronic filing.
3. By fax to: the attention of Jim Bartel
at 760–431–5901.
4. Via the Federal eRulemaking Portal
at: http://www.regulations.gov. Follow
the instructions for submitting
comments.
FOR FURTHER INFORMATION CONTACT: Jim
Bartel, Field Supervisor, Carlsbad Fish
and Wildlife Office, 6010 Hidden Valley
Road, Carlsbad, CA 92011; telephone
760–431–9440 ; facsimile 760–431–
5901. If you use a telecommunications
device for the deaf (TDD), call the
Federal Information Relay Service
(FIRS) at 800–877–8339.
SUPPLEMENTARY INFORMATION:
Public Comments
We intend that any final action
resulting from this proposal to revise the
current critical habitat designation for
the Peninsular bighorn sheep will be as
accurate and as effective as possible.
Therefore, we request comments or
suggestions on this proposed rule. We
particularly seek comments concerning:
(1) The reasons why we should or
should not designate habitat as ‘‘critical
habitat’’ under section 4 of the Act (16
U.S.C. 1531 et seq.), including whether
there are threats to the subspecies from
human activity, the degree of which can
be expected to increase due to the
designation, that outweigh the benefit of
designation, such that the designation of
critical habitat is not prudent, and
whether there are areas we previously
designated, but are not proposing for
revised designation here, that should be
designated as critical habitat;
(2) Specific information on the
amount and distribution of Peninsular
bighorn sheep habitat, what areas
occupied at the time of listing and that
contain features essential for the
conservation of the subspecies we
should include in the designation and
why, and what areas not occupied at the
time of listing are essential for the
conservation of the subspecies and why;
(3) The appropriateness of the
proposed exclusion of approximately
4,512 ac (1,826 ha) of Peninsular
bighorn sheep habitat from the final
designation in consideration of
Secretarial Order 3206, ‘‘American
Indian Tribal Rights, Federal Tribal
Trust Responsibilities, and the
Endangered Species Act’’ (June 5, 1997);
the President’s memorandum of April
29, 1994, ‘‘Government-to-Government
Relations with Native American Tribal
Governments’’ (59 FR 22951); Executive
Order 13175; and the relevant provision
of the Departmental Manual of the
Department of the Interior (512 DM 2)
(see ‘‘Proposed Exclusion of Agua
Caliente Band of Cahuilla Indians Tribal
Lands Under Section 4(b)(2) of the Act’’
for a detailed discussion); specifically
any additional information regarding
the benefits of including these Tribal
lands in the designation or of excluding
these lands from the designation;
(4) The appropriateness of the
possible exclusion of approximately
19,211 acres (ac) (7,774 hectares (ha)) of
Peninsular bighorn sheep habitat from
the final designation based on the
benefits to the conservation of the
subspecies and its PCEs provided by the
draft Coachella Valley Multiple Species
Habitat Conservation Plan (MSHCP) (see
‘‘Areas Considered for Exclusion Under
Section 4(b)(2) of the Act’’ for a detailed
discussion), specifically any additional
information on the benefits of including
land covered by the draft Coachella
Valley Multiple Species Habitat
Conservation Plan in the designation or
of excluding these lands from the
designation. At this time we are only
considering private lands under the
draft Coachella Valley MSHCP for
exclusion and soliciting comment on
the appropriateness of excluding
California Department of Fish and
Game, and Bureau of Land Management
lands as Memorandum of
Understanding partners to the MSHCP;
(5) Land use designations and current
or planned activities in the subject areas
and their possible impacts on proposed
revised critical habitat;
(6) Any foreseeable economic,
national security, or other potential
impacts resulting from the proposed
revised designation and, in particular,
any impacts on small entities, and the
benefits of including or excluding areas
that exhibit these impacts; and
(7) Whether we could improve or
modify our approach to designating
critical habitat in any way to provide for
greater public participation and
understanding, or to better
accommodate public concerns and
comments.
You may submit your comments and
materials concerning this proposal by
one of several methods (see ADDRESSES).
If you use e-mail to submit your
comments, please include ‘‘Attn:
Peninsular bighorn sheep’’ in your
e-mail subject header, preferably with
your name and return address in the
body of your message. If you do not
receive a confirmation from the system
that we have received your e-mail,
contact us directly by calling our
Carlsbad Fish and Wildlife Office at
760–431–9440. Please note that we must
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57741 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
receive comments by the date specified
in the DATES section in order to consider
them in our final determination.
Before including your address, phone
number, e-mail address, or other
personal identifying information in your
comment, you should be aware that
your entire comment—including your
personal identifying information—may
be made publicly available at any time.
While you may ask us in your comment
to withhold your personal identifying
information from public review, we
cannot guarantee that we will be able to
do so.
Comments and materials we receive,
as well as supporting documentation we
used in the preparation of this proposed
rule, will be available for public
inspection, by appointment, during
normal business hours at the Carlsbad
Fish and Wildlife Office, 6010 Hidden
Valley Road, Carlsbad, CA 92011
(telephone 760–431–9440).
Background
In this proposed rule, it is our intent
to discuss only those topics directly
relevant to the revision of designated
critical habitat for the Peninsular
bighorn sheep and the proposed
taxonomic revision of the current listed
entity. For more information on the
biology, and ecology of the Peninsular
bighorn sheep, refer to the final listing
rule published in the Federal Register
on March 18, 1998 (63 FR 13134), and
the proposed and final critical habitat
rules published in the Federal Register
on July 5, 2000, and February 1, 2001,
respectively (65 FR 41405 and 66 FR
8650).
In the 1998 final listing rule,
Peninsular bighorn sheep were listed as
a distinct population segment (DPS) of
the species Ovis canadensis. As stated
in the 2001 critical habitat rule, based
on morphometric and genetic analysis,
Wehausen and Ramey (1993, p. 9)
synonymized Peninsular bighorn sheep
with the subspecies nelsoni, which is
the current taxonomy. Although we
accepted this taxonomy at the time of
the designation in 2001, we have yet to
formally revise the taxonomy of the
listed entity. Therefore, we are formally
proposing a taxonomic revision to
amend the final listing rule from a DPS
of the species Ovis canadensis, to a DPS
of the subspecies Ovis canadensis
nelsoni. Therefore, within this proposed
critical habitat rule we will refer to the
listed entity as a subspecies and not a
species. The taxonomic revision does
not materially affect discreteness and
significance of the Peninsular bighorn
sheep as a DPS entity. As stated in the
final listing rule (63 FR 13134),
regardless of taxonomic issues
surrounding this species at the time of
listing, the biological evidence supports
recognition of Peninsular bighorn sheep
as a distinct vertebrate population
segment in the Service’s Recognition of
Distinct Vertebrate Population Segments
(DPS) (61 FR 4722). For a detailed
discussion of the DPS analysis for
Peninsular bighorn sheep, see the
Distinct Vertebrate Population Segment
section of the final listing rule.
Peninsular bighorn sheep (a large
mammal in the family Bovidae)
occupying the Peninsular Ranges of
southern California were determined, at
the time of listing in 1998, to be a
distinct vertebrate population segment
(DPS) of bighorn sheep based on their
geographic isolation and separation
from other desert bighorn sheep (63 FR
13134; March 18, 1998). Peninsular
bighorn sheep occur on moderate to
steep (greater than 20 percent) (NRCS
1993, p. 66) open slopes, canyons, and
washes in hot and dry desert regions of
the Peninsular Ranges of southern
California in Riverside, San Diego, and
Imperial counties (66 FR 8650; February
1, 2001). Peninsular bighorn sheep use
several different habitat types,
elevations, and slopes depending on
seasonal environmental conditions and/
or their life history stage. The 2001 final
critical habitat rule (66 FR 8650) stated
that most Peninsular bighorn sheep live
between 300 and 4,000 feet (ft) (91 and
1,219 meters (m)) in elevation. Upon
review of available literature, we now
believe 4,600 ft (1,400 m) (below
forested vegetation) is a more widely
accepted upper elevational limit in the
Peninsular Ranges (Jorgensen and
Turner 1975, p. 51; DeForge et al. 1997,
p. 11; Rubin et al. 1998, p. 541; Ernest
et al. 2002, p. 76). Desert bighorn sheep
are frequently found on slopes greater
than 20 percent (Elenowitz 1983, p. 87;
Andrew and Bleich 1999, p. 13; Dunn
1996, p. 5), and our Geographic
Information System (GIS) records and
occurrence data confirm this
observation for Peninsular bighorn
sheep. Steep terrains with slopes of 60
percent or greater used for predator
evasion and lambing are a crucial
component of Peninsular bighorn sheep
habitat (Dunn 1996, p. 1; Service 2000,
p. 6). Peninsular bighorn sheep will use
caves and rock outcrops for shelter
during inclement weather and for shade
during summer months. Bighorn sheep
are primarily diurnal (Krausman et al.
1985, p. 25), but Peninsular bighorn
sheep may be active at any time of day
or night (Miller et al. 1984, p. 24). A
wide range of forage resources and
vegetation associations are required by
this subspecies to meet annual and
drought-related variations in forage
quality and availability. In a study of
Peninsular bighorn sheep, Scott (1986,
p. 21) found that diets were dominated
by shrub species, while grasses and
forbs species made up a smaller portion
of the Peninsular bighorn sheep’s diet
depending on the season. Valley floors,
rolling hills, and alluvial fans and
washes with productive soils provide
seasonal vegetation and water resources
important to the Peninsular bighorn
sheep, especially for ewes during the
reproductive season (Service 2000, p. 8).
Please see the ‘‘Primary Constituent
Elements’’ section of this proposed rule
for a detailed discussion of the habitat
requirements of this subspecies.
At the time of listing (1998),
Peninsular bighorn sheep were known
to occupy habitat along the Peninsular
Mountain Ranges from the San Jacinto
Mountains of southern California into
the Volcan Tres Virgenes Mountains in
Baja California, Mexico (63 FR 13134;
March 18, 1998). Population estimates
at the time indicated approximately 280
Peninsular bighorn sheep existed within
the United States, divided amongst
approximately 8 subpopulations or ewe
groups (63 FR 13134; March 18, 1998).
At the time of the final critical habitat
designation in 2001, a range-wide
census estimated approximately 400
Peninsular bighorn sheep existed within
the United States (Torres 2000, p. 1). We
have extensive occurrence data
documenting bighorn sheep within the
entire range identified in the listing
rule. Population estimates for 2006,
derived from data collected by the
Bighorn Institute, California Department
of Fish and Game (CDFG), and Anza
Borrego Desert State Park, indicate
approximately 793 adult and yearling
Peninsular bighorn sheep exist within
the United States (Torres 2007).
Population estimates for various regions
within the Peninsular Ranges in 2006
are as follows: San Jacinto Mountains,
21; North Santa Rosa Mountains, 49;
Central Santa Rosa Mountains, 163;
South Santa Rosa Mountains, 179;
Coyote Canyon, 42; North San Ysidro
Mountains, 79; South San Ysidro
Mountains, 38; Vallecito and Fish Creek
Mountains, 77; and Carrizo Canyon, 145
(Torres 2007).
A captive breeding program has been
maintained by the Bighorn Institute
since 1984 in cooperation with CDFG,
the Bureau of Land Management (BLM),
and the Service (Ostermann et al. 2001,
p. 751). Originally instituted to conduct
disease research on low lamb survival,
the captive breeding program was
formalized in 1995, with the goals of
safeguarding a sample of the Peninsular
bighorn sheep gene pool and
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57742 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
augmenting and reestablishing wild
populations (Ostermann et al. 2001, p.
751). Captive-bred Peninsular bighorn
sheep have been released in the
northern Santa Rosa Mountains and the
San Jacinto Mountains (Ostermann et al.
2001, p. 751), areas historically
occupied by the subspecies.
Within the Peninsular Ranges, habitat
is patchy, and the sheep populations are
naturally fragmented (Bleich et al. 1990,
p. 386; Rubin et al. 1998, p. 547). Male
and female bighorn sheep remain
loosely segregated much of the year and
come together during the breeding
period or rut (Bleich et al. 1997, p. 7).
In the Peninsular Ranges, the rut occurs
in the late summer and fall months
(Service 2000, p. 15), peaking from
August to October (Rubin et al. 2000, p.
774). As parturition (giving birth)
approaches, ewes seek isolated sites
(escape terrain) with shelter and
unobstructed views (Turner and Hansen
1980, p. 148), seclude themselves from
other females, and find sites to give
birth (Geist 1971, p. 239; Etchberger and
Krausman 1999, p. 358). Ewes usually
give birth to one lamb after an
approximately 6-month gestation period
(Geist 1971, p. 239; Turner and Hansen
1980, p. 146). During the period of
sexual segregation, ewes and their lambs
are typically found in steeper, more
secure habitat, while rams inhabit less
steep or less rugged terrain (Geist 1971,
p. 239; Bleich et al. 1997, p. 23).
Previous Federal Actions
On February 1, 2001, we designated
approximately 844,897 ac (341,919 ha)
of land in Riverside, San Diego, and
Imperial counties, California, as critical
habitat. The designation followed the
Service’s release of the final Recovery
Plan for Bighorn Sheep in the
Peninsular Ranges, California (dated
October 25, 2000). On March 7, 2005,
the Agua Caliente Band of Cahuilla
Indians filed a complaint against the
Service alleging that the economic
analysis developed for our 2001
designation used a methodology similar
to that ruled to be insufficient by the
Tenth Circuit Court in New Mexico
Cattle Growers Association v. U.S. Fish
and Wildlife Service, 248 F.3d 1277
(10th Cir. 2001). Other parties
subsequently intervened as plaintiffs in
the case. A July 31, 2006, court-
approved consent decree enacted a
limited partial vacatur of Tribal, mining,
and Desert Riders lands (29,925 ac
(12,110 ha)) and remanded the critical
habitat designation back to the Service
for new rulemaking. Publication of this
proposed revision of critical habitat
satisfies our obligation under the
consent decree to submit a revised
proposed rule to the Federal Register on
or before September 30, 2007. The final
rule is due to the Federal Register on or
before September 30, 2008. For more
information on previous Federal actions
concerning the Peninsular bighorn
sheep, refer to the final listing rule
published in the Federal Register on
March 18, 1998 (63 FR 13134), and the
designation of critical habitat for the
Peninsular bighorn sheep published in
the Federal Register on February 1,
2001 (66 FR 8650).
Critical Habitat
Critical habitat is defined in section 3
of the Act as:
(1) The specific areas within the
geographical area occupied by a species,
at the time it is listed in accordance
with the Act, on which are found those
physical or biological features
(a) Essential to the conservation of the
species and
(b) That may require special
management considerations or
protection; and
(2) Specific areas outside the
geographical area occupied by a species
at the time it is listed, upon a
determination that such areas are
essential for the conservation of the
species.
Conservation, as defined under
section 3 of the Act, means the use of
all methods and procedures that are
necessary to bring any endangered
species or threatened species to the
point at which the measures provided
under the Act are no longer necessary.
Critical habitat receives protection
under section 7 of the Act through the
prohibition against Federal agencies
carrying out, funding, or authorizing the
destruction or adverse modification of
critical habitat. Section 7(a)(2) of the Act
requires consultation on Federal actions
that may affect critical habitat. The
designation of critical habitat does not
affect land ownership or establish a
refuge, wilderness, reserve, preserve, or
other conservation area. Such
designation does not allow the
government or public to access private
lands. Such designation does not
require implementation of restoration,
recovery, or enhancement measures by
the landowner. Where the landowner
seeks or requests federal agency funding
or authorization that may affect a listed
species or critical habitat, the
consultation requirements of Section
7(a)(2) would apply, but even in the
event of a destruction or adverse
modification finding, the landowner’s
obligation is not to restore or recover the
species, but to implement reasonable
and prudent alternatives to avoid
destruction or adverse modification of
critical habitat.
For inclusion in a critical habitat
designation, habitat within the
geographical area occupied by the
species at the time it was listed must
first have features that are essential to
the conservation of the species. Critical
habitat designations identify, to the
extent known using the best scientific
data available, habitat areas that provide
essential life cycle needs of the species
(areas on which are found the primary
constituent elements, as defined at 50
CFR 424.12(b)).
Occupied habitat that contains the
features essential to the conservation of
the species meets the definition of
critical habitat only if its essential
features may require special
management considerations or
protection.
Under the Act, we can designate
unoccupied areas as critical habitat only
when we determine that the best
available scientific data demonstrate
that the designation of that area is
essential to the conservation needs of
the species.
Section 4 of the Act requires that we
designate critical habitat on the basis of
the best scientific and commercial data
available. Further, our Policy on
Information Standards Under the
Endangered Species Act (published in
the Federal Register on July 1, 1994 (59
FR 34271)), the Information Quality Act
(section 515 of the Treasury and General
Government Appropriations Act for
Fiscal Year 2001 (Pub. L. 106–554; H.R.
5658)), and our associated Information
Quality Guidelines provide criteria,
establish procedures, and provide
guidance to ensure that our decisions
are based on the best scientific data
available. They require our biologists, to
the extent consistent with the Act and
with the use of the best scientific data
available, to use primary and original
sources of information as the basis for
recommendations to designate critical
habitat.
When we are determining which areas
should be proposed as critical habitat,
our primary source of information is
generally the information developed
during the listing process for the
species. Additional information sources
may include the recovery plan for the
species, articles in peer-reviewed
journals, conservation plans developed
by States and counties, scientific status
surveys and studies, biological
assessments, or other unpublished
materials and expert opinion or
personal knowledge.
Habitat is often dynamic, and species
may move from one area to another over
time. Furthermore, we recognize that
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57743 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
designation of critical habitat may not
include all of the habitat areas that we
may eventually determine, based on
scientific data not now available to the
Service, are necessary for the recovery
of the species. For these reasons, a
critical habitat designation does not
signal that habitat outside the
designated area is unimportant or may
not be required for recovery of the
species.
Areas that support populations, but
are outside the critical habitat
designation, will continue to be subject
to conservation actions we implement
under section 7(a)(1) of the Act. They
are also subject to the regulatory
protections afforded by the section
7(a)(2) jeopardy standard, as determined
on the basis of the best available
scientific information at the time of the
agency action. Federally funded or
permitted projects affecting listed
species outside their designated critical
habitat areas may still result in jeopardy
findings in some cases. Similarly,
critical habitat designations made on the
basis of the best available information at
the time of designation will not control
the direction and substance of future
recovery plans, habitat conservation
plans (HCPs), or other species
conservation planning efforts if new
information available to these planning
efforts calls for a different outcome.
Methods
As required by section 4(b) of the Act,
we used the best scientific data
available in determining areas occupied
at the time of listing that contain the
features essential to the conservation of
the Peninsular bighorn sheep, and areas
unoccupied at the time of listing that are
essential to the conservation of the
Peninsular bighorn sheep, or both.
Material reviewed included information
from the final listing rule (63 FR 13134;
March 18, 1998) and final critical
habitat rule (66 FR 8650; February 1,
2001), information and survey
observations published in peer-
reviewed literature and provided in
academic theses and agency reports;
location data and survey information
provided in agency status and
monitoring reports and on GIS maps;
habitat analysis and other information
provided in the Peninsular bighorn
sheep recovery plan (Service 2000);
material submitted during section 7
consultations; data made available
through members of the Peninsular
Bighorn Sheep Recovery Team,
Coachella Valley Multiple Species
Habitat Conservation Plan program, and
Agua Caliente Band of Cahuilla Indians
Tribal Habitat Conservation Plan
program; and regional GIS coverages.
We are not proposing any areas outside
the geographical area presently
occupied by the Peninsular bighorn
sheep as revised critical habitat because
presently occupied areas are sufficient
for the conservation of the subspecies.
Primary Constituent Elements
In accordance with section 3(5)(A)(i)
of the Act and the regulations at 50 CFR
424.12, in determining which areas
occupied at the time of listing to
propose as critical habitat, we consider
the primary constituent elements (PCEs)
to be those physical and biological
features that are essential to the
conservation of the species and that may
require special management
considerations or protection. These
include, but are not limited to:
(1) Space for individual and
population growth and for normal
behavior;
(2) Food, water, air, light, minerals, or
other nutritional or physiological
requirements;
(3) Cover or shelter;
(4) Sites for breeding, reproduction, or
rearing (or development) of offspring;
and
(5) Habitats that are protected from
disturbance or are representative of the
historic geographical and ecological
distributions of a species.
We derive the specific primary
constituent elements (PCEs) required for
the Peninsular bighorn sheep from its
biological needs.
Space for Individual and Population
Growth and for Normal Behavior
Peninsular bighorn sheep occur on
moderately steep to very steep open
slopes, canyons, and washes in hot and
dry desert regions where the land is
rough and rocky, and sparsely vegetated
(66 FR 8650; February 1, 2001). This
subspecies is primarily restricted to the
east-facing lower elevation slopes
(generally below 4,600 ft (1,400 m)) of
the Peninsular Ranges along the
northwestern edge of the Sonoran Desert
(Jorgensen and Turner 1975, p. 51;
DeForge et al. 1997, p. 11; Rubin et al.
1998, p. 541; Ernest et al. 2002, p. 76).
A wide range of topography provides a
diversity of habitats and plant
communities across the mountainous
slopes, canyons, washes, and alluvial
fans within the home range of the
Peninsular bighorn sheep (Service 2000,
p. 156). This diverse topography is
necessary to provide shelter from the
elements and predators, areas for
rearing, areas used to meet thermal
requirements, seasonal water and forage
sources, and space for mating and
movement of this subspecies.
Diverse topographic features are
especially important because of the
extreme temperatures Peninsular
bighorn sheep must cope with in this
desert region. During hot weather,
desert bighorn sheep seek shade under
boulders and cliffs, or move to north-
facing slopes (Merritt 1974, p. 14;
Andrew 1994, p. 52). In the event of
inclement weather they may seek
protected caves or overhangs, or move
to sunny, south-facing slopes (Andrew
1994, p. 52), or slopes that are protected
from strong winds. According to GIS
data and occurrence records, Peninsular
bighorn sheep largely utilize habitat
with 20 to 60 percent slopes, broken by
canyons and washes. The preference for
slopes greater than 20 percent has been
shown in other populations of desert
sheep as well (Andrew 1994, p. 53).
Nighttime bedding areas are chosen
carefully according to the topography of
the habitat and may be considered a
limiting factor in bighorn sheep
distribution (Hansen 1980, p. 78). These
bedding areas are usually located along
ridges and spurs with long distance
visibility where bighorn sheep can
escape if necessary in a matter of
seconds (Hansen 1980, p. 78).
Generally, bighorn sheep primarily
rely on their sense of sight to detect
predators. They prefer the lower
elevations of the Peninsular Ranges
where the vegetation associations are
less dense and provide better visibility
than those at higher elevations.
Research has shown that bighorn sheep
will avoid habitat in which dense
vegetation reduces visibility and
regularly use habitat with vegetative
canopy cover less than or equal to 30
percent (Risenhoover and Bailey 1985,
p. 799; Etchberger et al. 1989, p. 906;
Dunn 1996, p. 1). Bighorn sheep in the
Peninsular Ranges avoid higher
elevations (above 4,600 ft (1,400 m)),
likely due to decreased visibility (and
therefore increased predation risk)
associated with the denser vegetation
(chaparral and conifer woodland) found
at higher elevations (Service 2000,
p. 10).
Along with occupying open habitat,
bighorn sheep also use very steep,
precipitous terrain for predator evasion
(Service 2000, p. 6). Bighorn sheep use
their climbing abilities rather than
speed to escape from predators, and
mountainous slopes of greater than or
equal to 60 percent (escape habitat) are
steep enough to provide this function
(Andrew 1994, p. 57; Dunn 1996, p. 1;
McKinney et al. 2003, p. 1231; Service
2000, p. 6). Very steep escape habitat is
also used for lambing (Service 2000, p.
6). As parturition approaches, ewes seek
isolated sites (escape terrain with slopes
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60 percent or greater) with shelter and
unobstructed views (Turner and Hansen
1980, p. 148), and seclude themselves
from other females while finding sites to
give birth (Geist 1971, p. 239; Etchberger
and Krausman 1999, p. 358). Ewes
usually give birth to one lamb born after
an approximately 6-month gestation
period (Geist 1971, p. 239; Turner and
Hansen 1980, p. 146). These areas of
steep and very steep terrain are vital to
Peninsular bighorn sheep because lambs
have increased vulnerability to
predation, and these protective slopes
are rarely visited by predators (Geist
1971, p. 239). Ewe groups with lambs
usually stay close to escape terrain,
while feeding on lower gradient slopes.
Berger (1991, p. 72) reported that when
feeding on bajadas (compound alluvial
fans) or away from escape terrain, ewes
and lambs were more than three times
more vulnerable to predation. Predators
of Peninsular bighorn sheep include
mountain lion, bobcat, and coyote
(Hayes et al. 2000, p. 954; 66 FR 8650).
Metapopulation Structure
Within desert mountain ranges like
the Peninsular Ranges, bighorn sheep
habitat is patchy, and the population
structure is naturally fragmented (Bleich
et al. 1990, p. 384). This fragmentation
has led to the application of a broad
landscape approach to their population
ecology, grouping geographically
distinct herds into metapopulations,
which are networks of interacting ewe
groups or subpopulations (Schwartz et
al. 1986, pp. 182–183; Bleich et al. 1990,
p. 386). This approach considers long-
term viability not of individual
subpopulations, but rather of entire
metapopulations; thus both genetic and
demographic factors are considered.
Decreasing population sizes can lead to
decreasing levels of heterozygosity that
may have negative demographic effects
through inbreeding depression (Lande
1988, p. 1,456) and loss of adaptability.
A small amount of genetic exchange
among herds by movements of males
can counteract inbreeding and
associated increases in homozygosity
that might otherwise develop within
small, isolated populations (Schwartz et
al. 1986, p. 185). Males have larger
home ranges and have a much greater
tendency than females to explore new
areas, which they may do in search of
females during the mating season. If
geographic distances between female
groups within metapopulations are not
extreme (greater than 31 miles (mi) 50
kilometers (km) (Witham and Smith
1979, p. 24)), and no insurmountable
barriers exist, movement by males
occurs readily. If movement is
precluded by human-constructed
obstacles, populations will become
isolated and the metapopulation
structure dismantled.
A study of Peninsular bighorn sheep
distribution and abundance by Rubin et
al. (1998, p. 545) concluded that ewes
exhibit a fragmented distribution within
the Peninsular Ranges making up at
least eight ewe groups or
subpopulations. It is suggested that
although the distribution of these ewe
groups could be considered naturally
fragmented, construction and use of
roads through bighorn sheep habitat
may have increased fragmentation
within the Peninsular Ranges because
ewes avoided crossing highways (Rubin
et al. 1998, p. 547). Ewes show strong
gregarious and philopatric behavior
(faithful to natal home range), which
limits their dispersal abilities (Boyce et
al. 1999, p. 99; Service 2000, p. 10).
Movement of ewes between ewe groups
appears infrequent, but direct
observation and aerial-telemetry
locations and genetic analysis revealed
ram movement between up to three ewe
groups (Boyce et al. 1999, p. 99; Rubin
et al. 1998, pp. 543–544).
Substructuring also can occur within
single herds (ewe groups) of bighorn
sheep (Festa-Bianchet 1986, pp. 327–
330; Andrew et al. 1997, pp. 74–75;
Rubin et al. 1998, pp. 543–548). Such
substructuring is defined by separate
home range patterns. Although
demonstrated more with females, it can
occur in both sexes.
Another important long-term process
in metapopulation dynamics is the
balance between rates of natural
extinction and colonization among
subpopulations. Colonization rates must
exceed extinction rates for a
metapopulation to persist (Hanski and
Gilpin 1991, pp. 8–9). In recent history
this balance has not occurred for
Peninsular bighorn sheep due to
fragmentation, disease, predation, and
low recruitment (Rubin et al. 1998, pp.
545–547; Rubin et al. 2002, p. 803–805).
In addition to fragmentation, remaining
subpopulations consist of small,
isolated groups of bighorn sheep. Small
groups are more vulnerable to
extirpation due to random naturally
occurring events, disease, or predation
because of their small population size.
Local extinction of small
subpopulations can be prevented by
occasional immigrants from neighboring
subpopulations (rescue effect) (Brown
and Kodric-Brown 1977, p. 445).
Because of the metapopulation
structure of the Peninsular bighorn
sheep population, it is important for
genetic exchange and the conservation
of the subspecies to ensure space for
movement and connectivity between
ewe groups. Furthermore, maintaining
connectivity within the metapopulation
will help safeguard against local
extinctions of the remaining
subpopulations.
Food
A wide range of forage resources and
vegetation associations are required by
Peninsular bighorn sheep to meet
annual and drought-related variations in
forage quality and availability (Hansen
1980, p. 76). Valley floors, rolling hills,
and alluvial fans and washes with
productive soils provide seasonal
vegetation and water resources
important to the Peninsular bighorn
sheep. In a mountainous environment
like the Peninsular Ranges, temperature
and soil moisture vary widely with
slope and elevation. This causes
variation in plant growth throughout
this subspecies’ habitat on a seasonal
basis. Peninsular bighorn sheep need to
have access to the seasonal abundance
of plant life at various elevations to
maximize resources and survive in the
desert environment. Berger (1991, p. 70)
found that bighorn sheep adjusted their
feeding ranges to exploit more nutritive
portions of their home ranges, such as
bajadas, early in the season when high
protein grasses were emerging. Due to
the high energetic costs of pregnancy
and lactation, ewes are especially
dependent on areas with nutritious
forage to increase success of rearing
offspring (Service 2000, p. 8). Berbach
(1987, p. 97) reported that when ewes
were confined to an enclosure and
prevented from using all vegetation
associations during late gestation and
early lactation, they and their lambs
died of malnutrition. During the
reproductive season for Peninsular
bighorn sheep, ewe foraging is typically
concentrated on specific sites, such as
alluvial fans, bajadas, and washes,
where more productive, wetter soils
support greater herbaceous growth than
steeper, drier, rockier soils (Service
2000, p. 8). There is a tendency for
plants that dry out during summer
months on the mountain sides to remain
green longer (and thus more nutritious,
higher in protein, and more easily
digested) because groundwater is
generally closer to the surface and in
greater quantity. Furthermore, the
greater soil moisture supports a suite of
nutritious plants that do not grow on the
dry mountain sides. Therefore, washes
and alluvial fans play an important role
in allowing desert bighorn sheep to
acquire quality forage during the heat of
summer months and through times of
drought.
In a study of Peninsular bighorn
sheep, Scott (1986, p. 21) found that
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diets were dominated by shrub species
(64 to 76 percent), with grasses and
forbs species making up a smaller
portion of the diet (19 to 30 percent and
2 to 6 percent, respectively). In the
following section, plant nomenclature
has been updated to conform to
treatments in Hickman (1993). Common
names generally conform with those
given in Hickman (1993) and/or Abrams
et al. (1992–1960). Cited scientific
names are retained in brackets for ease
of reference. Foraging studies by Scott
(1986, p. 21) and Cunningham (1982, p.
31) noted that Peninsular bighorn sheep
preferentially feed on different plants
seasonally. Shrubs such as Ambrosia
dumosa (burro bush), Caesalpinia
virgata [Hoffmannseggia microphylla]
(small-leaved Hoffmannseggia), Hyptis
emoryi (desert lavender), Sphaeralcea
spp. (globemallow), and Simmondsia
chinensis (joboba) are a primary food
source year round; grasses such as
Aristida adscensionis (sixweeks
threeawn) and Bromus rubens (red
brome) along with cacti Opuntia spp.
(cholla) are a primary food source in the
fall; forbs such as Plantago spp. (woolly
plantain), Plantago ovata [insularis] var.
fastigiata (woolly plantain), and Ditaxis
neomexicana (common ditaxis) are a
primary food source in the spring.
However, Peninsular bighorn sheep are
generalist foragers, and will browse on
a wide variety of plant species
depending on seasonal availability.
Other plants reportedly consumed by
Peninsular bighorn sheep include
Ephedra spp. (Mormon tea), Agave
deserti (desert agave), Quercus spp.
(scrub oak), Phoradendron californicum
(desert mistletoe), Eriogonum
fasciculatum (California buckwheat),
Prunus fremontii (desert apricot),
Acacia greggii (catclaw), Prosopis
juliflora (mesquite), Krameria grayi
(ratany), and Malosma laurina (laurel-
leaf sumac) (Browning and Monson
1980, p. 88).
Water
In the Peninsular Ranges, the
presence of perennial water is known to
be a limiting factor only during
prolonged droughts or summers without
significant thunderstorm activity
(Service 2000, p. 156). Water sources are
most valuable to bighorn sheep if they
occur in proximity to escape terrain
with good visibility (Service 2000, p. 9).
However, bighorn sheep have been
observed to travel at least 10 mi (16 km)
from sources of perennial water.
According to Service biologists familiar
with the subspecies, bighorn sheep
usually visit a water source every 2 to
3 days, but it is not unusual for them to
drink more often. During the hot
summer months, desert bighorn sheep
typically stay close to reliable sources of
water and drink large quantities of water
at a time. It has been hypothesized that
desert bighorn sheep can survive
without a permanent water source,
although this view is not widely
accepted (Turner and Weaver 1980, p.
104). In desert ranges like the
Peninsular Ranges, rainwater can collect
in natural collection tanks and potholes
in the rock and provide seasonal or
perennial water sources. Natural springs
also provide a reliable source of water
for Peninsular bighorn sheep. Desert
sheep also rely on consuming
vegetation, including cacti, to meet
water requirements when standing
water sources are scarce (Turner and
Weaver 1980, p. 102). Water is
especially important to lactating ewes,
as they need sufficient water to produce
milk. Water sources contribute greatly to
the Peninsular bighorn sheep’s ability to
survive the hot and dry summer
months.
Primary Constituent Elements for the
Peninsular Bighorn Sheep
Within the geographical area
occupied by the Peninsular bighorn
sheep at the time of listing, we must
identify the PCEs that may require
special management considerations or
protection.
Based on the above needs and our
current knowledge of the life history,
biology, and ecology of the subspecies,
we have determined that the Peninsular
bighorn sheep’s PCEs are:
(1) Moderate to steep, open slopes (20
to 60 percent) and canyons, with canopy
cover of 30 percent or less (below 4,600
feet (1,402 meters) elevation in the
Peninsular Ranges) that provide space
for sheltering, predator detection,
rearing of young, foraging and watering,
mating, and movement within and
between ewe groups.
(2) Presence of a variety of forage
plants, indicated by the presence of
shrubs (e.g., Ambrosia spp., Caesalpinia
spp., Hyptis spp., Sphaeralcea spp.,
Simmondsia spp.), that provide a
primary food source year round, grasses
(e.g., Aristida spp., Bromus spp.) and
cacti (e.g., Opuntia spp.) that provide a
source of forage in the fall, and forbs
(e.g., Plantago spp., Ditaxis spp.) that
provide a source of forage in the spring.
(3) Steep, rugged, slopes (60 percent
slope or greater) (below 4,600 feet (1,402
meters) elevation in the Peninsular
Ranges) that provide secluded space for
lambing as well as terrain for predator
evasion.
(4) Alluvial fans, washes, and valley
bottoms that provide important foraging
areas where nutritious and digestible
plants can be more readily found during
times of drought and lactation and that
provide and maintain habitat
connectivity by serving as travel routes
between and within ewe groups,
adjacent mountain ranges, and
important resources areas, such as
foraging areas and escape terrain.
(5) Intermittent and permanent water
sources that are available during
extended dry periods and that provide
relatively nutritious plants and drinking
water.
This proposed revision to currently
designated critical habitat for the
Peninsular bighorn sheep is designed
for the conservation of PCEs necessary
to support the life history functions that
are the basis for our proposal and the
areas containing those PCEs.
We propose units for designation
based on sufficient PCEs being present
to support at least one of the subspecies’
life history functions. For this
subspecies, all of the units proposed
contain all of the PCEs and support the
multiple essential life history functions
identified above.
Special Management Considerations or
Protection
When designating critical habitat, we
assess whether the occupied areas
contain the features that are essential to
the conservation of the subspecies and
that may require special management
considerations or protection. We have
also considered how revising the
current critical habitat designation for
the Peninsular bighorn sheep highlights
habitat that needs special management
considerations or protection.
Peninsular bighorn sheep habitat and
the PCEs upon which the sheep
depends are threatened by the direct
and indirect effects of: Development and
expansion of urban areas; human
disturbance related to recreation;
construction of roadways and power
lines; and mineral extraction and
mining operations.
The development and expansion of
urban and associated industrial areas
threaten Peninsular bighorn sheep and
their habitat through direct and indirect
effects. Habitat loss (especially in
canyon bottoms), degradation, and
fragmentation associated with the
proliferation of residential and
commercial development, roads and
highways, water projects, and vehicular
and pedestrian recreational uses
threaten the Peninsular bighorn sheep
throughout its range (63 FR 13134;
March 18, 1998). The cities that occur
along the eastern boundary of proposed
revised critical habitat, from the base of
the San Jacinto and Santa Rosa
Mountains to the Salton Sea area (Units
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1 and 2A), continue to grow.
Development adjacent to and within
Peninsular bighorn sheep habitat affects
the quality and quantity of lower
elevation habitat and associated
vegetation, alluvial fans, and water
sources (PCEs 1, 2, 4, and 5). By 2000,
at least 18,500 ac (7,490 ha) of suitable
Peninsular bighorn sheep habitat had
been lost to urbanization and agriculture
along the urban interface between the
cities of Palm Springs and La Quinta
(Service 2000, p. 38). Much of the lost
habitat consisted of low elevation
alluvial fans and washes that provided
important sources of nutrients to ewes
when they are rearing their lambs (PCE
2 and 4) (66 FR 8650; February 1, 2001).
Moreover, in the northern Santa Rosa
Mountains, from 1991 to 1996, 34
percent of adult mortalities appear to
have been directly caused by
urbanization (66 FR 8650; February 1,
2001). Five Peninsular bighorn sheep
were killed by cars; five died from
feeding on toxic, nonnative ornamental
plants; and one was strangled in a wire
fence (DeForge and Ostermann 1997,
p. 1).
Continued urban and commercial
development within the range of
Peninsular bighorn sheep could
fragment the Peninsular bighorn sheep
metapopulation into isolated groups too
small to maintain long-term viability.
Maintenance of genetic diversity allows
small ewe groups like those in the
Peninsular Ranges to persist. The
inability of rams and occasional ewes to
move between groups erodes the genetic
fitness of isolated groups (PCE 1 and 4)
(63 FR 13134; March 18, 1998). Special
management considerations or
protection may be needed to alleviate
the effects of development on
Peninsular bighorn sheep habitat,
especially lower elevation habitat,
alluvial fans, and areas of possible ewe
group connectivity near urban areas.
This protection could be accomplished
by controlling the expansion of urban,
industrial, and agricultural development
into these areas.
In the Peninsular Ranges (Units 1, 2
and 3), increased activity and
disturbance adjacent to, and within
Peninsular bighorn sheep habitat are
adversely affecting bighorn sheep by
altering their normal behavior. This
altered behavior can lead to
abandonment of habitat and prevent use
of preferred habitat, including lambing
areas, water sources, and foraging areas,
and cause negative physiological effects
(PCE 1, 2, 3, 4, and 5) (66 FR 8650; 63
FR 13134). A variety of human
activities, such as hiking, mountain
biking, horseback riding, camping,
hunting, livestock grazing, and use of
aircraft and off-road vehicles, have the
potential to disrupt normal bighorn
sheep social behaviors. Special
management considerations or
protection may be needed to alleviate
the effects of human activity and
disturbance to Peninsular bighorn
sheep. Restricting human use of trail
systems and natural areas during
lambing season and exclusionary
fencing around urban areas may reduce
human effects on Peninsular bighorn
sheep behavior.
Roadways and power line structures
occur in, and are proposed for
construction within, Peninsular bighorn
sheep habitat. Two major highways run
through the Peninsular Ranges and
fragment bighorn sheep habitat. In the
northern portion of the Peninsular
Ranges, State Route 74 runs through the
Santa Rosa Mountains (Unit 2A).
Further south, State Route 78 cuts
through habitat between the San Ysidro
Mountains and Pinyon Mountains (Unit
2B). These roadways have degraded
habitat and have generally impeded the
movement of Peninsular bighorn sheep
(especially ewes) between ewe groups in
the surrounding areas (PCE 1, 2, 3, 4,
and 5) (Rubin et al. 1998, p. 547), which
can erode the genetic fitness of isolated
groups (63 FR 13134; March 18, 1998).
However, some movement has been
documented across State Route 74
(Service 2004, pp. 1–2). Epps et al.
(2005, p. 1035) showed that nuclear
genetic diversity of desert bighorn sheep
populations was negatively correlated
with the presence of human-made
barriers (highways), which essentially
eliminated dispersal. Furthermore, in
some portions of their range, collisions
with automobiles can be a significant
cause of Peninsular bighorn sheep
mortality (DeForge and Ostermann
1997, p. 1). The construction of power
lines and associated structures may also
degrade and fragment bighorn sheep
habitat. Currently, a large power line
(Sunrise Powerlink) is proposed for
construction through Unit 2B along
Highway 78. Special management
considerations or protection may be
needed to alleviate the effects of
roadway and power line structures on
Peninsular bighorn sheep and their
habitat. Future construction of roadways
and power lines should be avoided, and
if unavoidable, should be constructed in
a way that minimizes effects to habitat
and allows for continued connectivity
among ewe groups.
Mining operations occur within
southern portions of the habitat used by
Peninsular bighorn sheep. Mining
activities and associated facilities
threaten Peninsular bighorn sheep by
causing the loss of vegetation structure
required for foraging activities and
destroying habitats used for escape,
bedding, lambing, or connectivity
between ranges (PCE 1, 2, 3, 4, and 5).
Disturbance could modify the sheep’s
behavior or cause bighorn sheep to flee
an area. Mining occurs within the
habitat of Peninsular bighorn sheep in
Units 2B and 3. Special management
considerations or protection may be
needed to alleviate the effects of mining
operations on Peninsular bighorn sheep
habitat. Further mining operations
should avoid to the maximum extent
possible, areas considered essential to
Peninsular bighorn sheep conservation.
Criteria Used To Identify Critical
Habitat
All proposed revised critical habitat
units are within areas that we have
determined were occupied at the time of
listing, and that contain sufficient PCEs
to support the life history functions
essential for the conservation of the
subspecies. Lands were proposed for
designation based on sufficient PCEs
being present to support the life
processes.
We used the following data to
delineate proposed revised critical
habitat: (1) Areas known to be occupied
at the time of listing (1998) and
currently occupied; (2) areas within the
ewe group distribution (subpopulations)
boundaries identified by Rubin et al.
(1998); (3) areas where occupancy data
points indicate repeated Peninsular
bighorn sheep use, but which were not
captured within the ewe groups
distribution boundaries identified by
Rubin et al. (1998); and (4) areas that
contain the PCEs required by the
subspecies as determined from aerial
imagery and GIS data on vegetation,
elevation, and slope.
We also gathered information from
our files, staff biologists, the California
Department of Fish and Game, the
Bighorn Institute, and Dr. Ester Rubin.
Our proposed revision to critical habitat
is designed to capture ewe groups;
lambing areas; foraging areas, including
alluvial fans; water sources; ram groups;
and areas used for associated herd
(male, female, and young) movements
and migrations.
We delineated the proposed revised
critical habitat boundaries using the
following steps:
(1) As a first step in the delineation
process, we mapped ewe group areas
from Rubin et al. (1998) over GIS
imagery of the Peninsular Ranges to
delineate the distribution of ewe groups
in the proposed revised critical habitat.
We consider Rubin et al. (1998) to be the
best available data on Peninsular
bighorn sheep ewe group distribution.
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57747 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
Rubin et al. (1998) examined the
population structure, distribution, and
abundance of Peninsular bighorn sheep
in California using observational data
from radio-collared and uncollared male
(ram) and female (ewe) sheep between
1971 and 1996. This is the only data we
are aware of that identifies the
distribution of ewe groups and
subgroups within the Peninsular
Ranges.
(2) To ensure that Rubin et al. (1998,
pp. 539–561) still accurately represents
the boundaries of the ewe groups and to
capture possible ram movement, we
compared the ewe group delineation
from Rubin et al. (1998, pp. 539–561)
with all occupancy data collected since
the time of listing on GIS imagery maps.
We then expanded the ewe group
delineation to include areas where
occupancy data points indicate repeated
Peninsular bighorn sheep use and recent
sheep movements (post Rubin et al.
1998, pp. 539–561), and areas that
contain the PCEs for Peninsular bighorn
sheep. In particular, we expanded the
northernmost ewe group delineation
(San Jacinto Mountains) to include the
area north of Chino Canyon where (1)
we have evidence of recent ewe and ram
movements and (2) the Bighorn Institute
has released, and continues to release,
captive-born sheep to help recover this
subspecies. We also expanded the
southernmost ewe group delineation
(Carizzo Canyon area) to the south to
capture water sources (PCE 5), including
habitat near the Interstate 8-State Route
98 split, where there are consistent,
recent sightings of uncollared
Peninsular bighorn sheep.
(3) We then examined all pre-listing
occurrence data in our files to determine
if our revised critical habitat missed any
areas of historical repeated Peninsular
bighorn sheep use. We identified an
area of historical repeated use that was
occupied at the time of listing between
two ewe subgroups documented in
Rubin et al. (1998, pp. 539–561) as (1)
Santa Rosa Mountains east of State
Route 74 (Martinez Canyon) and (2)
Santa Rosa Mountains east of State
Route 74 (south)). Use of this area is
consistent with the Rubin et al. (1998,
pp. 539–561) demographic study, which
indicated possible connectivity between
these subgroups through this area. This
area is important in light of genetic
findings by Boyce et al. (1999, pp. 99–
106) that indicate ewe groups within
these ranges maintain genetic
connectivity, probably through male-
mediated nuclear gene flow. Based on
the importance of this area for
connectivity between subgroups, we
expanded the proposed revised critical
habitat boundaries to include areas
where occupancy data points indicate
historically occupied habitat. Since the
number of occurrence data points in
historically occupied areas is relatively
small, we delineated the unit
boundaries in these areas to follow the
boundaries of the PCEs, such as
elevations below 4,600 ft (1,400 m),
areas with 30 percent canopy cover or
less, escape terrain, alluvial fans,
washes, and water sources immediately
adjacent to the identified ewe groups.
(4) As a final step in refining our
delineation, we closely examined our
revised units to ensure they capture all
of the PCEs to support life history
functions essential for the conservation
of the subspecies. Where appropriate,
we expanded the boundaries to capture
the extent of an alluvial fan or water
source (PCE 4 or 5, respectively). We
also removed areas that we determined
do not contain the PCEs or otherwise do
not contain suitable Peninsular bighorn
sheep habitat, such as areas above 4,600
ft (1,400 m) elevation (PCE 1), areas
containing conifer woodland with
canopy cover greater than 30 percent
(PCE 1), and slopes less than 20 percent
(PCE 1), unless those areas overlapped
specifically with Rubin et al.’s (1998,
pp. 539–561) ewe group distributions
and had documented use by Peninsular
bighorn sheep.
On May 22, 2007, Drs. Esther Rubin
and Walter Boyce, in cooperation with
Steve Torres and Chris Stermer of the
California Department of Fish and
Game, submitted a draft predictive
habitat model for bighorn sheep in the
Peninsular Ranges. We did not adopt
this predictive habitat model to
delineate critical habitat because the
model was submitted in draft form,
prior to final steps of model validation
and peer review, and model
development was based on just two
years of Global Positioning System
(GPS) data (Rubin 2007, p. 2);
nevertheless, the model supports our
proposed delineation. Areas we are
designating roughly fall within the
upper level habitat suitability classes
derived from the preliminary model.
When determining the proposed
revisions to critical habitat boundaries
within this proposed rule, we made
every effort to avoid including
developed areas such as buildings,
paved areas, and other structures that
lack PCEs for the Peninsular bighorn
sheep. The scale of the maps we
prepared under the parameters for
publication within the Code of Federal
Regulations may not reflect the
exclusion of such developed areas. Any
such structures and the land under them
inadvertently left inside critical habitat
boundaries shown on the maps of this
proposed revision to critical habitat
have been excluded by text in the
proposed rule and are not proposed for
designation as revised critical habitat.
Therefore, Federal actions limited to
these areas would not trigger section 7
consultation, unless they may affect the
subspecies or primary constituent
elements in adjacent critical habitat.
Summary of Proposed Changes From
Previously Designated Critical Habitat
The areas identified in this proposed
rule constitute a proposed revision to
the areas we designated as critical
habitat for the Peninsular bighorn sheep
on February 1, 2001 (66 FR 8650). The
main differences include the following:
(1) The 2001 final rule used a
generalized methodology for delineating
critical habitat that resulted in the
designation of one critical habitat unit
for Peninsular bighorn sheep totaling
844,897 ac (341,919 ha) (66 FR 8650;
February 1, 2001). This proposed
revision is based on a more specific
methodology that resulted in three
critical habitat units including
approximately 384,410 ac (155,564 ha)
of land in Riverside, San Diego, and
Imperial counties, California, a
reduction of 460,487 ac (186,355 ha)
from the 2001 final rule (66 FR 8650).
The areas included in this proposed
revised critical habitat are almost
entirely within the boundaries of the
existing (2001) critical habitat. There are
approximately 72 ac (29 ha) of BLM
land in Unit 3 that are outside the
boundary of the 2001 critical habitat.
The reduction in total area from the
2001 final critical habitat designation is
primarily the result of using a revised
methodology to delineate critical habitat
in this proposed revision. In our 2001
final critical habitat designation, we
delineated critical habitat based on the
methodology used in the Recovery Plan
for Bighorn Sheep in the Peninsular
Ranges, California (Service 2000).
In developing this proposed revision,
we reexamined the methodology
outlined in the 2000 recovery plan and
the 2001 critical habitat designation,
and updated that methodology based on
the best available information to
identify areas essential for the
conservation of the subspecies (see
‘‘Criteria Used To Identify Critical
Habitat’’ section). Since publication of
the 2000 recovery plan and the 2001
critical habitat designation, more
specific and up-to-date information has
become available regarding habitat use
by Peninsular bighorn sheep and areas
containing the features essential to the
conservation of this subspecies. New
information indicates that many areas
included in the 2001 critical habitat
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57748 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
designation do not support the features
essential for the conservation of the
Peninsular bighorn sheep and/or
otherwise contain unsuitable habitat for
the subspecies. For example, the 2001
final rule included high elevation
(above 4,600 ft (1,402 m)), densely
vegetated, and forested habitat that is
inappropriate for sheep use in the San
Jacinto, Santa Rosa, and Vallecito
Mountains. The differences between the
generalized methodology applied in the
2001 critical habitat designation and the
methodology used in this proposed rule,
including our reasons for revising the
approach, are outlined below.
The recovery plan generally used two
criteria, the presence of escape terrain
and unobstructed view, as key habitat
requirements when delineating the areas
essential to Peninsular bighorn sheep
with little consideration of the presence
of the PCEs required by this subspecies.
In this proposed revision, we have
considered all five of the revised PCEs
in delineating proposed revised critical
habitat which results in a more precise
determination of essential habitat (see
‘‘Primary Constituent Elements for the
Peninsular Bighorn Sheep’’ and
‘‘Criteria Used to Identify Critical
Habitat’’ sections).
Additionally, little consideration was
given to occurrence data in the recovery
plan methodology and specific ewe
group distributions, resulting in
expanses of critical habitat in the 2001
designation in which we have little to
no occurrence records that would
indicate sheep use those areas. For
example, we have occupancy data
dating back to 1940, yet extensive areas
along the western and southern
boundary of the 2001 designation
contain little to no documented sheep
use. In light of all the recent research
efforts and occupancy data, we are not
including those lands in this proposed
revision as we have determined that
those lands are not essential to the
conservation of Peninsular bighorn
sheep. Because a detailed vegetation
map was not available at the time of the
recovery plan, a team of biologists flew
the entire western boundary in a
helicopter and visually assessed
vegetation associations (Service 2000, p.
159). The western boundary was
determined by consensus and recorded
by GPS from the helicopter position
every ten seconds (Service 2000, p. 159).
A 0.5 mi (0.8 km) buffer was added to
this line to account for the advent of fire
suppression (Service 2000, p. 160). In
determining the western boundary of
essential habitat in this proposed
revision, we used vegetation maps that
cover the entire range of the Peninsular
bighorn sheep, along with detailed
aerial photography, expert opinion, and
sheep use data to delineate boundaries,
which we have determined more
precisely captures the areas essential to
the subspecies.
Like our methodology for this
proposed revision, the 2001
methodology used a minimum slope
criterion of 20 percent to delineate
essential habitat; however, a 0.5 mi (0.8
km) buffer was included around slopes
of greater than or equal to 20 percent
(Service 2000, p. 158). This proposed
rule does not include a buffer zone area
around habitat determined to be
essential to the subspecies.
In summary, we consider the recent
data and methodology used in this
proposed revision to more accurately
and specifically delineate the areas
essential to the Peninsular bighorn
sheep. The methods used in the 2000
recovery plan and the 2001 critical
habitat designation resulted in a more
inclusive delineation of essential habitat
due to limited data. Application of the
revised methodology, based on the best
available information, identified
460,487 ac (186,355 ha) of previously
designated critical habitat that is not
essential to the subspecies, and
therefore we are not including these
areas in this proposed revision to the
critical habitat designation.
(2) We re-evaluated and revised the
PCEs in light of the Alameda whipsnake
court case (Homebuilder’s Ass’n of
Northern Cal. v. U.S. Fish and Wildlife
Service, 268 F. Supp.2d 1197 (E.D. Cal.
2003)) and other relevant case law, and
followed current Service guidelines and
policies. The PCEs differ from those in
the existing critical habitat rule in that
they are reorganized into five separate
PCEs for clarity. Furthermore, we have
added specific information on
elevational range, plant species used for
foraging, and range of slopes required by
the subspecies. This additional
specificity was gained by evaluating the
recovery plan and examining all recent
sheep data, including data from radio
collars and GPS collars providing
precision to the identification of
habitats used and preferred by
Peninsular bighorn sheep. Applying the
more precise PCEs to the mountain
ranges inhabited by Peninsular bighorn
sheep allowed us to fine tune the
proposed revision to those areas
containing preferred habitat for sheep
use, and removing those areas unlikely
to be used by Peninsular bighorn sheep.
(3) Approximately 29,924 ac (12,110
ha) of designated critical habitat were
vacated in the July 31, 2006, consent
decree. A portion of those acres are now
within proposed revised critical habitat.
Of the 13,213 ac (5,347 ha) of vacated
Agua Caliente Band of Cahuilla Indians
Tribal lands, approximately 4,512 ac
(1,826 ha) are now included in this
proposal. However, we are proposing to
exclude all Tribal lands from the final
designation. Approximately 16,691 ac
(6,756 ha) of mining lands at Ocotillo
Mineral Material Sites and Fish Canyon
Quarry property were vacated. In this
proposed revision to critical habitat we
are including roughly 50 percent of
those vacated lands; specifically, we are
including lands along the northernmost
portion of the Ocotillo Mineral Material
Sites property and the middle to
southern portion of the Fish Canyon
Quarry property. Both of these mining
properties contain actively mined lands,
but also contain areas in which we have
recent documented use by Peninsular
bighorn sheep and areas that meet the
criteria used to identify critical habitat
as described above. The Desert Riders
lands vacated in the consent decree
(approximately 20 ac (8 ha)) are not
included in this proposed revision.
Our 2001 final critical habitat rule
included the statement that ‘‘* * *; we
are not aware of any information
suggesting that particular areas within
designated critical habitat are currently
unsuitable or unused over the
generational timeframe needed for the
long-term conservation of bighorn sheep
in the Peninsular Ranges’’ (66 FR 8655).
However, we have reconsidered the
information that was available to us at
the time of the 2001 designation in light
of all the information currently available
to us, and we have determined that the
methodology used in this proposed
revision, which utilized the best
available information, provides a more
accurate and specific delineation of the
areas essential to the Peninsular bighorn
sheep, than that relied upon in the 2001
critical habitat designation.
Proposed Revisions to the Critical
Habitat Designation
We are proposing four units as critical
habitat for the Peninsular bighorn
sheep. These units, which are almost
entirely within the area included in the
2001 designation, if finalized, would
replace the current critical habitat
designation for the Peninsular bighorn
sheep at 50 CFR 17.95(a). The critical
habitat areas we describe below
constitute our current best assessment of
areas that meet the definition of critical
habitat for the Peninsular bighorn
sheep. Table 1 shows the occupancy
status of each unit being proposed as
revised critical habitat.
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57749 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
TABLE 1.—OCCUPANCY STATUS OF CRITICAL HABITAT UNITS PROPOSED FOR THE PENINSULAR BIGHORN SHEEP
Unit Occupied at time of listing? Currently occupied?
Size of proposed revised
critical habitat unit in acres
(Hectares)
1. San Jacinto Mts. ........................... Yes ................................................... Yes ................................................... 15,273 (6,180 ha).
2A. N. Santa Rosa Mts. .................... Yes ................................................... Yes ................................................... 74,998 ac (30,350 ha).
2B. S. Santa Rosa Mts. south to
Vallecito Mts..
Yes ................................................... Yes ................................................... 226,211 ac (91,545 ha).
3. Carrizo Canyon ............................. Yes ................................................... Yes ................................................... 67,928 ac (27,489 ha).
Total ........................................... ........................................................... ........................................................... 384,410 ac (155,564 ha).
The four areas we propose as revised
critical habitat are: (1) Unit 1—San
Jacinto Mountains, (2) Unit 2A—North
Santa Rosa Mountains, (3) Unit 2B—
South Santa Rosa Mountains south to
Vallecito Mountains, and (4) Unit 3—
Carrizo Canyon.
The approximate area of each
proposed revised critical habitat unit is
shown in Table 2.
TABLE 2.—PROPOSED REVISED CRITICAL HABITAT UNITS FOR THE PENINSULAR BIGHORN SHEEP WITH LAND OWNERSHIP
[Area estimates reflect all land within proposed critical habitat unit boundaries]
Critical habitat unit Land ownership by type
Size of proposed revised
critical habitat unit in acres
(Hectares)
1. San Jacinto Mts. .......................................................... Tribal
1 .............................................................................. 4,512 ac (1,826 ha).
BLM 2 ............................................................................... 3,757 ac (1,520 ha).
USFS 3 ............................................................................. 1,266 ac (512 ha).
Private .............................................................................. 5,738 ac (2,322 ha).
Subtotal ............................................................................ 15,273 ac (6,180 ha).
2A. N. Santa Rosa Mts. ................................................... BLM ................................................................................. 44,669 ac (18,077 ha).
State 4 .............................................................................. 16,856 ac (6,821 ha).
Private .............................................................................. 13,473 ac (5,452 ha).
Subtotal ............................................................................ 74,998 ac (30,350 ha).
2B. S. Santa Rosa Mts. south to Vallecito Mts. .............. BLM ................................................................................. 16,266 ac (6,583 ha).
State 5 .............................................................................. 197,509 ac (79,929 ha).
Private .............................................................................. 12,436 ac (5,033 ha).
Subtotal ............................................................................ 226,211 ac (91,545 ha).
3. Carrizo Canyon ............................................................ BLM ................................................................................. 27,762 ac (11,235 ha).
State 6 .............................................................................. 35,475 ac (14,356 ha).
Private .............................................................................. 4,177 ac (1,690 ha).
Local 7 .............................................................................. 514 ac (208 ha).
Subtotal ............................................................................ 67,928 ac (27,489 ha).
Total ................................................................... .......................................................................................... 384,410 ac (155,564 ha).
1—Tribal = Agua Caliente Band of Cahuilla Indians Reservation and Tribal Lands
2—BLM = Bureau of Land Management
3—USFS = United States Forest Service
4—State = California Department of Fish and Game (CDFG) and California State Lands Commission (CSLC)
5—State = CDFG, CSLC, and California Department of Parks and Recreation (CDPR)
6—State = CDPR
7—Local = City/County Park
We present brief descriptions of all
units and reasons why they meet the
definition of critical habitat for the
Peninsular bighorn sheep below.
Unit 1: San Jacinto Mountains
Unit 1 consists of approximately
15,273 ac (6,180 ha) in the San Jacinto
Mountains, Riverside County. Unit 1 is
generally located within an area
bounded on the east by the city of Palm
Springs; bounded on the north by
Windy Point and Snow Canyon; and
that extends south to the northern Palm
Canyon area. Land ownership within
the unit includes approximately 4,512
ac (1,826 ha) of Agua Caliente Band of
Cahuilla Indians Tribal land; 3,757 ac
(1,520 ha) of BLM land; 1,266 ac (512
ha) of USFS land; and 5,738 ac (2,322
ha) of private land (Table 2).
Unit 1 begins at a low elevation of
about 450 ft (137 m) on the eastern slope
and rises to about 4,600 ft (1,400 m) to
the west. It is the northernmost unit
proposed as revised critical habitat for
the Peninsular bighorn sheep. This unit
was occupied at the time of listing and
is currently occupied (Table 1). Habitat
in this unit contains features that are
essential to the conservation of the
Peninsular bighorn sheep including a
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57750 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
range of vegetation types (PCE 2),
foraging and watering areas including
alluvial fans (PCE 4 and 5), and steep to
very steep, rocky terrain with elevations
and slopes that provide for sheltering,
lambing, mating, movement among and
between ewe groups (PCE 1), and
predator evasion (PCE 3).
The PCEs in Unit 1 may require
special management considerations or
protection to ameliorate the threats of
urban and industrial development,
particularly in lower elevation areas,
and to decrease the direct and indirect
effects of human disturbance to the
Peninsular bighorn sheep and its
habitat, due to the proximity of this unit
to the Palms Springs area. Please see the
‘‘Special Management Considerations or
Protection’’ section of this proposed rule
for a detailed discussion of the threats
to Peninsular bighorn sheep habitat and
potential management considerations.
This unit includes approximately
4,512 ac (1,826 ha) of Agua Caliente
Band of Cahuilla Indians (Tribe) tribal
lands supporting essential Peninsular
bighorn sheep habitat. We are proposing
to exclude these lands from the final
designation. The designation of critical
habitat would be expected to adversely
impact our working relationship with
the Tribe and we believe that Federal
regulation through critical habitat
designation would be viewed as an
unwarranted and unwanted intrusion
into tribal natural resource programs.
Furthermore, these approximately 4,512
ac (1,826 ha) of Tribal land are currently
managed by the Tribe in a manner that
provides some conservation benefits to
the Peninsular bighorn sheep, and are
also within the plan area of the draft
Agua Caliente Band of Cahuilla Indians
Tribal Habitat Conservation Plan (Tribal
HCP) (see ‘‘Proposed Exclusion of Agua
Caliente Band of Cahuilla Indians Tribal
Lands Under Section 4(b)(2) of the Act’’
for a detailed discussion).
This unit also includes lands within
the plan area for the draft Coachella
Valley Multiple Species Habitat
Conservation Plan (MSHCP). We are
considering the possible exclusion of
approximately 5,738 ac (2,322 ha) of
private land from the final critical
habitat designation based on benefits
provided to the Peninsular bighorn
sheep and its PCEs by the MSCHP,
which is in draft form and under review
by the Service (see ‘‘Lands Covered by
Management Plans ‘‘ Exclusions Under
Section 4(b)(2) of the Act’’ for a detailed
discussion).
Unit 2A: North Santa Rosa Mountains
Unit 2A consists of approximately
74,998 ac (30,350 ha) in the northern
Santa Rosa Mountains, Riverside
County. Unit 2A is generally located on
the east-facing slopes of the northern
Santa Rosa Mountains, is loosely
bounded on the east by communities of
the northern Coachella Valley, and
extends from the Rancho Mirage area in
the north to Martinez Canyon in the
south. Land ownership within the unit
includes approximately 44,669 ac
(18,077 ha) of BLM land; 16,856 ac
(6,821 ha) of land owned by the State of
California; and 13,473 ac (5,452 ha) of
private land (Table 2).
Unit 2A begins at a low elevation of
about 50 ft (15 m) on the eastern slope
and rises to about 4,600 ft (1,400 m) to
the west. This unit was occupied at the
time of listing and is currently occupied
(Table 1). Habitat in this unit contains
features that are essential to the
conservation of the Peninsular bighorn
sheep including a range of vegetation
types (PCE 2), foraging and watering
areas including alluvial fans (PCE 4 and
5), and steep to very steep, rocky terrain
with elevations and slopes that provide
for sheltering, lambing, mating,
movement among and between ewe
groups (PCE 1), and predator evasion
(PCE 3).
The PCEs in Unit 2A may require
special management considerations or
protection to ameliorate the threats of
urban, industrial, and agricultural
development, and to decrease the direct
and indirect effects of human
disturbance to Peninsular bighorn sheep
and its habitat, due to the proximity of
this unit to the highly developed
northern Coachella Valley.
Additionally, the PCEs in this unit may
require special management
considerations or protection to alleviate
threats to Peninsular bighorn sheep and
its habitat associated with roadways;
State Route 74 cuts through the
midsection of this unit and may impede
movement between ewe groups. Please
see the ‘‘Special Management
Considerations or Protection’’ section of
this proposed rule for a detailed
discussion of the threats to Peninsular
bighorn sheep habitat and potential
management considerations.
This unit includes lands that are
within the plan area for the draft
Coachella Valley Multiple Species
Habitat Conservation Plan (MSHCP). We
are considering the possible exclusion
of approximately 13,473 ac (5,452 ha) of
private land in Unit 2A from the final
critical habitat designation based on
benefits provided to the Peninsular
bighorn sheep habitat under this plan,
which is in draft form and under review
by the Service (see ‘‘Areas Considered
for Exclusion Under Section 4(b)(2) of
the Act’’ for a detailed discussion).
Unit 2B: South Santa Rosa Mountains
south to Vallecito Mountains
Unit 2B consists of approximately
226,211 ac (91,545 ha) in the southern
Santa Rosa Mountains, Coyote Canyon,
San Ysidro Mountains, Pinyon
Mountains, and Vallecito Mountains, in
Riverside, San Diego, and Imperial
counties. Unit 2B is generally located on
the east-facing slopes of the above
ranges; it is loosely bounded on the east
by the Coachella Valley floor and
extends from the southern Santa Rosa
Mountains in the north to the Fish
Creek Mountains in the south. Land
ownership within the unit includes
approximately 16,266 ac (6,583 ha) of
BLM land; 197,509 ac (79,929 ha) of
land owned by the State of California;
and 12,436 ac (5,033 ha) of private land
(Table 2). Portions of the Anza-Borrego
Desert State Park occur within this unit.
Unit 2B begins at a low elevation of
about 150 ft (45 m) on the eastern slope
and rises to about 4,600 ft (1,400 m) to
the west. This unit was occupied at the
time of listing and is currently occupied
(Table 1). Habitat in this unit contains
features that are essential to the
conservation of the Peninsular bighorn
sheep including a range of vegetation
types (PCE 2), foraging and watering
areas including alluvial fans (PCE 4 and
5), and steep to very steep, rocky terrain
with elevations and slopes that provide
for sheltering, lambing, mating,
movement among and between ewe
groups (PCE 1), and predator evasion
(PCE 3).
The PCEs in Unit 2B may require
special management considerations or
protection to ameliorate the threats of
urban, industrial, and agricultural
development due to the proximity of
this unit to the Coachella Valley,
especially the lower elevation areas in
the northeastern portions of this unit.
Additionally, the PCEs in this unit may
require special management
considerations or protection to decrease
the direct and indirect effects of human
disturbance to Peninsular bighorn sheep
and its habitat due to recreational
activity. Most of this unit includes lands
within Anza-Borrego Desert State Park,
which is open to recreation activities.
Furthermore, the PCEs in this unit may
require special management
considerations or protection to alleviate
threats to Peninsular bighorn sheep and
its habitat associated with State Route
78, which cuts through the southern
portion of this unit and may impede
movement between ewe groups, and
mining operations at Fish Canyon
Quarry. Please see the ‘‘Special
Management Considerations or
Protection’’ section of this proposed rule
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57751 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
for a detailed discussion of the threats
to Peninsular bighorn sheep habitat and
potential management considerations.
Unit 3: Carrizo Canyon
Unit 3 consists of approximately
67,928 ac (27,489 ha) in the Carrizo
Canyon area, in San Diego and Imperial
counties. Unit 3 is generally located in
Carrizo Canyon and the surrounding In-
Ko-Pah Mountains, Jacumba Mountains,
Coyote Mountains, and Tierra Blanca
Mountains; it is loosely bounded on the
north, east, and west by the Coachella
Valley floor. Land ownership within the
unit includes approximately 27,762 ac
(11,235 ha) of BLM land; 35,475 ac
(14,356 ha) of land owned by the State
of California; 4,177 ac (1,690 ha) of
private land; and 514 ac (208 ha) of
local park land (Table 2). Portions of the
Anza-Borrego Desert State Park occur
within this unit.
Unit 3 begins at a low elevation of
about 400 ft (122 m) on the eastern slope
and rises to about 4,600 ft (1,400 m) to
the west. This unit was occupied at the
time of listing and is currently occupied
(Table 1). Habitat in this unit contains
features that are essential to the
conservation of the Peninsular bighorn
sheep including a range of vegetation
types (PCE 2), foraging and watering
areas including alluvial fans (PCE 4 and
5), and steep to very steep, rocky terrain
with elevations and slopes that provide
for sheltering, lambing, mating,
movement among and between ewe
groups (PCE 1), and predator evasion
(PCE 3).
The PCEs in Unit 3 may require
special management considerations or
protection to decrease the direct and
indirect effects of human disturbance
due to recreational activity to
Peninsular bighorn sheep and its
habitat. Most of this unit occurs within
the Anza-Borrego Desert State Park,
which is open to recreation activities.
The PCEs in Unit 3 may also require
special management considerations or
protection to protect Peninsular bighorn
sheep habitat from mining operations at
Ocotillo Mineral Material Site. Please
see the ‘‘Special Management
Considerations or Protection’’ section of
this proposed rule for a detailed
discussion of the threats to Peninsular
bighorn sheep habitat and potential
management considerations.
Table 3 provides approximate areas
(ac, ha) of lands that meet the definition
of critical habitat but that we are
proposing to exclude from the final
revised critical habitat designation.
Table 3 also provides reasons for the
proposed exclusions.
TABLE 3.—PROPOSED EXCLUSIONS BY CRITICAL HABITAT UNIT
Unit Statutory Reason for proposal
exclusion
Area meeting the definition
of critical habitat in acres
(Hectares)
Area proposed for
exclusion in acres
(Hectares)
1. San Jacinto Mts. 4(b)(2) ............................... Government-to-Govern-
ment Relationship 1
4,512 ac (1,826 ha) 4,512 ac (1,826 ha).
Total ........................... ........................................... ........................................... ........................................... 4,512 ac (1,826 ha).
1 Government-to-Government Relationship = Secretarial Order 3206, ‘‘ American Indian Tribal Rights, Federal Tribal Trust Responsibilities, and
the Endangered Species Act’’ (June 5, 1997); the President’s memorandum of April 29, 1994, ‘‘ Government-to-Government Relations with Na-
tive American Tribal Governments’’ (59 FR 22951); Executive Order 13175; and the relevantprovision of the Departmental Manual of the Depart-
ment of the Interior (512 DM 2).
Effects of Critical Habitat Designation
Section 7 Consultation
Section 7(a)(2) of the Act requires
Federal agencies, including the Service,
to ensure that actions they fund,
authorize, or carry out are not likely to
destroy or adversely modify critical
habitat. Decisions by the 5th and 9th
Circuit Court of Appeals have
invalidated our definition of
‘‘destruction or adverse modification’’
(50 CFR 402.02) (see Gifford Pinchot
Task Force v. U.S. Fish and Wildlife
Service, 378 F. 3d 1059 (9th Cir. 2004)
and Sierra Club v. U.S. Fish and
Wildlife Service et al., 245 F.3d 434, 442
(5th Cir. 2001)), and we do not rely on
this regulatory definition when
analyzing whether an action is likely to
destroy or adversely modify critical
habitat. Under the statutory provisions
of the Act, we determine destruction or
adverse modification on the basis of
whether, with implementation of the
proposed Federal action, the affected
critical habitat would remain functional
(or retain the current ability for the PCEs
to be functionally established) to serve
its intended conservation role for the
species.
Section 7(a)(4) of the Act requires
Federal agencies to confer with us on
any action that is likely to jeopardize
the continued existence of a species
proposed for listing or result in
destruction or adverse modification of
proposed critical habitat. This is a
procedural requirement only, as any
conservation recommendations in a
conference report or opinion are strictly
advisory. However, once a species
proposed for listing becomes listed, or
proposed critical habitat is designated
as final, the full prohibitions of section
7(a)(2) apply to any discretionary
Federal action.
The primary utility of the conference
procedures is to allow a Federal agency
to maximize its opportunity to
adequately consider species proposed
for listing and proposed critical habitat
and to avoid potential delays in
implementing their proposed action
because of the section 7(a)(2)
compliance process, if we list those
species or designate critical habitat. We
may conduct conferences either
informally or formally. We typically use
informal conferences as a means of
providing advisory conservation
recommendations to assist the agency in
eliminating conflicts that the proposed
action may cause. We typically use
formal conferences when we or the
Federal agency believes the proposed
action is likely to jeopardize the
continued existence of the species
proposed for listing or adversely modify
proposed critical habitat.
We generally provide the results of an
informal conference in a conference
report, while we provide the results of
a formal conference in a conference
opinion. We typically prepare
conference opinions on proposed
species or critical habitat in accordance
with procedures contained at 50 CFR
402.14, as if the proposed species were
already listed or the proposed critical
habitat was already designated. We may
adopt the conference opinion as the
biological opinion when the species is
listed or the critical habitat is
designated, if no substantial new
information or changes in the action
alter the content of the opinion (see 50
CFR 402.10(d)).
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57752 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
If a species is listed or critical habitat
is designated, section 7(a)(2) of the Act
requires Federal agencies to ensure that
activities they authorize, fund, or carry
out are not likely to jeopardize the
continued existence of the species or to
destroy or adversely modify its critical
habitat. If a Federal action may affect a
listed species or its critical habitat, the
responsible Federal agency (action
agency) must enter into consultation
with us. As a result of this consultation,
we document compliance with the
requirements of section 7(a)(2) through
our issuance of:
(1) A concurrence letter for Federal
actions that may affect, but are not
likely to adversely affect, listed species
or critical habitat; or
(2) A biological opinion for Federal
actions that may affect, and are likely to
adversely affect, listed species or critical
habitat.
When we issue a biological opinion
concluding that a project is likely to
jeopardize the continued existence of a
listed species or destroy or adversely
modify critical habitat, we also provide
reasonable and prudent alternatives to
the project, if any are identifiable. We
define ‘‘Reasonable and prudent
alternatives’’ at 50 CFR 402.02 as
alternative actions identified during
consultation that:
•Can be implemented in a manner
consistent with the intended purpose of
the action,
•Can be implemented consistent
with the scope of the Federal agency’s
legal authority and jurisdiction,
•Are economically and
technologically feasible, and
•Would, in the Director’s opinion,
avoid jeopardizing the continued
existence of the listed species or
destroying or adversely modifying
critical habitat.
Reasonable and prudent alternatives
can vary from slight project
modifications to extensive redesign or
relocation of the project. Costs
associated with implementing a
reasonable and prudent alternative are
similarly variable.
Regulations at 50 CFR 402.16 require
Federal agencies to reinitiate
consultation on previously reviewed
actions in instances where we have
listed a new species or subsequently
designated critical habitat that may be
affected and the Federal agency has
retained discretionary involvement or
control over the action (or the agency’s
discretionary involvement or control is
authorized by law). Consequently,
Federal agencies may sometimes need to
request reinitiation of consultation with
us on actions for which formal
consultation has been completed, if
those actions with discretionary
involvement or control may affect
subsequently listed species or
designated critical habitat.
Federal activities that may affect the
Peninsular bighorn sheep or its
designated critical habitat require
section 7(a)(2) consultation under the
Act. Activities on State, Tribal, local, or
private lands requiring a Federal permit
(such as a permit from the U.S. Army
Corps of Engineers under section 404 of
the Clean Water Act (33 U.S.C. 1251 et
seq.) or a permit from us under section
10 of the Act) or involving some other
Federal action (such as funding from the
Federal Highway Administration,
Federal Aviation Administration, or the
Federal Emergency Management
Agency) are subject to the section 7(a)(2)
consultation process. Federal actions
not affecting listed species or critical
habitat, and actions on State, Tribal,
local, or private lands that are not
federally funded, authorized, or
permitted, do not require section 7(a)(2)
consultations.
Application of the ‘‘Adverse
Modification’’ Standard
The key factor related to the adverse
modification determination is whether,
with implementation of the proposed
Federal action, the affected critical
habitat would continue to serve its
intended conservation role for the
species, or would retain its current
ability for the primary constituent
elements to be functionally established.
Activities that may destroy or adversely
modify critical habitat are those that
alter the PCEs to an extent that
appreciably reduces the conservation
value of critical habitat for the
Peninsular bighorn sheep. Generally,
the conservation role of the Peninsular
bighorn sheep critical habitat units is to
support viable core area populations.
Section 4(b)(8) of the Act requires us
to briefly evaluate and describe, in any
proposed or final regulation that
designates critical habitat, activities
involving a Federal action that may
destroy or adversely modify such
habitat, or that may be affected by such
designation.
Activities that, when carried out,
funded, or authorized by a Federal
agency, may affect critical habitat and
therefore should result in consultation
for the Peninsular bighorn sheep
include, but are not limited to:
(1) Actions that would significantly
reduce ongoing management and
conservation efforts that benefit the
Peninsular bighorn sheep on public
lands. Such activities could include, but
are not limited to, the sale, exchange, or
lease of lands managed by BLM or other
Federal agencies, and the State of
California. These activities could reduce
the amount of space that is available for
individual and population growth and
normal behavior, as well as reduce or
eliminate the number and extent of sites
for foraging, watering, breeding,
reproduction, and rearing of offspring.
These activities could also reduce the
opportunities available to Federal
agencies to exercise their section 7(a)(1)
responsibilities to carry out programs to
conserve listed species.
(2) Actions that would significantly
reduce the availability of or accessibility
to seasonal ranges. Such activities could
include, but are not limited to, grazing,
mining, and power line and road
construction activities. These activities
could degrade, reduce, fragment, or
eliminate available foraging resources or
alter current foraging activities of
Peninsular bighorn sheep.
(3) Actions that would result in the
significant expansion of dense
vegetation communities within
Peninsular bighorn sheep habitat. Such
activities could include, but are not
limited to, fire suppression. These
activities could allow expansion of
vegetation cover such that movement
patterns of bighorn sheep are altered by
avoidance of these areas. Tall, dense
vegetation decreases visibility for
bighorn sheep and provides cover for
predators such as the mountain lion, a
common predator of Peninsular bighorn
sheep.
(4) Actions that would create
significant barriers to movement. Such
activities could include, but are not
limited to, road construction, residential
development, and resort or campground
facility development or expansion.
These activities could interfere with
movement within and between habitats,
thereby reducing the availability of
habitat for foraging, watering, breeding,
reproduction, sheltering, and rearing of
offspring. These activities could also
reduce opportunities for movement
between existing populations, dispersal,
and genetic interchange between ewe
groups.
(5) Actions that would significantly
degrade habitat or cause a disturbance
to Peninsular bighorn sheep. Such
activities could include, but are not
limited to, recreational activities, such
as off-road vehicle use, hiking, camping,
rock climbing, horseback riding, and
outfitter guided activities. These
activities could displace animals from
foraging areas, water sources, and
escape terrain, and could impact the
quality and quantity of forage.
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Exemptions and Exclusions
Application of Section 4(b)(2) of the Act
Section 4(b)(2) of the Act states that
the Secretary must designate and revise
critical habitat on the basis of the best
available scientific data after taking into
consideration the economic impact,
impact on national security, and any
other relevant impact of specifying any
particular area as critical habitat. The
Secretary may exclude an area from
critical habitat if he determines that the
benefits of such exclusion outweigh the
benefits of specifying such area as part
of the critical habitat, unless he
determines, based on the best scientific
data available, that the failure to
designate such area as critical habitat
will result in the extinction of the
species. In making that determination,
the legislative history is clear that the
Secretary has broad discretion regarding
which factor(s) to use and how much
weight to give to any factor.
Under section 4(b)(2) of the Act, in
considering whether to exclude a
particular area from the designation, we
must identify the benefits of including
the area in the designation, identify the
benefits of excluding the area from the
designation, and determine whether the
benefits of exclusion outweigh the
benefits of inclusion. If we consider an
exclusion we must determine whether
excluding the area would result in the
extinction of the species.
In the following sections, we address
a number of general issues that are
relevant to the exclusions we are
considering. In addition, we are
conducting an economic analysis of the
impacts of the proposed critical habitat
designation, which will be available for
public review and comment when it is
complete. Based on public comment on
that document, the proposed
designation itself, and the information
in the final economic analysis, the
Secretary may exclude from critical
habitat additional areas beyond those
identified in this assessment under the
provisions of section 4(b)(2) of the Act.
This is also addressed in our
implementing regulations at 50 CFR
424.19.
Benefits of Designating Critical Habitat
The process of designating critical
habitat as described in the Act requires
that the Service identify those lands on
which are found the physical or
biological features essential to the
conservation of the species that may
require special management
considerations or protection, and those
areas outside the geographical area
occupied by the species at the time of
listing that are essential to the
conservation of the species. In
identifying those lands, the Service
must consider the recovery needs of the
species, such that, on the basis of the
best scientific and commercial data
available at the time of designation, the
habitat that is identified, if managed,
could provide for the survival and
recovery of the species.
The identification of those areas that
are essential for the conservation of the
species and can, if managed, provide for
the recovery of a species is beneficial.
The process of proposing and finalizing
a critical habitat rule provides the
Service with the opportunity to
determine the features or PCEs essential
for conservation of the species within
the geographical area occupied by the
species at the time of listing, as well as
to determine other areas essential to the
conservation of the species. The
designation process includes peer
review and public comment on the
identified features and areas. This
process is valuable to land owners and
managers in developing conservation
management plans for identified areas,
as well as any other occupied habitat or
suitable habitat that may not have been
included in the Service’s determination
of essential habitat.
The consultation provisions under
section 7(a) of the Act constitute the
regulatory benefits of critical habitat. As
discussed above, Federal agencies must
consult with us on actions that may
affect critical habitat and must avoid
destroying or adversely modifying
critical habitat. Federal agencies must
also consult with us on actions that may
affect a listed species and refrain from
undertaking actions that are likely to
jeopardize the continued existence of
such species. The analysis of effects to
critical habitat is a separate and
different analysis from that of the effects
to the species. Therefore, the difference
in outcomes of these two analyses
represents the regulatory benefit of
critical habitat. For some species, and in
some locations, the outcome of these
analyses will be similar, because effects
on habitat will often result in effects on
the species. However, the regulatory
standard is different: the jeopardy
analysis looks at the action’s impact on
survival and recovery of the species,
while the adverse modification analysis
looks at the action’s effects on the
designated habitat’s contribution to the
species’ conservation. This will, in
many instances, lead to different results
and different regulatory requirements.
For 30 years prior to the Ninth
Circuit’s decision in Gifford Pinchot,
consistent with the 1986 regulations, we
essentially combined the jeopardy
standard with the standard for
destruction or adverse modification of
critical habitat when evaluating Federal
actions that affected currently occupied
critical habitat. However, the court of
appeals ruled that the two standards are
distinct and that adverse modification
evaluations require consideration of
impacts on species recovery. Thus,
critical habitat designations may
provide greater regulatory benefits to the
recovery of a species than would listing
alone.
There are two limitations to the
regulatory effect of critical habitat. First,
a section 7(a)(2) consultation is required
only where there is a Federal nexus (an
action authorized, funded, or carried out
by any Federal agency)—if there is no
Federal nexus, the critical habitat
designation of private lands itself does
not restrict any actions that destroy or
adversely modify critical habitat.
Second, the designation only limits
destruction or adverse modification. By
its nature, the prohibition on adverse
modification is designed to ensure that
the conservation role and function of
those areas that contain the physical
and biological features essential to the
conservation of the species or of
unoccupied areas that are essential to
the conservation of the species is not
appreciably reduced. Critical habitat
designation alone, however, does not
require property owners to undertake
specific steps toward recovery of the
species.
Once an agency determines that
consultation under section 7(a)(2) of the
Act is necessary, the process may
conclude informally when we concur in
writing that the proposed Federal action
is not likely to adversely affect critical
habitat. However, if we determine
through informal consultation that
adverse impacts are likely to occur, then
we would initiate formal consultation,
which would conclude when we issue
a biological opinion on whether the
proposed Federal action is likely to
result in destruction or adverse
modification of critical habitat.
For critical habitat, a biological
opinion that concludes in a
determination of no destruction or
adverse modification may contain
discretionary conservation
recommendations to minimize adverse
effects to primary constituent elements,
but it would not suggest the
implementation of any reasonable and
prudent alternative. We suggest
reasonable and prudent alternatives to
the proposed Federal action only when
our biological opinion results in an
adverse modification conclusion.
As stated above, the designation of
critical habitat does not require that any
management or recovery actions take
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57754 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
place on the lands included in the
designation. Even in cases where
consultation has been initiated under
section 7(a)(2) of the Act, the end result
of consultation is to avoid jeopardy to
the species and/or adverse modification
of its critical habitat, but not specifically
to manage remaining lands or institute
recovery actions on remaining lands.
Conversely, voluntary conservation
efforts implemented through
management plans institute proactive
actions over the lands they encompass
and are put in place to remove or reduce
known threats to a species or its habitat;
therefore, implementing recovery
actions. We believe that in many
instances the benefit to a species and/
or its habitat realized through the
designation of critical habitat is low
when compared to the conservation
benefit that can be achieved through
voluntary conservation efforts or
management plans. The conservation
achieved through implementing HCPs
or other habitat management plans can
be greater than what we achieve through
multiple site-by-site, project-by-project,
section 7(a)(2) consultations involving
consideration of critical habitat.
Management plans may commit
resources to implement long-term
management and protection to
particular habitat for at least one and
possibly additional listed or sensitive
species. Section 7(a)(2) consultations
commit Federal agencies to preventing
adverse modification of critical habitat
caused by the particular project only,
and not to providing conservation or
long-term benefits to areas not affected
by the proposed project. Thus,
implementation of any HCP or
management plan that considers
enhancement or recovery as the
management standard may often
provide as much or more benefit than a
consultation for critical habitat
designation.
Another benefit of including lands in
critical habitat is that designation of
critical habitat serves to educate
landowners, State and local
governments, and the public regarding
the potential conservation value of an
area. This helps focus and promote
conservation efforts by other parties by
clearly delineating areas of high
conservation value for the Peninsular
bighorn sheep. In general, critical
habitat designation always has
educational benefits; however, in some
cases, they may be redundant with other
educational effects. For example, HCPs
have significant public input and may
largely duplicate the educational
benefits of a critical habitat designation.
Including lands in critical habitat also
would inform State agencies and local
governments about areas that could be
conserved under State laws or local
ordinances.
Conservation Partnerships on Non-
Federal Lands
Most federally listed species in the
United States will not recover without
cooperation of non-Federal landowners.
More than 60 percent of the United
States is privately owned (National
Wilderness Institute 1995, p. 2), and at
least 80 percent of endangered or
threatened species occur either partially
or solely on private lands (Crouse et al.
2002, p. 720). Stein et al. (1995, p. 400)
found that only about 12 percent of
listed species were found almost
exclusively on Federal lands (90 to 100
percent of their known occurrences
restricted to Federal lands) and that 50
percent of federally listed species are
not known to occur on Federal lands at
all.
Given the distribution of listed
species with respect to land ownership,
conservation of listed species in many
parts of the United States is dependent
upon working partnerships with a wide
variety of entities and the voluntary
cooperation of many non-Federal
landowners (Wilcove and Chen 1998, p.
1407; Crouse et al. 2002, p. 720; James
2002, p. 271). Building partnerships and
promoting voluntary cooperation of
landowners are essential to our
understanding the status of species on
non-Federal lands, and necessary for us
to implement recovery actions such as
reintroducing listed species and
restoring and protecting habitat.
Many non-Federal landowners derive
satisfaction from contributing to
endangered species recovery. We
promote these private-sector efforts
through the Department of the Interior’s
Cooperative Conservation philosophy.
Conservation agreements with non-
Federal landowners (HCPs, safe harbor
agreements, other conservation
agreements, easements, and State and
local regulations) enhance species
conservation by extending species
protections beyond those available
through section 7 consultations. In the
past decade, we have encouraged non-
Federal landowners to enter into
conservation agreements, based on the
view that we can achieve greater species
conservation on non-Federal land
through such partnerships than we can
through regulatory methods (61 FR
63854; December 2, 1996).
Many private landowners, however,
are wary of the possible consequences of
attracting endangered species to their
property. Mounting evidence suggests
that some regulatory actions by the
Federal Government, while well-
intentioned and required by law, can
(under certain circumstances) have
unintended negative consequences for
the conservation of species on private
lands (Wilcove et al. 1996, pp. 5–6;
Bean 2002, pp. 2–3; Conner and
Mathews 2002, pp. 1–2; James 2002, pp.
270–271; Koch 2002, pp. 2–3; Brook et
al. 2003, pp. 1639–1643). Many
landowners fear a decline in their
property value due to real or perceived
restrictions on land-use options where
threatened or endangered species are
found. Consequently, harboring
endangered species is viewed by many
landowners as a liability. This
perception results in anti-conservation
incentives because maintaining habitats
that harbor endangered species
represents a risk to future economic
opportunities (Main et al. 1999, pp.
1264–1265; Brook et al. 2003, pp. 1644–
1648).
According to some researchers, the
designation of critical habitat on private
lands significantly reduces the
likelihood that landowners will support
and carry out conservation actions
(Main et al. 1999, p. 1263; Bean 2002,
p. 2; Brook et al. 2003, pp. 1644–1648).
The magnitude of this outcome is
greatly amplified in situations where
active management measures (such as
reintroduction, fire management, and
control of invasive species) are
necessary for species conservation (Bean
2002, pp. 3–4). We believe that the
judicious use of excluding specific areas
of non-federally owned lands from
critical habitat designations can
contribute to species recovery and
provide a superior level of conservation
than critical habitat alone.
The purpose of designating critical
habitat is to contribute to the
conservation of threatened and
endangered species and the ecosystems
upon which they depend. The outcome
of the designation, triggering regulatory
requirements for actions funded,
authorized, or carried out by Federal
agencies under section 7(a)(2) of the
Act, can sometimes be
counterproductive to its intended
purpose on non-Federal lands. Thus the
benefits of excluding areas that are
covered by effective partnerships or
other conservation commitments can
often be high.
Benefits of Excluding Lands With
Approved Management Plans
The benefits of excluding lands
within approved long-term management
plans (including HCPs) from critical
habitat designation include relieving
landowners, communities, and counties
of any additional regulatory burden that
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might be imposed by critical habitat.
Many conservation plans provide
conservation benefits not only to listed
species, but to unlisted sensitive species
as well, resulting in enhanced
ecosystem management. Imposing an
additional regulatory review as a result
of the designation of critical habitat may
undermine conservation efforts and
partnerships in many areas. Designation
of critical habitat within the boundaries
of management plans that provide
conservation measures for a species
could be viewed as a disincentive to
entities currently developing these
plans or contemplating them in the
future, because one of the incentives for
undertaking conservation is greater ease
of permitting where listed species will
be affected. Addition of a new
regulatory requirement would remove a
significant incentive for undertaking the
time and expense of management
planning.
A related benefit of excluding lands
within management plans from critical
habitat designation is the unhindered,
continued ability it gives us to seek new
partnerships with future plan
participants, including States, counties,
local jurisdictions, conservation
organizations, and private landowners,
which together can implement
conservation actions that we would be
unable to accomplish otherwise.
Designating lands within approved
management plan areas as critical
habitat would likely have a negative
effect on our ability to establish new
partnerships to develop these plans,
particularly plans that address
landscape-level conservation of species
and habitats. By preemptively excluding
these lands, we preserve our current
partnerships and encourage additional
conservation actions in the future.
Furthermore, both HCP and Natural
Community Conservation Plan (NCCP)–
HCP applications require consultation,
which would review the effects of all
HCP–covered activities that might
adversely impact the species under a
jeopardy standard, including possibly
significant habitat modification (see
definition of ‘‘harm’’ at 50 CFR 17.3),
even without the critical habitat
designation. In addition, Federal actions
occurring within the plan area that may
affect listed species would still require
consultation under section 7(a)(2) of the
Act, and we would review these actions
for possibly significant habitat
modification, in accordance with the
definition of harm referenced above.
The information provided in the
previous sections applies to all the
following discussions of the benefits of
inclusion and exclusion of critical
habitat.
Areas Considered For Exclusion Under
Section 4(b)(2) of the Act
We are proposing to exclude Tribal
lands in Unit 1 in consideration of
Secretarial Order 3206, ‘‘American
Indian Tribal Rights, Federal Tribal
Trust Responsibilities, and the
Endangered Species Act’’ (June 5, 1997);
the President’s memorandum of April
29, 1994, ‘‘‘‘Government-to-Government
Relations with Native American Tribal
Governments’’ (59 FR 22951); Executive
Order 13175; and the relevant provision
of the Departmental Manual of the
Department of the Interior (512 DM 2).
Furthermore, we are evaluating and
considering the possible exclusion of
private lands in Unit 1 and 2A, which
are covered under the draft Coachella
Valley Multiple Species Habitat
Conservation Plan (MSHCP), under
section 4(b)(2) of the Act, and may
exclude them from the final revised
critical habitat designation for the
Peninsular bighorn sheep. With regard
to the draft Coachella Valley MSHCP
plan area, we are only considering
private lands for exclusion at this time,
while also soliciting comment on the
appropriateness of excluding CDFG and
BLM lands as Memorandum of
Understanding (MOU) partners to the
MSHCP. We are considering the
possible exclusion of the areas covered
by the draft MSHCP because we believe
when the plan is finalized that:
(1) The lands’ value for conservation
will be preserved for the foreseeable
future by existing protective actions,
and
(2) They are appropriate for exclusion
under the ‘‘other relevant factor’’
provisions of section 4(b)(2) of the Act.
We specifically solicit comments on
the inclusion or exclusion of these
areas. In the paragraphs below, we
provide a detailed analysis for
consideration of exclusion of these
lands under section 4(b)(2) of the Act.
Proposed Exclusion of Agua Caliente
Band of Cahuilla Indians Tribal Lands
Under Section 4(b)(2) of the Act—
American Indian Tribal Rights, Federal-
Tribal Trust Responsibilities, and the
Endangered Species Act
In accordance with the Secretarial
Order 3206, ‘‘American Indian Tribal
Rights, Federal-Tribal Trust
Responsibilities, and the Endangered
Species Act’’ (June 5, 1997); the
President’s memorandum of April 29,
1994, ‘‘Government-to-Government
Relations with Native American Tribal
Governments’’ (59 FR 22951); Executive
Order 13175; and the relevant provision
of the Departmental Manual of the
Department of the Interior (512 DM 2),
we believe that fish, wildlife, and other
natural resources on Tribal lands are
better managed under Tribal authorities,
policies, and programs than through
Federal regulation wherever possible
and practicable. Based on this
philosophy, we believe that, in most
cases, designation of tribal lands as
critical habitat provides very little
additional benefit to threatened and
endangered species. Conversely, such
designation is often viewed by tribes as
unwarranted and an unwanted intrusion
into tribal self governance, thus
compromising the government-to-
government relationship essential to
achieving our mutual goals of managing
for healthy ecosystems upon which the
viability of threatened and endangered
species populations depend.
We have determined that
approximately 4,512 ac (1,826 ha) of
tribal land owned by the Agua Caliente
Band of Cahuilla Indians are essential to
the conservation of the Peninsular
bighorn sheep, and are proposing to
exclude these lands under section
4(b)(2) of the Act. In making our final
decision with regard to these Tribal
lands, we will be considering several
factors including our relationship with
the Tribe, the Tribe’s current
management of Peninsular bighorn
sheep habitat, and the Tribe’s ongoing
cooperation with us in the development
of the Agua Caliente Band of Cahuilla
Indians Tribal Habitat Conservation
Plan (Tribal HCP).
The Agua Caliente Band of Cahuilla
Indians highly values its wildlife and
natural resources, and is charged to
preserve and protect these resources
under the Tribal Constitution.
Consequently, the Tribe has long
worked to manage the habitat of wildlife
on its lands, including the habitat of
endangered and threatened species. The
Tribe currently implements a
conservation strategy for the Peninsular
bighorn sheep to protect and manage
bighorn sheep habitat on Tribal lands
(as set forth in the draft Tribal Habitat
Conservation Plan adopted by the Tribe
on or about November 11, 2002). This
conservation strategy requires
conservation of at least 85 percent of
bighorn sheep habitat identified by the
Tribe on Tribal lands and 100 percent
of bighorn sheep use areas and habitat
linkages identified by the Tribe on
Tribal lands. These management
measures provide a substantial
conservation benefit to the subspecies.
In addition, we are currently working
with the Tribe to develop the first Tribal
multiple-species HCP in the United
States. Through this cooperative effort,
the Tribe has demonstrated a sustained
commitment to manage its lands in a
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manner consistent with the subspecies’
conservation. We are currently
processing the Tribe’s application for a
section 10(a)(1)(B) permit based on a
revised draft Tribal Habitat
Conservation Plan (2007), and anticipate
publishing a Notice of Availability for
public review in the Federal Register in
October 2007.
The Tribal HCP area will cover
approximately 36,720 ac (14,860 ha) of
land, including approximately 4,512 ac
(1,826 ha) in Unit 1. The Tribe’s goals
for conservation of Peninsular bighorn
sheep are: (1) Conserving habitat within
the Tribal HCP plan area (PCE 1, 2, 3,
4, and 5); (2) maintaining connectivity,
preventing fragmentation, and allowing
movement within key linkage areas
(PCE 1 and 4); and (3) adaptively
managing habitat quality and
subpopulations/ewe groups to alleviate
threats in the Tribal HCP plan area
(Tribal HCP 2007, p. 4–8). Conservation
objectives of the draft Tribal HCP for
Peninsular bighorn sheep include the
following: (1) Ensure implementation of
the Tribal HCP is consistent with the
recovery plan (Service 2000); (2)
conserve a minimum of 17,692 ac (7,160
ha) of habitat within the plan area; (3)
conserve 100 percent of Use Areas
(areas defined by the Tribal HCP to have
high functional value); (4) conserve land
necessary to maintain linkages/
connectivity; (5) minimize direct and
indirect impacts from Covered
Activities by ensuring implementation
of development standards, including
avoidance and minimization measures;
(6) minimize impacts from recreational
activities; (7) alleviate threat of disease
transfer from livestock or nonnative
wildlife; (8) monitor population size
and mortality rates; (9) fund or
undertake additional studies regarding
this subspecies; (10) ensure
management action thresholds are
routinely assessed; (11) implement
adaptive management; and (12)
conserve habitat quality through plan
implementation (Tribal HCP 2007, p. 4–
9).
To aid in the public review of this
proposed revised critical habitat, we are
providing maps of the areas that we are
proposing to exclude. Maps and GIS
layers for areas proposed for exclusion
are available from the Carlsbad Fish and
Wildlife Office (see ADDRESSES) and on
our Web site at http://www.fws.gov/
Carlsbad.
The Benefits of Exclusion Outweigh the
Benefits of Inclusion
The general benefits of critical habitat
described in the ‘‘Benefits of Critical
Habitat Designation’’ section would
apply to habitat designated on Tribal
lands. Activities occurring on Tribal
lands will generally involve a Federal
nexus. However, as discussed above, the
Tribe is aware of the value of Tribal
lands to the conservation of the
Peninsular bighorn sheep and currently
implements management measures that
contribute to the conservation of the
subspecies and protect its essential
habitat. Conservation measures will
continue to be implemented by the
Tribe regardless of whether the areas are
designated as critical habitat. In light of
this continued commitment by the Tribe
to manage its lands in a manner that
promotes the conservation of the
Peninsular bighorn sheep, the
designation of critical habitat would
provide minimal additional benefit to
the subspecies on these Tribal lands.
The designation of critical habitat
would be expected to adversely impact
our working relationship with the Tribe
and we believe that Federal regulation
through critical habitat designation
would be viewed as an unwarranted and
unwanted intrusion into tribal natural
resource programs. Our working
relationship with the Tribe has been
extremely beneficial in implementing
natural resource programs of mutual
interest. The benefits of excluding Agua
Caliente Band of Cahuilla Indians Tribal
lands from critical habitat include: (1)
The advancement of our Federal Indian
Trust obligations and our deference to
tribal conservation and natural resource
management plans for their lands and
resources, which includes the
Peninsular bighorn sheep and other
Federal trust species; (2) the
maintenance of effective working
relationships to promote the
conservation of the Peninsular bighorn
sheep and its habitat; (3) the allowance
for continued meaningful collaboration
and cooperation on Peninsular bighorn
sheep management and other resources
of interest to the Federal government;
and (4) the provision of conservation
benefits to desert ecosystems and a host
of species, including the Peninsular
bighorn sheep and its habitat, that might
not otherwise occur.
We believe that the Tribe should be
the governmental entity to manage and
promote the conservation of the
Peninsular bighorn sheep on its lands.
We recognize and endorse the Tribe’s
fundamental right to provide for tribal
resource management activities,
including those relating to Peninsular
bighorn sheep. We have determined that
the identified benefits of excluding the
Tribal lands from the critical habitat
designation outweigh the minimal
benefits of inclusion, and are proposing
to exclude approximately 4,512 ac
(1,826 ha) of Tribal lands in Unit 1 from
the final designation under section
4(b)(2) of the Act.
Exclusion Will Not Result in Extinction
of the Species
We have determined that the
exclusion of approximately 4,512 ac
(1,826 ha) from the final designation of
critical habitat for Peninsular bighorn
sheep will not result in the extinction of
the subspecies because the Tribe
currently implements a conservation
strategy for the Peninsular bighorn
sheep that requires conservation of at
least 85 percent of bighorn sheep habitat
identified by the Tribe on Tribal lands
and 100 percent of bighorn sheep use
areas and habitat linkages identified by
the Tribe on Tribal lands. In addition,
working cooperatively with us, the
Tribe has made substantial progress in
developing its Tribal HCP. Through this
cooperative effort, the Tribe has
demonstrated a sustained commitment
to manage its lands in a manner
consistent with the subspecies’
conservation. Furthermore, the area
proposed for exclusion is occupied by
the Peninsular bighorn sheep, and the
jeopardy standard of section 7 and
routine implementation of conservation
measures through the section 7
consultation process also provide
assurances that the subspecies will not
go extinct. The proposed exclusion of
critical habitat leaves these protections
unchanged from those that would exist
if the proposed excluded areas were
designated as critical habitat. Therefore,
we have determined that the exclusion
of the Tribal lands will not result in the
extinction of the subspecies.
Lands Covered by Management Plans—
Exclusions Under Section 4(b)(2) of the
Act
When performing the required
analysis under section 4(b)(2) of the Act,
the existence of a management plan
(HCPs as well as other types) that
considers enhancement or recovery of
listed species as its management
standard is relevant to our weighing of
the benefits of inclusion of a particular
area in the critical habitat designation.
In analyzing particular areas covered by
management plans under section 4(b)(2)
of the Act, we generally consider a
number of factors including the
following:
(1) Whether the plan is complete and
provides the same or better level of
protection from adverse modification or
destruction than that provided through
a consultation under section 7(a)(2) of
the Act;
(2) Whether there is a reasonable
expectation that the conservation
management strategies and actions will
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be implemented for the foreseeable
future, based on past practices, written
guidance, or regulations; and
(3) Whether the plan provides
conservation strategies and measures
consistent with currently accepted
principles of conservation biology.
Coachella Valley Multiple Species
Habitat Conservation Plan (MSHCP)
We believe that the Coachella Valley
MSHCP, when implemented, will
provide conservation strategies and
measures consistent with the
conservation of the Peninsular bighorn
sheep. We are confident that the plan
will be completed in the near future,
and are considering the exclusion of
non-Federal lands covered by the plan
that provide for the conservation of the
Peninsular bighorn sheep and its PCEs.
We are requesting comments on the
benefit to the Peninsular bighorn sheep
and its PCEs from the conservation
measures established by the Coachella
Valley MSHCP.
The draft MSHCP has been in
development from the mid-1990s to
present. The following entities signed
an MOU (Planning Agreement) to
govern the preparation of the MSHCP:
the Coachella Valley Association of
Governments (CVAG); Cities of
Cathedral City, Coachella, Desert Hot
Springs, Indian Wells, Indio, La Quinta,
Palm Desert, Palm Springs, and Rancho
Mirage; County of Riverside; Service;
California Department of Fish and
Game; BLM; U.S. Forest Service; and
National Park Service. Subsequently,
the California Department of
Transportation, Coachella Valley Water
District, Imperial Irrigation District,
Riverside County Flood Control and
Water Conservation District, Riverside
County Regional Parks and Open Space
District, Riverside County Waste
Management District, California
Department of Parks and Recreation,
and Coachella Valley Mountains
Conservancy decided to participate in
preparation of the MSHCP. The parties
later amended the Planning Agreement
to also address the requirements of the
Natural Community Conservation
Planning (NCCP) Act and prepared an
NCCP pursuant to California Fish and
Game Code Section 2810. The Coachella
Valley Association of Governments,
Coachella Valley Conservation
Commission, County of Riverside,
Riverside County Flood Control and
Water Conservation District, Riverside
County Regional Parks and Open Space
District, Riverside County Waste
Resources Management District, City of
Cathedral City, City of Coachella, City of
Indian Wells, City of Indio, City of La
Quinta, City of Palm Desert, City of
Palm Springs, City of Rancho Mirage,
Coachella Valley Water District,
Imperial Irrigation District, Coachella
Valley Mountains Conservancy,
California Department of
Transportation, and California
Department of Parks and Recreation
have submitted an application to the
Service for a section 10(a)(1)(B) permit
under the Act.
The MSHCP area encompasses
approximately 1.2 million ac (485,623
ha), of which 69,000 ac (27,923 ha) are
Tribal lands and are not included in the
MSHCP, leaving a total of
approximately 1.1 million ac (445,154
ha) addressed by the MSHCP in
Riverside County. BLM has been an
official participant in the draft
Coachella Valley MSHCP planning
process and has committed, under their
California Desert Conservation Area
Plan Amendment (CDCAPA), 95 percent
of their public land base within the
conservation areas of the MSHCP to be
managed consistent with the Coachella
Valley MSHCP once it is completed.
CVAG has demonstrated a sustained
commitment to develop the MSHCP to
comply with section 10(a)(1)(B) of the
Act, the California Endangered Species
Act, and the State’s NCCP program. On
April 21, 2006, the Service published a
notice of availability of the Final
Environmental Impact Statement/
Environmental Impact Report (EIS/EIR)
for the MSHCP (71 FR 20719). On
March 30, 2007, the Service published
a notice of availability of a supplement
to the Final EIS for the MSHCP (72 FR
15148).
The MSHCP adopted the Peninsular
bighorn sheep habitat model described
in the 2000 recovery plan for this
subspecies (Service 2000). Accordingly,
the MSHCP area includes 172,811 ac
(69,934 ha) of modeled Peninsular
bighorn sheep habitat. These 172,811 ac
(69,934 ha) include the approximately
10,761 ac (4,354 ha) we are proposing in
Unit 1 and the approximately 74,998 ac
(30,350 ha) we are proposing in Unit
2A. The draft MSHCP proposes to
ensure conservation of a minimum of 97
percent of all modeled habitat for
Peninsular bighorn sheep as part of the
preferred alternative reserve design that
includes large areas of suitable habitat
(CVAG 2007, p. 9–261). Approximately
78 percent of the proposed conserved
modeled habitat are within Existing
Conservation Lands and will be
managed as part of the Reserve System
(CVAG 2007, p. 9–261); the remaining
19 percent will also be conserved
according to the draft MSHCP (CVAG
2007, p. 9–261). Conservation objectives
of this draft MSHCP include: (1)
Ensuring conservation of important
habitat (PCE 1, 2, 3, 4, and 5); (2)
ensuring connectivity by preventing
fragmentation and maintaining
biological corridors and linkages within
essential habitat to allow dispersal,
provide for population fluctuation, and
enhance genetic diversity (PCE 1 and 4);
and (3) ensuring conservation of habitat
quality through biological monitoring
and adaptive management (PCE 1, 2, 3,
4, and 5) (CVAG 2007, p. 9–261).
According to the draft MSHCP,
disturbance to Peninsular bighorn sheep
with implementation of the plan is
expected to be low because: (1)
Conserved habitat areas are large
enough to maintain self-sustaining
populations of Peninsular bighorn sheep
and incorporate key habitat elements for
the subspecies; (2) implementation of
the MSHCP is consistent with the
recovery strategy delineated in the 2000
recovery plan; (3) implementation of the
conservation objectives to protect
habitat for this subspecies will provide
connectivity; and (4) lands in the
MSHCP reserve system would be
managed and monitored to address
significant edge effect problems, human
disturbance, fragmentation, impacts
from exotic species, and other stressors
to Peninsular bighorn sheep (CVAG
2007, p. 9–261).
Although not yet completed and
implemented, CVAG has made
significant progress in the development
of its MSHCP to meet the requirements
outlined in section 10(a)(1)(B) of the
Act. In light of the Service’s confidence
that CVAG will reach a successful
conclusion to its MSHCP development
process, we are evaluating and
considering the possible exclusion of
approximately 19,211 ac (7,774 ha) of
private land within their preferred
alternative reserve design from the final
revised critical habitat designation for
Peninsular bighorn sheep depending on
the progress made on the draft MSHCP
between now and the publication of the
final rule. We are requesting comments
on the benefits to the Peninsular
bighorn sheep and its PCEs from the
conservation measures established by
the MSHCP.
Included within the MSHCP plan area
are BLM lands, outside of the Coachella
Valley Preserve System, which we are
soliciting comment on the
appropriateness of excluding from the
final revised critical habitat designation
based on BLM’s official participation in
the draft Coachella Valley MSHCP
planning process and commitment
under their CDCAPA to manage their
lands consistent with the Coachella
Valley MSHCP once it is completed. We
are also soliciting comment on the
appropriateness of excluding CDGF
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lands within the MSHCP plan area
based on their involvement with the
Coachella Valley MSHCP.
Provisions of the Coachella Valley
MSHCP Specific to Peninsular Bighorn
Sheep
In general, we find that the benefits of
critical habitat designation on lands
within pending HCPs that cover those
species are small, while the benefits of
excluding such lands from designation
of critical habitat are substantial. We are
evaluating and considering the possible
exclusion of approximately 19,211 ac
(7,774 ha) of private land within
CVAG’s MSHCP preferred alternative
reserve design area from the designation
of critical habitat. The evaluation
process involves determining whether
the benefits of excluding these lands
from Units 1 and 2A outweigh the
benefits of including these lands. We
expect the PCEs required by Peninsular
bighorn sheep to benefit by the
conservation measures outlined in the
MSHCP and as described above. In
summary, these conservation measures
include: Conservation of habitat and
implementation of the MSHCP
consistent with the recovery plan
(Service 2000); preservation of essential
habitat and connectivity; biological
monitoring and adaptive management;
and minimization of disturbance and
edge effects. These specific conservation
actions, avoidance and minimization
measures, and management for
Peninsular bighorn sheep and PCEs, if
implemented, are expected to exceed
any conservation value that could be
provided as a result of regulatory
protections afforded through a critical
habitat designation.
Designation of critical habitat alone
does not achieve recovery or require
management of those lands identified in
the critical habitat rule. The exclusion
of these lands that we are currently
evaluating and considering for possible
exclusion from the final critical habitat
designation would help preserve the
partnerships that we have developed
with the local jurisdictions and project
proponents in the development of the
MSHCP. The benefits of excluding these
lands from critical habitat, should the
MSHCP be finalized and implemented,
are expected to outweigh the minimal
benefits of including these lands as
critical habitat, including the
educational benefits of critical habitat
designation through informing the
public of areas important for the long-
term conservation of Peninsular bighorn
sheep. Such educational benefits can
still be accomplished from materials
provided on our Internet website and
through the overall designation process,
including the notice and public
comment period, which will occur
whether or not these particular areas are
designated.
Economics
We are preparing an analysis of the
economic impacts of proposing revised
critical habitat for the Peninsular
bighorn sheep. We will announce the
availability of the draft economic
analysis as soon as it is completed, at
which time we will seek public review
and comment. At that time, copies of
the draft economic analysis will be
available for downloading from the
Internet at http://carlsbad.fws.gov, or by
contacting the Carlsbad Fish and
Wildlife Office directly (see ADDRESSES).
We may exclude areas from the final
revised rule based on the information in
the economic analysis.
Peer Review
In accordance with our joint policy
published in the Federal Register on
July 1, 1994 (59 FR 34270), we are
requesting the expert opinions of at least
three appropriate independent
specialists regarding this proposed rule.
The purpose of peer review is to ensure
that our proposed revised critical
habitat designation is based on
scientifically sound data, assumptions,
and analyses. We have invited these
peer reviewers to comment during this
public comment period on our specific
assumptions and conclusions in this
proposed revision of critical habitat.
We will consider all comments and
information we receive during this
comment period on this proposed
revised critical habitat rule during our
preparation of a final determination.
Accordingly, our final decision may
differ from this proposal.
Public Hearings
The Act provides for one or more
public hearings on this proposal, if we
receive any request for hearings. We
must receive your request for a public
hearing within 45 days after the date of
publication in the Federal Register.
Send your request to the person named
in FOR FURTHER INFORMATION CONTACT.
We will schedule public hearings on
this proposal, if any are requested, and
announce the dates, times, and places of
those hearings, as well as how to obtain
reasonable accommodations, in the
Federal Register and local newspapers
at least 15 days before the first hearing.
Required Determinations
Regulatory Planning and Review
In accordance with Executive Order
(E.O.) 12866, this document is a
significant rule in that it may raise novel
legal and policy issues. However, based
on information available from the
previous designation, we do not
anticipated that it will have an annual
effect on the economy of $100 million
or more or to affect the economy in a
material way. To determine the
economic consequences of designating
the specific area as critical habitat, we
are preparing a draft economic analysis
of this proposed action, which will be
available for public comment. This
economic analysis also will be used to
determine compliance with E.O. 12866,
the Regulatory Flexibility Act, the Small
Business Regulatory Enforcement
Fairness Act, E.O. 12630, and E.O.
13211.
Further, E.O. 12866 directs Federal
agencies promulgating regulations to
evaluate regulatory alternatives (OMB
Circular A–4, September 17, 2003).
Under Circular A–4, once an agency
determines that the Federal regulatory
action is appropriate, the agency must
consider alternative regulatory
approaches. Because the determination
of critical habitat is a statutory
requirement under the Act, we must
evaluate alternative regulatory
approaches, where feasible, when
promulgating a designation of critical
habitat.
In developing our designations of
critical habitat, we consider economic
impacts, impacts to national security,
and other relevant impacts under
section 4(b)(2) of the Act. Based on the
discretion allowable under this
provision, we may exclude any
particular area from the designation of
critical habitat providing that the
benefits of such exclusion outweigh the
benefits of specifying the area as critical
habitat and that such exclusion would
not result in the extinction of the
species. As such, we believe that the
evaluation of the inclusion or exclusion
of particular areas, or a combination of
both, constitutes our regulatory
alternative analysis for designations.
We will announce the availability of
the draft economic analysis in the
Federal Register and in local
newspapers so that it is available for
public review and comments. At that
time, the draft economic analysis will
also be available on the Internet at
http://carlsbad.fws.gov, or by contacting
the Carlsbad Fish and Wildlife Office
directly (see ADDRESSES).
Regulatory Flexibility Act (5 U.S.C. 601
et seq.)
Under the Regulatory Flexibility Act
(RFA: 5 U.S.C. 601 et seq., as amended
by the Small Business Regulatory
Enforcement Fairness Act (SBREFA) of
1996), whenever an agency must
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57759 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
publish a notice of rulemaking for any
proposed or final rule, it must prepare
and make available for public comment
a regulatory flexibility analysis that
describes the effects of the rule on small
entities (small businesses, small
organizations, and small government
jurisdictions). However, no regulatory
flexibility analysis is required if the
head of the agency certifies the rule will
not have a significant economic impact
on a substantial number of small
entities. SBREFA amended RFA to
require Federal agencies to provide a
statement of the factual basis for
certifying that the rule will not have a
significant economic impact on a
substantial number of small entities.
At this time, we lack the available
economic information necessary to
provide an adequate factual basis for the
required RFA finding. Therefore, we
defer the RFA finding until completion
of the draft economic analysis prepared
under section 4(b)(2) of the Act and E.O.
12866. This draft economic analysis will
provide the required factual basis for the
RFA finding. Upon completion of the
draft economic analysis, we will
announce availability of the draft
economic analysis of the proposed
revised designation in the Federal
Register and reopen the public
comment period for the proposed
revised designation. We will include
with this announcement, as appropriate,
an initial regulatory flexibility analysis
or a certification that the rule will not
have a significant economic impact on
a substantial number of small entities
accompanied by the factual basis for
that determination. We have concluded
that deferring the RFA finding until
completion of the draft economic
analysis is necessary to meet the
purposes and requirements of the RFA.
Deferring the RFA finding in this
manner will ensure that we make a
sufficiently informed determination
based on adequate economic
information and provide the necessary
opportunity for public comment.
Unfunded Mandates Reform Act
In accordance with the Unfunded
Mandates Reform Act (2 U.S.C. 1501 et
seq.), we make the following findings:
(a) This proposed rule will not
produce a Federal mandate. In general,
a Federal mandate is a provision in
legislation, statute, or regulation that
would impose an enforceable duty upon
State, local, or Tribal governments, or
the private sector, and includes both
‘‘Federal intergovernmental mandates’’
and ‘‘Federal private sector mandates.’’
These terms are defined in 2 U.S.C.
658(5)–(7). ‘‘Federal intergovernmental
mandate’’ includes a regulation that
‘‘would impose an enforceable duty
upon State, local, or Tribal
governments’’ with two exceptions. It
excludes ‘‘a condition of Federal
assistance.’’ It also excludes ‘‘a duty
arising from participation in a voluntary
Federal program,’’ unless the regulation
‘‘relates to a then-existing Federal
program under which $500,000,000 or
more is provided annually to State,
local, and Tribal governments under
entitlement authority,’’ if the provision
would ‘‘increase the stringency of
conditions of assistance’’ or ‘‘place caps
upon, or otherwise decrease, the Federal
Government’s responsibility to provide
funding,’’ and the State, local, or Tribal
governments ‘‘lack authority’’ to adjust
accordingly. At the time of enactment,
these entitlement programs were:
Medicaid; AFDC work programs; Child
Nutrition; Food Stamps; Social Services
Block Grants; Vocational Rehabilitation
State Grants; Foster Care, Adoption
Assistance, and Independent Living;
Family Support Welfare Services; and
Child Support Enforcement. ‘‘Federal
private sector mandate’’ includes a
regulation that ‘‘would impose an
enforceable duty upon the private
sector, except (i) a condition of Federal
assistance or (ii) a duty arising from
participation in a voluntary Federal
program.’’
The designation of critical habitat
does not impose a legally binding duty
on non-Federal Government entities or
private parties. Under the Act, the only
regulatory effect is that Federal agencies
must ensure that their actions do not
destroy or adversely modify critical
habitat under section 7. While non-
Federal entities that receive Federal
funding, assistance, or permits, or that
otherwise require approval or
authorization from a Federal agency for
an action may be indirectly impacted by
the designation of critical habitat, the
legally binding duty to avoid
destruction or adverse modification of
critical habitat rests squarely on the
Federal agency. Furthermore, to the
extent that non-Federal entities are
indirectly impacted because they
receive Federal assistance or participate
in a voluntary Federal aid program, the
Unfunded Mandates Reform Act would
not apply, nor would critical habitat
shift the costs of the large entitlement
programs listed above onto State
governments.
(b) Due to current public knowledge
of the subspecies’ protection, the
prohibition against take of the
subspecies both within and outside of
the areas proposed in this rule for
designation and the fact that the vast
majority of the areas proposed in this
rule are currently designated as critical
habitat, we do not believe that this
proposed rule will significantly or
uniquely affect small governments.
Therefore, a Small Government Agency
Plan is not required. However, as we
conduct our economic analysis, we will
further evaluate this issue and revise
this assessment if appropriate.
Takings
In accordance with E.O. 12630
(Government Actions and Interference
with Constitutionally Protected Private
Property Rights), we have analyzed the
potential takings implications of
designating revised critical habitat for
the Peninsular bighorn sheep in a
takings implications assessment. The
takings implications assessment
concludes that this proposed revised
designation of critical habitat for the
Peninsular bighorn sheep does not pose
significant takings implications for
lands within or affected by the
designation.
Federalism
In accordance with E.O. 13132
(Federalism), this proposed rule does
not have significant Federalism effects.
A Federalism assessment is not
required. In keeping with Department of
the Interior and Department of
Commerce policy, we requested
information from, and coordinated
development of, this proposed revised
critical habitat designation with
appropriate State resource agencies in
California. Critical habitat is already
designated for the Peninsular bighorn
sheep. If finalized, this proposal to
revise the designated critical habitat
will result in a significant decrease in
the area designated. Thus, the
designation of revised critical habitat for
the Peninsular bighorn sheep would not
impose any additional regulatory
restrictions to those currently in place
and, therefore, has little incremental
impact on State and local governments
and their activities. The designation
may have some benefit to these
governments because the areas that
contain the features essential to the
conservation of the subspecies are more
clearly defined, and the PCEs of the
habitat necessary to the conservation of
the subspecies are specifically
identified. This information does not
alter where and what federally
sponsored activities may occur.
However, it may assist local
governments in long-range planning
(rather than having them wait for case-
by-case section 7 consultations to
occur).
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57760 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
Civil Justice Reform
In accordance with E.O. 12988 (Civil
Justice Reform), the Office of the
Solicitor has determined that this
proposed rule does not unduly burden
the judicial system and that it meets the
requirements of sections 3(a) and 3(b)(2)
of the Order. We have proposed revised
critical habitat in accordance with the
provisions of the Act. This proposed
rule uses standard property descriptions
and identifies the PCEs within the areas
proposed for designation to assist the
public in understanding the habitat
needs of the Peninsular bighorn sheep.
Paperwork Reduction Act of 1995 (44
U.S.C. 3501 et seq.)
This proposed rule does not contain
any new collections of information that
require approval by OMB under the
Paperwork Reduction Act of 1995 (44
U.S.C. 3501 et seq.). This rule will not
impose recordkeeping or reporting
requirements on State or local
governments, individuals, businesses, or
organizations. An agency may not
conduct or sponsor, and a person is not
required to respond to, a collection of
information unless it displays a
currently valid OMB control number.
National Environmental Policy Act
(NEPA) (42 U.S.C. 4321 et. seq.)
It is our position that, outside the
jurisdiction of the Circuit Court of the
United States for the Tenth Circuit, we
do not need to prepare environmental
analyses as defined by NEPA (42 U.S.C.
4321 et seq.) in connection with
designating critical habitat under the
Act. We published a notice outlining
our reasons for this determination in the
Federal Register on October 25, 1983
(48 FR 49244). This assertion was
upheld by the Circuit Court of the
United States for the Ninth Circuit Court
(Douglas County v. Babbitt, 48 F.3d
1495 (9th Cir. Ore. 1995), cert. denied
116 S. Ct. 698 (1996)).
Clarity of the Rule
We are required by Executive Orders
12866 and 12988 and by the
Presidential Memorandum of June 1,
1998, to write all rules in plain
language. This means that each rule we
publish must:
(a) Be logically organized;
(b) Use the active voice to address
readers directly;
(c) Use clear language rather than
jargon;
(d) Be divided into short sections and
sentences; and
(e) Use lists and tables wherever
possible.
If you feel that we have not met these
requirements, send us comments by one
of the methods listed in the ADDRESSES
section. To better help us revise the
rule, your comments should be as
specific as possible. For example, you
should tell us the numbers of the
sections or paragraphs that are unclearly
written, which sections or sentences are
too long, the sections where you feel
lists or tables would be useful, etc.
Government-to-Government
Relationship With Tribes
In accordance with the President’s
memorandum of April 29, 1994,
Government-to-Government Relations
with Native American Tribal
Governments’ (59 FR 22951), E.O.
13175, and the Department of the
Interior’s manual at 512 DM 2, we
readily acknowledge our responsibility
to communicate meaningfully with
recognized Federal Tribes on a
government-to-government basis. In
accordance with Secretarial Order 3206
of June 5, 1997 (American Indian Tribal
Rights, Federal-Tribal Trust
Responsibilities, and the Endangered
Species Act), we readily acknowledge
our responsibilities to work directly
with Tribes in developing programs for
healthy ecosystems, to acknowledge that
tribal lands are not subject to the same
controls as Federal public lands, to
remain sensitive to Indian culture, and
to make information available to Tribes.
We have identified Tribal lands that
meet the definition of critical habitat for
the Peninsular bighorn sheep, and have
included them in this proposal.
However, we are proposing to exclude
all Tribal lands from the final critical
habitat designation under section 4(b)(2)
of the Act (see ‘‘Proposed Exclusion of
Agua Caliente Band of Cahuilla Indians
Tribal Lands Under Section 4(b)(2) of
the Act’’ for a detailed discussion). We
will continue to coordinate with the
Tribe during the designation process.
Energy Supply, Distribution, or Use
On May 18, 2001, the President issued
an Executive Order (E.O. 13211; Actions
Concerning Regulations That
Significantly Affect Energy Supply,
Distribution, or Use) on regulations that
significantly affect energy supply,
distribution, and use. E.O. 13211
requires agencies to prepare Statements
of Energy Effects when undertaking
certain actions. While this proposed
rule to designate revised critical habitat
for the Peninsular bighorn sheep is a
significant regulatory action under E.O.
12866 in that it may raise novel legal
and policy issues, we do not expect it
to significantly affect energy supplies,
distribution, or use. Therefore, this
action is not a significant energy action,
and no Statement of Energy Effects is
required. However, we will further
evaluate this issue as we conduct our
economic analysis, and review and
revise this assessment as warranted.
References Cited
A complete list of all references cited
in this rulemaking is available upon
request from the Field Supervisor,
Carlsbad Fish and Wildlife Office (see
ADDRESSES).
Author
The primary author of this package is
Justin Shoemaker of the Carlsbad Fish
and Wildlife Office.
List of Subjects in 50 CFR Part 17
Endangered and threatened species,
Exports, Imports, Reporting and
recordkeeping requirements,
Transportation.
Proposed Regulation Promulgation
Accordingly, we propose to amend
part 17, subchapter B of chapter I, title
50 of the Code of Federal Regulations,
as set forth below:
PART 17—[AMENDED]
1. The authority citation for part 17
continues to read as follows:
Authority: 16 U.S.C. 1361–1407; 16 U.S.C.
1531–1544; 16 U.S.C. 4201–4245; Pub. L. 99–
625, 100 Stat. 3500; unless otherwise noted.
2. In §17.11(h), revise the entry for
‘‘Sheep, bighorn’’ under ‘‘MAMMALS’’
in the List of Endangered and
Threatened Wildlife to read as follows:
§17.11 Endangered and threatened
wildlife.
* * * * *
(h) * * *
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57761 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
Species
Historic range
Vertebrate popu-
lation where endan-
gered or threatened
Status When listed Critical
habitat
Special
rules Common name Scientific name
MAMMALS
*******
Sheep, Peninsular
bighorn.
Ovis canadensis
nelsoni.
U.S.A. (western
conterminous
States), Canada
(south-western),
Mexico (northern).
U.S.A. (CA) Penin-
sular Ranges.
E 634 17.95(a) NA.
*******
3. In §17.95(a), revise the entry for
Bighorn Sheep (Peninsular Ranges)(Ovis
canadensis) to read as follows:
§17.95 Critical habitat—fish and wildlife.
(a) Mammals.
* * * * *
Bighorn Sheep (Peninsular Ranges)
(Ovis canadensis nelsoni)
(1) Critical habitat units are depicted
for Riverside, San Diego, and Imperial
Counties, California, on the maps below.
(2) The primary constituent elements
of critical habitat for the Peninsular
bighorn sheep are:
(i) Moderate to steep, open slopes (20
to 60 percent) and canyons, with canopy
cover of 30 percent or less (below 4,600
feet (1,402 meters) elevation in the
Peninsular Ranges) that provide space
for sheltering, predator detection,
rearing of young, foraging and watering,
mating, and movement within and
between ewe groups.
(ii) Presence of a variety of forage
plants, indicated by the presence of
shrubs (e.g., Ambrosia spp., Caesalpinia
spp., Hyptis spp., Sphaeralcea spp.,
Simmondsia spp.), that provide a
primary food source year round, grasses
(e.g., Aristida spp., Bromus spp.) and
cacti (e.g., Opuntia spp.) that provide a
source of forage in the fall, and forbs
(e.g., Plantago spp., Ditaxis spp.) that
provide a source of forage in the spring.
(iii) Steep, rugged, slopes (60 percent
slope or greater) (below 4,600 feet (1,402
meters) elevation in the Peninsular
Ranges) that provide secluded space for
lambing as well as terrain for predator
evasion.
(iv) Alluvial fans, washes, and valley
bottoms that provide important foraging
areas where nutritious and digestible
plants can be more readily found during
times of drought and lactation and that
provide and maintain habitat
connectivity by serving as travel routes
between and within ewe groups,
adjacent mountain ranges, and
important resources areas, such as
foraging areas and escape terrain.
(v) Intermittent and permanent water
sources that are available during
extended dry periods and that provide
relatively nutritious plants and drinking
water.
(3) Critical habitat does not include
manmade structures (such as buildings,
aqueducts, roads, and other paved areas)
and the land on which they are located
existing within the legal boundaries on
the effective date of this rule.
(4) Critical habitat map units. Data
layers defining map units were created
on a base of USGS 1:24,000 maps, and
critical habitat units were then mapped
using Universal Transverse Mercator
(UTM) coordinates.
(5) Note: Index map of critical habitat
units for the Peninsular bighorn sheep
(Map 1) follows:
BILLING CODE 4310–55–P
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57762 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
BILLING CODE 4310–55–C
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57763 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
(6) Unit 1: San Jacinto Mountains,
Riverside County, California.
(i) From USGS 1:24,000 quadrangles
Desert Hot Springs, Palm Springs, and
San Jacinto Peak, and White Water.
Land bounded by the following
Universal Transverse Mercator (UTM)
North American Datum of 1927
(NAD27) coordinates (E, N): 534134,
3750021; 534465, 3749681; 534495,
3749651; 534495, 3749651; 534495,
3749651; 534495, 3749651; 534572,
3749621; 534997, 3749456; 534792,
3749102; 534885, 3748934; 535128,
3748785; 535310, 3748807; 535426,
3748822; 535471, 3748798; 535663,
3748697; 535706, 3748674; 535706,
3748652; 535713, 3748654; 535739,
3748650; 535777, 3748637; 535816,
3748627; 535834, 3748623; 535944,
3748624; 535999, 3748624; 536000,
3748624; 536000, 3748624; 536056,
3748624; 536056, 3748656; 536499,
3748909; 536927, 3749153; 537308,
3748794; 538009, 3748134; 538064,
3748082; 538535, 3747726; 538535,
3747703; 538566, 3747702; 538901,
3747449; 539106, 3747293; 539235,
3746550; 539240, 3746463; 539240,
3746455; 539254, 3746181; 539088,
3745848; 539244, 3745133; 539265,
3745144; 539562, 3745200; 539802,
3745192; 540194, 3745168; 540512,
3745097; 540512, 3744900; 540511,
3744851; 540512, 3744847; 540521,
3744847; 540607, 3744847; 540817,
3744847; 540900, 3744846; 540900,
3744846; 540900, 3744800; 540900,
3744700; 540900, 3744600; 540900,
3744500; 540900, 3744400; 540800,
3744400; 540800, 3744300; 540700,
3744300; 540600, 3744300; 540600,
3744200; 540511, 3744200; 540504,
3744200; 540500, 3744200; 540500,
3744100; 540503, 3744100; 540511,
3744100; 540600, 3744100; 540600,
3744000; 540600, 3743900; 540700,
3743900; 540700, 3743800; 540700,
3743700; 540800, 3743700; 540800,
3743600; 540800, 3743500; 540885,
3743501; 540883, 3743342; 540906,
3743287; 541006, 3743322; 541083,
3743355; 541120, 3743355; 541171,
3743337; 541299, 3743351; 541300,
3743300; 541300, 3743238; 541300,
3743231; 541300, 3743200; 541321,
3743200; 541321, 3743196; 541330,
3743175; 541340, 3743160; 541342,
3743145; 541344, 3743138; 541348,
3743132; 541353, 3743127; 541356,
3743122; 541362, 3743116; 541368,
3743111; 541371, 3743107; 541376,
3743098; 541377, 3743095; 541379,
3743089; 541378, 3743082; 541380,
3743075; 541381, 3743070; 541384,
3743064; 541388, 3743060; 541395,
3743053; 541403, 3743047; 541413,
3743043; 541417, 3743039; 541425,
3743032; 541431, 3743027; 541436,
3743021; 541441, 3743015; 541446,
3743006; 541451, 3742997; 541455,
3742984; 541464, 3742970; 541466,
3742965; 541471, 3742960; 541477,
3742957; 541484, 3742953; 541494,
3742952; 541501, 3742951; 541508,
3742951; 541523, 3742951; 541527,
3742951; 541532, 3742952; 541539,
3742952; 541547, 3742951; 541555,
3742952; 541559, 3742952; 541562,
3742951; 541571, 3742947; 541581,
3742942; 541589, 3742939; 541594,
3742933; 541600, 3742929; 541607,
3742925; 541616, 3742918; 541624,
3742914; 541633, 3742910; 541640,
3742907; 541651, 3742905; 541659,
3742905; 541659, 3742904; 541653,
3742806; 541679, 3742804; 541670,
3742734; 541637, 3742740; 541625,
3742693; 541648, 3742693; 541662,
3742659; 541682, 3742612; 541683,
3742557; 541683, 3742510; 541683,
3742508; 541670, 3742508; 541661,
3742507; 541661, 3742507; 541661,
3742554; 541615, 3742554; 541616,
3742507; 541598, 3742507; 541598,
3742517; 541517, 3742516; 541476,
3742516; 541436, 3742516; 541411,
3742516; 541400, 3742516; 541395,
3742516; 541377, 3742516; 541376,
3742507; 541385, 3742432; 541375,
3742432; 541375, 3742390; 541374,
3742350; 541368, 3742344; 541374,
3742328; 541354, 3742228; 541329,
3742228; 541330, 3742217; 541331,
3742061; 541331, 3742036; 541331,
3742016; 541332, 3741932; 541340,
3741932; 541369, 3741932; 541369,
3741922; 541370, 3741805; 541370,
3741803; 541370, 3741745; 541357,
3741745; 541334, 3741730; 541294,
3741729; 541261, 3741729; 541261,
3741677; 541271, 3741677; 541271,
3741641; 541271, 3741640; 541271,
3741640; 541271, 3741632; 541126,
3741630; 541100, 3741630; 541100,
3741600; 541100, 3741500; 541100,
3741400; 541100, 3741281; 541176,
3741283; 541189, 3741189; 541192,
3741167; 541203, 3741100; 541300,
3741100; 541400, 3741100; 541500,
3741100; 541600, 3741100; 541600,
3741000; 541600, 3740900; 541600,
3740800; 541600, 3740700; 541600,
3740600; 541653, 3740533; 541700,
3740495; 541700, 3740400; 541800,
3740400; 541900, 3740400; 541934,
3740399; 541935, 3740284; 542001,
3740285; 542000, 3740200; 542000,
3740135; 541936, 3740129; 541942,
3740080; 541965, 3740053; 541966,
3740025; 541939, 3740025; 541815,
3740026; 541744, 3740027; 541718,
3740027; 541660, 3740028; 541660,
3740023; 541656, 3739951; 541628,
3739931; 541607, 3739915; 541605,
3739900; 541600, 3739900; 541600,
3739876; 541596, 3739853; 541587,
3739805; 541586, 3739800; 541584,
3739767; 541582, 3739736; 541584,
3739712; 541586, 3739702; 541584,
3739694; 541585, 3739694; 541586,
3739694; 541586, 3739694; 541587,
3739693; 541587, 3739693; 541587,
3739693; 541588, 3739693; 541588,
3739692; 541588, 3739692; 541589,
3739692; 541589, 3739692; 541589,
3739691; 541589, 3739691; 541590,
3739691; 541590, 3739690; 541590,
3739690; 541590, 3739689; 541590,
3739689; 541591, 3739689; 541591,
3739688; 541591, 3739688; 541591,
3739687; 541591, 3739687; 541591,
3739686; 541591, 3739686; 541590,
3739675; 541587, 3739630; 541587,
3739629; 541587, 3739629; 541587,
3739628; 541587, 3739628; 541587,
3739627; 541587, 3739627; 541587,
3739626; 541587, 3739626; 541587,
3739625; 541587, 3739625; 541587,
3739624; 541588, 3739624; 541588,
3739623; 541588, 3739623; 541588,
3739623; 541588, 3739622; 541589,
3739622; 541589, 3739621; 541589,
3739621; 541589, 3739621; 541590,
3739620; 541590, 3739620; 541590,
3739620; 541591, 3739619; 541591,
3739619; 541591, 3739619; 541592,
3739618; 541592, 3739618; 541592,
3739618; 541593, 3739618; 541593,
3739618; 541593, 3739617; 541594,
3739617; 541594, 3739617; 541595,
3739617; 541595, 3739616; 541596,
3739616; 541596, 3739616; 541596,
3739616; 541597, 3739616; 541597,
3739616; 541598, 3739616; 541598,
3739616; 541600, 3739615; 541600,
3739613; 541563, 3739614; 541552,
3739562; 541589, 3739529; 541590,
3739528; 541608, 3739475; 541612,
3739464; 541663, 3739439; 541692,
3739425; 541695, 3739423; 541700,
3739418; 541700, 3739400; 541716,
3739400; 541731, 3739383; 541733,
3739381; 541755, 3739364; 541790,
3739336; 541792, 3739334; 541800,
3739324; 541800, 3739300; 541700,
3739300; 541700, 3739296; 541644,
3739296; 541644, 3739061; 541644,
3738884; 541866, 3738884; 541933,
3738882; 541933, 3738883; 541952,
3738884; 541952, 3738835; 541969,
3738835; 541969, 3738764; 541969,
3738731; 541969, 3738713; 541969,
3738680; 541976, 3738680; 541951,
3738614; 541948, 3738608; 541944,
3738600; 541900, 3738600; 541900,
3738500; 541900, 3738419; 541900,
3738415; 541900, 3738400; 542000,
3738400; 542000, 3738300; 542000,
3738200; 542000, 3738100; 541900,
3738100; 541900, 3738000; 541900,
3737900; 541900, 3737800; 541800,
3737800; 541800, 3737700; 541800,
3737600; 541800, 3737500; 541800,
VerDate Aug<31>2005 17:33 Oct 09, 2007 Jkt 214001 PO 00000 Frm 00025 Fmt 4701 Sfmt 4702 E:\FR\FM\10OCP2.SGM 10OCP2pwalker on PROD1PC71 with PROPOSALS2
57764 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
3737400; 541800, 3737300; 541800,
3737200; 541800, 3737100; 541800,
3737000; 541654, 3736803; 541356,
3736400; 540393, 3735196; 540363,
3735192; 540248, 3735176; 540154,
3735163; 539396, 3735059; 539294,
3735160; 539283, 3735171; 539017,
3735437; 538757, 3735957; 538752,
3735967; 538746, 3735980; 538742,
3735987; 538295, 3736400; 538230,
3736767; 538230, 3736770; 538226,
3736793; 538192, 3736985; 538020,
3738154; 538050, 3738381; 538054,
3738413; 538089, 3738670; 538554,
3740001; 538562, 3740021; 538570,
3740046; 538536, 3741559; 538504,
3741614; 538492, 3741634; 538054,
3742384; 537372, 3743203; 537372,
3743212; 537364, 3743212; 537345,
3743236; 537276, 3743318; 537194,
3743416; 536728, 3743936; 536656,
3744024; 536634, 3744087; 536100,
3744346; 535828, 3744823; 535817,
3744844; 535732, 3744992; 535666,
3745108; 535665, 3745109; 535413,
3745553; 535253, 3746458; 535247,
3746495; 534970, 3746845; 534866,
3746975; 534865, 3746975; 534176,
3746882; 534115, 3746840; 534063,
3746805; 533524, 3746435; 531977,
3746795; 531267, 3747050; 530862,
3747228; 530502, 3747386; 530397,
3748001; 530372, 3748150; 530502,
3749549; 530595, 3749599; 530839,
3749730; 531024, 3749829; 531605,
3749724; 531646, 3749716; 531687,
3749709; 531689, 3749708; 531720,
3749703; 531721, 3749703; 531721,
3749703; 531733, 3749728; 531811,
3749890; 532087, 3750462; 532854,
3750401; 533216, 3750372; 533936,
3750224; 534059, 3750098; thence
returning to 534134, 3750021.
(ii) Note: Map of Unit 1, San Jacinto
Mountains (Map 2) follows:
BILLING CODE 4310–55–P
VerDate Aug<31>2005 17:33 Oct 09, 2007 Jkt 214001 PO 00000 Frm 00026 Fmt 4701 Sfmt 4702 E:\FR\FM\10OCP2.SGM 10OCP2pwalker on PROD1PC71 with PROPOSALS2
57765 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
BILLING CODE 4310–55–C
VerDate Aug<31>2005 17:33 Oct 09, 2007 Jkt 214001 PO 00000 Frm 00027 Fmt 4701 Sfmt 4702 E:\FR\FM\10OCP2.SGM 10OCP2 EP10OC07.001</GPH>pwalker on PROD1PC71 with PROPOSALS2
57766 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
(7) Unit 2A: North Santa Rosa
Moutains, Riverside County, California.
(i) From USGS 1:24,000 quadrangles
Cathedral City, Clark Lake NE, La
Quinta, Martinez Mountain, Palm
Springs, Palm View Peak, Rabbit Peak,
Rancho Mirage, Toro Peak, and Valerie.
Land bounded by the following
Universal Transverse Mercator (UTM)
North American Datum of 1927
(NAD27) coordinates (E, N): 548200,
3735505; 548200, 3735500; 548211,
3735500; 548229, 3735493; 548242,
3735488; 548253, 3735483; 548278,
3735474; 548285, 3735471; 548300,
3735465; 548300, 3735400; 548400,
3735400; 548500, 3735400; 548500,
3735480; 548515, 3735478; 548523,
3735478; 548560, 3735481; 548580,
3735488; 548591, 3735491; 548607,
3735496; 548608, 3735496; 548608,
3735496; 548644, 3735490; 548659,
3735497; 548673, 3735503; 548690,
3735520; 548716, 3735546; 548720,
3735550; 548736, 3735569; 548768,
3735606; 548773, 3735615; 548783,
3735631; 548778, 3735657; 548778,
3735659; 548799, 3735678; 548821,
3735687; 548825, 3735689; 548844,
3735682; 548868, 3735674; 548874,
3735672; 548890, 3735664; 548892,
3735663; 548909, 3735654; 548955,
3735628; 549021, 3735590; 549038,
3735580; 549075, 3735551; 549085,
3735544; 549101, 3735534; 549131,
3735513; 549131, 3735526; 549125,
3735553; 549111, 3735581; 549105,
3735594; 549077, 3735654; 549074,
3735660; 549074, 3735680; 549089,
3735687; 549102, 3735682; 549097,
3735720; 549094, 3735745; 549093,
3735749; 549102, 3735757; 549132,
3735749; 549145, 3735755; 549157,
3735754; 549169, 3735738; 549180,
3735744; 549175, 3735804; 549186,
3735810; 549195, 3735817; 549205,
3735819; 549238, 3735827; 549245,
3735846; 549250, 3735853; 549251,
3735854; 549278, 3735863; 549285,
3735868; 549280, 3735880; 549283,
3735883; 549285, 3735886; 549307,
3735894; 549331, 3735897; 549350,
3735888; 549369, 3735874; 549387,
3735876; 549392, 3735881; 549418,
3735882; 549440, 3735896; 549472,
3735885; 549482, 3735882; 549484,
3735894; 549462, 3735909; 549457,
3735936; 549469, 3735963; 549475,
3735976; 549488, 3735971; 549491,
3735983; 549476, 3736004; 549481,
3736011; 549496, 3736013; 549480,
3736033; 549471, 3736057; 549476,
3736063; 549495, 3736054; 549524,
3736058; 549532, 3736058; 549543,
3736072; 549566, 3736077; 549559,
3736095; 549544, 3736095; 549536,
3736099; 549533, 3736119; 549533,
3736122; 549534, 3736122; 549535,
3736125; 549536, 3736127; 549538,
3736129; 549540, 3736131; 549542,
3736134; 549544, 3736136; 549545,
3736138; 549545, 3736139; 549545,
3736142; 549545, 3736143; 549543,
3736147; 549540, 3736154; 549532,
3736170; 549540, 3736182; 549548,
3736181; 549550, 3736180; 549552,
3736180; 549554, 3736181; 549556,
3736181; 549558, 3736182; 549560,
3736183; 549562, 3736184; 549563,
3736186; 549564, 3736187; 549565,
3736189; 549566, 3736190; 549566,
3736193; 549566, 3736194; 549566,
3736195; 549566, 3736198; 549566,
3736208; 549565, 3736223; 549565,
3736226; 549565, 3736230; 549567,
3736233; 549568, 3736235; 549571,
3736237; 549573, 3736239; 549579,
3736240; 549587, 3736243; 549612,
3736250; 549636, 3736257; 549656,
3736252; 549662, 3736252; 549670,
3736252; 549686, 3736237; 549699,
3736225; 549708, 3736216; 549711,
3736214; 549715, 3736211; 549718,
3736209; 549722, 3736208; 549725,
3736207; 549729, 3736207; 549733,
3736208; 549738, 3736209; 549742,
3736211; 549761, 3736197; 549759,
3736139; 549767, 3736122; 549786,
3736105; 549767, 3736083; 549769,
3736079; 549756, 3736075; 549727,
3736047; 549720, 3736025; 549719,
3736021; 549712, 3736002; 549700,
3735923; 549700, 3735922; 549700,
3735920; 549700, 3735919; 549700,
3735918; 549700, 3735917; 549700,
3735916; 549700, 3735915; 549700,
3735914; 549701, 3735913; 549701,
3735912; 549701, 3735911; 549701,
3735910; 549702, 3735909; 549702,
3735908; 549702, 3735907; 549703,
3735906; 549703, 3735905; 549704,
3735904; 549704, 3735903; 549705,
3735902; 549705, 3735901; 549706,
3735900; 549707, 3735900; 549707,
3735899; 549708, 3735898; 549709,
3735897; 549709, 3735896; 549710,
3735896; 549711, 3735895; 549712,
3735894; 549713, 3735894; 549714,
3735893; 549714, 3735893; 549715,
3735892; 549743, 3735876; 549745,
3735880; 549781, 3735853; 549789,
3735826; 549791, 3735825; 549791,
3735824; 549791, 3735824; 549791,
3735823; 549791, 3735822; 549791,
3735821; 549791, 3735821; 549791,
3735820; 549791, 3735819; 549791,
3735818; 549791, 3735818; 549791,
3735817; 549792, 3735816; 549792,
3735815; 549792, 3735815; 549793,
3735814; 549793, 3735813; 549794,
3735812; 549795, 3735812; 549795,
3735811; 549796, 3735811; 549796,
3735810; 549797, 3735810; 549798,
3735809; 549799, 3735809; 549800,
3735808; 549800, 3735800; 549800,
3735800; 549796, 3735781; 549806,
3735744; 549822, 3735720; 549826,
3735715; 549829, 3735715; 549829,
3735714; 549829, 3735713; 549829,
3735712; 549829, 3735712; 549829,
3735711; 549829, 3735710; 549830,
3735709; 549830, 3735709; 549830,
3735708; 549831, 3735707; 549831,
3735706; 549832, 3735706; 549832,
3735705; 549833, 3735704; 549834,
3735704; 549834, 3735703; 549835,
3735703; 549836, 3735702; 549837,
3735702; 549837, 3735701; 549824,
3735668; 549838, 3735639; 549839,
3735612; 549849, 3735609; 549848,
3735608; 549848, 3735608; 549848,
3735607; 549848, 3735606; 549848,
3735605; 549848, 3735605; 549848,
3735604; 549848, 3735603; 549848,
3735602; 549849, 3735602; 549849,
3735601; 549849, 3735600; 549849,
3735599; 549850, 3735599; 549850,
3735598; 549851, 3735597; 549851,
3735596; 549823, 3735574; 549824,
3735562; 549827, 3735533; 549826,
3735518; 549825, 3735502; 549830,
3735469; 549808, 3735401; 549818,
3735395; 549817, 3735395; 549817,
3735394; 549817, 3735393; 549817,
3735392; 549816, 3735392; 549816,
3735391; 549816, 3735390; 549816,
3735389; 549816, 3735389; 549816,
3735388; 549816, 3735387; 549816,
3735386; 549816, 3735386; 549816,
3735385; 549817, 3735384; 549817,
3735383; 549817, 3735383; 549818,
3735382; 549818, 3735381; 549818,
3735380; 549819, 3735380; 549820,
3735379; 549820, 3735378; 549821,
3735378; 549821, 3735377; 549822,
3735377; 549953, 3735297; 549954,
3735296; 549954, 3735296; 549955,
3735296; 549956, 3735295; 549957,
3735295; 549958, 3735295; 549959,
3735295; 549960, 3735295; 549961,
3735295; 549962, 3735295; 549963,
3735295; 549964, 3735295; 549965,
3735296; 549967, 3735296; 549967,
3735297; 549968, 3735297; 549969,
3735298; 549969, 3735298; 549970,
3735299; 549971, 3735300; 549971,
3735301; 549972, 3735301; 549978,
3735298; 549990, 3735306; 550026,
3735349; 550020, 3735384; 550027,
3735388; 550056, 3735480; 550056,
3735481; 550057, 3735483; 550056,
3735589; 550057, 3735589; 550103,
3735589; 550104, 3735589; 550105,
3735590; 550106, 3735591; 550106,
3735592; 550107, 3735594; 550108,
3735595; 550109, 3735596; 550110,
3735597; 550111, 3735598; 550111,
3735598; 550127, 3735614; 550129,
3735617; 550135, 3735612; 550136,
3735614; 550137, 3735616; 550139,
3735617; 550140, 3735619; 550141,
3735621; 550142, 3735622; 550142,
3735624; 550143, 3735626; 550144,
3735628; 550145, 3735630; 550146,
VerDate Aug<31>2005 17:33 Oct 09, 2007 Jkt 214001 PO 00000 Frm 00028 Fmt 4701 Sfmt 4702 E:\FR\FM\10OCP2.SGM 10OCP2pwalker on PROD1PC71 with PROPOSALS2
57767 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
3735631; 550147, 3735633; 550147,
3735635; 550148, 3735637; 550149,
3735639; 550150, 3735641; 550150,
3735642; 550151, 3735644; 550151,
3735646; 550152, 3735648; 550152,
3735650; 550153, 3735652; 550153,
3735654; 550154, 3735656; 550154,
3735658; 550154, 3735660; 550155,
3735662; 550155, 3735664; 550155,
3735666; 550155, 3735668; 550155,
3735670; 550155, 3735672; 550156,
3735675; 550156, 3735675; 550157,
3735675; 550158, 3735675; 550159,
3735676; 550160, 3735676; 550161,
3735677; 550161, 3735678; 550162,
3735678; 550163, 3735679; 550163,
3735680; 550163, 3735681; 550163,
3735681; 550164, 3735682; 550164,
3735683; 550165, 3735684; 550165,
3735684; 550166, 3735685; 550167,
3735686; 550167, 3735686; 550168,
3735687; 550172, 3735689; 550173,
3735690; 550174, 3735690; 550175,
3735690; 550176, 3735690; 550177,
3735690; 550178, 3735690; 550179,
3735690; 550179, 3735690; 550180,
3735689; 550181, 3735689; 550182,
3735689; 550182, 3735688; 550183,
3735688; 550184, 3735688; 550185,
3735687; 550186, 3735687; 550186,
3735687; 550187, 3735687; 550188,
3735687; 550189, 3735688; 550190,
3735688; 550191, 3735688; 550192,
3735689; 550193, 3735689; 550196,
3735684; 550266, 3735736; 550288,
3735753; 550283, 3735771; 550307,
3735790; 550308, 3735790; 550309,
3735791; 550310, 3735792; 550311,
3735792; 550312, 3735793; 550313,
3735793; 550347, 3735814; 550364,
3735827; 550365, 3735828; 550366,
3735829; 550366, 3735829; 550367,
3735830; 550367, 3735830; 550368,
3735831; 550368, 3735831; 550369,
3735832; 550370, 3735833; 550371,
3735834; 550372, 3735835; 550373,
3735837; 550373, 3735837; 550374,
3735839; 550375, 3735839; 550375,
3735841; 550376, 3735841; 550376,
3735842; 550377, 3735843; 550377,
3735844; 550378, 3735845; 550378,
3735846; 550379, 3735847; 550380,
3735848; 550380, 3735849; 550381,
3735850; 550381, 3735851; 550382,
3735852; 550383, 3735853; 550384,
3735854; 550384, 3735855; 550385,
3735856; 550386, 3735856; 550386,
3735857; 550387, 3735858; 550388,
3735859; 550389, 3735860; 550390,
3735860; 550391, 3735861; 550391,
3735862; 550392, 3735863; 550393,
3735864; 550394, 3735864; 550394,
3735865; 550394, 3735866; 550395,
3735867; 550395, 3735868; 550395,
3735868; 550396, 3735869; 550396,
3735870; 550396, 3735871; 550397,
3735871; 550397, 3735872; 550398,
3735873; 550398, 3735874; 550399,
3735875; 550399, 3735876; 550400,
3735876; 550401, 3735877; 550401,
3735878; 550402, 3735878; 550402,
3735879; 550403, 3735879; 550404,
3735880; 550405, 3735880; 550405,
3735881; 550406, 3735881; 550407,
3735882; 550408, 3735882; 550409,
3735883; 550409, 3735883; 550410,
3735883; 550411, 3735883; 550412,
3735884; 550413, 3735884; 550414,
3735884; 550415, 3735884; 550415,
3735884; 550417, 3735884; 550418,
3735885; 550419, 3735885; 550420,
3735886; 550420, 3735886; 550421,
3735887; 550421, 3735887; 550422,
3735888; 550422, 3735889; 550423,
3735890; 550423, 3735890; 550423,
3735891; 550423, 3735892; 550423,
3735893; 550423, 3735894; 550423,
3735895; 550423, 3735896; 550424,
3735896; 550424, 3735897; 550424,
3735898; 550425, 3735899; 550425,
3735900; 550425, 3735901; 550426,
3735902; 550426, 3735903; 550427,
3735903; 550427, 3735904; 550428,
3735905; 550428, 3735906; 550429,
3735906; 550429, 3735907; 550430,
3735908; 550431, 3735909; 550431,
3735909; 550432, 3735910; 550446,
3735922; 550449, 3735924; 550450,
3735926; 550452, 3735927; 550453,
3735928; 550455, 3735929; 550456,
3735930; 550457, 3735931; 550458,
3735931; 550459, 3735932; 550460,
3735932; 550461, 3735933; 550462,
3735933; 550463, 3735934; 550465,
3735934; 550466, 3735934; 550466,
3735935; 550467, 3735935; 550469,
3735935; 550470, 3735935; 550472,
3735935; 550473, 3735935; 550474,
3735935; 550476, 3735935; 550478,
3735935; 550479, 3735935; 550480,
3735936; 550481, 3735936; 550482,
3735937; 550484, 3735937; 550484,
3735938; 550485, 3735938; 550486,
3735939; 550487, 3735940; 550488,
3735940; 550488, 3735941; 550489,
3735942; 550490, 3735942; 550491,
3735943; 550491, 3735943; 550492,
3735944; 550493, 3735944; 550494,
3735945; 550494, 3735945; 550495,
3735946; 550496, 3735946; 550497,
3735947; 550498, 3735947; 550498,
3735948; 550499, 3735948; 550500,
3735948; 550501, 3735949; 550502,
3735949; 550503, 3735950; 550504,
3735950; 550505, 3735950; 550505,
3735951; 550506, 3735951; 550507,
3735951; 550508, 3735951; 550509,
3735952; 550510, 3735952; 550511,
3735952; 550512, 3735953; 550513,
3735953; 550514, 3735954; 550515,
3735954; 550515, 3735955; 550516,
3735955; 550517, 3735956; 550517,
3735956; 550518, 3735957; 550518,
3735957; 550519, 3735958; 550520,
3735959; 550520, 3735960; 550521,
3735960; 550529, 3735973; 550530,
3735973; 550542, 3735983; 550544,
3735984; 550545, 3735984; 550546,
3735984; 550547, 3735984; 550548,
3735985; 550549, 3735985; 550550,
3735985; 550551, 3735985; 550552,
3735985; 550553, 3735986; 550554,
3735986; 550555, 3735987; 550556,
3735987; 550556, 3735988; 550557,
3735989; 550567, 3736004; 550568,
3736005; 550568, 3736006; 550569,
3736007; 550570, 3736008; 550570,
3736009; 550571, 3736010; 550572,
3736011; 550572, 3736012; 550573,
3736013; 550574, 3736013; 550575,
3736014; 550575, 3736015; 550576,
3736016; 550577, 3736017; 550578,
3736017; 550579, 3736018; 550580,
3736019; 550581, 3736020; 550581,
3736020; 550582, 3736021; 550583,
3736022; 550584, 3736022; 550585,
3736023; 550586, 3736024; 550587,
3736024; 550588, 3736025; 550589,
3736025; 550590, 3736026; 550591,
3736026; 550592, 3736027; 550593,
3736028; 550594, 3736028; 550595,
3736028; 550596, 3736029; 550597,
3736029; 550599, 3736030; 550600,
3736031; 550601, 3736031; 550601,
3736032; 550602, 3736032; 550602,
3736033; 550610, 3736042; 550610,
3736042; 550611, 3736043; 550611,
3736044; 550612, 3736045; 550612,
3736045; 550612, 3736046; 550612,
3736047; 550612, 3736048; 550612,
3736049; 550612, 3736049; 550612,
3736050; 550612, 3736051; 550612,
3736052; 550612, 3736053; 550612,
3736054; 550612, 3736054; 550612,
3736055; 550612, 3736056; 550613,
3736057; 550613, 3736058; 550613,
3736058; 550613, 3736059; 550613,
3736060; 550614, 3736061; 550614,
3736061; 550614, 3736062; 550615,
3736063; 550615, 3736064; 550616,
3736065; 550617, 3736066; 550617,
3736067; 550618, 3736068; 550618,
3736068; 550619, 3736069; 550619,
3736069; 550620, 3736070; 550621,
3736070; 550621, 3736071; 550622,
3736071; 550623, 3736072; 550624,
3736072; 550624, 3736073; 550626,
3736073; 550627, 3736074; 550627,
3736074; 550629, 3736075; 550629,
3736075; 550630, 3736075; 550631,
3736075; 550632, 3736076; 550633,
3736076; 550633, 3736077; 550660,
3736090; 550661, 3736090; 550662,
3736090; 550663, 3736091; 550664,
3736091; 550665, 3736092; 550666,
3736092; 550667, 3736092; 550668,
3736093; 550669, 3736093; 550670,
3736093; 550671, 3736094; 550672,
3736094; 550673, 3736094; 550674,
3736094; 550709, 3736105; 550736,
3736113; 550737, 3736113; 550738,
3736114; 550739, 3736114; 550741,
3736115; 550742, 3736115; 550743,
3736115; 550744, 3736115; 550765,
VerDate Aug<31>2005 17:33 Oct 09, 2007 Jkt 214001 PO 00000 Frm 00029 Fmt 4701 Sfmt 4702 E:\FR\FM\10OCP2.SGM 10OCP2pwalker on PROD1PC71 with PROPOSALS2
57768 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
3736119; 550789, 3736125; 550790,
3736125; 550791, 3736125; 550792,
3736126; 550792, 3736126; 550793,
3736127; 550794, 3736127; 550796,
3736128; 550796, 3736128; 550797,
3736129; 550798, 3736129; 550799,
3736129; 550800, 3736129; 550801,
3736130; 550802, 3736130; 550802,
3736130; 550803, 3736131; 550804,
3736131; 550805, 3736131; 550806,
3736131; 550807, 3736131; 550808,
3736131; 550809, 3736132; 550810,
3736132; 550811, 3736132; 550812,
3736132; 550812, 3736132; 550813,
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3736132; 550816, 3736132; 550821,
3736132; 550824, 3736132; 550827,
3736132; 550831, 3736132; 550834,
3736131; 550837, 3736131; 550841,
3736131; 550844, 3736130; 550847,
3736130; 550850, 3736129; 550854,
3736129; 550857, 3736128; 550860,
3736127; 550863, 3736126; 550864,
3736126; 550865, 3736126; 550866,
3736126; 550867, 3736126; 550868,
3736126; 550868, 3736125; 550869,
3736125; 550870, 3736125; 550871,
3736125; 550872, 3736125; 550873,
3736125; 550874, 3736125; 550875,
3736125; 550901, 3736125; 550902,
3736125; 550903, 3736125; 550904,
3736125; 550905, 3736125; 550906,
3736125; 550907, 3736124; 550908,
3736124; 550909, 3736124; 550910,
3736124; 550911, 3736125; 550912,
3736125; 550913, 3736125; 550915,
3736126; 550917, 3736126; 550918,
3736127; 550918, 3736127; 550919,
3736128; 550920, 3736128; 550967,
3736165; 550968, 3736166; 550969,
3736167; 550970, 3736168; 550971,
3736169; 550972, 3736170; 550973,
3736171; 550974, 3736172; 550975,
3736173; 550975, 3736174; 550976,
3736175; 550977, 3736176; 550977,
3736176; 550978, 3736177; 550978,
3736178; 550980, 3736180; 550989,
3736173; 551157, 3736197; 551241,
3736173; 551268, 3736187; 551319,
3736092; 551324, 3736042; 551317,
3736031; 551311, 3736021; 551310,
3736020; 551307, 3736011; 551303,
3735998; 551303, 3735997; 551294,
3735983; 551293, 3735983; 551285,
3735979; 551264, 3735969; 551264,
3735967; 551264, 3735960; 551264,
3735960; 551244, 3735943; 551190,
3735896; 551189, 3735895; 551187,
3735886; 551171, 3735873; 551165,
3735873; 551154, 3735873; 551150,
3735865; 551115, 3735830; 551102,
3735816; 551102, 3735815; 551098,
3735805; 551091, 3735791; 551072,
3735779; 551076, 3735764; 551063,
3735753; 551050, 3735741; 551041,
3735722; 551043, 3735708; 551049,
3735682; 551057, 3735667; 551060,
3735659; 551065, 3735644; 551065,
3735641; 551073, 3735648; 551077,
3735648; 551101, 3735619; 551116,
3735585; 551133, 3735573; 551160,
3735560; 551186, 3735546; 551205,
3735511; 551228, 3735497; 551233,
3735494; 551304, 3735476; 551311,
3735469; 551381, 3735436; 551411,
3735419; 551435, 3735404; 551468,
3735383; 551536, 3735343; 551572,
3735315; 551594, 3735296; 551617,
3735278; 551634, 3735258; 551670,
3735214; 551675, 3735190; 551679,
3735168; 551674, 3735152; 551671,
3735135; 551674, 3735122; 551674,
3735100; 551675, 3735046; 551674,
3735025; 551672, 3735012; 551662,
3734991; 551653, 3734968; 551652,
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3734918; 551652, 3734900; 551655,
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3734832; 551654, 3734815; 551650,
3734802; 551638, 3734790; 551632,
3734783; 551625, 3734774; 551625,
3734773; 551622, 3734768; 551616,
3734755; 551619, 3734741; 551627,
3734719; 551640, 3734696; 551648,
3734679; 551658, 3734666; 551663,
3734656; 551671, 3734648; 551676,
3734638; 551676, 3734621; 551675,
3734604; 551673, 3734581; 551672,
3734567; 551669, 3734541; 551667,
3734521; 551667, 3734506; 551671,
3734496; 551670, 3734466; 551676,
3734459; 551687, 3734445; 551692,
3734430; 551692, 3734419; 551692,
3734404; 551689, 3734390; 551682,
3734375; 551673, 3734362; 551669,
3734353; 551663, 3734334; 551658,
3734324; 551648, 3734316; 551654,
3734312; 551660, 3734312; 551666,
3734306; 551700, 3734301; 551700,
3734300; 551700, 3734297; 551679,
3734251; 551673, 3734237; 551670,
3734230; 551664, 3734220; 551643,
3734193; 551640, 3734187; 551634,
3734168; 551630, 3734153; 551631,
3734133; 551630, 3734122; 551628,
3734112; 551637, 3734102; 551646,
3734106; 551650, 3734105; 551650,
3734096; 551653, 3734090; 551653,
3734075; 551657, 3734063; 551677,
3734010; 551680, 3734004; 551711,
3734004; 551715, 3734004; 551737,
3734004; 551805, 3734027; 551809,
3734042; 551810, 3734043; 551816,
3734047; 551825, 3734048; 551836,
3734048; 551839, 3734048; 551881,
3734101; 551889, 3734112; 551904,
3734125; 551945, 3734158; 551979,
3734170; 552082, 3734080; 552090,
3734061; 552137, 3734072; 552160,
3734053; 552187, 3734097; 552187,
3734109; 552184, 3734126; 552185,
3734139; 552193, 3734173; 552186,
3734186; 552185, 3734198; 552181,
3734210; 552188, 3734225; 552190,
3734240; 552195, 3734278; 552198,
3734300; 552200, 3734300; 552200,
3734311; 552201, 3734320; 552206,
3734342; 552209, 3734353; 552215,
3734369; 552219, 3734382; 552228,
3734400; 552240, 3734412; 552251,
3734427; 552255, 3734430; 552266,
3734440; 552290, 3734453; 552300,
3734460; 552323, 3734473; 552352,
3734482; 552373, 3734483; 552390,
3734479; 552404, 3734471; 552423,
3734463; 552437, 3734454; 552449,
3734445; 552456, 3734437; 552463,
3734429; 552464, 3734429; 552478,
3734419; 552499, 3734405; 552500,
3734405; 552500, 3734400; 552512,
3734400; 552530, 3734395; 552545,
3734391; 552561, 3734387; 552562,
3734386; 552576, 3734336; 552585,
3734300; 552588, 3734278; 552594,
3734268; 552595, 3734255; 552599,
3734243; 552612, 3734239; 552620,
3734223; 552624, 3734212; 552635,
3734201; 552648, 3734193; 552652,
3734182; 552657, 3734170; 552665,
3734162; 552669, 3734155; 552673,
3734116; 552673, 3734111; 552676,
3734099; 552679, 3734087; 552684,
3734076; 552687, 3734065; 552687,
3734051; 552691, 3734031; 552721,
3734010; 552735, 3733982; 552739,
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3733960; 552751, 3733951; 552754,
3733942; 552758, 3733934; 552763,
3733930; 552768, 3733929; 552776,
3733926; 552783, 3733923; 552795,
3733920; 552803, 3733920; 552811,
3733922; 552820, 3733923; 552835,
3733924; 552845, 3733925; 552853,
3733926; 552862, 3733928; 552875,
3733930; 552883, 3733934; 552892,
3733938; 552903, 3733940; 552914,
3733944; 552960, 3733965; 552972,
3733975; 552987, 3733986; 553031,
3734027; 553078, 3734057; 553095,
3734078; 553101, 3734109; 553111,
3734152; 553098, 3734180; 553091,
3734204; 553077, 3734242; 553050,
3734295; 553047, 3734301; 553054,
3734339; 553061, 3734356; 553070,
3734363; 553077, 3734368; 553083,
3734373; 553085, 3734375; 553086,
3734382; 553090, 3734386; 553094,
3734384; 553098, 3734391; 553111,
3734399; 553113, 3734400; 553200,
3734400; 553223, 3734400; 553229,
3734398; 553245, 3734392; 553258,
3734384; 553273, 3734376; 553286,
3734370; 553286, 3734370; 553288,
3734369; 553305, 3734357; 553327,
3734344; 553341, 3734334; 553348,
3734327; 553354, 3734324; 553352,
3734318; 553352, 3734310; 553354,
3734302; 553356, 3734293; 553355,
3734284; 553351, 3734275; 553351,
3734275; 553345, 3734268; 553343,
3734257; 553346, 3734250; 553356,
3734234; 553367, 3734225; 553372,
3734218; 553383, 3734201; 553385,
VerDate Aug<31>2005 17:33 Oct 09, 2007 Jkt 214001 PO 00000 Frm 00030 Fmt 4701 Sfmt 4702 E:\FR\FM\10OCP2.SGM 10OCP2pwalker on PROD1PC71 with PROPOSALS2
57769 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
3734195; 553388, 3734187; 553389,
3734172; 553390, 3734162; 553390,
3734151; 553391, 3734140; 553394,
3734132; 553400, 3734124; 553404,
3734115; 553408, 3734104; 553408,
3734097; 553415, 3734087; 553427,
3734080; 553443, 3734064; 553452,
3734060; 553468, 3734052; 553473,
3734043; 553476, 3734033; 553484,
3734028; 553492, 3734022; 553498,
3734016; 553500, 3734015; 553502,
3734011; 553510, 3734003; 553519,
3733988; 553525, 3733981; 553533,
3733977; 553546, 3733969; 553548,
3733960; 553554, 3733947; 553566,
3733938; 553576, 3733942; 553608,
3733921; 553618, 3733926; 553630,
3733936; 553634, 3733939; 553637,
3733934; 553642, 3733928; 553652,
3733919; 553654, 3733918; 553667,
3733915; 553670, 3733840; 553672,
3733783; 553675, 3733743; 553682,
3733693; 553685, 3733673; 553690,
3733628; 553698, 3733560; 553640,
3733444; 553565, 3733353; 553564,
3733352; 553549, 3733377; 553473,
3733275; 553350, 3733112; 553321,
3733073; 553304, 3733037; 553301,
3733029; 553293, 3733010; 553218,
3732821; 553124, 3732581; 553005,
3732465; 552984, 3732425; 552896,
3732424; 552891, 3732422; 552879,
3732417; 552870, 3732413; 552888,
3732400; 553005, 3732318; 553037,
3732269; 553039, 3732265; 553039,
3732265; 553071, 3732232; 553084,
3732224; 553103, 3732215; 553125,
3732202; 553140, 3732194; 553159,
3732187; 553179, 3732187; 553284,
3732144; 553284, 3732142; 553286,
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3732136; 553300, 3732137; 553304,
3732150; 553310, 3732161; 553322,
3732172; 553327, 3732179; 553337,
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3732196; 553361, 3732200; 553383,
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3732224; 553404, 3732245; 553408,
3732262; 553404, 3732290; 553402,
3732310; 553383, 3732340; 553374,
3732345; 553374, 3732358; 553382,
3732367; 553391, 3732365; 553408,
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3732372; 553456, 3732333; 553466,
3732314; 553479, 3732295; 553492,
3732277; 553511, 3732265; 553524,
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3732116; 553998, 3732115; 553996,
3732100; 554041, 3732073; 554057,
3732063; 554077, 3732092; 554080,
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3732099; 554105, 3732116; 554109,
3732150; 554368, 3730690; 554245,
3729777; 554239, 3729775; 554201,
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3729655; 553984, 3729646; 553966,
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3729318; 553816, 3729275; 553806,
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3729226; 553793, 3729224; 553792,
3729223; 553791, 3729222; 553790,
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3729218; 553787, 3729217; 553786,
3729216; 553785, 3729215; 553784,
3729214; 553783, 3729213; 553782,
3729212; 553781, 3729211; 553780,
3729210; 553779, 3729209; 553777,
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3729199; 553762, 3729199; 553760,
3729198; 553759, 3729198; 553758,
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3729194; 553752, 3729194; 553751,
3729193; 553750, 3729192; 553749,
3729192; 553748, 3729191; 553747,
3729190; 553746, 3729189; 553745,
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3729187; 553742, 3729186; 553741,
3729185; 553740, 3729184; 553739,
3729183; 553738, 3729182; 553738,
3729181; 553737, 3729180; 553736,
3729179; 553735, 3729178; 553734,
3729177; 553733, 3729176; 553733,
3729175; 553732, 3729174; 553731,
3729173; 553730, 3729172; 553730,
3729171; 553729, 3729170; 553728,
3729169; 553728, 3729168; 553727,
3729166; 553726, 3729165; 553726,
3729164; 553725, 3729163; 553725,
3729162; 553724, 3729161; 553724,
3729159; 553723, 3729158; 553723,
3729157; 553722, 3729156; 553722,
3729155; 553721, 3729153; 553721,
3729152; 553721, 3729151; 553720,
3729150; 553720, 3729148; 553720,
3729147; 553719, 3729146; 553719,
3729144; 553719, 3729143; 553719,
3729142; 553719, 3729141; 553718,
3729139; 553718, 3729138; 553718,
3729137; 553718, 3729135; 553718,
3729134; 553718, 3729133; 553718,
3729132; 553718, 3729130; 553718,
3729129; 553718, 3729128; 553718,
3729126; 553718, 3729125; 553718,
3729124; 553718, 3729122; 553718,
3729121; 553719, 3729120; 553719,
3729119; 553719, 3729117; 553719,
3729116; 553720, 3729115; 553720,
3729113; 553720, 3729112; 553721,
3729111; 553721, 3729110; 553721,
3729108; 553722, 3729107; 553722,
3729106; 553723, 3729105; 553723,
3729104; 553723, 3729102; 553724,
3729101; 553725, 3729100; 553725,
3729099; 553726, 3729098; 553726,
3729096; 553727, 3729095; 553727,
3729094; 553728, 3729093; 553729,
3729092; 553729, 3729091; 553730,
3729090; 553731, 3729089; 553732,
3729088; 553732, 3729087; 553733,
3729086; 553734, 3729084; 553735,
3729083; 553736, 3729082; 553736,
3729081; 553737, 3729081; 553738,
3729080; 553739, 3729079; 553740,
3729078; 553741, 3729077; 553742,
3729076; 553743, 3729075; 553743,
3729075; 553744, 3729074; 553746,
3729073; 553747, 3729072; 553748,
3729071; 553749, 3729071; 553750,
3729070; 553751, 3729069; 553753,
3729069; 553754, 3729068; 553755,
3729067; 553756, 3729067; 553758,
3729066; 553759, 3729065; 553760,
3729065; 553762, 3729064; 553763,
3729064; 553764, 3729063; 553766,
3729063; 553767, 3729062; 553768,
3729062; 553770, 3729061; 553771,
3729061; 553772, 3729061; 553774,
3729060; 553775, 3729060; 553776,
3729060; 553778, 3729060; 553779,
3729059; 553781, 3729059; 553782,
3729059; 553783, 3729059; 553785,
3729059; 553786, 3729058; 553788,
3729058; 553791, 3729058; 553792,
3729058; 553793, 3729058; 553795,
3729058; 553796, 3729058; 553802,
3729059; 553808, 3729059; 553814,
3729059; 553819, 3729059; 553825,
3729058; 553831, 3729058; 553837,
3729058; 553843, 3729057; 553849,
3729057; 553855, 3729056; 553861,
VerDate Aug<31>2005 17:33 Oct 09, 2007 Jkt 214001 PO 00000 Frm 00031 Fmt 4701 Sfmt 4702 E:\FR\FM\10OCP2.SGM 10OCP2pwalker on PROD1PC71 with PROPOSALS2
57770 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
3729055; 553863, 3729055; 553866,
3729054; 553868, 3729054; 553871,
3729053; 553874, 3729053; 553877,
3729052; 553879, 3729051; 553882,
3729050; 553885, 3729050; 553887,
3729049; 553890, 3729048; 553892,
3729047; 553895, 3729046; 553898,
3729045; 553900, 3729044; 553903,
3729043; 553905, 3729042; 553908,
3729041; 553910, 3729039; 553913,
3729038; 553915, 3729037; 553918,
3729036; 553920, 3729034; 553922,
3729033; 553925, 3729031; 553927,
3729030; 553929, 3729028; 553931,
3729027; 553933, 3729025; 553935,
3729024; 553937, 3729022; 553939,
3729021; 553941, 3729020; 553943,
3729018; 553946, 3729017; 553948,
3729016; 553950, 3729015; 553952,
3729013; 553955, 3729012; 553957,
3729011; 553959, 3729010; 553961,
3729009; 553964, 3729008; 553966,
3729007; 553968, 3729006; 553971,
3729005; 553973, 3729004; 553976,
3729004; 553978, 3729003; 553980,
3729002; 553983, 3729002; 553985,
3729001; 553988, 3729000; 553990,
3729000; 553993, 3728999; 553995,
3728999; 553998, 3728999; 554000,
3728998; 554003, 3728998; 554005,
3728998; 554007, 3728997; 554008,
3728997; 554010, 3728997; 554011,
3728997; 554013, 3728997; 554014,
3728996; 554015, 3728996; 554017,
3728996; 554018, 3728996; 554020,
3728995; 554021, 3728995; 554023,
3728995; 554024, 3728994; 554025,
3728994; 554027, 3728993; 554028,
3728993; 554030, 3728992; 554031,
3728992; 554032, 3728991; 554034,
3728990; 554035, 3728990; 554036,
3728989; 554038, 3728989; 554039,
3728988; 554040, 3728987; 554042,
3728986; 554043, 3728986; 554044,
3728985; 554045, 3728984; 554047,
3728983; 554048, 3728982; 554049,
3728982; 554050, 3728981; 554051,
3728980; 554053, 3728979; 554054,
3728978; 554055, 3728977; 554056,
3728976; 554057, 3728975; 554058,
3728974; 554059, 3728973; 554060,
3728972; 554061, 3728971; 554062,
3728970; 554063, 3728969; 554064,
3728968; 554065, 3728966; 554066,
3728965; 554067, 3728964; 554069,
3728962; 554071, 3728960; 554072,
3728957; 554074, 3728955; 554076,
3728953; 554079, 3728950; 554081,
3728948; 554083, 3728946; 554085,
3728944; 554087, 3728942; 554089,
3728940; 554092, 3728938; 554094,
3728936; 554095, 3728935; 554097,
3728934; 554098, 3728933; 554100,
3728931; 554102, 3728930; 554103,
3728929; 554105, 3728928; 554107,
3728927; 554109, 3728926; 554110,
3728925; 554112, 3728924; 554114,
3728923; 554116, 3728922; 554118,
3728921; 554119, 3728920; 554121,
3728919; 554123, 3728918; 554125,
3728917; 554127, 3728916; 554129,
3728916; 554113, 3728802; 554092,
3728802; 554032, 3728802; 553931,
3728801; 553728, 3728800; 553627,
3728799; 553526, 3728799; 553426,
3728798; 553426, 3728726; 553427,
3728678; 553427, 3728598; 553326,
3728597; 553327, 3728496; 553328,
3728395; 553328, 3728294; 553329,
3728192; 553329, 3728091; 553330,
3727992; 553331, 3727895; 553331,
3727792; 553332, 3727689; 553333,
3727590; 553333, 3727489; 553334,
3727388; 553334, 3727287; 553335,
3727187; 553486, 3727188; 553488,
3727145; 553491, 3727087; 553492,
3727080; 553500, 3726986; 553518,
3726879; 553591, 3726724; 553600,
3726707; 553600, 3726700; 553600,
3726600; 553600, 3726500; 553600,
3726400; 553700, 3726400; 553748,
3726400; 553749, 3726399; 553747,
3726395; 553758, 3726342; 553758,
3726341; 553945, 3726216; 554135,
3726156; 554149, 3726142; 554187,
3726105; 554178, 3726042; 554182,
3726038; 554187, 3726031; 554187,
3726030; 554186, 3726026; 554186,
3726025; 554186, 3726022; 554186,
3726018; 554187, 3726015; 554188,
3726013; 554188, 3726011; 554190,
3726008; 554192, 3726005; 554212,
3725983; 554215, 3725979; 554217,
3725977; 554217, 3725976; 554237,
3725975; 554251, 3725960; 554333,
3725946; 554367, 3725967; 554380,
3725976; 554393, 3725984; 554474,
3725956; 554551, 3725915; 554600,
3725889; 554600, 3725800; 554620,
3725800; 554619, 3725760; 554611,
3725760; 554610, 3725760; 554610,
3725760; 554609, 3725760; 554608,
3725760; 554608, 3725760; 554608,
3725760; 554607, 3725760; 554607,
3725760; 554606, 3725760; 554606,
3725760; 554605, 3725760; 554605,
3725759; 554605, 3725759; 554604,
3725759; 554604, 3725759; 554604,
3725759; 554603, 3725759; 554603,
3725759; 554602, 3725759; 554602,
3725758; 554601, 3725758; 554601,
3725758; 554600, 3725758; 554600,
3725757; 554600, 3725757; 554599,
3725757; 554599, 3725757; 554598,
3725756; 554598, 3725756; 554598,
3725756; 554597, 3725756; 554597,
3725755; 554597, 3725755; 554597,
3725755; 554596, 3725755; 554596,
3725755; 554596, 3725754; 554596,
3725754; 554595, 3725754; 554595,
3725753; 554595, 3725753; 554595,
3725753; 554595, 3725753; 554594,
3725752; 554594, 3725752; 554594,
3725751; 554593, 3725751; 554593,
3725751; 554593, 3725750; 554593,
3725750; 554592, 3725750; 554592,
3725749; 554592, 3725749; 554592,
3725749; 554592, 3725748; 554592,
3725748; 554591, 3725748; 554591,
3725747; 554591, 3725747; 554591,
3725747; 554591, 3725746; 554590,
3725746; 554590, 3725746; 554590,
3725745; 554590, 3725745; 554590,
3725744; 554590, 3725744; 554590,
3725744; 554589, 3725743; 554589,
3725743; 554589, 3725743; 554589,
3725742; 554589, 3725742; 554589,
3725741; 554589, 3725741; 554589,
3725741; 554589, 3725740; 554588,
3725740; 554588, 3725740; 554588,
3725739; 554588, 3725739; 554588,
3725739; 554588, 3725738; 554588,
3725738; 554588, 3725738; 554588,
3725737; 554588, 3725737; 554588,
3725736; 554588, 3725736; 554588,
3725735; 554588, 3725735; 554588,
3725735; 554588, 3725734; 554588,
3725734; 554588, 3725733; 554588,
3725733; 554588, 3725732; 554588,
3725732; 554588, 3725730; 554588,
3725729; 554588, 3725729; 554588,
3725728; 554588, 3725728; 554588,
3725727; 554588 3725727; 554588,
3725726; 554588, 3725726; 554589,
3725725; 554589, 3725725; 554589,
3725724; 554589, 3725724; 554589,
3725723; 554589, 3725723; 554589,
3725723; 554589, 3725722; 554590,
3725722; 554590, 3725722; 554590,
3725721; 554590, 3725721; 554590,
3725721; 554590, 3725720; 554590,
3725720; 554590, 3725719; 554591,
3725719; 554591, 3725719; 554591,
3725718; 554591, 3725718; 554591,
3725717; 554592, 3725717; 554592,
3725717; 554592, 3725716; 554592,
3725716; 554593, 3725715; 554593,
3725715; 554593, 3725715; 554593,
3725714; 554594, 3725714; 554594,
3725714; 554594, 3725713; 554595,
3725713; 554595, 3725713; 554595,
3725712; 554595, 3725712; 554596,
3725712; 554596, 3725711; 554596,
3725711; 554597, 3725711; 554597,
3725710; 554597, 3725710; 554598,
3725710; 554598, 3725709; 554598,
3725709; 554599, 3725709; 554599,
3725708; 554599, 3725708; 554600,
3725708; 554600, 3725708; 554601,
3725707; 554601, 3725707; 554601,
3725707; 554602, 3725707; 554602,
3725706; 554602, 3725706; 554603,
3725706; 554603, 3725706; 554603,
3725706; 554604, 3725706; 554604,
3725705; 554604, 3725705; 554605,
3725705; 554605, 3725705; 554605,
3725705; 554606, 3725705; 554606,
3725704; 554607, 3725704; 554607,
3725704; 554607, 3725704; 554608,
3725704; 554608, 3725704; 554609,
3725704; 554609, 3725703; 554609,
3725703; 554610, 3725703; 554610,
3725703; 554618, 3725707; 554632,
3725706; 554660, 3725699; 554705,
VerDate Aug<31>2005 17:33 Oct 09, 2007 Jkt 214001 PO 00000 Frm 00032 Fmt 4701 Sfmt 4702 E:\FR\FM\10OCP2.SGM 10OCP2pwalker on PROD1PC71 with PROPOSALS2
57771 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
3725687; 554759, 3725672; 554789,
3725603; 554789, 3725602; 554857,
3725444; 554913, 3725363; 554955,
3725411; 554966, 3725423; 554994,
3725457; 555049, 3725501; 555038,
3725534; 555037, 3725534; 554953,
3725581; 554954, 3725584; 556747,
3725031; 557936, 3724088; 558510,
3724252; 559822, 3725688; 560478,
3727041; 561094, 3727369; 561750,
3727082; 562570, 3725442; 562693,
3724006; 562980, 3722489; 563513,
3721997; 564088, 3722418; 564089,
3722418; 564122, 3722411; 564155,
3722405; 564169, 3722414; 564188,
3722426; 564188, 3722427; 564189,
3722427; 564189, 3722427; 564189,
3722428; 564190, 3722428; 564190,
3722428; 564190, 3722428; 564191,
3722429; 564191, 3722429; 564191,
3722429; 564191, 3722429; 564191,
3722430; 564192, 3722430; 564192,
3722431; 564192, 3722431; 564193,
3722431; 564193, 3722432; 564193,
3722432; 564193, 3722432; 564194,
3722433; 564194, 3722433; 564194,
3722434; 564194, 3722434; 564194,
3722435; 564194, 3722435; 564195,
3722435; 564195, 3722435; 564195,
3722436; 564195, 3722436; 564195,
3722437; 564195, 3722437; 564195,
3722438; 564195, 3722438; 564195,
3722438; 564196, 3722439; 564196,
3722439; 564196, 3722440; 564196,
3722440; 564196, 3722441; 564196,
3722441; 564196, 3722442; 564196,
3722442; 564196, 3722442; 564196,
3722443; 564196, 3722443; 564196,
3722444; 564196, 3722444; 564196,
3722444; 564196, 3722445; 564209,
3722445; 564209, 3722447; 564208,
3722593; 564207, 3722807; 564206,
3722886; 564204, 3723251; 564211,
3723251; 564211, 3723251; 564210,
3723363; 564243, 3723406; 564268,
3723438; 564398, 3723605; 564418,
3723631; 564418, 3723632; 564419,
3723632; 564419, 3723632; 564419,
3723633; 564419, 3723633; 564420,
3723633; 564420, 3723634; 564420,
3723634; 564421, 3723635; 564421,
3723635; 564421, 3723635; 564422,
3723636; 564422, 3723637; 564422,
3723637; 564423, 3723637; 564423,
3723638; 564423, 3723638; 564423,
3723638; 564423, 3723638; 564423,
3723639; 564424, 3723639; 564424,
3723639; 564424, 3723640; 564424,
3723640; 564425, 3723641; 564425,
3723641; 564425, 3723641; 564425,
3723642; 564426, 3723642; 564426,
3723643; 564426, 3723644; 564427,
3723644; 564427, 3723645; 564427,
3723645; 564428, 3723646; 564428,
3723646; 564428, 3723647; 564428,
3723647; 564429, 3723648; 564429,
3723648; 564429, 3723649; 564430,
3723649; 564430, 3723650; 564430,
3723650; 564430, 3723650; 564430,
3723651; 564431, 3723652; 564431,
3723652; 564431, 3723652; 564431,
3723653; 564432, 3723653; 564432,
3723654; 564432, 3723654; 564432,
3723655; 564432, 3723655; 564433,
3723656; 564433, 3723656; 564438,
3723663; 564442, 3723714; 564442,
3723714; 564435, 3723789; 564440,
3723798; 564463, 3723846; 564481,
3723875; 564488, 3723896; 564506,
3723919; 564509, 3723922; 564514,
3723928; 564568, 3723964; 564581,
3723968; 564581, 3723969; 564582,
3723969; 564582, 3723969; 564583,
3723969; 564640, 3723990; 564641,
3723991; 564641, 3723991; 564642,
3723991; 564642, 3723991; 564653,
3723995; 564653, 3724000; 564700,
3724000; 564700, 3724073; 564917,
3724081; 564924, 3724081; 565084,
3724082; 565162, 3724083; 565138,
3724144; 565147, 3724163; 565165,
3724200; 565176, 3724200; 565187,
3724196; 565216, 3724186; 565378,
3724172; 565428, 3724264; 565296,
3724353; 565282, 3724363; 565257,
3724379; 565257, 3724421; 565274,
3724448; 565290, 3724441; 565310,
3724432; 565317, 3724438; 565346,
3724460; 565355, 3724622; 565348,
3724812; 565307, 3724890; 565266,
3724966; 565240, 3725013; 565289,
3725063; 565312, 3725087; 565341,
3725165; 565422, 3725156; 565464,
3725152; 565490, 3725149; 565493,
3725149; 565522, 3725145; 565556,
3725116; 565619, 3725062; 565757,
3725065; 565842, 3725067; 565907,
3725026; 565944, 3725002; 565945,
3725002; 565945, 3725002; 565945,
3725002; 565946, 3725001; 565946,
3725001; 565946, 3725001; 565947,
3725001; 565947, 3725001; 565947,
3725001; 565948, 3725000; 565948,
3725000; 565948, 3725000; 565948,
3725000; 565949, 3725000; 565949,
3725000; 565949, 3725000; 565950,
3725000; 565950, 3725000; 565950,
3725000; 565951, 3725000; 565951,
3724999; 565952, 3724999; 565952,
3724999; 565953, 3724999; 565953,
3724999; 565954, 3724999; 565954,
3724999; 565955, 3724999; 565955,
3724999; 565956, 3724999; 565956,
3724999; 565956, 3724999; 565957,
3724999; 565957, 3725000; 565958,
3725000; 565958, 3725000; 565959,
3725000; 565959, 3725000; 565959,
3725000; 565960, 3725000; 565960,
3725000; 565960, 3725000; 565961,
3725000; 565961, 3725001; 565961,
3725001; 565962, 3725001; 565962,
3725001; 565962, 3725001; 565962,
3725001; 565963, 3725001; 565963,
3725002; 565964, 3725002; 565964,
3725002; 565964, 3725002; 565965,
3725003; 565965, 3725003; 565965,
3725003; 565966, 3725003; 565966,
3725004; 565966, 3725004; 565967,
3725004; 565967, 3725005; 565967,
3725005; 565968, 3725005; 565968,
3725006; 565968, 3725006; 565969,
3725006; 565969, 3725007; 565969,
3725007; 565969, 3725007; 565970,
3725008; 565970, 3725008; 565970,
3725009; 565970, 3725009; 565971,
3725009; 565971, 3725010; 565971,
3725010; 565971, 3725011; 565971,
3725011; 565971, 3725011; 565971,
3725011; 565972, 3725012; 565972,
3725012; 565972, 3725013; 565972,
3725013; 565972, 3725013; 565972,
3725014; 565972, 3725014; 565972,
3725015; 565972, 3725015; 565972,
3725015; 565972, 3725016; 565972,
3725016; 565972, 3725016; 565972,
3725017; 565972, 3725017; 565972,
3725018; 565972, 3725018; 565972,
3725019; 565972, 3725019; 565972,
3725019; 565972, 3725020; 565972,
3725020; 565972, 3725020; 565972,
3725021; 565972, 3725021; 565972,
3725022; 565972, 3725022; 565972,
3725023; 565972, 3725023; 565971,
3725024; 565971, 3725024; 565971,
3725025; 565903, 3725182; 565900,
3725220; 565900, 3725300; 565892,
3725300; 565888, 3725336; 565867,
3725351; 565866, 3725352; 565800,
3725398; 565800, 3725400; 565800,
3725424; 565845, 3725432; 565848,
3725480; 565865, 3725483; 565865,
3725483; 565883, 3725486; 565899,
3725489; 565909, 3725521; 565910,
3725530; 565910, 3725531; 565910,
3725532; 565913, 3725559; 565900,
3725588; 565900, 3725600; 565900,
3725669; 565900, 3725670; 565900,
3725670; 565900, 3725700; 565888,
3725700; 565864, 3725716; 565856,
3725765; 565849, 3725813; 565849,
3725814; 565849, 3725814; 565849,
3725815; 565849, 3725815; 565849,
3725816; 565849, 3725817; 565849,
3725817; 565849, 3725818; 565849,
3725818; 565849, 3725819; 565849,
3725819; 565849, 3725820; 565849,
3725821; 565849, 3725822; 565849,
3725822; 565849, 3725823; 565849,
3725824; 565849, 3725825; 565849,
3725825; 565849, 3725826; 565849,
3725826; 565849, 3725827; 565849,
3725827; 565849, 3725828; 565850,
3725829; 565850, 3725830; 565850,
3725831; 565850, 3725831; 565850,
3725832; 565851, 3725833; 565851,
3725834; 565851, 3725834; 565851,
3725835; 565852, 3725836; 565852,
3725837; 565852, 3725837; 565852,
3725838; 565853, 3725838; 565853,
3725839; 565853, 3725839; 565853,
3725840; 565854, 3725841; 565854,
3725842; 565855, 3725842; 565855,
3725843; 565856, 3725844; 565856,
3725845; 565857, 3725846; 565858,
VerDate Aug<31>2005 17:33 Oct 09, 2007 Jkt 214001 PO 00000 Frm 00033 Fmt 4701 Sfmt 4702 E:\FR\FM\10OCP2.SGM 10OCP2pwalker on PROD1PC71 with PROPOSALS2
57772 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
3725848; 565859, 3725849; 565860,
3725850; 565861, 3725851; 565861,
3725851; 565862, 3725852; 565862,
3725852; 565862, 3725852; 565863,
3725853; 565863, 3725854; 565864,
3725854; 565865, 3725855; 565865,
3725855; 565866, 3725856; 565867,
3725856; 565867, 3725857; 565868,
3725857; 565869, 3725858; 565870,
3725858; 565871, 3725859; 565872,
3725860; 565873, 3725860; 565875,
3725861; 565876, 3725862; 565876,
3725862; 565877, 3725862; 565877,
3725862; 565878, 3725862; 565878,
3725863; 565879, 3725863; 565879,
3725863; 565880, 3725863; 565881,
3725863; 565881, 3725864; 565882,
3725864; 565882, 3725864; 565883,
3725864; 565884, 3725864; 565884,
3725864; 565885, 3725865; 565885,
3725865; 565886, 3725865; 565887,
3725865; 565888, 3725865; 565888,
3725865; 565889, 3725865; 565890,
3725865; 565891, 3725865; 565892,
3725865; 565892, 3725866; 565893,
3725866; 565894, 3725866; 565895,
3725866; 565896, 3725866; 565896,
3725866; 565897, 3725866; 565898,
3725865; 565899, 3725865; 565899,
3725865; 565900, 3725865; 565901,
3725865; 565902, 3725865; 565903,
3725865; 565904, 3725865; 565904,
3725865; 565905, 3725864; 565906,
3725864; 565907, 3725864; 565907,
3725864; 565907, 3725864; 565908,
3725863; 565909, 3725863; 565910,
3725863; 565910, 3725863; 565911,
3725863; 565911, 3725862; 565912,
3725862; 565912, 3725862; 565913,
3725862; 565913, 3725862; 565914,
3725861; 565916, 3725860; 565917,
3725860; 565918, 3725859; 565919,
3725858; 565920, 3725858; 565921,
3725857; 565922, 3725857; 565922,
3725856; 565923, 3725856; 565924,
3725855; 565939, 3725842; 566014,
3725778; 566029, 3725765; 566057,
3725765; 566059, 3725761; 566071,
3725742; 566082, 3725731; 566094,
3725726; 566108, 3725722; 566115,
3725717; 566125, 3725710; 566130,
3725706; 566131, 3725705; 566137,
3725700; 566142, 3725694; 566145,
3725691; 566149, 3725684; 566153,
3725676; 566159, 3725672; 566165,
3725666; 566168, 3725659; 566168,
3725650; 566168, 3725642; 566166,
3725633; 566165, 3725623; 566164,
3725616; 566165, 3725610; 566167,
3725601; 566172, 3725597; 566177,
3725585; 566179, 3725577; 566176,
3725567; 566173, 3725557; 566168,
3725546; 566167, 3725538; 566165,
3725530; 566163, 3725523; 566161,
3725517; 566161, 3725508; 566165,
3725500; 566171, 3725495; 566175,
3725490; 566182, 3725484; 566190,
3725478; 566194, 3725470; 566199,
3725462; 566206, 3725451; 566210,
3725444; 566219, 3725437; 566229,
3725432; 566240, 3725430; 566253,
3725428; 566260, 3725428; 566261,
3725428; 566272, 3725422; 566278,
3725422; 566283, 3725422; 566293,
3725425; 566302, 3725425; 566313,
3725422; 566315, 3725410; 566313,
3725407; 566314, 3725394; 566318,
3725382; 566322, 3725373; 566329,
3725363; 566336, 3725359; 566348,
3725352; 566355, 3725352; 566368,
3725343; 566372, 3725337; 566376,
3725330; 566388, 3725326; 566396,
3725323; 566407, 3725320; 566417,
3725320; 566426, 3725319; 566439,
3725318; 566449, 3725323; 566461,
3725327; 566468, 3725336; 566476,
3725344; 566481, 3725346; 566493,
3725350; 566501, 3725350; 566510,
3725350; 566515, 3725350; 566525,
3725346; 566537, 3725338; 566546,
3725332; 566555, 3725328; 566566,
3725321; 566575, 3725317; 566581,
3725314; 566591, 3725305; 566593,
3725302; 566597, 3725297; 566602,
3725292; 566608, 3725283; 566615,
3725272; 566620, 3725257; 566623,
3725246; 566623, 3725233; 566623,
3725228; 566595, 3725205; 566576,
3725168; 566573, 3725134; 566569,
3725089; 566569, 3725063; 566576,
3725025; 566599, 3724984; 566610,
3724954; 566629, 3724932; 566644,
3724920; 566670, 3724913; 566672,
3724913; 566693, 3724920; 566715,
3724924; 566749, 3724920; 566771,
3724905; 566773, 3724904; 566798,
3724890; 566820, 3724860; 566846,
3724853; 566906, 3724838; 566910,
3724834; 566924, 3724825; 566940,
3724819; 566951, 3724811; 566963,
3724802; 566967, 3724791; 567005,
3724744; 567014, 3724733; 567023,
3724718; 567031, 3724710; 567045,
3724692; 567054, 3724680; 567063,
3724664; 567072, 3724655; 567113,
3724636; 567119, 3724630; 567136,
3724576; 567136, 3724575; 567136,
3724575; 567136, 3724573; 567137,
3724572; 567137, 3724572; 567137,
3724570; 567137, 3724569; 567137,
3724568; 567137, 3724567; 567137,
3724566; 567137, 3724565; 567137,
3724564; 567137, 3724563; 567138,
3724562; 567138, 3724561; 567138,
3724560; 567138, 3724559; 567138,
3724558; 567138, 3724556; 567138,
3724555; 567138, 3724554; 567138,
3724553; 567138, 3724552; 567138,
3724551; 567138, 3724550; 567138,
3724549; 567138, 3724548; 567138,
3724547; 567138, 3724545; 567138,
3724544; 567138, 3724544; 567138,
3724542; 567138, 3724541; 567138,
3724540; 567138, 3724539; 567138,
3724538; 567138, 3724537; 567138,
3724536; 567138, 3724535; 567137,
3724534; 567137, 3724533; 567137,
3724532; 567137, 3724531; 567137,
3724530; 567137, 3724528; 567137,
3724527; 567137, 3724527; 567137,
3724525; 567137, 3724524; 567136,
3724523; 567136, 3724522; 567136,
3724521; 567136, 3724520; 567136,
3724519; 567136, 3724518; 567135,
3724517; 567135, 3724516; 567135,
3724515; 567135, 3724514; 567135,
3724513; 567135, 3724512; 567134,
3724511; 567134, 3724510; 567134,
3724509; 567134, 3724508; 567134,
3724507; 567133, 3724506; 567133,
3724505; 567133, 3724504; 567133,
3724503; 567133, 3724502; 567132,
3724501; 567132, 3724500; 567132,
3724500; 567132, 3724499; 567131,
3724498; 567131, 3724497; 567131,
3724496; 567131, 3724495; 567130,
3724494; 567130, 3724493; 567130,
3724492; 567130, 3724491; 567129,
3724490; 567129, 3724490; 567129,
3724489; 567129, 3724488; 567128,
3724487; 567128, 3724486; 567128,
3724485; 567127, 3724484; 567127,
3724483; 567127, 3724482; 567126,
3724481; 567126, 3724480; 567126,
3724479; 567125, 3724479; 567125,
3724478; 567125, 3724476; 567124,
3724475; 567124, 3724474; 567123,
3724473; 567123, 3724472; 567122,
3724471; 567122, 3724470; 567121,
3724469; 567121, 3724467; 567120,
3724466; 567120, 3724465; 567119,
3724464; 567119, 3724463; 567119,
3724462; 567118, 3724461; 567117,
3724460; 567117, 3724459; 567082,
3724391; 567079, 3724385; 567078,
3724384; 567078, 3724384; 567077,
3724383; 567077, 3724382; 567076,
3724381; 567076, 3724381; 567076,
3724380; 567075, 3724380; 567075,
3724379; 567075, 3724379; 567074,
3724378; 567074, 3724378; 567074,
3724377; 567073, 3724376; 567072,
3724375; 567072, 3724374; 567071,
3724373; 567071, 3724373; 567071,
3724372; 567070, 3724372; 567070,
3724371; 567070, 3724371; 567069,
3724370; 567069, 3724370; 567069,
3724369; 567068, 3724369; 567068,
3724368; 567067, 3724367; 567066,
3724366; 567066, 3724365; 567066,
3724365; 567066, 3724364; 567065,
3724364; 567065, 3724363; 567065,
3724363; 567064, 3724362; 567064,
3724362; 567064, 3724361; 567063,
3724361; 567063, 3724360; 567062,
3724359; 567062, 3724358; 567061,
3724357; 567061, 3724357; 567061,
3724356; 567060, 3724356; 567060,
3724355; 567060, 3724355; 567059,
3724354; 567059, 3724354; 567059,
3724354; 567059, 3724353; 567058,
3724353; 567058, 3724352; 567057,
3724351; 567056, 3724350; 567056,
3724349; 567055, 3724348; 567055,
VerDate Aug<31>2005 17:33 Oct 09, 2007 Jkt 214001 PO 00000 Frm 00034 Fmt 4701 Sfmt 4702 E:\FR\FM\10OCP2.SGM 10OCP2pwalker on PROD1PC71 with PROPOSALS2
57773 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
3724348; 567055, 3724347; 567054,
3724347; 567054, 3724346; 567054,
3724345; 567039, 3724324; 566895,
3724115; 566884, 3724097; 566839,
3724025; 566839, 3724025; 566838,
3724023; 566821, 3723993; 566820,
3723992; 566820, 3723991; 566820,
3723991; 566820, 3723990; 566819,
3723990; 566819, 3723990; 566819,
3723989; 566819, 3723989; 566819,
3723988; 566818, 3723988; 566818,
3723988; 566818, 3723987; 566818,
3723987; 566818, 3723987; 566817,
3723986; 566817, 3723985; 566817,
3723984; 566816, 3723984; 566816,
3723983; 566816, 3723983; 566816,
3723982; 566816, 3723982; 566816,
3723981; 566815, 3723981; 566815,
3723980; 566815, 3723980; 566815,
3723979; 566815, 3723979; 566815,
3723978; 566814, 3723978; 566814,
3723977; 566814, 3723977; 566814,
3723976; 566814, 3723976; 566814,
3723975; 566814, 3723975; 566814,
3723974; 566814, 3723974; 566813,
3723973; 566813, 3723973; 566813,
3723972; 566813, 3723972; 566813,
3723971; 566813, 3723971; 566813,
3723970; 566813, 3723970; 566813,
3723969; 566813, 3723969; 566813,
3723968; 566812, 3723968; 566812,
3723967; 566812, 3723967; 566812,
3723966; 566812, 3723966; 566812,
3723965; 566812, 3723964; 566812,
3723964; 566812, 3723964; 566812,
3723963; 566812, 3723962; 566812,
3723962; 566812, 3723962; 566812,
3723961; 566812, 3723961; 566812,
3723960; 566812, 3723960; 566812,
3723960; 566812, 3723959; 566812,
3723958; 566812, 3723958; 566812,
3723957; 566812, 3723957; 566812,
3723956; 566812, 3723956; 566812,
3723955; 566812, 3723955; 566812,
3723954; 566812, 3723954; 566812,
3723953; 566812, 3723953; 566812,
3723952; 566812, 3723951; 566812,
3723951; 566812, 3723951; 566812,
3723950; 566812, 3723950; 566813,
3723949; 566813, 3723949; 566813,
3723948; 566813, 3723947; 566813,
3723947; 566813, 3723946; 566813,
3723945; 566813, 3723944; 566814,
3723944; 566814, 3723944; 566814,
3723943; 566814, 3723943; 566814,
3723942; 566814, 3723942; 566814,
3723941; 566814, 3723941; 566814,
3723941; 566815, 3723940; 566815,
3723940; 566815, 3723939; 566815,
3723939; 566815, 3723938; 566815,
3723938; 566815, 3723937; 566816,
3723936; 566816, 3723936; 566816,
3723935; 566816, 3723935; 566817,
3723934; 566817, 3723934; 566817,
3723933; 566817, 3723932; 566818,
3723932; 566818, 3723931; 566819,
3723930; 566819, 3723929; 566819,
3723928; 566819, 3723928; 566819,
3723928; 566671, 3723064; 566260,
3722203; 566388, 3720917; 566353,
3720941; 566309, 3720971; 566293,
3721009; 566274, 3721104; 566129,
3721224; 566033, 3721260; 565979,
3721270; 565929, 3721299; 565866,
3721304; 565805, 3721314; 565738,
3721360; 565701, 3721350; 565674,
3721325; 565625, 3721325; 565563,
3721312; 565562, 3721295; 565593,
3721249; 565653, 3721198; 565713,
3721195; 565711, 3721141; 565795,
3721105; 565837, 3721053; 565887,
3721000; 565873, 3720960; 565914,
3720923; 565964, 3720933; 566048,
3720990; 566160, 3720977; 566281,
3720895; 566354, 3720846; 566351,
3720048; 566360, 3720048; 566412,
3720050; 566456, 3720051; 566458,
3720048; 566457, 3720047; 566454,
3720018; 566442, 3720000; 566437,
3719984; 566429, 3719963; 566423,
3719950; 566417, 3719935; 566406,
3719905; 566400, 3719883; 566395,
3719847; 566399, 3719820; 566424,
3719800; 566540, 3719832; 566999,
3718635; 567828, 3717445; 567827,
3717445; 567829, 3717248; 567928,
3717248; 567929, 3717165; 567939,
3717140; 567971, 3717071; 567988,
3717040; 568014, 3717016; 568023,
3717007; 568033, 3716998; 568041,
3716990; 568074, 3716970; 568095,
3716962; 568130, 3716955; 568172,
3716953; 568253, 3716953; 568338,
3716956; 568383, 3716953; 568408,
3716950; 568432, 3716940; 568731,
3716735; 568868, 3716640; 568956,
3716595; 569647, 3716127; 569648,
3716053; 569752, 3716056; 570607,
3715478; 572371, 3713796; 572894,
3712888; 572887, 3712888; 572887,
3712879; 572896, 3712879; 572899,
3712879; 573765, 3711377; 574462,
3708958; 574216, 3707153; 574298,
3706046; 575487, 3704652; 576963,
3703504; 577258, 3703086; 577373,
3702643; 577399, 3702239; 577935,
3700356; 578628, 3698965; 578791,
3698763; 578557, 3698773; 577751,
3698805; 577343, 3698821; 577106,
3698831; 576945, 3698837; 576140,
3698869; 575492, 3698895; 575417,
3698897; 575143, 3699674; 574762,
3700457; 573744, 3701312; 573761,
3701319; 573705, 3701330; 572330,
3701986; 568229, 3704405; 565194,
3706660; 563472, 3709736; 563267,
3710843; 564169, 3711499; 564702,
3712729; 564333, 3714083; 563867,
3714714; 563618, 3714947; 563515,
3715053; 563462, 3715152; 563469,
3715251; 563434, 3715340; 563397,
3715452; 563355, 3715541; 563245,
3715540; 563208, 3715425; 563139,
3715304; 563044, 3715285; 561914,
3715805; 561616, 3715959; 561616,
3715994; 561549, 3715994; 559453,
3717076; 558346, 3717568; 557485,
3717322; 554983, 3717158; 554614,
3717404; 554573, 3718921; 554447,
3719696; 554448, 3719696; 554445,
3719707; 554327, 3720439; 554179,
3720908; 554179, 3720989; 554154,
3720988; 554068, 3721263; 554083,
3721362; 554090, 3721407; 554098,
3721458; 554128, 3721481; 554148,
3721477; 554175, 3721498; 554178,
3721519; 554219, 3721553; 554219,
3721572; 554218, 3721660; 554218,
3721768; 554218, 3721789; 554126,
3721860; 554087, 3721860; 554067,
3721861; 554067, 3721862; 554067,
3721863; 554067, 3721864; 554067,
3721866; 554067, 3721867; 554067,
3721868; 554066, 3721869; 554066,
3721870; 554066, 3721871; 554066,
3721873; 554065, 3721874; 554065,
3721875; 554064, 3721876; 554064,
3721877; 554063, 3721878; 554063,
3721879; 554062, 3721880; 554046,
3721903; 554046, 3721904; 554045,
3721905; 554044, 3721906; 554044,
3721907; 554043, 3721908; 554042,
3721909; 554041, 3721910; 554041,
3721911; 554040, 3721912; 554040,
3721913; 554039, 3721914; 554038,
3721915; 554038, 3721917; 554037,
3721918; 554037, 3721919; 554036,
3721920; 554035, 3721921; 554035,
3721922; 554034, 3721923; 554034,
3721924; 554033, 3721925; 554033,
3721926; 554032, 3721927; 554032,
3721929; 554031, 3721930; 554031,
3721931; 554031, 3721932; 554030,
3721933; 554030, 3721934; 554029,
3721935; 554029, 3721937; 554028,
3721938; 554028, 3721939; 554028,
3721940; 554027, 3721941; 554027,
3721942; 554027, 3721944; 554026,
3721945; 554026, 3721946; 554026,
3721947; 554025, 3721948; 554025,
3721949; 554025, 3721951; 554025,
3721952; 553999, 3721944; 553976,
3721944; 553975, 3722106; 553974,
3722219; 553974, 3722282; 553973,
3722374; 553883, 3722373; 553766,
3722372; 553692, 3722372; 553644,
3722371; 553488, 3722370; 553366,
3722369; 553367, 3722268; 553367,
3722255; 553367, 3722115; 553368,
3721997; 553368, 3721995; 553015,
3722079; 552072, 3722079; 551826,
3722325; 551621, 3722940; 550924,
3723924; 550473, 3725155; 550719,
3725770; 551498, 3726549; 551457,
3727574; 550596, 3728599; 549324,
3729132; 547479, 3730649; 546905,
3731511; 546126, 3733438; 545593,
3735324; 545593, 3736021; 546126,
3736842; 546659, 3736924; 547192,
3736637; 548109, 3735861; 548109,
3735861; 548109, 3735860; 548109,
3735859; 548109, 3735859; 548109,
3735858; 548109, 3735858; 548109,
3735857; 548108, 3735856; 548108,
VerDate Aug<31>2005 17:33 Oct 09, 2007 Jkt 214001 PO 00000 Frm 00035 Fmt 4701 Sfmt 4702 E:\FR\FM\10OCP2.SGM 10OCP2pwalker on PROD1PC71 with PROPOSALS2
57774 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
3735856; 548108, 3735855; 548108,
3735855; 548108, 3735854; 548108,
3735853; 548108, 3735853; 548099,
3735741; 548160, 3735740; 548150,
3735603; 548130, 3735533; 548155,
3735523; 548181, 3735513; 548190,
3735509; thence returning to 548200,
3735505.
(ii) Note: Map of Unit 2A, North Santa
Rosa Mountains (Map 3) follows:
BILLING CODE 4310–55–P
BILLING CODE 4310–55–C
VerDate Aug<31>2005 17:33 Oct 09, 2007 Jkt 214001 PO 00000 Frm 00036 Fmt 4701 Sfmt 4702 E:\FR\FM\10OCP2.SGM 10OCP2 EP10OC07.002</GPH>pwalker on PROD1PC71 with PROPOSALS2
57775 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
(8) Unit 2B: South Santa Rosa
Mountains south to Vallecito
Mountains, Riverside, San Diego, and
Imperial Counties, California.
(i) From USGS 1:24,000 quadrangles
Agua Caliente Hot Springs, Arroyo
Tapiado, Borrego Mountain, Borrego
Mountain SE, Borrego Palm Canyon,
Borrego Sink, Bucksnort Mountain,
Carrizo Mountain NE, Clark Lake, Clark
Lake NE, Collins Valley, Earthquake
Valley, Fonts Point, Harper Canyon,
Plaster City NW, Rabbit Peak, Seventeen
Palms, Tubb Canyon, and Whale Peak.
Land bounded by the following
Universal Transverse Mercator (UTM)
North American Datum of 1927
(NAD27) coordinates (E, N): 552772,
3702586; 552772, 3702567; 552801,
3702567; 552801, 3702539; 552829,
3702539; 552829, 3702511; 552914,
3702511; 552914, 3702482; 552943,
3702482; 552943, 3702454; 552971,
3702454; 552971, 3702426; 552999,
3702426; 552999, 3702397; 553113,
3702397; 553113, 3702369; 553170,
3702369; 553170, 3702340; 553198,
3702340; 553198, 3702312; 553255,
3702312; 553255, 3702284; 553311,
3702284; 553311, 3702255; 553340,
3702255; 553340, 3702284; 553368,
3702284; 553368, 3702312; 553453,
3702312; 553453, 3702284; 553538,
3702284; 553538, 3702255; 553567,
3702255; 553567, 3702227; 553624,
3702227; 553624, 3702199; 553652,
3702199; 553652, 3702227; 553709,
3702227; 553709, 3702255; 553717,
3702255; 554616, 3702119; 556163,
3701891; 557619, 3701709; 559531,
3701800; 560669, 3701800; 561670,
3701390; 562899, 3700617; 564310,
3699934; 569738, 3698190; 570758,
3697602; 570758, 3697546; 570730,
3697546; 570730, 3697433; 570702,
3697433; 570702, 3697404; 570673,
3697404; 570673, 3697262; 570702,
3697262; 570702, 3697206; 570730,
3697206; 570730, 3697177; 570787,
3697177; 570787, 3697206; 570815,
3697206; 570815, 3697234; 570900,
3697234; 570900, 3697177; 570929,
3697177; 570929, 3697149; 570957,
3697149; 570957, 3697121; 571014,
3697121; 571014, 3697092; 571042,
3697092; 571042, 3697064; 571014,
3697064; 571014, 3697036; 570985,
3697036; 570985, 3696950; 570957,
3696950; 570957, 3696894; 571212,
3696894; 571212, 3696865; 571382,
3696865; 571382, 3696752; 571411,
3696752; 571411, 3696667; 571382,
3696667; 571382, 3696553; 571411,
3696553; 571411, 3696525; 571468,
3696525; 571468, 3696497; 571496,
3696497; 571496, 3696440; 571468,
3696440; 571468, 3696326; 571439,
3696326; 571439, 3696270; 571496,
3696270; 571496, 3696241; 571524,
3696241; 571524, 3696184; 571638,
3696184; 571638, 3696156; 571666,
3696156; 571666, 3696128; 571694,
3696128; 571694, 3696071; 571723,
3696071; 571723, 3696043; 571751,
3696043; 571751, 3695901; 571723,
3695901; 571723, 3695759; 571751,
3695759; 571751, 3695731; 571780,
3695731; 571780, 3695702; 571808,
3695702; 571808, 3695645; 571836,
3695645; 571836, 3695589; 571808,
3695589; 571808, 3695532; 571780,
3695532; 571780, 3695475; 571751,
3695475; 571751, 3695447; 571723,
3695447; 571723, 3695390; 571751,
3695390; 571751, 3695362; 571723,
3695362; 571723, 3695333; 571694,
3695333; 571694, 3695192; 571723,
3695192; 571723, 3695163; 571751,
3695163; 571751, 3695192; 571836,
3695192; 571836, 3695163; 571865,
3695163; 571865, 3695078; 571978,
3695078; 571978, 3695050; 572007,
3695050; 572007, 3694993; 571978,
3694993; 571978, 3694965; 571950,
3694965; 571950, 3694879; 571978,
3694879; 571978, 3694851; 572007,
3694851; 572007, 3694823; 572063,
3694823; 572063, 3694738; 572035,
3694738; 572035, 3694709; 572007,
3694709; 572007, 3694624; 571978,
3694624; 571978, 3694596; 571921,
3694596; 571921, 3694511; 571950,
3694511; 571950, 3694369; 572092,
3694369; 572092, 3694340; 572177,
3694340; 572177, 3694312; 572205,
3694312; 572205, 3694085; 572177,
3694085; 572177, 3693830; 572319,
3693830; 572319, 3693660; 572290,
3693660; 572290, 3693546; 572319,
3693546; 572319, 3693518; 572347,
3693518; 572347, 3693489; 572404,
3693489; 572404, 3693461; 572432,
3693461; 572432, 3693489; 572460,
3693489; 572460, 3693518; 572489,
3693518; 572489, 3693546; 572517,
3693546; 572517, 3693574; 572546,
3693574; 572546, 3693603; 572602,
3693603; 572602, 3693660; 572631,
3693660; 572631, 3693688; 572687,
3693688; 572687, 3693716; 572744,
3693716; 572744, 3693773; 572801,
3693773; 572801, 3693745; 572829,
3693745; 572829, 3693716; 572858,
3693716; 572858, 3693603; 572886,
3693603; 572886, 3693575; 572914,
3693575; 572914, 3693518; 572971,
3693518; 572971, 3693489; 572999,
3693489; 572999, 3693404; 573028,
3693404; 573028, 3693149; 573056,
3693149; 573056, 3693121; 573085,
3693121; 573085, 3693007; 573113,
3693007; 573113, 3692979; 573141,
3692979; 573141, 3692950; 573170,
3692950; 573170, 3692979; 573198,
3692979; 573198, 3692950; 573312,
3692950; 573312, 3692894; 573340,
3692894; 573340, 3692837; 573368,
3692837; 573368, 3692809; 573425,
3692809; 573425, 3692752; 573453,
3692752; 573453, 3692723; 573482,
3692723; 573482, 3692667; 573510,
3692667; 573510, 3692638; 573538,
3692638; 573538, 3692610; 573567,
3692610; 573567, 3692582; 573595,
3692582; 573595, 3692525; 573624,
3692525; 573624, 3692411; 573652,
3692411; 573652, 3692355; 573680,
3692355; 573680, 3692326; 573709,
3692326; 573709, 3692270; 573737,
3692270; 573737, 3692241; 573765,
3692241; 573765, 3692184; 573794,
3692184; 573794, 3692128; 573822,
3692128; 573822, 3692071; 573879,
3692071; 573879, 3692099; 573907,
3692099; 573907, 3692326; 573879,
3692326; 573879, 3692468; 573851,
3692468; 573851, 3692610; 573822,
3692610; 573822, 3692752; 573851,
3692752; 573851, 3692780; 573822,
3692780; 573822, 3692979; 573851,
3692979; 574588, 3693121; 574588,
3693064; 574560, 3693061; 574560,
3693035; 574531, 3693035; 574531,
3693007; 574503, 3693007; 574503,
3692979; 574475, 3692979; 574475,
3692865; 574560, 3692865; 574560,
3692837; 574645, 3692837; 574645,
3692780; 574730, 3692780; 574730,
3692752; 574758, 3692752; 574758,
3692695; 574730, 3692695; 574730,
3692638; 574702, 3692638; 574702,
3692582; 574730, 3692582; 574730,
3692610; 574815, 3692610; 574815,
3692553; 574843, 3692553; 574843,
3692525; 574872, 3692525; 574872,
3692411; 574900, 3692411; 574900,
3692383; 574985, 3692383; 574985,
3692496; 575014, 3692496; 575014,
3692610; 575042, 3692610; 575042,
3692667; 575127, 3692667; 575127,
3692638; 575156, 3692638; 575156,
3692610; 575184, 3692610; 575184,
3692582; 575212, 3692582; 575212,
3692553; 575326, 3692553; 575326,
3692582; 575354, 3692582; 575354,
3692610; 575382, 3692610; 575382,
3692582; 575411, 3692582; 575411,
3692525; 575439, 3692525; 575439,
3692468; 575411, 3692468; 575411,
3692355; 575439, 3692355; 575439,
3692326; 575468, 3692326; 575468,
3692298; 575553, 3692298; 575553,
3692270; 575581, 3692270; 575581,
3692213; 575553, 3692213; 575553,
3692184; 575581, 3692184; 575581,
3692128; 575609, 3692128; 575609,
3692099; 575638, 3692099; 575638,
3692071; 575609, 3692071; 575609,
3692014; 575581, 3692014; 575581,
3691957; 575553, 3691957; 575553,
3691901; 575524, 3691901; 575524,
3691787; 575581, 3691787; 575581,
3691645; 575609, 3691645; 575609,
3691589; 575666, 3691589; 575666,
VerDate Aug<31>2005 17:33 Oct 09, 2007 Jkt 214001 PO 00000 Frm 00037 Fmt 4701 Sfmt 4702 E:\FR\FM\10OCP2.SGM 10OCP2pwalker on PROD1PC71 with PROPOSALS2
57776 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
3691560; 575695, 3691560; 575695,
3691504; 575723, 3691504; 575723,
3691475; 575751, 3691475; 575751,
3691447; 575780, 3691447; 575780,
3691390; 575808, 3691390; 575808,
3691362; 575836, 3691362; 575836,
3691277; 575893, 3691277; 575893,
3691305; 575921, 3691305; 575921,
3691333; 575950, 3691333; 575978,
3691333; 575978, 3691447; 575950,
3691447; 575950, 3691532; 576007,
3691532; 576007, 3691504; 576120,
3691504; 576120, 3691475; 576148,
3691475; 576148, 3691447; 576177,
3691447; 576177, 3691248; 576205,
3691248; 576205, 3691220; 576262,
3691220; 576262, 3691248; 576319,
3691248; 576319, 3691532; 576347,
3691532; 576347, 3691617; 576375,
3691617; 576375, 3691674; 576347,
3691674; 576347, 3691759; 576404,
3691759; 576404, 3691816; 576489,
3691816; 576489, 3691759; 576517,
3691759; 576517, 3691731; 576546,
3691731; 576546, 3691702; 576574,
3691702; 576574, 3691504; 576744,
3691504; 576744, 3691447; 576716,
3691447; 576716, 3691333; 576687,
3691333; 576687, 3691305; 576659,
3691305; 576659, 3691248; 576631,
3691248; 576631, 3691163; 576687,
3691163; 576687, 3691135; 576744,
3691135; 576744, 3691021; 576716,
3691021; 576716, 3690879; 576744,
3690879; 576744, 3690851; 576801,
3690851; 576801, 3690879; 576886,
3690879; 576886, 3690851; 576943,
3690851; 576943, 3690879; 576971,
3690879; 576971, 3690908; 576943,
3690908; 576943, 3690965; 576971,
3690965; 576971, 3691050; 576999,
3691050; 576999, 3691106; 577028,
3691106; 577028, 3691191; 577056,
3691191; 577056, 3691220; 577085,
3691220; 577085, 3691248; 577170,
3691248; 577170, 3691220; 577198,
3691220; 577198, 3691191; 577226,
3691191; 577226, 3691163; 577255,
3691163; 577255, 3691135; 577283,
3691135; 577283, 3691163; 577312,
3691163; 577312, 3691191; 577340,
3691191; 577340, 3691277; 577397,
3691277; 577397, 3691248; 577453,
3691248; 577453, 3691220; 577510,
3691220; 577510, 3691248; 577567,
3691248; 577567, 3691277; 577624,
3691277; 577624, 3691248; 577652,
3691248; 577652, 3691220; 577680,
3691220; 577680, 3691191; 577737,
3691191; 577737, 3691277; 577765,
3691277; 577765, 3691305; 577794,
3691305; 577794, 3691362; 577822,
3691362; 577822, 3691390; 577851,
3691390; 577851, 3691418; 577936,
3691418; 577936, 3691447; 578021,
3691447; 578021, 3691475; 578049,
3691475; 578049, 3691560; 578021,
3691560; 578021, 3691617; 577992,
3691617; 577992, 3691731; 577964,
3691731; 577964, 3691759; 577942,
3691813; 577944, 3691860; 577997,
3691933; 578006, 3692036; 578030,
3692165; 578021, 3692284; 577993,
3692375; 577954, 3692414; 577905,
3692446; 577824, 3692457; 577748,
3692443; 577660, 3692384; 577557,
3692341; 577449, 3692316; 577381,
3692264; 577315, 3692216; 577182,
3692146; 577141, 3692070; 577077,
3692027; 577006, 3692042; 576933,
3691993; 576879, 3691970; 576836,
3691965; 576798, 3691978; 576773,
3692043; 576744, 3692043; 576744,
3692383; 576659, 3692383; 576659,
3692411; 576574, 3692411; 576574,
3692440; 576460, 3692440; 576460,
3692468; 576404, 3692468; 576404,
3692496; 576290, 3692496; 576290,
3692525; 576234, 3692525; 576234,
3692582; 576177, 3692582; 576177,
3692610; 576148, 3692610; 576148,
3692638; 576092, 3692638; 576092,
3692723; 576063, 3692723; 576063,
3692809; 576092, 3692809; 576092,
3692837; 576063, 3692837; 576063,
3692979; 576035, 3692979; 576035,
3693036; 576007, 3693036; 576007,
3693121; 575978, 3693121; 575978,
3693149; 575950, 3693149; 575950,
3693177; 575921, 3693177; 575921,
3693149; 575836, 3693149; 575836,
3693177; 575723, 3693177; 575723,
3693262; 575751, 3693262; 575751,
3693348; 575780, 3693348; 575780,
3693376; 575808, 3693376; 575808,
3693404; 575780, 3693404; 575780,
3693433; 575638, 3693433; 575638,
3693404; 575524, 3693404; 575524,
3693433; 575439, 3693433; 575439,
3693404; 575382, 3693404; 575382,
3693433; 575241, 3693433; 575241,
3693489; 575212, 3693489; 575212,
3693518; 575127, 3693518; 575127,
3693489; 575099, 3693489; 575099,
3693433; 575070, 3693433; 575070,
3693461; 575014, 3693461; 575014,
3693546; 574985, 3693546; 574985,
3693575; 575014, 3693575; 575014,
3693603; 574985, 3693603; 574985,
3693631; 574957, 3693631; 574957,
3693603; 574929, 3693603; 574882,
3693602; 574694, 3694053; 574529,
3694524; 574506, 3694971; 574529,
3695794; 574647, 3696406; 574906,
3696664; 575258, 3696758; 575280,
3696752; 575274, 3696773; 575645,
3697220; 575513, 3698626; 575417,
3698897; 575492, 3698895; 576140,
3698869; 576945, 3698837; 577106,
3698831; 577343, 3698821; 577751,
3698805; 578557, 3698773; 578791,
3698763; 579475, 3697914; 580051,
3696677; 579551, 3693708; 582948,
3690942; 583903, 3689828; 584752,
3688448; 585283, 3687440; 585601,
3686060; 585176, 3685052; 584327,
3684415; 583001, 3683885; 581412,
3683518; 578544, 3683407; 573769,
3685728; 571103, 3688624; 569357,
3691796; 568621, 3693129; 566231,
3694186; 563703, 3695151; 561175,
3695013; 558785, 3695335; 558279,
3694324; 558279, 3693450; 559382,
3692439; 560945, 3692347; 563703,
3692072; 564438, 3691198; 565312,
3687981; 565266, 3686326; 564209,
3684533; 563611, 3684809; 558831,
3689222; 557452, 3689314; 556533,
3689176; 556165, 3688256; 554924,
3681592; 554740, 3679385; 555843,
3676536; 556900, 3673686; 559934,
3670560; 564071, 3668400; 571333,
3665412; 576113, 3663390; 580066,
3661735; 582640, 3660448; 583515,
3655760; 585457, 3653852; 588867,
3652806; 590732, 3652397; 592550,
3651942; 594597, 3650441; 595642,
3648486; 595506, 3647213; 594960,
3645894; 593824, 3644985; 591505,
3645076; 589095, 3645485; 587412,
3646167; 583884, 3649167; 581648,
3650315; 578804, 3650497; 574811,
3651340; 572685, 3651727; 570688,
3651276; 569658, 3650825; 568964,
3650527; 568047, 3650310; 567279,
3650197; 566460, 3650255; 565466,
3650948; 564605, 3651791; 564019,
3652596; 563917, 3652839; 563977,
3653013; 564098, 3653155; 564244,
3653230; 564404, 3653262; 564518,
3653262; 564546, 3653262; 564546,
3653205; 564575, 3653205; 564575,
3653177; 564631, 3653177; 564631,
3653205; 564688, 3653205; 564688,
3653233; 564716, 3653233; 564716,
3653262; 564773, 3653262; 564773,
3653290; 564830, 3653290; 564830,
3653319; 564858, 3653319; 564858,
3653347; 564915, 3653347; 564915,
3653319; 565057, 3653319; 565057,
3653347; 565142, 3653347; 565142,
3653319; 565227, 3653319; 565227,
3653290; 565539, 3653290; 565539,
3653262; 565567, 3653262; 565567,
3653233; 565596, 3653233; 565596,
3653205; 565624, 3653205; 565624,
3653148; 565596, 3653148; 565596,
3653092; 565709, 3653092; 565709,
3653063; 565738, 3653063; 565738,
3653035; 565794, 3653035; 565794,
3653006; 565823, 3653006; 565823,
3652978; 565851, 3652978; 565851,
3652950; 565936, 3652950; 565936,
3652978; 565965, 3652978; 565965,
3653006; 565993, 3653006; 565993,
3653035; 566021, 3653035; 566021,
3653063; 566078, 3653063; 566078,
3653148; 566050, 3653148; 566050,
3653177; 566021, 3653177; 566021,
3653205; 566135, 3653205; 566135,
3653177; 566163, 3653177; 566163,
3653205; 566192, 3653205; 566192,
3653262; 566220, 3653262; 566220,
3653290; 566277, 3653290; 566277,
VerDate Aug<31>2005 17:33 Oct 09, 2007 Jkt 214001 PO 00000 Frm 00038 Fmt 4701 Sfmt 4702 E:\FR\FM\10OCP2.SGM 10OCP2pwalker on PROD1PC71 with PROPOSALS2
57777 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
3653319; 566305, 3653319; 566305,
3653375; 566277, 3653375; 566277,
3653404; 566248, 3653404; 566248,
3653432; 566277, 3653432; 566277,
3653517; 566248, 3653517; 566248,
3653574; 566305, 3653574; 566305,
3653631; 566277, 3653631; 566277,
3653659; 566248, 3653659; 566248,
3653687; 566192, 3653687; 566192,
3653659; 566135, 3653659; 566135,
3653744; 566163, 3653744; 566163,
3653801; 566192, 3653801; 566192,
3653829; 566248, 3653829; 566248,
3653801; 566277, 3653801; 566277,
3653772; 566333, 3653772; 566333,
3653744; 566390, 3653744; 566390,
3653716; 566560, 3653716; 566560,
3653687; 566589, 3653687; 566589,
3653659; 566645, 3653659; 566645,
3653631; 566674, 3653631; 566674,
3653602; 566702, 3653602; 566702,
3653574; 566731, 3653574; 566731,
3653545; 566759, 3653545; 566759,
3653517; 566844, 3653517; 566844,
3653489; 566816, 3653489; 566816,
3653460; 566787, 3653460; 566787,
3653432; 566759, 3653432; 566759,
3653404; 566731, 3653404; 566731,
3653347; 566702, 3653347; 566702,
3653319; 566674, 3653319; 566674,
3653262; 566645, 3653262; 566645,
3653233; 566589, 3653233; 566589,
3653205; 566560, 3653205; 566560,
3653233; 566532, 3653233; 566532,
3653177; 566504, 3653177; 566504,
3653148; 566532, 3653148; 566532,
3653092; 566560, 3653092; 566560,
3653063; 566589, 3653063; 566589,
3653035; 566674, 3653035; 566674,
3653063; 566731, 3653063; 566731,
3653092; 566759, 3653092; 566759,
3653120; 566787, 3653120; 566787,
3653148; 566872, 3653148; 566872,
3653177; 566957, 3653177; 566957,
3653205; 566986, 3653205; 566986,
3653233; 567014, 3653233; 567014,
3653290; 566986, 3653290; 566986,
3653319; 566957, 3653319; 566957,
3653347; 566901, 3653347; 566901,
3653375; 566872, 3653375; 566872,
3653432; 566901, 3653432; 566901,
3653489; 566957, 3653489; 566957,
3653517; 567071, 3653517; 567071,
3653489; 567241, 3653489; 567241,
3653517; 567355, 3653517; 567355,
3653545; 567440, 3653545; 567440,
3653517; 567468, 3653517; 567468,
3653489; 567496, 3653489; 567496,
3653432; 567553, 3653432; 567553,
3653460; 567582, 3653460; 567582,
3653489; 567638, 3653489; 567638,
3653517; 567667, 3653517; 567667,
3653489; 567780, 3653489; 567780,
3653545; 567752, 3653545; 567752,
3653602; 567723, 3653602; 567723,
3653631; 567695, 3653631; 567695,
3653659; 567667, 3653659; 567667,
3653687; 567638, 3653687; 567638,
3653829; 567610, 3653829; 567610,
3653943; 567468, 3653943; 567468,
3653914; 567411, 3653914; 567411,
3653886; 567355, 3653886; 567355,
3653858; 567298, 3653858; 567298,
3653829; 567270, 3653829; 567270,
3653858; 567184, 3653858; 567184,
3653886; 567156, 3653886; 567156,
3653914; 567099, 3653914; 567099,
3653943; 567071, 3653943; 567071,
3653971; 567099, 3653971; 567099,
3654028; 567128, 3654028; 567128,
3654056; 567156, 3654056; 567156,
3654084; 567241, 3654084; 567241,
3654113; 567298, 3654113; 567298,
3654141; 567355, 3654141; 567355,
3654340; 567383, 3654340; 567383,
3654397; 567298, 3654397; 567298,
3654425; 567270, 3654425; 567270,
3654510; 567326, 3654510; 567326,
3654595; 567270, 3654595; 567270,
3654624; 567156, 3654624; 567156,
3654652; 567128, 3654652; 567128,
3654680; 567071, 3654680; 567071,
3654709; 567014, 3654709; 566216,
3654880; 565299, 3655720; 564154,
3656560; 563753, 3657028; 562755,
3657358; 562092, 3657629; 561252,
3657782; 560641, 3658164; 558413,
3659512; 557263, 3660178; 557445,
3662054; 557021, 3663264; 556335,
3663929; 556009, 3665045; 555823,
3665882; 555172, 3666626; 554521,
3667556; 554196, 3668486; 554010,
3669462; 554242, 3670113; 554661,
3670585; 554903, 3671311; 552665,
3672703; 552483, 3673973; 551273,
3676030; 550747, 3676670; 550555,
3677054; 550555, 3677601; 550849,
3678390; 551092, 3679540; 550870,
3680865; 550929, 3680865; 550929,
3680893; 550957, 3680893; 550957,
3680922; 550985, 3680922; 550985,
3680950; 551127, 3680950; 551127,
3680922; 551156, 3680922; 551156,
3680950; 551354, 3680950; 551354,
3680978; 551383, 3680978; 551383,
3681035; 551411, 3681035; 551411,
3681092; 551383, 3681092; 551383,
3681120; 551354, 3681120; 551354,
3681149; 551326, 3681149; 551326,
3681205; 551298, 3681205; 551298,
3681262; 551269, 3681262; 551269,
3681319; 551298, 3681319; 551298,
3681461; 551326, 3681461; 551326,
3681574; 551298, 3681574; 551298,
3681603; 551127, 3681603; 551127,
3681631; 551099, 3681631; 551099,
3681659; 551071, 3681659; 551071,
3681688; 551042, 3681688; 551042,
3681716; 550985, 3681716; 550985,
3681688; 550957, 3681688; 550957,
3681631; 550929, 3681631; 550929,
3681603; 550872, 3681603; 550872,
3681574; 550844, 3681574; 550844,
3681546; 550702, 3681546; 550702,
3681517; 550617, 3681517; 550617,
3681546; 550416, 3681546; 550333,
3681652; 550333, 3681659; 550327,
3681659; 550305, 3681688; 550305,
3681716; 550283, 3681716; 550276,
3681724; 550276, 3681744; 550261,
3681744; 549760, 3682384; 549700,
3683291; 550486, 3684441; 551515,
3685469; 550849, 3686679; 549518,
3689342; 548671, 3690854; 546070,
3695090; 544980, 3695937; 544617,
3696905; 545888, 3697631; 546191,
3698478; 545222, 3699809; 545172,
3700536; 544779, 3700891; 543838,
3701122; 543700, 3701200; 543600,
3701200; 543600, 3701500; 543769,
3701639; 544355, 3701901; 544740,
3702171; 545195, 3702271; 547397,
3702286; 547571, 3702255; 547729,
3702212; 547826, 3702175; 547943,
3702114; 548059, 3702055; 548190,
3701939; 548253, 3701863; 548253,
3701768; 548209, 3701711; 548133,
3701673; 547949, 3701603; 547891,
3701565; 547891, 3701476; 548006,
3701380; 548076, 3701279; 548203,
3701234; 548317, 3701247; 548431,
3701272; 548602, 3701347; 548744,
3701347; 548744, 3701376; 548772,
3701376; 548772, 3701461; 548801,
3701461; 548801, 3701489; 548886,
3701489; 549375, 3701732; 549903,
3701990; 550456, 3702236; 551046,
3702494; 551673, 3702715; 552177,
3702794; 552296, 3702778; 552431,
3702734; 552589, 3702681; 552696,
3702627; thence returning to 552772,
3702586.
(ii) Note: Map of Unit 2B, South Santa
Rosa Mountains south to Vallecito
Mountains (Map 4) follows:
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57778 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
BILLING CODE 4310–55–C
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57779 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
(9) Unit 3: Carrizo Canyon, San Diego
and Imperial Counties, California.
(i) From USGS 1:24,000 quadrangles
Agua Caliente Hot Springs, Arroyo
Tapiado, Carrizo Mountain, In-Ko-Pah
Gorge, Jacumba, Painted Gorge,
Sombrero Peak, and Sweeney Pass.
Land bounded by the following
Universal Transverse Mercator (UTM)
North American Datum of 1927
(NAD27) coordinates (E, N): 574159,
3634261; 574922, 3634108; 575915,
3634261; 577290, 3634566; 578359,
3634566; 579199, 3634261; 580039,
3633879; 581032, 3633421; 582406,
3633192; 583705, 3632810; 584697,
3632810; 586225, 3633039; 587370,
3633497; 588134, 3633726; 588821,
3633879; 589738, 3634795; 589508,
3635253; 589738, 3635635; 590119,
3635941; 590959, 3635941; 591952,
3635559; 592792, 3635406; 593632,
3634871; 594320, 3634031; 595083,
3632810; 595771, 3631511; 596000,
3630519; 595923, 3629679; 595312,
3628915; 594702, 3628304; 594167,
3628075; 592411, 3627998; 591189,
3627998; 590425, 3627998; 589280,
3628228; 588058, 3628915; 587141,
3629144; 586301, 3629449; 585003,
3629984; 583857, 3630595; 583170,
3630748; 582330, 3630671; 581566,
3630824; 580650, 3630824; 579581,
3630671; 578664, 3629679; 578283,
3628915; 578283, 3628151; 578206,
3626700; 578130, 3625784; 577595,
3625631; 577290, 3625326; 577214,
3624791; 577290, 3623951; 577825,
3623187; 578512, 3622653; 579275,
3621736; 580039, 3621126; 583136,
3619091; 585446, 3617261; 585698,
3616826; 585744, 3615522; 585561,
3614538; 584920, 3613898; 584193,
3613692; 583552, 3613600; 583021,
3614241; 582399, 3615485; 581960,
3616712; 580596, 3618451; 580070,
3618565; 579046, 3618300; 578054,
3617918; 578061, 3617609; 577347,
3616950; 576981, 3616492; 576221,
3616085; 575763, 3615856; 574923,
3615933; 574159, 3616238; 573548,
3616620; 573013, 3616849; 572326,
3617154; 571562, 3617765; 570875,
3618453; 570799, 3618987; 570417,
3619751; 570493, 3620515; 570722,
3621813; 570722, 3622500; 570722,
3623493; 570646, 3624333; 570417,
3625097; 570417, 3625937; 570188,
3626700; 570417, 3627846; 572249,
3630519; 572555, 3631664; 572478,
3632657; 572020, 3633955; 571486,
3634872; 570951, 3635864; 570187,
3637239; 569729, 3637774; 569042,
3638156; 568125, 3638308; 567209,
3638614; 566674, 3638996; 566522,
3639606; 566216, 3640294; 565911,
3641134; 565681, 3641668; 565376,
3642050; 564841, 3642508; 564460,
3642890; 564536, 3643425; 565147,
3644265; 565452, 3645029; 567132,
3644799; 568278, 3644189; 569271,
3643501; 569958, 3642508; 570111,
3641897; 570874, 3641668; 571715,
3640676; 572249, 3639072; 572937,
3638232; 573318, 3637086; 573318,
3635635; 573548, 3634643; thence
returning to 574159, 3634261.
(ii) Note: Map of Unit 3, Carrizo
Canyon (Map 5) follows:
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57780 Federal Register /Vol. 72, No. 195/Wednesday, October 10, 2007/Proposed Rules
* * * * *
Dated: September 28, 2007.
Todd Willens,
Acting Assistant Secretary for Fish and
Wildlife and Parks.
[FR Doc. 07–4959 Filed 10–9–07; 8:45 am]
BILLING CODE 4310–55–C
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Exhibit 2
Diagram of bighorn sheep (Ovis canadensis)contributed by Ken Carison for listing of endangered status
of Peninsularbighorn sheep.Copyright granted by Mr.Carison.
Recovery Plan
for
Bighorn Sheep in the Peninsular Ranges,
California
U.S.Fish and Wildlife Service
Region 1
Manager,C ia/Nevada Operations Office
Region ,U.S.Fish and Wildlife Service
Approved:
Date:
The Recovery Plan for Bighorn Sheep in the Peninsular Ranges,California,was
developed in cooperation with:
Bureau of Land Management
U.S.Forest Service
Agua Caliente Band of Cahuilla Indians
California Department of Fish and Game
CaliforniaDepartment of Parks and Recreation
Date:~
Date:IQ41.7./L2Q.
Tnbal Chairman, Agua Caliente Band of Cahuilla Indians
Date:/Pz—00Ii._Director. Ca fornia Department Fish and Game
Date:__________
Director, California Dep yent of Parks and Recrcation
PrimaryAuthor
The primary author of this recoveryplan is:
Esther Rubin
University of California, Davis
Davis,California
The plan was written with the assistance of the Peninsular Bighom Sheep
Recovery Team (see Acknowledgments).
i
Disclaimer
Recovery plans delineate reasonable actions required to recover andlorprotect
listed species.We,the Fish and Wildlife Service,publish recovery plans,
sometimes preparing them with the assistance of recovery teams,contractors,
State and other Federal agencies,Tribes,and otheraffected and interested parties.
Recoveryteams serve as independent advisors to the Fish and Wildlife Service.
Objectives of the plan will be attained and any necessaryfunds made available,
subject to budgetary and other constraints affecting theparties involved.
Recoveryplans do not obligate cooperating or otherparties to undertake specific
tasks and maynot represent the views nor the official positions or approval of any
individuals or agencies involved in the plan formulation,other than our own.
Theyrepresent ourofficial position only after theyhave been signed by the
Director,Regional Director,or Operations Manageras approved.Approved
recovery plans are subject to modification asdictated by new findings,changes in
species status,and the completion of recovery tasks.
Literature citation should read as follows:
U.S.Fish and Wildlife Service.2000.Recovery plan forbighorn sheep in the
Peninsular Ranges,California.U.S.Fish and Wildlife Service, Portland,
OR.xv+251 pp.
Additional copiesmay be purchased from:
Fish and Wildlife Reference Service
5430 Grosvenor Lane,Suite 110
Bethesda, Maryland 208 14-2158
(301)492-6403 or 1-800-582-3421
FAX:301-564-4059
E-mail:fwrs~mail.fws.gov
http://fa.r9.fws.gov/r9fwrsi
The fee for the plan varies depending on the number of pages of the plan.
ii
Acknowledgments
This recoveryplan wasprimarily prepared by Esther Rubin,with important
contributions from Dr.Vein Bleich,Dr.Walter Boyce,Jim DeForge, Dr. Ben
Gonzales,Mark Jorgensen, Stacey Osterrnann,Pete Sorensen, Steve Torres, and
Dr.John Wehausen. The planbenefitted greatly from numerous discussions with
Don Armentrout, Kevin Brennan,Ken Corey,Tom Davis, Diane Freeman, Paul
Jorgensen,Jeff Manning, Lilia Martinez,Scott McCarthy,Nancy Nicoli,Dr.
Jenny Rechel,Dr.Oliver Ryder, and Gavin Wright.The plan was revised and
approved by the Recovery Team and cooperating agencies.Special thanks is
extended to Randy Botta for providing telemetry data,and Jim Scrivner, Victoria
Smith,Tom Zmudka, and L.Louise Jee for theirGeographical Information
System support.
An administrative draft of the recoveryplan wassubmitted for technical review,
comments were received from Dr.Phil Hedrick,Dr. Dale Toweill,Dr.David
Jessup,Dr.Paul Krausman,and Dr.Rob Roy Ramey II.These reviewers also
were provided copies of the public review draft for comment.Two of the these
technical reviewers also submitted comments on the public review draft.
Technical comments deemed not appropriate to incorporate into the public
review draft and final recoveryplans are addressed as substantive issues in
Appendix G.The Fish and Wildlife Service and Recovery Team appreciate the
thoughtful review and comments by these colleagues.Preparation of the final
recoveryplanby the Recovery Team,and incorporation of comments from
technical reviewers in the public review and final recovery plans, was conducted
in conformance with thepeer reviewprocess under applicable Fish and Wildlife
Service policy.
iii
Mission of the U.S. Fish and Wildlife Service in Recovery Planning
Section 4(f)of the Endangered Species Act of 1973,as amended (the Act),directs
the Secretary of the Interior to develop and implement recovery plans for species
of animals and plants listed as endangered and threatened unless such recovery
plans will not promote the conservation of the species. The Fish and Wildlife
Servicehas been delegated the responsibility of administering the Act.Recovery
is theprocess by which the decline of endangered or threatened species is arrested
or reversed,and threats to survival are neutralized,ensuring long-term survival in
nature.The goal ofrecovery is the maintenance of secure,self-sustaining wild
populations of species with the minimum necessaryinvestment of resources.A
recoveryplan delineates,justifies,and schedulesthe management and research
actions necessary to support recovery of listed species.Recovery plans do not,of
themselves, commit staffing or funds,but are used in setting regional and national
funding priorities and providing direction to local,regional,and State planning
efforts.Means withinthe Act to achieve recovery goals include the responsibility
of all Federal agencies to seek to conserve listed species;and the Secretary’s
ability to designate critical habitat,to enter into cooperative agreements with
States,to provide financial assistance to therespective State agencies,to acquire
land,and to develop habitat conservation plans with non-Federal applicants.
Peninsular Bighorn Sheep Recovery Team
Don Armentrout, Bureau of Land Management, Susanville,California
Dr. Vein Bleich,California Department of Fish and Game,Bishop,California
Dr. Walter Boyce,University of California,Davis, California
Tom Davis, Agua Caliente Band of Cahuilla Indians,Palm Springs,California
James DeForge, Bighorn Institute,Palm Desert,California
Diane Freeman,U.S.Forest Service,Idyllwild,California
Mark Jorgensen, California State Parks,ColoradoDesert District, Borrego
Springs, California
Stacey Ostermann, Bighorn Institute,Palm Desert,California
Esther Rubin,University of California,Davis,California
Dr.Oliver A.Ryder,Zoological Society of San Diego,San Diego,California
Pete Sorensen,U.S.Fish and Wildlife Service,Carlsbad,California
Steve Torres,California Department of Fish and Game,Sacramento,California
Dr.John Wehausen, University of California,White Mountain Research Station,
Bishop,California
v
EXECUTIVE SUMMARY
Current Species Status:The population of bighorn sheep in the United States~
Peninsular Ranges was listed as an endangered species on March 18,1998.The
current population is approximately 334 animals,distributed in 8 known ewe
groups (subpopulations)in Riverside, Imperial,and San Diego Counties from the
San Jacinto Mountains south to the Mexican border.
Habitat Requirements and Limiting Factors:The Peninsular bighorn sheep is
restrictedto the east facing,lower elevation slopes [typicallybelow 1,400 meters
(4,600 feet)]of thePeninsular Ranges alongthe northwestern edge of theSonoran
Desert.Bighorn sheep are wide-ranging animals that require a variety of habitat
characteristics related to topography, visibility,water availability,and forage
quality and quantity.Steep topography is required for lambing and rearing habitat
and for escaping from predators.Openterrain with good visibility is critical
because bighorn primarily rely on their sense of sight to detect predators.In their
hot,aridhabitat, water availability in some form is critical,especially during the
summer.Awide range of forage resources and vegetation associations is needed
to meet annual and drought related variations in forage quality and availability.
Limiting factors apparently vary with each ewe group and are not well understood
in all cases.The range of factors appear to include predation,urban related
sources of mortality,low rates of lamb recruitment,disease, habitat loss,and
human related disturbance.
Recovery Objective:The objective of this recoveryplan is to secure and manage
habitat in order to alleviate threats so that population levels will increase to the
pointthat this speciesmaybe reclassified to threatened status,and ultimately
delisted.
Recovery Priority:3C,per criteriapublished by Federal Register Notice (48 FR
43098;September21,1983).
Downlisting Criteria:Peninsular bighom sheep may be considered for
downlisting to threatened status as an interim management goal,when all of the
following objective, measurable criteria are met:
vi
Downlisting Criterion 1:As determined by a scientifically credible monitoring
plan, at least 25 ewes must be present in each of the following 9 regions of the
Peninsular Ranges during each of 6 consecutive years (equivalent to
approximately 1 bighorn sheep generation),without continued population
augmentation:
1)San Jacinto Mountains
2) Santa Rosa Mountains--North of Highway 74
3) Santa Rosa Mountains--South of Highway 74 through Martinez
Canyon
4) Santa Rosa Mountains--South of Martinez Canyon
5)Coyote Canyon
6)North San Ysidro Mountains (Henderson Canyon to County Road S-22)
7)South San Ysidro Mountains (County Road S-22 to State Highway 78)
8)Vallecito Mountains
9) Carrizo Canyon/Tierra Blanca Mountains/Coyote Mountains Area
Down/isting Criterion 2:Regulatory mechanisms and land management
commitments have been established that provide for long-term protection of
Peninsular bighorn sheep and all essential habitat as described in section II.D.1 of
this recovery plan. Given the major threat of fragmentation to species with
metapopulation structures, connectivity among all portions of habitat must be
established and assured through land management commitments, such that
bighorn sheep are able to move freelythroughout all habitat. In preparation for
delisting,protection by means otherthan the Endangered Species Act must be
assured.Such protection should include alternative mechanisms for regulation by
Federal,State,and local governments,and land management commitments that
would provide the protection needed for continued population stability.
Delisting Criteria:Peninsularbighorn sheep may be considered recovered to a
status no longer requiring protection under the Endangered Species Act and
thereafter removed from theList of Endangered and Threatened Wildlife (50 CFR
Part 17)when all of the following criteria are met:
Delisting Criterion 1:As determined by a scientificallycredible monitoring plan,
at least 25 ewes must be present in each of the 9 regions of the Peninsular Ranges
vii
listed under Downlisting Criterion #1 above,during each of 12 consecutive years
(approximately 2 bighorn sheep generations) including the 6 years under
Downlisting Criterion #1,without continued population augmentation.
Delisting Criterion 2:The range-wide population must average 750 individuals
(adults and yearlings)with an overall stable or increasing population trendover
the sameperiod of 12 consecutive years (approximately 2 generations)as in
delisting criterion 1.
Delisting Criterion 3:Regulatory mechanisms and land management
commitments havebeen established that provide for long-term protection of
Peninsularbighorn sheep and all essential habitat as described in section lID.I of
this recoveryplan.Furthermore,connectivity among all portions of habitat must
be established,and assuredthrough landmanagement commitments,such that
bighorn sheep are able to move freelythroughout the Peninsular Ranges.
Delisting would result in loss of protection under the Endangered Species Act;
therefore continued protection by othermeans must be assured.This protection
should include alternative regulatory mechanisms,land management
commitments,or conservation programs that would providethe long-term
protection needed for continued population viability.
Actions Needed:In the short-term,improving adult survivorship appears to hold
themost benefit to population increase.Over the long-term,the primary actions
needed to attain recovery involve conservation of the habitat base upon which
Peninsular bighorn sheep depend,and effective management of bighorn sheep and
conserved lands.Prevention of further fragmentation,primarily by minimizing
adverse effects of human disturbance,will be critical to thepersistence of ewe
groups borderingthe Coachella Valley.Adequate space along the urban interface
to absorb anthropogenic effects,and prudent management of human activities
within ewe group home ranges,will also be necessary.
Recovery Costs:Total cost of recovery tasks in the Implementation Schedule is
estimated at $73,253,000.In addition,costs of certain specific recovery tasks will
be determined as information is obtained and/or final actions are undertaken.
These items are designated as “to be determined”in the Implementation Schedule.
viii
Date of Recovery:Several to manydecades likely willbe required before a
delisting target date can be accurately estimated. Fecundity (reproductive
potential) and rate of population increase is low compared to some ungulates of
similar size,such as deer.Periodically depressed recruitment rates and high adult
mortality rates also lengthen the time to achievethe population objectives
described in this recovery plan.If the population increases sufficiently and all
recovery criteria are met,the species couldbe considered for delisting by
approximately 2025.However,this time frame is uncertain and could be
substantially extended if population status and protective measures fail to meet
criteria.
ix
Table of Contents
I.INTRODUCTION .1
A.BRIEF OVERVIEW 1
1.LISTING OF BIGHORN SHEEPIN THE PENINSULAR
RANGES 1
2.ORIGIN 2
3.MORPHOLOGY AND TAXONOMY 3
4.GENETICS 4
B.ECOLOGY 6
1.HABITAT REQUTREMENTS 6
2.BEHAVIOR 10
3.REPRODUCTION 15
4.SURVIVORSHIP 20
5.CAUSES OF MORTALITY 22
6.COMPETITION 25
7.DISEASE AND PARASITISM 28
C.ABUNDANCE AND DISTRIBUTION 30
1.HISTORIC ABUNDANCE AND DISTRIBUTION 30
2.RECENT ABUNDANCE AND DISTRIBUTION 32
3.POPULATION TRENDS 35
D.REASONS FOR LISTING 38
1.THE PRESENT ORTHREATENED DESTRUCTION,
MOD IFICATION,OR CURTAILMENT OF THEIR
HABITAT ORRANGE 38
2.OVERUTILIZATION FOR COMMERCIAL,
RECREATIONAL, SCIENTIFIC,OR EDUCATIONAL
PURPOSES 40
3.DISEASE AND PREDATION 40
4.THE INADEQUACY OF EXISTING REGULATORY
MECHANISMS 41
5.OTHER NATURAL OR MANMADE FACTORS
AFFECTING THEIR CONTINUED EXISTENCE ....42
x
E.PAST AND CURRENT MANAGEMENT!CONSERVATION
ACTIVITIES 46
I.FEDERAL AGENCIES 46
2.STATE AGENCIES 49
3.LOCAL ORGANIZATIONS AND AGENCIES 52
4.iNDIAN TRIBES 56
II.RECOVERY 57
A.CONSERVATION PRINCIPLES USED IN THIS RECOVERY
PLAN 57
1.POPULATION CONSIDERATIONS 57
2.GENETIC CONSIDERATIONS 58
3.ECOSYSTEM PROTECTION 60
4.THE USE OF POPULATION MODELS TO HELP GUIDE
RECOVERY ACTIONS 61
B.OBJECTIVES AND CRITERIA 62
1.RECOVERY OBJECTIVE 62
2.DOWNLISTING CRITERIA 62
3.DELISTING CRITERIA 65
C.RECOVERY STRATEGY 67
D.NARRATIVE OUTLINE FOR RECOVERY ACTIONS
ADDRESSING THREATS 69
1.PROMOTE POPULATION INCREASE AND PROTECT
HABITAT 69
1 .1 Protect, acquire,enhance,and restorehabitat 69
1.2 Reduce or eliminate direct and indirect human impacts
80
1.3 Reduce mortality rates 91
1.4 Develop a long-term strategy and maintain the current
capability forcaptive breeding, reintroduction,and
augmentation programs 94
2.INITIATE OR CONTINUE RESEARCH PROGRAMS
NECESSARY TO MONITOR AND GUIDE RECOVERY
EFFORTS 95
2.1 Monitor population status 96
2.2 Developpopulation models 98
xi
2.3 Research the relationships between bighom sheep,
mountain lions,mule deer,and habitat 99
2.4 Investigate the relationships betweenbighorn sheep
and coyotes and bobcats 100
2.5 Investigate theefficacy of temporary suppression of
natural predation 100
2.6 Research habitat use/selection and dispersalbehavior
100
2.7 Evaluatethe effect of human activities on bighorn
sheep 101
2.8 Research disease and preventive measures 102
2.9 Research genetics of bighom sheep in the Peninsular
Ranges 103
3.DEVELOP AND IIMPLEMENT EDUCATION AND PUBLIC
AWARENESS PROGRAMS 104
3.1 Distribute information related to recovery efforts
105
3.2 Continue,update, and coordinate existing education
programs 105
3.3 Develop additional educational programs 106
3.4 Distribute a protocol to select law enforcement,public
health,and safety officials forthe humane treatment
of injured bighorn sheep 107
E.SITE SPECIFIC RECOVERY TASKS 107
III.IMPLEMENTATION SCHEDULE Ill
IV.LITERATURE CITED 117
V.APPENDICES 148
APPENDIX A.AN OVERVIEW OF THE PENINSULAR RANGES
148
APPENDIX B.DELINEATION OF ESSENTIAL HABITAT FOR
BIGHORN SHEEP IN THE PENINSULAR RANGES 153
xii
APPENDIX C.GUIDELINES FOR DEVELOPING A LONG-TERM
STRATEGY FOR REINTRODUCTION,AUGMENTATION,
AND CAPTIVE BREEDING OF BIGHORN SHEEP IN THE
PENINSULAR RANGES 168
APPENDIX D.GUIDELINES FOR SAFELY CAPTURING,
HANDLING,AND MONITORING BIGHORN SHEEP 195
APPENDIX E.PROTOCOLS FOR MONITORING POPULATION
ABUNDANCE 205
APPENDIX F.RECOMMENDED CONSERVATION GUIDELINES
216
APPENDIX G.RESPONSE TO COMMENTS 221
LIST OF TABLES
Table 1.Lamb survivalper ewe group in the Peninsular Ranges from
1993to1996 17
Table 2.Peninsular bighorn ewe population estimates and recruitment (lamb
survival until December)for captive-reared and wild-reared ewes in
the northern Santa Rosa Mountains 18
Table 3.Annual survival estimates for yearling and adult bighorn sheep in the
northern Santa Rosa Mountains ewe group for calendar years 1985 to
1998 (excluding captive-reared animals)21
Table 4.Annual survival of adult bighorn sheep between Highway 74 and the
United States -Mexico border,1992 to 1998 22
Table 5.Abundance estimates of bighorn sheep in the PeninsularRanges north
of the United States -Mexico border during 1994, 1996,and 1998 .34
xiii
Table 6.Ewe abundance estimates per ewe group generatedfrom helicopter
surveys during 1994,1996,and 1998 35
Table 7.Ewe population estimates for the San Jacinto Mountains from 1993 to
1999 37
Table 8.Fall population estimates of adult bighorn sheep in the northern Santa
Rosa Mountains from 1985 to 1998 37
Table 9.Past and present conservation activities in Anza-Borrego Desert State
Park 54
Table 10.Trails and areas with potential conflicts that should be addressed in the
interagency trails management plan 88
Table 11.Recovery criteria regions 108
Table 12.Site specific tasks recommended for each recovery region 109
LIST OF FIGURES
Figure 1.Distribution of seven mitochondrial DNA haplotypes among bighorn
sheep ewe home-range groups in the Peninsular Ranges,southern
California S
Figure 2.Peninsular bighorn sheep essential habitat and physical features ...11
Figure 3.Distribution of bighorn ewe groups in the Peninsular Ranges,
California,1992 to 1995 33
Figure 4.Peninsular bighorn sheep essential habitat and land
ownership/management 50
Figure 5.Peninsular bighorn sheep essential habitat with recovery regions ...63
xiv
Figure 6.Peninsular bighorn sheep essential habitat and sheep observations .71
Figure 7.Palm Springs -Cathedral City interfacewith Peninsular bighorn sheep
essential habitat 72
Figure 8.Rancho Mirage -Palm Desert interface with Peninsular bighorn sheep
essential habitat 73
Figure 9.Indian Wells -La Quinta interfacewith Peninsular bighorn sheep
essential habitat 74
xv
I.INTRODUCTION
The purpose of this recoveryplan is to (1)establish interim and long-term goals
and objectives,(2)describe site-specific management actions to achieve these
goals,and (3) establish a schedule and estimate the costs required to reclassify as
threatened and ultimately delist the distinct population segment of bighorn sheep
(Ovis canadensis)in the Peninsular Ranges of California,a northerly extension of
the mountainous formations of the Baja California Peninsula.This recovery plan
provides guidelines and recommendations to be used in developing and assessing
conservation and management activities to achieve recovery.
A.BRIEF OVERVIEW
1.LISTING OF BIGHORN SHEEP IN THE PENINSULAR RANGES
The California Fish and Game Commission listed bighorn sheep inhabiting the
Peninsular Ranges as “rare”in 1971.In 1984,the designation was changed to
“threatened”by the California Department of Fish and Game to conform with
terminology of the amended California Endangered Species Act.We(the Fish
and Wildlife Service)listed the distinct vertebrate population segment of bighorn
sheep occupying the Peninsular Ranges of southern California (see Appendix A)
as endangered on March 18,1998 (63 FR 13134).For a population to be listed
under the Endangered Species Act as a distinct vertebrate population segment,
three elements are considered (61 FR 4722,February 7,1996):(1)the
discreteness of the population segment in relation to the remainder of the species
to which it belongs;(2)the significance of the population segment to the species
to which itbelongs,and (3)the population segment’s conservation status in
relation to the Endangered Species Act’s standards for listing (i.e.,is the
population segment, when treated as if it were a species,endangered or
threatened?).The Peninsular Ranges population will hereafter be referred to in
this recovery plan asthe Peninsular bighorn sheep and will alternatively be
referred to as a species,following the definition of”species”in section 3(15)of
the Endangered Species Act.
1
Species Distribution
The population of bighorn sheep addressed in this recovery plan extends along the
Peninsular Mountain Ranges from the San Jacinto Mountains of southern
California south to the United States -Mexico international border.Though the
range extends south to Volcan Tres Virgenes near Santa Rosalia,Baja California,
Mexico,only the distinct vertebrate population segment within the United States
is listed as endangered and addressed in this recovery plan.
The decision to list the Peninsular bighorn sheep as federally endangered was
made because of declining population numbers and continuing habitat loss,
degradation,and fragmentation throughout a significant portion of the Peninsular
bighorn sheep’s range.In addition,periods of depressed recruitment,likely
associated with disease,and high predation,coinciding with low population
numbers,endanger the continued existence of these animals in southern
California.Per recovery planning criteria published in the Federal Register (48
FR 43098,September 21,1983),the Peninsular bighorn sheep has a recovery
priority of 3C,indicating that it is a subspecies facing a high degree of threat but
has a high potential for recovery if appropriately managed.The “C”indicates that
recovery is in conflict with construction or other forms of economic activity.
2.ORIGIN
Wild sheep became established in North America after crossing the Bering land
bridge from Eurasia during the late Pleistocene (Geist 1971),which began about
1,000,000 years ago and ended 10,000 years ago at the time of thelast Ice Ages
and the beginning of the Holocene.Therange ofbighorn sheep has since spread
to include deserthabitats as far south as northern Mexico(Manville 1980).In
North America,two species of wild sheep currently are recognized:the thinhorn
sheep (Ovis dalli)and the bighorn sheep (Ovis canadensis).Bighorn sheep,
originallydescribed by Shaw in 1804 (Wilson and Reeder 1993),were once
divided into seven recognized subspecies based on differences in skull
measurements (Cowan 1940,Buechner 1960,Shackleton 1985).These
subspecies included Audubon bighorn sheep (Oviscanadensis auduboni),
2
Peninsular bighorn sheep (Ovis canadensis creinnobates),Nelson bighorn sheep
(Ovis canadensis nelsoni),Mexican bighorn sheep (Ox’is canadensis inexicana),
Weems bighorn sheep (Ovis canadensis weemsi),California bighorn sheep (Ovis
canadensis californiana),and Rocky Mountain bighorn sheep (Ovis canadensis
canadensis).Audubon bighorn sheep are now extinct.As described below, this
taxonomy has since been revised.
3.MORPHOLOGY AND TAXONOMY
The term “desert bighorn”is used to describe bighorn sheep that inhabit dry and
relatively barren desert environments,and typically includes bighorn sheep
subspecies that have, to date, been classified as nelsoni, mexicana,cremnobates,
and weemsi (Manville 1 980).~Thevalidity of these subspecies delineations has
been questioned and reassessed on thebasis of additional morphological and
genetic analyses (Wehausen and Ramey 1993;Ramey 1993, 1995;Gutierrez-
Espeleta et al.1998;refer to section I.A.4).Bighorn sheep in the Peninsular
Ranges were once considered a separate subspecies and were one of the four
desert subspecies recognized by Cowan (1940)based on cranial measurements.
Cowan’s (1940)Peninsular subspecies (Ovis canadensis cremnobates)did not
include the northern end of thePeninsular Ranges in California and extended east
across theImperial Valley north of theMexican border.Wehausen and Ramey
(1993) noted that various authors have arbitrarilychanged the geographic
boundaries of this subspecies over time based on no additional data or analyses.
Ramey (1993)reanalyzed Cowan’s (1940)original data using modern statistical
methods and found little support for his subspecies of bighorn sheep.In that
reanalysis,the apparent distinction of the Peninsular subspecies was found to be
an artifact of unequal age distributions among samples.Wehausen and Ramey
(1993)conducted a new cranial morphometric analysis using a new and much
larger sample and found no statistical support for a Peninsular subspecies.Ramey
(1993,1995)also investigated this question using restriction site polymorphism
data for mitochondrial DNA and similarly found no statistical support for
description of a subspecies in thePeninsular Ranges. Based on these
morphometric and genetic results,Wehausen and Ramey (1993)placed Peninsular
3
bighorn within theNelson subspecies (Ovis canadensis nelsoni),which is the
current taxonomy.
4.GENETICS
By analyzing micro-satellite and major histocompatibility complex loci,Boyce et
al.(1997) found high levels of genetic diversity within and between populations
of desert bighorn sheep,including sheep subpopulations within the Peninsular
Ranges.Similarly,Gutierrez-Espeleta et al.(1998) found significant amounts of
variation atmicrosatellite loci among all bighorn sheep populations studied.
However,Ramey (1995)found very little mitochondrial DNA variation between
groups of desert bighorn.The results of Ramey (1995),Boyce et al.(1997),and
Gutierrez-Espeleta et al.(1998)differ because various molecular markers and
analytical techniques were employed.Different molecular markers (e.g.,
mitochondrial DNA,microsatellites,allozymes)are subject to various rates of
mutation and are likely affected by different evolutionary processes,thereby
providing different levels of insight into the genetic variability of a species.One
similarity that has been found in all genetic studies of desert bighorn to date is that
genetic distance increases with geographic distance.For example,Boyce et al.
(1997)and Bleich et al.(1996)found support forpartitioning of genetic variation
among metapopulations (e.g.,the Mojave and Peninsular metapopulations),with
high levels of gene flow within metapopulations, including the Peninsular Ranges,
and low levels between metapopulations.
Within the Peninsular Ranges,at least eight subpopulations, or ewe groups,
currently exist (Rubin et al.1998,refer to section I.C.l).Based on sampling of
about one-third of the animals in the metapopulation,Boyce et al.(1999) found
that seven haplotypes were distributed in a non-random fashion among these ewe
groups and that a significant amount of mitochondrial DNA variation was
partitioned amongewe groups,indicating a high level of genetic structureamong
these subpopulations (Figure 1).The observed structure among ewe groups likely
was primarily influenced by differences in founding ewes and their limited
movements through the range (W.Boyce,University of California,Davis,pers.
comm.).Boyce et al.(1999)concluded that the movement of ewes (and therefore
4
Figure 1.Distribution of seven mitochondrial DNA haplotypes among bighorn sheep ewe
home-range groups in the Peninsular Ranges,California (SJ,San Jacinto Mountains,n=6;D,Deep
Canyon,n=18;M,Martinez Canyon,n6;SSR,South Santa Rosa Mountains,n=3;COY,Coyote
Canyon,n=13;NSY,North San Ysidro Mountains,n=18;SSY,South San Ysidro Mountains,n~7;V,
Vallecito Mountains, n=14;CAR,Carrizo Canyon,n19).Note that the ewe groups are distributed
approximately along a north-south gradient.A ewe group composed primarily of captive-bred
animals,located between the Deep Canyon and San Jacinto Mountains groups, was not included in
the analysis.(Reprinted with permission from Boyce et al.1999).
5
the flow of mitochondrial DNA)between ewe groups is limited but has occurred
at low levels in the past.This result is in contrast to the greater level of nuclear
gene flow (indicated by the analyses of micro-satellite and major
histocompatibility complex loci markers discussed above),which is mediated by
the movement of rams among ewe groups (refer to section I.B.2).
B.ECOLOGY
1.HABITAT REQUIREMENTS
Bighorn sheep have important habitat requirements that relate to topography,
visibility,water availability,and forage quality and quantity.During their
evolution,bighorn sheep developed predator evasion behaviors that depend
critically on theuse of escape terrain,which is generallydefined as steep,rugged
terrain (Hansen 1 980c,Cunningham 1989).Escape terrain is importantbecause
bighorn sheep typically do not outrun their predators but,rather,use their
climbing abilities to escape their enemies (Geist 1971,McQuivey 1978).When
ewes areready to givebirth theywill typically seek out the most precipitous
terrain, where their lambs will presumably be safest (Geist 1971).The presence
of such steep terrain for predator evasion and lambing is,therefore,a crucial
component of sheep habitat (see Appendix B).Variation in slope and aspect also
help bighorn sheep to survive in a harsh environment.During hot weather,
bighorn seek shade under boulders and cliffs,or may move to north facing slopes
(Merritt 1974,Andrew 1994).During inclement weather they may again seek
protected caves or overhangs, or move to sunny,south facing slopes (Andrew
1994),or slopes that are protected from strong winds.
In addition to mountainous terrain,other types of habitat are crucial to the
viability of bighom sheep populations.M.Jorgensen (California State Parks,
pers. comm.) has observed bighorn at various times of the year on numerous
alluvial fans and in washes,such as (1)the Borrego Palm Canyon alluvial fan,
used for forage during cooler months and for water from May to November;(2)
Palm Wash tinajas in the southern SantaRosa Mountains, a water source in late
summer/fall before winter rains; (3) Harper Flat in Anza-Borrego Desert State
6
Park;and (4)Chino Canyon,most recently in 1982,when seven ewes and lambs
were observed.Areas of flat terrain,such as valley floors,serve as important
linkages between neighboring mountainous regions,thereby allowing sheep
temporary access to resources (e.g.,forage,water, or lambing habitat) in
neighboring areas,and allowing gene flow to occur between subpopulations
(Krausman and Leopold 1986,Schwartz et al.1986,Bleich et al.1990a,Bleich et
al.1996).
Inthe Sierra Nevada and Moj ave Desert,the timing of forage green-upin winter
is strongly influenced by elevation and mediated through temperature (J.
Wehausen,White Mountain Research Station,pers.comm.;Wehausen 1980,
1983).Low rolling terrain and washes seasonallyprovide an important source of
high quality forage,with a greater diversity of browse species than in steeper
terrain (Leslie and Douglas 1979).Washes also provide a source of high quality
browse for longer in the summerthan do other areas (Andrew 1994). Leslie and
Douglas (1979)noted that these areasbecame increasinglyimportant to bighorn
sheep not only in summer but during any period of limited forage availability.
Bates and Workman (1983)observed bighorn sheep feeding in flatterrain in
Canyonlands National Park,and reported that plant production was higher in
flatterterrain than in steeper areas.Similarly,Bleich et al.(1997)reported that
during periods of sexual segregation,rams exploited rolling hills and flat terrain
for their superior forage.After localized summer rainfall events, washesand
alluvial fans provide the diverse,high quality forage that is especially important to
lactating ewes (Turner 1976,Bureau of Land Management 1996).Hansen and
Deming (1980)describe theimportance of succulent spring foods at lower
elevations to lactating ewes.
Inthe PeninsularRanges, bighorn sheep use a wide variety of plant species as
their food source.Turner (1973) recorded the use of atleast 43 species, with
browsebeing the food category most frequently consumed(Turner 1976,Scott
1986).Cunningham and Ohmart (1986)determined that the bighorn sheep diet in
Carrizo Canyon (at the south end of the U.S.PeninsularRanges) consisted of 57
percent shrubs,32 percent forbs,8 percent cacti,and 2 percent grasses.Scott
(1986)and Turner(1976) reported similar diet compositions at thenorth end of
7
the range. Plant species eaten by bighorn sheep in the Peninsular Ranges were
also reported by Jorgensen and Turner (1973)and Weaver et al.(1968).Diet
composition varied among seasons (Cunningham and Ohrnart 1986,Scott 1986),
presumably because of variability in forage availability,selection of specific plant
species during different times ofthe year (Scott 1986),and seasonal movements
of bighorn sheep.In Arizona,bighorn sheep also used a wide variety of forage
species throughout the year to cope with thechanging desert environment (Miller
and Gaud 1989).
In ruminants,such as bighorn sheep,fetal growth is relatively slow during the
early stages of gestation,with the majority of fetal growth occurring during the
final two months of gestation (Robbins 1993).Following lambing,ewesare faced
with the costs of lactation,which are typically two to three times higher than the
energetic costs of gestation and mayrange from four to seven times the basal
metabolic rate (Robbins 1993).Consequently,the time period surrounding
lambing and nursing is very demanding in terms of the energy and protein
required by bighorn ewes.Failure to acquire sufficient nutrients during the last
two months of gestation and during nursing can adversely affect the survival of
newborn ungulates (Thorne et al.1976,Julander et al.1961,Holl et al.1979).
Furthermore, females in poor condition may fail to provide adequate maternal care
following parturition (Langenau and Lerg 1976,Festa-Bianchet and Jorgenson
1996). Crude protein and digestible energy values of early green-up species,such
as annual grasses and forbs,are usually much higher than those of dormant
forages during the critical late gestation, lambing,and rearing seasons.With their
high nutrient content,evenminor volumes of these forages within the overall diet
composition maycontributeimportant nutritional value at critical life stages
(Wagner 2000).However, during the reproductive season,due to the varied
topography of bighorn sheep habitat,these forages typically are concentrated on
specific sites, such as alluvial fans and washes, where more productive soils
support greater herbaceous growththan steeper,rockier soils.Berbach (1987)
foundthat when ewes were confined to a pen and prevented from using all
vegetation associations during late gestation and early lactation,they and their
lambs died of malnutrition.
8
In hot, arid deserts, water is considered to be an important resource for bighorn
sheep (Jones et at.1957,Blong and Pollard 1968,Leslie and Douglas 1979,
Turner and Weaver 1980,Elenowitz 1984,Cunningham and Ohmart 1986).A
number of studies have shown that desert bighorn sheep will concentrate around
water sources in the summer,with most animals found within a 3- to 5-kilometer
(2-to 3-mile) radius of water (Jones et at.1957,Leslie and Douglas 1979,
Cunningham and Ohmart 1986).Lactating ewes and lambs often are more
dependent on water and may thus be found closer to water (Blong and Pollard
1968,Leslie and Douglas 1979,Bleich et at.1997).However, these patterns have
not been observed in all habitats (summarized by Andrew 1994).Water sources
are most valuable to bighorn sheep if they occur in proximity to adequateescape
terrain with good visibility. Therefore,the juxtaposition of open escape terrain to
water sources will influence drinkingpatterns (Cunningham 1989,Andrew 1994).
During periods of high rainfall,sheep distribution is less coincident with
permanent water sources (Leslie and Douglas 1979).The importance of water to
bighorn sheep has been questioned (Krausman and Leopold 1986,Broyles 1995),
and some small populations apparently exist withoutstanding water (Krausman et
at.1985,Krausman and Leopold 1986,and additional examples summarized in
Broyles 1995).Furthermore,it has been theorized that the addition of water to
bighorn sheep habitat would be detrimental if it attracted competing species to
areas of limited forage resources (Smith and Krausman 1988)or expanded the
range of mountain lions (Shaw 1993).However,in most populations bighorn
sheep will drink regularly when water is available and concentrate near water
during summer months,and it is likely that lack of water is a limiting factor for
some populations.In the Peninsular Ranges,bighorn sheep have been observed to
use areas without known perennial water during some months,including the
lambing season (E.Rubin,University of California,Davis,pers. comm.).
The predator evasion behavior of bighorn sheep depends on the ability to visually
detect danger at a distance.Visibility has long beenrecognized as an important
characteristic of bighorn sheep habitat (Hansen 198Gb).Researchers have found
that bighorn sheep will avoid habitat in which dense vegetation reduces visibility
(Risenhoover and Bailey 1985,Etchberger et at.1989).This appears to be the
9
case in the Peninsular Ranges, where bighorn sheep usuallyremain below the
elevation of chaparral and otherdense vegetation associations.
In the Peninsular Ranges,bighorn sheep habitat occurs along the east-facing
desert slopes, typically below approximately 1,400-meter (4,600-foot)elevations
(Jorgensen and Turner 1975).In these mountains,bighorn sheep avoid higher
elevations,likely because of decreased visibility (and therefore increased
predation risk)associated with the denser vegetation found at higher elevations.
The elevational patterns of vegetation associations in the Peninsular Ranges,in
combination with this predator avoidance behavior, have resulted in habitat use
that is more restricted to lower elevations than in most other bighorn sheep
populations.Results from helicopter surveys and a 5-year study of radio-collared
bighorn in the San Jacinto Mountains found that bighorn sheep in these
mountains,where elevations exceed 3,000 meters (9,842 feet),were largely
restricted to a narrow band of habitat between 213 and 1,037 meters (700 to 3,400
feet)in elevation (DeForge et at.1997).In thenorthern Coachella Valley,this
lower elevation limit generally coincides with the developed urban interface.At
the lowest elevations of their range,bighorn sheep movement onto the valley floor
(Coachella Valley,Imperial Valley)is restricted by a tendency to avoid venturing
far from escape terrain and by anthropogenic factors that now preclude
intermountain movements such ashave beenrecorded elsewhere in the desert.
The available habitat of Peninsular bighorn sheep can,therefore,be visualized as
a long,narrow band that runs north-south along the lower elevations of the
Peninsular Ranges (Figure 2).This pattern of predominantly low elevation habitat
use is unique among desert bighorn sheep populations.
2.BEHAVIOR
The social structure of bighorn sheep is matrilineal (based on female
associations).Gregarious and philopatric (faithful to natal home range)behaviors
confer adaptive advantage to prey species because home range familiarity and
group alertness decrease the risk of predation (Boyce et at.1999).The ranging
patterns and habits of ewes are learned by their offspring (Geist 1971). By
following older animals,young bighorn sheep gatherknowledge about escape
10
terrain,water sources, and lambing habitat (Geist 1971).Ewes that share the
same portion of a range,therefore,are likely to be more closely related to each
other than they are to other ewes (Festa-Bianchet 1991,Boyce et at.1999),and
the term “home range group”has been used to describe such groups (Geist 1971).
These groups are referred to as “ewe groups”in this recovery plan.Rams do not
show thesame level of philopatry and tend to range more widely,often moving
among ewe groups.As young rams reach 2 to 4 years of age,they follow older
rams away from their natal group during the fall breeding period, orrut,and often
return after this period (Geist 1971,Festa-Bianchet 1991).Rams may follow the
same travel routes year after year (Geist 1971,Wehausen 1980,DeForge et at.
1997).The sexes tend to loosely segregate during much of the year,coming
together primarily during the rut (Geist 1971,Bleich et at.1997),which typically
peaks from Augustthrough October in thePeninsular Ranges (Rubin et at.2000).
Duringthe rut,rams join the ewe groups and compete to breed with receptive
ewes.The largestrams presumably are themost successful breeders, but smaller
rams have been reported to breed as well (Hogg 1984).During theperiod of
sexual segregation,ewes and their lambs are typically found in steeper,more
secure habitat, while rams inhabit less steep or rugged terrain (Geist 1971,Bleich
etat.1997).
Bighorn sheep areprimarily diurnal (Krausman et at.1985)but may be active at
any time of day or night (Miller et at.1984).Their daily activity pattern includes
feeding and restingperiods that are not synchronous either within or between
groups. Forage quality influences activity patterns. When forages arelow in
digestibility,sheep must spend more time ruminating and digesting forage.
Particle sizemust be reduced sufficiently to pass from the rumen and reticulum to
the omasum (Van Soest 1982,Robbins 1993).As forages green-up and
digestibility increases, passage rates increase and ruminants can feed more
frequently (Risenhoover 1986).Sheep typically increase the number of feeding
bouts rather than the length of individual bouts. Consequently,sheep establish a
cycle of feeding and ruminating that reflects forage quality and optimizes nutrient
intake (Wagner 1999,2000).
12
Bighorn sheep rely on vigilance to detect predators.Therefore, theybenefit from
gregariousness and group alertness (Geist 1971,Berger 1978).Within a ewe
home range group,ewes appear to associate with other ewes based on their
availability rather than on their matrilineal relationships (Festa-Bianchet 1991,
Boyce et at.1999).Within home range groups,these subgroups are dynamic--
they may split,reform,or change membership on a daily or hourly basis as
animals move through their home ranges.
Burt (1943)defined home range as ‘...that area traversed by the individual in its
normal activities of food gathering,mating,and caring for young”.Size of the
home range depends on the juxtaposition of required resources (water,forage,
escape or lambing habitat)and,therefore,varies geographically.Home range size
also is affected by forage quantity and quality,season, sex, and age of the animal
(Leslie 1977,McQuivey 1978).In most populations,ram home ranges havebeen
found to be larger than those of ewes (Simmons 1980,DeForge et at.1997).
DeForge et at.(1997) reported average home range sizes (95 percent utilization
distribution)of 25.5 square kilometers (9.8 square miles)and 20.1 square
kilometers (7.8 square miles)for rams and ewes,respectively,in the San Jacinto
Mountains, using the fixed-kernel method (Seaman and Powell 1996).
Although most desert bighorn sheep do not seasonallymigrate along elevational
gradients like many populations in higher latitude mountain ranges,they do
exhibit seasonal differences in habitat use patterns. In many populations,animals
will have a smaller home range in summer (McQuivey 1978,Leslie and Douglas
1979,Elenowitz 1983),presumably due to their limited movement away from
permanent water sources.Duringthe cooleror wetter months of the year,bighorn
sheep oftenexhibit an expanded range as animals move farther from water
sources (Simmons 1980).In addition, seasonal changes in habitat use are
influenced by lambing and rutting behavior (Geist 1971,Bleich et at.1997).
Desert sheep also seek the earliest winter green-up of annuals and the first
flowering of brittlebush (Enceliafarinosa),which are elevation dependent
(J.Wehausen, pers. comm.).
13
The gregarious and philopatric behavior of ewes limits their dispersal and
exploratory abilities relative to those of rams (Geist 1967,1971).Geist (1971)
theorized,however,that a young ewe might switch to a new ewe group if she
encountered neighboring sheep and followed them away from her natal ewe
group.In the Peninsular Ranges,movement of radio-collared ewes between ewe
groups is rare. During a 3-year study,the most extensive movement documented
wasby one ewe that moved over 30 kilometers (18.6 miles)and temporarily
joined a second ewe group(Rubin et at.1998).No emigration of ewes has been
observed even though radio-collared animals have been regularly monitored in the
northern Santa Rosa Mountains since 1981 (Ostermann et at.in press)and
throughout the range since 1993 (li.Rubin,pers.comm.;DeForge et at.1997).
Genetic analyses of ewe dispersal suggest that a low rate has occurred in the
Peninsular Ranges in the evolutionarypast (Boyce et at.1999).Genetic and
observational data suggest,however,that rammovements among ewe groups are
common (Boyce et at.1997;DeForge et at.1997;Rubin et at.1998;Bighorn
Institute 1998, 1999).
An important consideration in the conservation of Peninsular bighorn sheep is
their behavioral response to humans and human activity.Bighorn have been
considered a wilderness animalbecause they do not thrive in contact with human
development (Leopold 1933).Theirresponse to human activity is highly variable
and depends on many factors,including but not limited to:the type of activity,
the animal’s previous experience with humans,size or composition of the bighorn
sheep group,location of bighorn sheep relative to elevation of the activity,
distance to escape terrain,and distance to the activity (Weaver 1973;McQuivey
1978;Hicks and Elder 1979;MacArthur et at.1979, 1982;Wehausen 1980;
Hamilton et at.1982;Whitacker and Knight 1998;Papouchis et at.1999).
Responses can range from cautious curiosity to immediate flight or abandonment
of habitat, as well asdisruption of normal social patterns and resource use.
Though the effect of human activity in bighorn habitat is not always obvious,
human presence or activity in many cases has been found to detrimentally alter
normal behavioral and habitat use patterns(refer to section I.D.5).For example,
bighorn began using urban sources of food and water in the northern Santa Rosa
Mountains when development began encroaching on sheep habitat in the 1950’s
14
(Tevis 1959).Though commonly thought to be the result of releasing captive
raised bighorn sheep, habituation of wild sheep to urban habitats occurred several
decades before the first release of any captive-rearedstock in 1985 (DeForge and
Scott 1982;Ostermann et at.in press;V.Bleich,California Department of Fish
and Game, pers.comm.).
3.REPRODUCTION
In the Peninsular Ranges,ewes estimated to be between 2 and 16 years of age
have been documented to produce lambs (Rubin et at.2000,Ostermann et at.in
press).Yearling ewes in captivity also have produced lambs (Bighorn Institute
1999).Some rams are believed to be capable of successful breeding as early as 6
months of age (Turner and Hansen 1980),though the breeding opportunities of
young rams are limited by the social pressure of larger rams (Hogg 1984).The
breeding period, or rut,occurs in the late summer and fallmonths.As parturition
approaches,ewes seek isolated sites with shelter and unobstructed views (Turner
and Hansen 1980),and secludethemselves from other females while finding sites
to bear their lambs (Etchberger and Krausman 1999).In the Little Harquahala
Mountains,the physical and biological characteristics of lambing sites did not
differ from sites used at other times of theyear (ibid).Lambs are born after a
gestation of approximately 6 months--171 to 185 days (Turner and Hansen 1980,
Shackleton et at.1984,Hass 1995).During a 4-year (1993 to 1996)study
conducted in the Peninsular Ranges south of the San Jacinto Mountains,the
lambing season extended from February through August;however,87 percent of
the lambs were born from February to April,and 55 percent of the lambs were
born in March (Rubin et at.2000).DeForge et at.(1997)and Cunningham (1982)
reported a similar onset of the lambing season in the San Jacinto Mountains and in
Carrizo Canyon, respectively.Inthe San Jacinto and northern Santa Rosa
Mountains ewe groups,the lambing season begins in January during some years
(Bighorn Institute 1997).Lambs usuallyare weaned by 6 months of age (Hansen
and Deming 1980,Wehausen 1980).
From 1993 to 1996, the reproductive patterns of fiveewe groups (Carrizo Canyon,
south San Ysidro Mountains,north San Ysidro Mountains, Santa Rosa Mountains
15
[Deep Canyon],and northern Santa Rosa Mountains)were monitored (refer to
section I.C.I for description of ewe groups)and annual lamb production averaged
77 percent (0.77 lambs born per “ewe-year”)for the4-year period (E.Rubin, pers.
comm.). Using a fecal-based enzyme immunoassay,Borjesson et at.(1996)
determined that in the fall of 1992,at least 85 percent of sampled adult ewes were
pregnant.Both of these observations suggest that conception rates are not
currently limiting population growth in thePeninsular Ranges.
Lamb survival (to 6 months of age)was variable among groups and across years.
A good year of lamb survival in one group was not necessarily a good year in
another group (Rubin et at.2000,Table 1).Of the four groups studied,the
northern Santa Rosa Mountains group typically had the lowest lamb survival,
while the neighboring Deep Canyon group,located less than 8 kilometers (5
miles)away,had the highest lamb survival.Researchers working in the northern
portion of the Santa Rosa Mountains have expressed concern over the low lamb
recruitment average observed in this areasince approximately 1977 (DeForge et
at.1982,DeForge and Scott 1982,Turner and Payson 1982).Although lamb to
ewe ratios observed in the Santa Rosa Mountains have fluctuated across years
(Wehausen et at.1987,DeForge et at.1995),fall lamb to ewe ratios were
consistently low in the northern Santa Rosa Mountains during 1983 to 1994
(DeForge et at.1995).During 1985 to 1998,recruitment in the northern Santa
Rosa Mountains averaged 13 lambs per 100 ewes (Ostermann et at.in press,
Table 2).Periods of low lamb to ewe ratios,as well as clinical signs of
pneumonia among lambs, have occasionally been observed in Anza-Borrego
Desert State Park (Jorgensen and Turner 1973,Jorgensen and Turner 1975,Hicks
1978),but years of high lamb to ewe ratios (Cunningham 1982,M.Jorgensen,
pers.comm.)and high lamb recruitment to 6 months of age (Rubin et at.2000)
have been observed in these areas as well.In the San Jacinto Mountains,low fall
lamb to ewe ratios were documented from 1977 to 1983.However,this group
exhibited variable recruitment thereafter,with relatively high (greater than or
equal to 0.50) fall lamb to ewe ratios from 1994 to 1996 (DeForge et at.1997).
Wehausen (1992) suggested that periods of low recruitment may not warrant
alarm because long-lived animals such as bighorn sheep can exist in viable
16
Table 1.Lamb survival per ewe group in thePeninsular Ranges during 1993 to
1996 (Rubin et al.2000,based on observations of radiocollared ewes).
Ewe
Group
Proportion (1.0~l0O percent)of lambs living to 6 months of age
1993 1994 1995 1996 1993 to 1996
(#lambs)
Carrizo
Canyon 0.67 0.78 0.50 0.50 0.68 (31)
San Ysidro
Mountains-
north and
southa
0.75 0.25 0.57 0.71 0.57 (42)
Deep
Canyon
NA 0.80 0.67 0.75 0.74 (23)
N.Santa
Rosa Mts.
NA 0.43 0.10 0.40 0.26 (23)
adata from the north and south San Ysidro groups were combined because of small
sample sizes in the south San Ysidro Mountains when years were considered separately.
populations if periods of low offspring recruitment areinterrupted by periodic
pulses of high offspring recruitment.Most ewe groups in thePeninsular Ranges
appear to have exhibited such pulses of high recruitment but declining population
trends (see section I.C.3)suggest that theyhave not been sufficient to balance
adult mortality over longer time periods.Chronically low lamb to ewe ratios
observed in the northern Santa Rosa Mountains ewe group (DeForge et at.1995,
Ostermann et at.in press)are a particular concern.Signs of illness havebeen
observed among lambs in this ewe group (DeForge et at.1982,DeForge and Scott
1982,DeForge and Ostermann 1998a),and it is possible that low lamb survival is
associated with disease or disease processes complicated by environmental
conditions, such as habitat modification (refer to sections I.B.7 and I.D).This
ewe group has been augmented by captive animals since 1985 (see sections L.C.I
and I.E.3),with similar average recruitment rates (to approximately 1 year of age)
observed among wild-reared and captive-reared ewes (Ostermann el at.in press,
Table 2).A 5-year study of radiocollared lambs has been initiated in this
population to determine cause-specific mortality (DeForge and Ostermann
I998b).
17
Table 2.Peninsular bighorn ewe population estimates and recruitment (lamb
survival until December) for captive-reared and wild-reared ewes in the northern
Santa Rosa Mountains (Ostermann et a!.in review~.
Year wild-captive-Total
1985 22 0 22
1986 25 0 25
1987 25 5 30
1988 24 9 33
1989 21 11 32
1990 12 12 24
1991 11 10 21
1992 11 13 24
1993 7 10 17
1994 3 8 11
1995 3 7 10
1996 3 7 10
1997 2 7 9
1998 4 6 10
Mean NA NA NA
Lambs recruited
n (lambs/lOO ewes)
3 (12)NA 3 (12)
0(0)0(0)0(0)
2(8)0(0)2(6)
0(0)1(9)1(3)
0(0) 0(0) 0(0)
0 (0)1 (10)1 (5)
1 (9)1 (8)2 (8)
1 (14)0 (0)1 (6)
1 (33)2 (25)3(27)
0(0)0(0)0(0)
0 (0)2 (29)2 (20)
1 (50)0 (0)1 (11)
2 (50)5 (83)7 (70)
1 (13.9)1(13.7)2(13.3)
Wild-reared Captiv Total
4 (18)NA 4 (18)
No.of ewes greater than or equal
to 2 years of age
Several studies have documenteda positive relationship between winter
precipitation and lamb recruitment in the following year (Douglas and Leslie
1986,Wehausen et at.1987).However, therelationship between precipitation
and lamb recruitment is not a simple one.Wehausen et at.(1987) found that
periods of low lamb survival,believed to be a result of a disease epizootic,
coincided with periods of increased rainfall.These authors hypothesized that
increased standing water caused populations of Cuticoides midges, a vector of
bluetongue and epizootic hemorrhagic disease viruses (Hoff and Trainer 1981),to
increase.Another hypothesis involving thepresence of livestock as an outside
disease reservoir also waspresented (Wehausen et at.1987).The relationships
between climate,lamb recruitment,and population trends likely differ among
different bighorn sheep populations,and are not fully understood (Rubin et at.
2000).
18
In ruminants,reproductive success is related to themothers body weight,access to
resources, quality of home range,and age (Etchbergerand Krausman 1999).
Survival of offspring also depends on birth weight and date.Festa-Bianchet and
Jorgenson (1996)found that female sheep reducethe care of lambs when
resources are scarce to favor theirown nutritional requirements over their lambs’
development.Excessive disturbance also can disrupt nutritional condition by
affecting optimum feeding-ruminating cycles (Wagner 2000). Ewes that fail to
acquire a minimum level of energyreserves (i.e.,body weight) maynot conceive
(Wehausen 1984)or will produce smaller offspring with a poorer chance of
survival (Price and White 1985).
Ewes in thecaptive herd at the Bighorn Institute had high lamb production (mean
83.6 percent)and recruitment (mean 71.0 percent)during 1985 to 1998.
Production and recruitment of individual ewes in captivity ranged from 0 to 108
percent;twins were produced twice.Between 1985 and 1998,71 lambs (30
males,41 females)were born to ewes 2 years of age or older,resulting in a sex
ratio at birth of 0.73:1.Eleven of 71 lambs (15.5 percent)born in captivity and 6
of 39 lambs (15.4 percent)captured from the wild died in captivity.Lamb
mortalities were attributed to disease (n=1 1),trauma or peritonitis (n=3), and
undetermined causes (n=3)(Ostermann et at.in press).Lamb survival in the
captive herd during 1999 was the lowest recorded for this population, with only
two of seven lambs surviving to yearling age.Results from necropsies performed
at the California Veterinary Diagnostic Laboratory indicated acute bacterial
pneumonia (Pasteuretta spp.)as the cause of death in all five lambs.Previous
studies have implicated severe stress as a factor in pasteurellosis in domestic
ruminants (Frank and Smith 1983,Gilmour and Gilmour 1989),and in bighorn
pneumonia epizootics (Feuerstein et at.1980,Spraker et at.1984,Festa-Bianchet
1988).During the 1999 lambing season,captive bighorn were observed fleeing
from the feeding area in response to construction noise from nearby development
projects on multiple occasions. Additionally,helicopters were documented flying
over or adjacent to the enclosures and causing alarm responses (e.g.,running
uphill)among captive bighorn on over 20 occasions between January and July
1999 (Bighorn Institute 1999).Stress resulting from human disturbance may have
played a role in predisposing captive lambs to disease.
19
4.SURVIVORSHIIP
In the San Jacinto Mountains, DeForge et at.(1997)monitored the survival of
adult (2 or more years of age)radiocollared bighorn sheep during 1993 to 1996
and estimated annual adult survival to be 0.75 (1 equals 100 percent).During
1997 and 1998,annual survival in this ewe group was 0.67 and 0.86,respectively
(Bighorn Institute 1997,1998).
In the northern Santa Rosa Mountains ewe group,adult survivorship was
monitored during a 14-year period (1985 to 1998),and was found to range
between 0.50 and 1.00 annually (Table 3;Ostermann et at.in press). Regression
analysis did not reveal an increasing or decreasing trend in survivorship during the
14 years.In this ewe group, which has been augmented with captive animals
since 1985 (refer to sections I.C.1 and I.E.3),annual survival of captive reared
animals (n equals 73,mean 0.80)was not statistically different from that of wild-
rearedanimals (n equals 43,mean 0.81;Ostermann et at.in press).
During November 1992 to May 1998,survivorship of 113 adult radio-collared
bighorn sheep (97 ewes and 16 rams) wasmonitored between Highway 74 (in the
Santa Rosa Mountains)and the U.S.-Mexico border.During this period,overall
annual adult survivalwas 0.79 (Table 4), with no significantdifference among
threeage classes of adults (Hayes et at.2000).Survivorship varied across years
(range:0.72 to 0.91,Hayes et at.2000), but regression analysis did not reveal a
decreasing or increasing trend in survivorship across years.Annual survivorship
of individualewe groupsranged from 0.70 to 0.87,and a year of high
survivorship in one group was not necessarily a year of high survivorship in other
groups (E.Rubin,pers. comm.).
Survival of adult bighorn sheep has been considered to be high until 10 years of
age (Hansen 198Gb),or until shortly before the age of ecological longevity
(Cowanand Geist 1971).However,observed values of annual adult survivorship
in the Peninsular bighorn sheep appear low relative to otherreported desert
populations:0.91 or greater in southeastern California (Andrew 1994),0.86 or
greater in northwest Arizona (when highway mortalities were excluded,
Cunningham and deVos 1992),0.82 in New Mexico (Logan et at.1996),and
20
Table 3. Annualsurvival estimatesa for yearling and adult bighorn sheep in the
northern Santa Rosa Mountains ewe group for calendaryears 1985 to 1998
(excluding captive-reared animals; Ostermann et at.in press).
Year Animal Months Survival
(1.0 =100
percent)
95 percent
Confidence
Interval
1985 305 0.70 0.54-0.86
1986 282 0.88 0.76-1.00
1987 264 0.91 0.80-1.00
1988 234 0.90 0.77-1.00
1989 203 0.78 0.59-1.00
1990 145 0.79 0.57-1.00
1991 105 0.80 0.55-1.00
1992 86 0.88 0.65-1.00
1993 73 0.86 0.60-1.00
1994 45 0.50 0.10-0.90
1995 61 0.83 0.54-1.00
1996 52 0.80 0.45-1.00
1997 42 0.75 0.33-1.00
1998 42 1.00 1.00-1.00
aSu~ival calcujated using the Kaplan-Meier method modified for a staggered entry design
(Pollock et al.1989).
0.85 or greater for four of five populations studied in the Mojave desert
(Wehausen 1992).The one exception in the Mojave desert was a small
population in the Granite Mountains,which was documented to have low adult
annual survival (0.72)resulting from predation by mountain lions (Wehausen
1992).
Survival of Bighorn Institute captive raised yearling and adult bighorn (n equals
73,1985-1998)12 months after release was 0.61.First year survival for females
(0.64)was higher (p less than 0.005)than for males (0.55).First year survival for
bighorn released asadults (0.75,n equals 12)was higher (p less than 0.01)than
for bighorn released as yearlings (n 61,mean 0.57).After the first year in the
wild,survival for captive-reared sheep improved substantially.Averageannual
survival for captive-reared bighorn excluding the first year after release (0.88)was
significantly higher than survival during the first year after release (p less than
21
Table 4.Annual survival of adult bighorn sheep (greater than or equal to 2 years of
age)a,between Highway 74 (inthe Santa Rosa Mountains) and the U.S.-Mexico
border,1992 to 1998 (Hayes et al.2000).
Year Animal
Months
Annual Survival
(1.0 =100 percent)
95 percent Confidence
Interval
244 0.91 0.79-1.00
1993-1994 758 0.79 0.70-0.89
1994-1995 808 0.79 0.70-0.88
1995-1996 605 0.72 0.62-0.85
1996-1997 368 0.82 0.70-0.96
1997-1998 384 0.83 0.70-0.96
Total 3167 0.79 0.75-0.84
a Calculated using the program MICROMORT (Heisey and Fuller 1985).
b June 1 of first year through May 31 of second year (except 1992,which started in November).
0.01)and survival for wild-reared bighorn during the same time period (p equals
0.05). Mountain lionpredation wasthe primarycause of death forreleased
bighorn,followed by urbanization (Ostermann et at.in press).
Between 1985 and 1998,survival for yearling and adult bighorn in the captive
population at the Bighorn Institute ranged from 0.89 to 1.0 and averaged 0.98.
The only adult bighorn mortality during this time periodwas the euthanasia of a
terminally ill 14-year-old ewe.Three yearlings died in captivity,two from disease
and one during transport for release (Ostermann et at.in press). In 1999,two
adults and a yearling died in captivity:a 15-year-old ramwas euthanized after
collapsing from abroken humerus;a 14-year-old ram died from complications
with old age and bronchopneumonia;and a yearling ram died from an extensive
cervical abscess (Bighorn Institute 1999).
5.CAUSES OF MORTALITY
Cause specific mortality in the San Jacinto Mountains was studied from 1992 to
1998.Duringthis period, five mortalities were attributed to mountain lion (Puma
concotor)predation, two were attributed to bobcat or mountain lion predation,and
three died of unknown causes (DeForge et at.1997;Bighorn Institute 1997,
1998).
22
In the northern SantaRosa Mountains,artificially irrigated vegetation attracts
bighorn sheep and creates a hazard. Though commonly thought to be the product
of releasing captive-reared animals into the wild,behavioral habituation to urban
sources of food and waterbegan when urbanizationstarted encroaching into
bighorn habitat in the 1950’s,several decadesbefore population augmentation
began in 1985 (Tevis 1959,DeForge and Scott 1982,Ostermann et at.in press,V.
Bleich,pers. comm.). A study of cause-specific mortality conducted from 1991 to
1996 revealed that predation accounted for 28 percent of 32 adult bighorn sheep
mortalities (25 percent due to lion predation and 3 percent due to either lionor
bobcat predation)and 34 percent were directly caused by urbanization (DeForge
and Ostermann 1998b).The remainder of mortalities were due to disease (3
percent)and undetermined causes (34 percent).Of the 11 adult mortalities
attributed to urbanization,5 were due to automobile collisions,5 were caused by
exotic plant poisoning,and 1 bighorn ram was strangled in a wire fence.An
additional four bighorn sheep were struck but not killed by vehicles.Toxic plants
causing mortality included oleander (Neriurn oleander)and laurel cherry (Prunus
sp.)(Bighorn Institute 1995,1996).In 1970,a toxic,ornamental nightshade plant
may havecaused the death of a young ram in PalmSprings (Weaver and Mensch
1970).Due to an absence of comprehensive studies of the toxicity of non-native
plants to bighorn sheep,it is unclear how many additional ornamental plant
species represent a risk to bighorn sheep in the Peninsular Ranges.Exposure to
chemicals, such as fertilizers,herbicides,and insecticides used in developed areas,
is also a concern (Turner 1978);however,little is known aboutthe level of
exposure or effects on bighorn sheep.Preliminaryresults from an ongoing study
of radiocollared lambs indicate that urbanization is also affecting lamb survival in
this ewe group.Of the nine lamb mortalities recorded in 1998 and 1999,five
were attributed to coyote or bobcat predation,one to mountain lion predation,and
three to thedirect and indirect effects of urbanization (automobile collision and
drowning in a swimming pool). Dogs also have been observed to chase bighorn
ewes and their lambs near residential areas (E.Rubin,pers. comm.).Eight of the
ninedeaths occurred within 300 meters (980 feet)of the urban interface (Bighorn
Institute 1999).
23
Though mule deer (Odocoiteus hemionus)arethe primary prey of mountain lions
in North America (Anderson 1983),and the range of bighorn sheep in the
PeninsularRanges largely avoids overlapwith mule deer, lion predation threatens
individualewe groups in the PeninsularRanges (Hayes et at.2000)and has the
potential to affect population recovery.From November 1992 to May 1998,
Hayes et at.(2000)found theprimary cause of death of radio-collared adult
bighorn sheep between Highway 74 (in the Santa Rosa Mountains)and the U.S.-
Mexico border was predation by mountain lions.Lion predation accounted for at
least 69 percent of the 61 adult mortalities and occurred in each of the ewe groups
in this portion of the range (Hayes et at.2000). Annually, lionpredation
accounted for 50 to 100 percent of the bighorn sheep mortality,and did not
exhibit a decreasing or increasing trend during 1993 to 1997.Lionpredation
appeared to show a seasonal pattern,with the majority of incidents occurring
during the cooler and wetter months of the year.A bighorn sheep’s risk of
predation did not appear to be related to its age. In this study,the remainder of
mortalities were classified as:16 percent--causes other than predation and 15
percent--undetermined cause.
It is unknown,however, how currentlevels of lion predation observed throughout
thePeninsular Ranges compare to historic levels.Lions or sign of lion havebeen
observed in the habitat of Peninsularbighorn sheep sincethe 1950’s (Jones et at.
1957,Jorgensen and Turner 1973,Gross 1987,Sanchez 1988,Bighorn Institute
1990).However, the literature indicates a lack of agreement on recent mountain
lion population trends in California (Smallwood 1994,Smallwood and Fitzhugh
1995,Torres et al.1996,Wehausen 1996).Past incidents of lionpredation were
documented by Jorgensen and Turner(1975), Gross (1987),and Bighorn Institute
(1998,1999).Reported incidents of lion predation were not common in the past
and predation was not considered to be a serious risk to bighorn sheep (Weaver
and Mensch 1970,Jorgensen and Turner 1975,Cunningham 1982),but it is
important to note that the increase in the number of radio-collared bighorn sheep
since 1993 has greatly increased thedetection of such mortalities. Because of the
rough desert terrain and the manner in which lions handle their prey (burying or
caching under dirt or brush),carcasses of lion-killed bighorn sheep are difficult to
find without the aid of telemetry.However, dead bighorn sheep without radio-
24
collars have been found opportunistically during early and recent field work,and•
it has been suggested that the proportion of these that were killed by lions may
have increased.It is possible that other causes of mortality,for example past
episodes of diseases, have altered the proportion of mortalities attributed to lion
predation.
Past field observations and records in areas far from the Coachella Valley urban
interfacedocumented mortalities resulting from predation (of lambs)by coyotes
(Canis tatrans)(Weaver and Mensch 1970,Jorgensen and Turner 1975,DeForge
and Scott 1982),train collisions (Jorgensen and Turner 1973),automobile
collisions (Turner 1976,Hicks 1978),poaching (Jones et at.1957,Jorgensen and
Turner 1973,Cunningham 1982),and accidental falls (Turner 1976).Golden
eagles (Aquita chrvsaetos)and bobcats (Lynx rufus)are also potential predators.
6.COMPETITION
In thePeninsular Ranges,bighorn sheep potentially compete for resources with
other native ungulates (mule deer), domestic livestock (cattle),feral animals
(horses),and humans.Bighorn sheep and deerhabitat overlap primarily atthe
upper elevations of bighorn habitat,with possible geographic and seasonal
differences in the degree ofoverlap. Jones (1980) summarized reports of possible
competition for food and water between deer and bighorn sheep in other mountain
ranges.Jones et at.(1957) and Weaver et at.(1968)speculated that competition
betweenthe two species may occur but likely was limited in the Peninsular
Ranges.Thehabitat use patterns of deer in the PeninsularRanges havenot been
studied;therefore,levels of competition arenot known.Recent observations
suggest that non-native honey bees (Apis meltifera)could affect bighorn sheep use
of certain watersources (W.Boyce, pers.comm.).
Numerous reports and observations indicate that cattlegrazing can be detrimental
to bighorn sheep populations,either through direct competition for forage or
water,or through vegetation changes in response to cattle grazing (reviewed by
McQuivey 1978 and Jones 1980)and potential disease transmission (e.g.,
DeForge et at.1982,Clark et at.1985,Jessup 1981,Jessup 1985,Clark et at.
25
1993,refer to section I.B.7 and I.D),although see Singer et at.(1997).
Historically,largenumbers of cattle were grazed in the Peninsular Ranges (Reed
1986;Appendix A).Numbers were greatly reduced when Anza-Borrego Desert
State Park was established in 1933 and grazing leases on park lands were
terminated in 1970,although cattle have continued to trespass on Park lands from
adjacent allotments. Cunningham and Ohmart (1986) found that dietary overlap
between cattle and Peninsular bighorn sheep in Carrizo Canyon was low (less than
or equal to 18.2 percent)but notedthat during their study,the two species used
different vegetation associations.These authors cautioned that competition might
increase if:1)cattle were introduced to bighorn sheep habitat (with the impact
being most serious atwater sources),or 2)drought reduced the availability of
annual plants. In 1989,cattle were observed ata water source used by bighorn
sheep in Carrizo Canyon (Clark et at.1993),indicating that cattlewere using
bighorn sheep habitat in the study site of Cunningham and Ohrnart (1986). Cattle
were also found in bighorn sheep habitat in Coyote Canyon, Rockhouse Canyon,
Hellhole Canyon,and Bow Willow Canyon (M.Jorgensen, pers.comm.). During
1987 to 1989,Anza-Borrego Desert State Park personnel removed 117 cattle from
park land (M.Jorgensen, pers.comm.);however, cattle (both feral or straying
cattle,and those currently grazed legally on grazing allotments)are still found in
or near bighorn sheep habitat in the Peninsular Ranges,and represent a potential
risk to bighorn sheep.
Domestic sheep presentproblems similar to cattle with regard to competition;
however,their presence represents an even greater threat due to an increased risk
of transmitting fatal diseases to bighorn (referto section I.B.7 and I.D).Domestic
goats also are potentially serious competitors because of their ability to maneuver
in rough country and their propensity to overgraze forage.Jones et at.(1957)
found approximately 30 goats in Martinez Canyon in the Santa Rosa Mountains in
1957 and observed that theyhad heavily used part of this canyon.R.Weaver
(California Department of Fish and Game retired,pers.comm.)also observed
goats in this area and atthe southern edge of the U.S.Peninsular Ranges (south of
Highway 8)in the late 1960’s.Goats persisted in Martinez and Sumac Canyons
(Santa Rosa Mountains)until the early 1980’s (Bighorn Institute 1983,1984a,
1984b, 1985a, 1985b;V.Bleich,pers.comm.;D.Jessup in tilt.1999).There are
26
currently no known domestic sheep or goats in therange of the Peninsularbighorn
sheep,though transient ram movements,suchas alongthe Sunrise Highway (51
in San Diego County)could encounter sheep or goats in peripheral areas;
reintroduction of these species would create a serious risk to Peninsular bighom
sheep.
Many researchers have documented high levels of competition,both forwater and
forage,between burros (Equus asinus)and bighorn sheep (e.g.,Weaver 1959,
1972, 1973;Mensch 1970;Seegmiller and Ohrnart 1981;Andrew et at.1997;
Jones 1980).Jones et al.(1957)reported the presence of burros in Martinez
Canyon and speculated that their use of water sources could interferewith bighorn
sheep use. Burros also inhabited Rockhouse Canyon (north)from approximately
the 1930’s to the early 1970’s (M.Jorgensen,pers. comm.). No burros are
currently known to inhabit thePeninsular Ranges,but they could pose a risk for
bighorn sheep if introduced.Feral horses (Equus cabattus)currently inhabit
Coyote Canyon in Anza-Borrego Desert State Park (Auza-Borrego Desert State
Park,unpublished data)and Palm Canyon (San Jacinto Mountains). Competition
between feral horses and bighorn sheep has not been extensively studied,but
increasing horse populations were reported to coincide with decreasing bighorn
sheep populations in the Silver Peak Range in Nevada (McQuivey 1978).
Similarly,during the 3-day waterhole counts at Anza-Borrego Desert State Park in
1999 and 2000,the continuous presence of 16 and 21 wild horses,respectively,
around a traditionallyused waterhole coincided with an absence of bighorn
coming to water overboth census periods (M.Jorgensen,pers.comm.).
M.Jorgensen has observed that during periods of poor range forage conditions,
horses congregate around water sourcesmorethan usual,causing damage similar
to that of burros by consuming thebest available forage and fouling surface
waters.
Competition with domestic livestock,especially domestic sheep (Brigandi 1995),
has affected bighorn sheep in the past (refer to Appendix A).Cattle were present
in the Peninsular Ranges as early as 1775 (Bolton 1930)and were grazed in large
numbers throughout the range (Turner 1976,Reed 1986,Cunningham and Ohmart
1986).Currently,competition with livestock is low in thePeninsular Ranges
27
because of past and current efforts to limit livestock numbers.However,
competition may still occur in localized situations.Forexample, bighorn use of
Hellhole Canyon has increased measurably since the removal of over two dozen
cattle from the canyon and 117 cattle throughout the park in 1987 (M.Jorgensen,
pers. comm.). In Canebrake Canyon,current Bureau of Land Management
grazing permits allowing cattle to use water sources located below bighorn sheep
lambing areasmaybe affectingthe Carrizo Canyon ewe group. This ewe group
also maybe affectedby cattle that stray out of a grazing allotment in McCain
Valley.In addition,thepotential risk of disease transmission exists as long as
livestock occur in bighorn sheep habitat.
7.DISEASE AND PARASITISM
It hasbeen hypothesized that disease has played an important role in population
dynamics of bighorn sheep in thePeninsular Ranges (DeForge et at.1982,
DeForge and Scott 1982,Turner and Payson 1982,Wehausen et at.1987).
Numerous pathogens havebeen isolated or detected by serologic assay from
bighorn sheep in these ranges.These pathogens include bluetongue virus,
contagious ecthyma virus,parainfluenza-3 virus,bovine respiratory syncytial
virus,Anaptasma, Chtamvdia, Leptospira,Pasz’euretta,Psoroptes,and
Dermacentor (DeForge et at.,1982;Clark et at.1985, 1993;Mazet et at.1992;
Elliott et at.1994;Boyce 1995;Crosbie et at.,1997,DeForge et at.1997).
DeForge et at.(1982) found multiple pathogens (contagious ecthyma virus,blue
tongue,Pasteuretta,and parainfluenza virus)and low lamb recruitment in
association with overall population declines.Between 1982 and 1998,39 lambs
showing signs of illness (lethargy,droopy ears,nasal discharge, and lung
consolidation) were collected from the Santa Rosa (northern and southern),
Jacumba,and In-Ko-PahMountains for disease research and rehabilitation atthe
Bighorn Institute (Ostermann et at.in press).Additionally,DeForge et at.(1995)
documented a population decline throughout the Santa Rosa Mountains during
1983 to 1994,resulting from inadequate recruitment.Although a cause and effect
relationship between disease and population decline has not been clearly
established in thePeninsular Ranges, results from several studies provide support
28
forthis hypothesis (DeForge et at.1982,Clark et at.1985,Wehausen et at.1987,
Clark et at.1993,Elliot et at.1994,DeForge et at.1995).The presence of feral
goats in portions of theSanta Rosa Mountains until the late 1970’s to early 1980’s
may have contributed to exposure of wild bighorn to disease during this period of
population decline (D.Jessup,in th~t.1999).
Analysis of spatial variation in pathogen exposure among bighorn sheep sampled
between 1978 to 1990 showed that Peninsular bighorn sheep populations and
other populations in southern California have higher levels of pathogen exposure
than other populations of bighorn sheep in the State (Elliott et al.1994).
However,serological tests have revealedthe presence of antibodies to several
infectious disease agents in both healthy and clinically-ill animals (Clark et at.
1993,Elliott et at.1994;Boyce 1995,DeForge et at.1997),and essentially all of
the viruses,bacteria,and parasites that have been reported from Peninsular
bighorn sheep appear to be widespread among desertbighorn sheep in thewestern
U.S.(Jessup et at.1990). All evidence indicates that the influence of disease in
thePeninsular Ranges has subsided in more recent years.For example,recent
sampling and examination of bighorn sheep throughout therange indicate that
most animals were clinicallynormal (Boyce 1995;DeForge et at.1997;Bighorn
Institute 1997, 1998,1999).Severalcaveats should be kept in mind when
interpreting serologic testresults of wild animals (Gardner et at.1996).An
animal testing positive for a specific pathogen:1)may ormay not be showing
clinical signs of the infection and may never havebeen adversely affected by the
infection, 2) may no longerharbor the pathogen, 3) mayor may not be resistant to
subsequent re-infection,or 4) may have been exposed to a related pathogen that
induced the formation of cross-reactive antibodies.Onthe other hand,an animal
testing negative:1)may neverhave been exposed to the pathogen, 2) may be
recently infected by the pathogen under scrutinybut not yetproducing antibodies,
or 3)may havebeen exposed to the pathogen and developed an antibody titer that
has subsequently abated.Detection of pathogens does not,in itself,imply a causal
relationship between disease and population declines. Additional research is
necessary to better understand this relationship.Furthermore,it appears that risk
of disease and parasites might differ among ewe groups based on their exposure
29
and their habitat use patterns,so future research should address these questions at
the level of the ewe group and the level of the population.
The reduced influence of disease on Peninsular bighorn sheep (asthey
simultaneously continue to decline)suggests that other factors,such as predation,
habitat loss/modification,and human related disturbance currently limit the
population.Nonetheless,disease and/orparasites may still threaten bighorn sheep
in the northern Santa Rosa Mountains.Bighorn sheep in this group have
exhibited low lamb recruitment (refer to section I.B.3),and clinical signs of
illness have been observed among adults and lambs (DeForge and Scott 1982;
Bighorn Institute 1997;DeForge and Ostermann 1998a;E.Rubin,pers.comm.).
Inaddition, during 1991 to 1998,internal parasites (trichostrongyles)were
detected in this ewe group (DeForge and Ostermann 1998b;E.Rubin and W.
Boyce,pers.comm.),while similar sampling failed to detect theseparasites in
bighorn sheep from the remainder of the range (DeForge ei’at.1997;Bighorn
Institute 1998;E.Rubin and W.Boyce,pers.comm.). Habitat modification and
altered habitat use patterns may increase the risk of disease and parasites in this
group by increasing parasite survival or transmission rates in irrigated landscapes
(Bighorn Institute 1997,DeForge and Ostermann 1998b).It has been suggested,
for instance,that the density of Rocky Mountain bighorn sheep is important in the
transmission of lungworms (Protostrongytus)in mesic areas where the snail
intermediate hosts aresufficiently common (Uhazy and Holmes 1973).The
different ewe groups in thePeninsular Ranges apparently havedifferent pathogen
exposure profiles and risks.
C.ABUNDANCE AND DISTRIBUTION
1.HISTORIC ABUNDANCE AND DISTRIBUTION
Bighorn sheep have been documented in thePeninsular Ranges since early
explorers such as Auza observed them in the 1700’s (Bolton 1930);however,
rangewide population estimates were not made until the I 970’s.Published
estimates were as high as 971 in 1972 (Weaver 1972),and 1,171 in 1974 (Weaver
1975),while more recent estimates were 570 in 1988 (Weaver 1989),400 in 1992
(U.S.Fish and Wildlife Service 1992),and between 327 to 524 in 1993 (Torres et
at.1994).Accuracy of the estimates in theearly 1970’s (pre-helicopter surveys),
30
especially in the San Jacinto Mountains,has been questioned by several
authorities (Wehausen 1999;V.Bleich,pers. comm.) (see section I.C.3 below for
more details).
An examination of past records and currentdata suggests that the distribution of
bighorn sheep has been altered during the past 25 years.No new ewe groups have
been documented to form,but ewe groups along the Mexican border and in the
northern San Jacinto Mountains (north of Chino Canyon)have disappeared since
the 1980’s.Loss of the border population was poorly documented but the
construction of Interstate 8 in themid-1960’s,railroad activity,livestock grazing,
poaching,and fire suppressionappear to be likely contributing causes (Rubin et
at.1998).DeForge et at.(1997)suggested that disturbance and habitat
fragmentation were theprincipal causes of changes in distribution in the northern
San Jacinto Mountains.In the northern Santa Rosa Mountains, the number and
distribution of ewes is substantiallyreduced from the 1980’s,with formerly
important use areas,such as Carrizo and Dead Indian Canyons,currently
supporting few animals (J. D.Goodman,University of Redlands,unpublished
data 1963;DeForge and Scott 1982;DeForge et at.1995;Bighorn Institute 1998,
1999).The Fish Creek Mountains and areas to the west of the Vallecito
Mountains (the Sawtooth Range,Oriflamme Mountains,and the lower elevations
of the Laguna Mountains) are believed to have supported “transient”use by sheep
in the past (Weaver et at.1968,Weaver 1972).
Thedistribution of ewes has become more fragmented in the recent past,although
evidence is not available to suggest that ram use has been curtailed.At the
southern distributional limits of the U.S.population, the construction of Interstate
8 preceded the later disappearance of bighorn sheep alongthe Mexican border,
though rams still continue to be foundoccasionally (Jessup,in titt.2000).At the
extreme northern end of their range,ewe group occupation ceased in the northern
San Jacinto Mountains about 20 years after construction of the Palm Springs
Aerial Tramway in Chino Canyon,though rams still cross Chino Canyon and
make use of much of the area formerlyoccupied by the ewe group.Rubin et at.
(1998) suggested that in portions of the range,roads or increased traffic have
contributed to fragmentation by restricting ewe movement, as evidenced by the
distributional limits of four ewe groups currently coinciding with roadways.In
the 1970’s,ewes were observed to crossHighway 74 in the Santa Rosa Mountains
31
(V.Bleich,pers.comm.;D.Jessup,in titt.1999)and sheep were struck by cars
“where ancestral bighorn trails arebisected by the highway”(Turner 1976).
Though a radio-collared ewe crossed Highway 74 in 1982 (DeForge and Scott
1982),no radio-collared ewes were observed to cross this road from 1993 to the
present. CaliforniaDepartment of Transportation records indicate that traffic on
this road has approximatelytripled since 1970.Since 1991,at least five rams
have been struck by cars while crossing Highway 74;two were killed (Bighorn
Institute 1991, 1999).In addition,a significant reduction in bighorn use in
portions of the Santa Rosa Mountains has been observed sincethe construction of
theDunn Road (DeForge in litt.1997).
2.RECENT ABUNDANCE AND DISTRIBUTION
Recent abundance estimates of Peninsularbighorn sheep north of the U.S.-Mexico
border were 347, 276,and 334 animals (excluding lambs)in 1994,1996,and
1998,respectively (Table 5).Currently,at least eight subpopulations (ewe
groups) exist in the range (Rubin et at.1998)(Figure 3,Table 6).It is possible
that the Santa RosaMountains southeast of Highway 74 and the Vallecito
Mountains are each inhabited by more than one ewe group,but additional data are
required to confirm this.During 1994 to 1998,thelargest ewe groups in the
Peninsular Ranges typically consisted of less than 30 ewes, while some groups
had less than 15 ewes (DeForge et at.1997;Rubin et at.1998, 1999;Ostermann
et at.in press)(Table 6). The San Jacinto ewe group currently consists of six
known ewes (Bighorn Institute 1999).Although permanent emigration of ewes
between groups has not been observed,a limited number of temporary moves
between some groups were documented in recent years (Bighorn Institute 1998,
1999;Rubin et at.1998),and genetic evidence indicates ewe movement in the
past (Boyce et at.1997).Ram movements between ewe groups aremore frequent
(DeForge et at.1997,Rubin et at.1998,refer to section I.B.2).These
observationaldata are supported by genetic analyses (Boyce et at.1997,Boyce et
at.1999,refer to section I.A.3).The existence of distinct ewe groups that are
connectedby limited movement of bighorn sheep suggests that Peninsular bighorn
sheep comprise a metapopulation (Levins 1970,Torres et at.1994,Bleich et at.
1996,Boyce et at.1997).Bighorn sheep exhibit a patchydistribution as a result
of natural breaks in mountainous habitat(Schwartz et at.1986;Bleich et at.
1 990a,1996),and genetic analyses support the hypothesis that discrete ewe
32
Figure 3.Distribution of bighorn ewes in the Peninsular Ranges, California,1992-1995.Stippled and
shaded areas indicate regions used by home-range groups of ewes identified in this study.1-Carrizo
Canyon,2a-south Vallecito Mountains,2b-northVallecito Mountains,3-south San Ysidro Mountains,
4-north San Ysidro Mountains, 5-Coyote Canyon,6a-Santa Rosa Mountains east of Highway 74
(south),6b-Santa Rosa Mountains east of Highway 74 (Martinez Canyon),6c-Santa Rosa Mountains
east of Highway 74 (Deep Canyon),7-Santa Rosa Mountains west of Highway 74,8-San Jacinto.
Mountains (U indicates general location of this group,DeForge et aI.1997).Wide hatch marks
indicate possible connectivity between ewe groups in the Vallecito Mountains and in the Santa Rosa
Mountains.(Reprinted with permission from Rubin et al.1998).
33
0 10 20 Kilometers Jacumua
Mtns
United StateS~Mexico border
groups existed in thepast (Boyce et at.1999).However,it appears that some
separations between groups are of anthropogenic origin and movement of ewes
has been reduced by human activity (DeForge et at.1997,Rubin ei at.1998,refer
to section L.C.2).
Two captive populations of Peninsular bighorn sheep currently exist.The Living
Desert Museum,an educational and zoo facility in Palm Desert,California,
maintains a small group (seven adult females and two adult males) at its facility.
Theseanimals are used primarily for educational purposes (Terrie Correll, The
Living Desert,pers. comm.). The Bighorn Institute,also in Palm Desert,
maintains a small captive herd of approximately 30 animals.This private,
nonprofit organization, established in 1982 under theauthorization of the
California Department of Fish and Game with a Memorandum of Understanding,
Table 5.Abundance estimates (and 95 percent confidence intervals) of bighorn
sheep in the Peninsular Ranges north of the U.S.-Mexico border during 1994, 1996,
and 1998. Estimates exclude lambs (DeForge et al.1995;Bighorn Institute 1996,
1998).
Region 1994 1996 1998 Source(s)
Anza-Borrego
Desert State Park
(including all
habitat outside of
Santa Rosa and San
Jacinto Mountains)
214.0
(149.8 to
278.6)
163.0
(131.8 to 194.2)
180.7
(149.5 to
211.9)
Rubin etat.
1998,1999
Santa Rosa
Mountains
115.5
(91.5 to 139.5)
93.8
(71.8 to 115.8)
129.0
(91.1 to 166.9)
DeForge et at.
1995,Bighorn
Institute 1996,
1998
San Jacinto
Mountainsa
17 (NA)19 (NA)24 (NA)DeForge et at.
1997,Bighorn
Institute 1998
Total 347
(253 to 458)
276
(210 to 439)
334
(262 to 434)
aMinimum number known to be alive, based on absolute counts (intensive field studies of radio-
collared animals in combination with annual helicopter surveys).Confidence intervals
unavailable.
34
conducts research and maintains a breeding herd at its facility (refer to section
J.E.3).Since 1985,77 animals from this herd have been released into the wild.
Ewe groups in the San Jacinto and northern Santa Rosa Mountains havebeen
augmented with captive-reared sheep (n equals 3 in 1997 and 74 during 1985-
1998,respectively)(Ostermann et at.in press).
3.POPULATION TRENDS
Although based on different techniques,a comparison of early (pre-1977) and
currentpopulation estimates suggests a great decline in Peninsular bighorn sheep
numbers.Early estimates were based on waterhole counts or foot surveys,
whereas helicopter surveys were used to generate population estimates starting in
Table 6.Ewe abundance estimates (and 95 percent confidence intervals) per ewe
group generated from helicopter surveys during 1994, 1996,and 1998 (Rubin et al.
1998,1999;DeForge et al.1997;DeForge et al.1995;Bighorn Institute 1996,1998).
Current ewe group
delineation
Year
1994
Year
1996
Year
1998
I.Carrizo Canyon 39.0
(20.9-57.2)
23.5
(17.7-29.3)
19.0
(19.0-19.0)
2.Vallecito Mountains 17.7
(6.7-28.6)
19.0
(19.0-19.0)
30.2
(24.3-36.1)
3.South SanYsidro
Mountains
15.3
(9.9-20.6)
12.3
(6.9-17.8)
23.0
(8.3-37.7)
4.North San Ysidro
Mountains
32.0
(9.5-54.5)
22.1
(16.2-28.1)
15.3
(6.2-24.5)
5.Coyote Canyon 21.8
(15.4-28.2)
23.0
(5.5-40.5)
22.8
(17.5-28.0)
6.Santa Rosa
Mountains
east of Hwy.74
66.2
(42.4-90.0)
83.0
(27.3-138.7)
48.3
(31.6-65.0)
7.SantaRosaMts.
west of Hwy.74
15.9
(13.5-18.3)
14
(14.0-14.0)
11.6
(9.7-13.5)
8.San Jacinto
Mountainsa
(
(na)
(
(na)
(
(na)
~Minimumnumber known to be alive,based on absolute population counts (intensive field studies
of radiocollared animals in combination with annual helicopter surveys).Confidence intervals are
unavailable.
35
1977.Annual helicopter surveys conducted in the Santa Rosa Mountains since
1977 indicate a regional population decline (DeForge et at.1995,Wehausen et at.
1987),with a 69 percent decline observed between 1984 and 1994 (DeForge et at.
1995).Rubin et at.(1998)examined trends in abundance outside of the Santa
Rosa Mountains with the use of a 26-yeardataset of annual waterhole count
observations in Auza-Borrego Desert State Park.These data indicated that
declines had occurred in some,but not all,ewe groups.This result suggests that
abundance trends are independent among ewe groups,and is in agreement with
field data that show independent differences in lamb recruitment and adult
survival among ewe groups (Rubin et at.2000.,Hayes et at.2000,refer to
sections I.B.3 and I.B.4).Climatic patterns are highly correlated across the
Peninsular Ranges,suggesting that other local factors specific to ewe groups play
important roles in determining long-term abundance trends (Rubin et at.1998).
Independent population trends also were observed among ewe groups in the
Mojave Desert (Wehausen 1992).
DeForge et at.(1997) found that bighorn sheep in the San JacintoMountains
declined between 1984 and 1987.Since that time the subpopulation inhabiting
these mountains has been stable but precariously small (Table 7).In the Santa
Rosa Mountains,mark-recapture estimatesgenerated from helicopter survey data
indicated that bighorn sheep numbers appeared to remain stable at low numbers
from 1990 to 1995,followinga large population decline (DeForge et at.1995).In
thenorthern part of these mountains,thecurrent number of animals is
approximately 50 percent of the number present during the 1980’s (Table 8).
Helicopter surveys south of theSanta Rosa Mountains, encompassing all
Peninsular bighorn sheep habitat outside of the Santa Rosa and San Jacinto
Mountains, indicated a 28 percent decline in ewe numbers in a recent 2-year
period (from an estimate of 141 females in 1994 to 102 females in 1996;Rubin et
at.1998),and a statistically non-significant increase (from approximately 102 to
112 females)from 1996 to 1998 (Rubin et at.1999).
Though cause and effect relationships for these population declines among ewe
groups have not been documented,likely contributing factors are:high predation
rates; disease;and cumulative effects of habitat loss,modification,fragmentation
and human-related disturbance.
36
a
Table 7.Ewe population estimates for the San Jacinto Mountains from 1993 to
1999 (DeForge et al.1997; Bighorn Institute 1997,1998,1999).
Year Number of ewes
(yearlings and adults)
1993 10
1994 7
1995 8
1996 7
1997 9
1998 8
1999 6
a
Table 8.Fall population estimates of adult (1 year or older) bighorn sheep in the
northern Santa Rosa Mountains from 1985 to 1998 (Ostermann et al.in press).
Fall population Number of captive-
estimate of reared bighorn in
yearling and adult the population
Year bighorn (ewes)
1985 40(22)1
1986 46(25)5
1987 52(30)16
1988 52(33)19
1989 50(32)20
1990 41(24)26
1991 30(21)17
1992 35 (24)20
1993 27(17)16
1994 23(11)16
1995 24(10)16
1996 21(10)16
1997 22(11)16
1998 22(10)15
a minimum number known to be alive,based on absolute population count.
37
D.REASONS FOR LISTING
The following discussion is organized according to the listing criteria under
section 4(a)(1)of the Endangered Species Act.
I.THE PRESENT ORTHREATENED DESTRUCTION,MODIIFICATION,
OR CURTAILMENT OF THEIR HABITAT OR RANGE
Habitat loss is a leading cause of current species extinctions and endangerment
(Burgman et at.1993).It represents a particularly serious threat to Peninsular
bighorn sheep because they live in a narrow band of lower elevation habitat that
represents some of the most desirable real estate in theCalifornia desert and is
beingdeveloped at a rapidpace.At least 7,490 hectares (18,500 acres or about 30
square miles)of suitable habitat has been lost to urbanization and agriculture
within the range of the three ewe groups that occuralong the urban interface
between Palm Springs and La Quinta (see the maps referenced in Appendix B).
Within the narrow band of habitat, bighorn sheep need to be able to move daily,
seasonally,and annually to make use of sparse and sometimes sporadically
available resources found within their home ranges.As humans encroach into this
habitat,these resources are eliminated or reduced in value,and the survival of ewe
groups is threatened. Bighorn sheep are also sensitive to habitat loss or
modification because they are poor dispersers (Geist 1967,1971),largely learning
their ranging patterns from older animals rather than on their own(refer to section
I.B.2).When habitat is lost or modified, the affected group is likely to remain
within their familiar surroundings but with reduced likelihood of population
persistence,due to reduced quantity and/or quality of resources.Habitat
fragmentation is a major threat to bighorn sheep (Schwartz et at.1986,Bleich et
at.1996)and Peninsular bighorn sheep are particularly vulnerable because of the
narrow elevational band of suitable habitat, behavior (use of low elevation habitat
and ewe home range fidelity),and population structure.Fragmentation poses a
particularly severe threat to species with a metapopulation structure because
overall survival depends on interaction among subpopulations.Encroaching
urban development and anthropogenic disturbances have the dual effect of
restricting animals to a smaller area and severing connections betweenewe
groups.Movements by rams through downtown Palm Springs (Tevis 1959,
Desert Sun,9/12/1995, DeForge et at.1997)mayprovide insight intopast bighorn
38
movement patterns.Former long-distance movements across the valley floor to
the north and east of the Coachella Valley,though never documented,likely
occurred as they currently still do between other mountain ranges in the desert
southwest (Bleich et at.1996;J. Wehausen, pers. comm.). The potential for such
movements now has been eliminated by high density urban development,major
freeways,fences,agriculture,and canals.The movement of rams and occasional
ewesbetween ewe groups maintains genetic diversity and augments populations
of individual ewe groups (Soul~1980,Krausman and Leopold 1986,Schwartz et
at.1986,Burgman et at.1993,refer to section II.A.2).The occasional movement
of ewes can result in a “rescue effect”(Brown and Kodric-Brown 1977)by
increasing the number of ewes in a declining ewe group.Temporary moves by
females between neighboring ewe groups could also provide new habitat
knowledge that facilitatesfuture range expansion (Geist 1971).Increased
fragmentation reduces such possibilities.
Beyond physical barriers to movement,fragmentation also canresult from less
obvious forms of habitat modification.As described above in section I.C.2,
increased traffic on roads apparently make bighorn sheep,especially ewes,
hesitant to crossthese roads (Rubin et at.1998).Animals that do crosssuffer an
additional risk of mortality (Turner 1976,McQuivey 1978,Cunningham and
deVos 1992,DeForge and Ostermann 1 998b,Bighorn Institute 1999),with the
result that a group whose range is bisected by the road can have reduced viability
in the long term (Cunningham and deVos 1992). Human disturbance along roads
and trails cancause sheep to avoid those areas (Papouchis et at.1999),potentially
affecting bighorn sheep movement and habitat use (refer to section I.B.2),thereby
“fragmenting”bighorn sheep distribution although the habitat appears to be intact.
Development and human populations along the eastern slope of the Peninsular
Ranges continue to grow ata rapidpace atthe lower and upper elevational
boundaries of Peninsularbighorn sheep habitat.TheCoachella Valley
Association of Governments anticipates that by the year 2010,the human
population there will increase from 227,000 to over 497,000,not including
165,000 to 200,000 seasonal residents. Bighorn population declines typically have
been most pronounced in ewe groups adjoining the urban interface in Coachella
Valley.The decline in local bighorn populations in the San Jacinto and northern
Santa Rosa Mountains parallels the demise of sheep populations near
39
Albuquerque and Tucson (Krausman et at.in prep.),other major metropolitan
areas that have encroached into sheep habitat in the desert southwest.Other
cumulative factors caused by human activities within bighorn sheep habitat are
discussed in detailbelow (refer to section I.D.5).
2.OVERUTILIZATION FOR COMMERCIAL,RECREATIONAL,
SCIENTIFIC,OR EDUCATIONAL PURPOSES
There is no regulated hunting season forPeninsular bighorn sheep in the United
States,and poaching is rarely documented.Precautions should continue to be
taken,however,to prevent poaching.The Bighorn Institute and Living Desert
Museum each maintain a captive population of Peninsular bighorn sheep for
scientific and educational purposes.This use is thought to have no negative
impact on free-ranging bighorn sheep.Researchers are required to obtain State
and Federalpermits before handling Peninsularbighorn sheep.Although current
research techniques are not believed to have a negative impact on bighorn sheep,
how research is carried out must always be a consideration (Bleich et at.1994, see
Appendix D).
3.DISEASE AND PREDATION
The westward spread of Europeans and their domestic livestock across North
America wasthought to play a significant role in reducing thedistribution and
abundance of bighorn sheep due to the introduction of new infectious diseases
(Spraker 1977,Onderka and Wishart 1984).In particular, domestic sheep have
beenrepeatedly implicated in Pasteuretta pneumonia die-offs of bighorn sheep.
In the Peninsular Ranges,a number of pathogens have been isolated or detected
by serological assay from bighorn sheep (refer to section I.B.7).In the Santa Rosa
Mountains,many years of high lamb mortality from an apparent disease epizootic
contributed to a population decline from inadequate recruitment (DeForge and
Scott 1982,Wehausen et at.1987,DeForge et at.1995).Although diseases do
not currently appear to be limiting population growth throughout the range,they
pose a potential threat that could occur at any time,especially if disease episodes
can be precipitated by chronic levels of disturbance (Geist 1971,Hamilton et at.
1982,Spraker et at.1984,King and Workman 1986,Festa-Bianchet 1988,Desert
Bighorn Council 1992).
40
Mountain lion predation is an apparent limiting factor for some ewe groups in the
Peninsular Ranges;69 percent of 61 mortalities of radiocollared sheep from 1992
to 1998 between Highway 74 in the Santa Rosa Mountains and Mexican border
are attributed to mountain lions (Hayes et at.2000).The relatively low
survivorship of adults (section I.B.4)and associated population declines have
recently affected therecovery of most ewe groups.
4.THE INADEQUACY OF EXISTING REGULATORY MECHANISMS
In 1971,the Peninsularbighorn sheep was listed under California State law as a
rare species.The designation was changed to “threatened”in 1984 to standardize
terminology of the amended California Endangered Species Act.The Peninsular
bighorn sheep also is listed by the State as a “fully protected species”under the
Fish and Game Code (Section 4700).The California Environmental Quality Act,
which allows public comment and generallyrequires mitigation for significant
environmental effects,including adverse impacts to State and federally listed
species, has not resulted in conservation benefits sufficient to maintain stable
populations.
The Bureau of Land Management and California Department of Fish and Game
jointly developed theSanta Rosa Mountains Habitat Management Plan in 1980
and McCainValley Habitat Management Plan in 1984 to address the needs,as
identified at that time,of bighorn sheep in these areas.The Department of Fish
and Game also established the Carrizo Canyon and Magnesia Spring Ecological
Reserves to protect important watering sites.Theeffectiveness of these
management areas in the SantaRosa Mountains has been limited because of
heavy human use, lack of management presence,and limited funding.The lack of
funds also has prevented acquisition of all private lands within theprotected areas,
resulting in continued fragmentation by development.The existence of private
inholdings within theboundaries of Anza-Borrego Desert State Park is also a
potential threat to Peninsular bighorn sheep because these lands include prime
bighorn sheep habitat,but a lack of funding and/or unwilling sellers have
prevented public acquisition to date.
In California,it is Bureau of Land Management policy to conserve State-listed
plants and animals and to use its authorities in furtherance of the purposes of the
41
State of California’s rare and endangered species laws. The Bureau of Land
Management and California Department of Fish and Game have developed
conference procedures to promotecooperation in the application of this policy,
although they are inconsistently implemented.Neither State listing nor the
proposed Federal listing of bighorn sheep prompted land management agencies to
effectively address adverse effects associated with land exchanges,recreational
and commercial uses,and livestock grazing programs.Although domestic sheep
on Federal lands in the Peninsular Ranges are not a current threat,adverse effects
from cattle grazing (including resource competition,degradation of water sources,
and disease transmission)require resolution.
A number of development projects with potentially significant adverse effects on
bighorn sheep recently have been approved because project proposals and local
General Plans for most of the cities in the Coachella Valley inadequately address
threats to the long-term conservation of Peninsularbighorn sheep.Though some
habitat protection is derived from the presence of the State and federally listed
least Bell’s vireo (Vireo bettii pusittus)and southwestern willow flycatcher
(Empidonax traitiji extimus),benefits are limited due to the specialized habitats
(riparian woodland)used by these birds.Section 404 of the Clean Water Act
provides protection through the U.S.Army Corps of Engineers’regulation of the
discharge of dredged and fill material into certainwaters and wetlands of the
United States,but Corps’jurisdiction can be avoided under various situations.
5.OTHER NATURAL OR MANMADE FACTORS AFFECTING THEIR
CONTINUED EXISTENCE
Drought:Prolonged drought is a natural factor that can have negative impacts on
desert bighorn sheep populations,either by limiting water sources or by affecting
forage quality (Rosenzweig 1968,Hansen 1980a,Monson 1980,Douglas and
Leslie 1986,Wehausen et at.1987,refer to section I.B.1).During drought years,
theconcentration of bighorn sheep nearremaining water sources may increase
competition for forage as wellas water,thereby limiting population growth
through densitydependent regulation (Caughley 1977,Gotelli 1995).In addition,
increased density potentially renders animals more susceptible to diseases or
parasites (Anderson and May 1979,May and Anderson 1979).
42
Human Disturbance:Human development affects sheep through habitat loss,
fragmentation,or other modification (refer to section I.D.1 .1),but these impacts
also extend intobighorn sheep habitat beyond the urban edge.Though a growing
humanpopulation and increased activity adjacent to and within bighorn sheep
habitat have potential to adversely affect bighorn sheep,accurate mapping of trail
locations and quantitative monitoring of recreational trail use have not been
conducted.In addition, incremental proliferation of trails has gone largely
unaddressed.
Numerous researchershave expressed concern over the impact of human activity
on Peninsularbighorn sheep (e.g.,Jorgensen and Turner 1973,Hicks 1978,Olech
1979,Cunningham 1982,DeForge and Scott 1982,Gross 1987,Sanchez et at.
1988),as well as on sheep in otherareas (Graham 1980,Gionfriddo and
Krausman 1986,Smith and Krausman 1988).Leopold (1933)considered bighorn
sheep a wilderness animal because they fail to thrive in contact with urban
development.A variety of human activities such ashiking,mountain biking, hang
gliding,horseback riding,camping,hunting,livestock grazing,dog walking,and
use of aircraft and off-road-vehicles havethe potential to disrupt normal bighorn
sheep social behaviors and use of essential resources,or cause bighorn sheep to
abandon traditional habitat (McQuivey 1978,MacArthur et at.1979,Olech 1979,
Wehausen 1979,Leslie and Douglas 1980,Graham 1980,MacArthur et at.1982,
Bates and Workman 1983,Wehausen 1983,Miller and Smith 1985,Krausman
and Leopold 1986,Krausman et at.1989,Goodson 1999,Papouchis et at.1999).
Attempts to ascribe relative importance,distinguish among,or generalize the
effects of different human activities on sheep behavior arenot supportable,given
the range of potential reactions reported in the literature and the different variables
impinging on given situations.
Although cases have been cited in which bighorn sheep populations did not
appear to be affected by human activity (e.g.,Hicks and Elder 1979,Hamilton et
at.1982),numerous researchers,including these authors,have documented altered
bighorn sheep behavior in response to anthropogenic disturbance.Even when
bighorn sheep appear to be tolerant of a particular activity,continued and frequent
use can cause them to avoid an area,eventually interferingwith use of resources,
such as water,mineral licks,lambing or feeding areas,or use of traditional
movement routes (Jorgensen and Turner 1973,McQuivey 1978,Graham 1980,
43
Leslie and Douglas 1980,DeForge and Scott 1982,Hamilton et’at.1982,
Krausman and Leopold 1986,Rubin ei’at.1998).In addition,disturbance can
result in physiological responses suchas elevated heart rate (MacArthur et at.
1979,1982),even when no behavioral response is discernable.It was repeatedly
cautioned that human disturbance threatened the viability of a bighorn sheep
population in the Santa Catalina Mountains,outside of Tucson,Arizona
(Etchberger et at.1989,Krausman et at.1989,Krausman 1993,Krausman et at.
1995).In these mountains,Etchberger ei’at.(1989)found that habitat abandoned
bybighorn sheep had greater human disturbance than occupied habitat. Today,
this population is extinct,or nearly so,and human activities apparently
contributed to its demise (Schoenecker 1997;Krausman et at.in prep.;
P.Krausman,pers.comm.).
A high level of humanactivity occurs in thehabitat of Peninsular bighorn sheep.
Forexample, during a recent 10-hourperiod in spring,49 hikers,2 mountain
bikers,and 13 dogs (9 unleashed)were counted in Carrizo Canyon in the northern
Santa Rosa Mountains (Bureau of Land Management,unpublished data).This
trail bisects a lambing areathat has receivedreduced levels of sheep use in recent
years.A ewe and her lamb were observed to wait for over S hours to come to
water because of continuous off-road vehicle traffic (Jorgensen and Turner 1973).
Jorgensen (1974)reported that bighorn sheep use of important waterholes was 50
percent lower on dayswith off-road vehicle traffic.In Carrizo Canyon,Hicks
(1978)observed a group of bighorn sheep flee from a spring area when a Navy
helicopterpassed overhead, Olech (1979)noted that bighorn sheep did not use
waterholes whenmotorcycles were heard nearby,and Cunningham (1982)
speculated that the use of springs by humans (recreationistsand persons entering
California across the U.S.-Mexico border)reduceduse of this resource by
bighorn sheep.Sanchez ei’at.(1988) recommended that future management
efforts should attempt to reduce human impacts on bighorn sheep in Carrizo
Canyon.As thehuman population of the southern Californiadesert grows,such
human activity in bighorn sheep habitat will increase.
Bighorn sheep responses to human activity are difficult to predict (Miller and
Smith 1985)and depend on type of activity,season of the activity,elevation of the
activity relative to resources (Hicks 1978,Graham 1980),and distance of the
activity from resources critical to bighorn sheep (Miller and Smith 1985),among
44
other variables.For instance,eweswith lambs typically aremore sensitive to
disturbance (Light and Weaver 1973,Wehausen 1980),as are animals that are
approached from higher elevations (Hicks 1977,Graham 1980).Papouchis et at.
(1999) found bighorn sheep to be more sensitive to disturbance during spring and
fall, corresponding with the lambing and rutting seasons.Etchberger and
Krausman (1999)observed the abandonment of lambing habitat while
construction activities were ongoing.
Livestock Grazing and Water Diversion:Human actions also indirectly affect
use of resources by bighorn sheep.Domestic livestock and feral animals can
reduce the availability and quality of resources (water and forage)required by
bighorn sheep (refer to section I.B.6),and can function as potential vectors for
diseases such as bluetongue virus.In portions of the range,water has been
pumped from aquifers and diverted away from springs for use by ranches and
private residences, reducing and eliminatingthe water sourcesupon which
bighorn sheep depend (Tevis 1961;Blong 1967;Turner 1976;M.Jorgensen,pers.
comm.).
Non-native Plants:In the Peninsular Ranges,the presence of tamarisk (Tamarix
sp.),also known as saltcedar,representsa serious threat to bighorn sheep.This
exotic plant was introduced as an ornamental and windbreakbut is now a major
weed problem (Lovich et at.1994).It consumes large amounts of water and has
rapidreproductive and dispersal rates (Sanchez 1975,Lovich et at.1994),
enabling it to outcompete native plant species in canyon bottoms and washes.It
has the following negative effects on bighorn sheep:1)itreduces or eliminates
standing water that bighorn sheep depend on,2) it outcompetes plant species that
bighorn sheep feed on,and 3)it occurs in thick,often impenetrable stands that
block access ofbighorn sheep to water sources and provide cover for predators.
Tamarisk has also beenrecognized as a threat to otherbighorn sheep populations
(Sanchez 1975)and native ecosystems in general (Lovich et at.1994). Effective
eradication methods are possible (Barrows 1994)and eradication programs
currently are underway by the Agua Caliente Band ofCahuilla Indians,Bureau of
Land Management,and Auza-Borrego Desert State Park.
Fire Suppression:As described in section I.B.2 of this recovery plan,bighorn
sheep rely on vigilance and visibilityto detect and avoid predators.Long-term
45
fire suppressionresults in taller and more dense stands of vegetation,thereby
reducing openness and visibility and in turn making bighorn sheep more
susceptible to predation (Sierra Nevada Bighorn Sheep Interagency Advisory
Group 1997).In this same manner,fire suppression can influence thedistribution
and habitat use patterns of bighorn sheep by causing avoidance of areas with low
visibility (Risenhoover and Bailey 1985,Wakelyn 1987,Etchberger et at.1989,
Etchberger et at.1990,Krausman 1993,Krausman et at.1996).In addition,Graf
(1980)suggested that fire suppression reduces forage conditions in some bighorn
sheep ranges.In the Peninsular Ranges,changes in vegetation succession are
evident in some portions of bighorn sheep range,primarily in higher elevation
chaparral and pinyon-juniper habitats,and have apparentlyinfluenced bighorn
sheep use of certain canyons and springs (M.Jorgensen, pers. comm.). Although
temperature and rainfall likely influence the pattern of vegetation associations
along the eastern slopes of the Peninsular Ranges more than fire frequency does,a
number of researchers have pointed out that fire is an important tool in the
management of bighorn sheep habitat (Graf 1980,Smith and Krausman 1988,
Krausman et at.1996,Sierra Nevada Bighorn Sheep Interagency Advisory Group
1997).
E.PAST AND CURRENT MANAGEMENT!CONSERVATION
ACTIVITIES
1.FEDERAL AGENCIES
1.1 United States Fish and Witdt~fe Service.We listed the Peninsular bighorn
sheep as a Category 2 candidate from September 18,1985 (50 FR 37958) until
May 8,1992,when it was proposedfor Federal listing as an endangered species
(57 FR 19837).Between the date of the proposed rule and final listing on March
18,1998 (63 FR 13134),certain Federal activities were reviewed under the
section 7 interagency regulations (50 CFR Part 402) and conference procedures
forproposed species.Since Federal listing,themandatory requirements of
sections 7,9,and 10 of the Endangered Species Act have been in effect,in
addition to theallocation of recovery funding to theState under sections 4 and 6
of the Act.On July 5,2000,we proposed to designate critical habitat throughout
the Peninsular Ranges in California (65 FR 41405).This recovery plan is
prepared pursuant to section 4(f)of the Endangered SpeciesAct, which requires
46
us to give priority to thepreparation and implementation of recovery plans to
those species that are most likely to benefit from such recovery plans,particularly
those that are,or may be,in conflict with construction or other development
projects or otherforms of economic activity.
1.2 Bureau of Land Management.Approximately 26 percent of bighom sheep
habitat in the PeninsularRanges is on public lands administered by the Bureau of
Land Management (Figure 4).This management was custodial in thePeninsular
Ranges until implementation of the California Desert Conservation Area Plan
began in 1980.Implementation of this plan included preparation of the Santa
Rosa Mountains Habitat Management Plan (1980), McCain Valley Wildlife
Habitat ManagementPlan (1984),and In-Ko-Pah Area of Critical Environmental
Concern Management Plan (1988), which identifiedactions to be taken for the
benefit of bighorn sheep in the Peninsular Ranges.From 1988 to the present,
using Land and Water Conservation Funddollars appropriated by Congress and
taking advantage of land gifts ftom private individuals,the Bureau of Land
Management acquired about 4,520 hectares (11,165 acres)of bighorn sheep
habitat in thePeninsularRanges, primarily in the Santa Rosa Mountains National
Scenic Area.It should be noted that withoutthehelp of the Santa Rosa
Mountains Conservancy,a group of private citizens concerned with conservation
of theSanta Rosa Mountains, the Land and Water Conservation Funds ‘might not
havebeen made available for these purchases.Other conservation activities
included:
•Installation of gap fencing to eliminate cattle grazingfrom steep terrain
and from water sources in canyons;
•Reduction in grazingpressure on allotments;
•Closure of most routes of travel east of McCain Valley Road, except to
private inholdings,to ranchers,and to Carrizo and Sacatone Overlooks;
•Designation of wilderness study areas and subsequent management for
non-impairment of wilderness values;
•Designation of Jacumba, Carrizo Gorge, Coyote Mountains, Sawtooth
Mountains,Fish Creek Mountains,and Santa Rosa Wilderness Areas by
Congress,with attendant elimination of vehicular access;
•Tamarisk control efforts around water sources;
•Establishment of the Santa Rosa Mountains National Scenic Area Visitors
Center to provide public education;
47
•Financial assistance to the Bighorn Institute during its formative years,as
well as land transfer and lease under the Recreation and Public Purposes
Act;
•Temporary closure to dogs on most lands in the Santa Rosa Mountains
National Scenic Area;and
•Closure of roads into Dead Indian Canyon and Carrizo Canyon.
OnOctober 25,2000,legislation was signed to create the Santa Rosa and San
Jacinto Mountains National Monument. The monument covers 110,000 hectares
(272,000 acres),including lands administered by the Bureau of Land
Management,U.S.Forest Service,California Department of Fish and Game,
California Department of Parks and Recreation,Agua Caliente Band of Cahuilla
Indians,Coachella Valley Conservancy,and private owners.The designation will
prohibit mining and off-road vehicle use on federal lands,support coordinated
land management by federal agencies,and increase the area’s funding priority.
1.3 US.Forest Service.The San Bernardino National Forest is responsible for
management of bighorn sheep habitat on some public lands.Approximately 3
percent of bighorn sheep habitat in the PeninsularRanges is on U.S.Forest
Service land (Figure 4).Since 1978,the Forest Service has acquired 3,107
hectares (7,680 acres)of land in orwithin 1.6 kilometers (1 mile)of Peninsular
bighorn sheep range.Current management of the San Bernardino National Forest
is guided by the Forest Land and Resource Management Plan (Forest Plan)
established in 1989.Forest Plan standards and guidelines pertaining to Peninsular
bighorn sheep include the following:“coordinate with Bureau of Land
Management to manage the Santa Rosa bighorn sheep population in accordance
with the (Santa Rosa Mountains Wildlife)habitat management plan”;“establish
seasonal closures as necessary to protect important habitat”; “manage domestic
sheep and goat grazing to prevent disease transfer to bighorn sheep [a minimum
3.2-kilometer (2-mile) buffer is recommended]”;and “avoid introducing barriers
to movement of bighorn sheep.”Recent proposed changes in management
relative to Peninsular bighorn sheep are discussed in a programmatic Biological
Assessment completed by the San Bernardino National Forest (January 27, 1999).
This assessment evaluated all ongoing activities occurring in Peninsular bighorn
sheep habitat within the San Bernardino National Forest.Specific actions that
will be implemented include:1)cattle will be removed from portions of
allotments that overlap bighorn sheep habitat (Wellman allotment), 2)fences
48
within and adjacent to bighorn sheep habitat will comply with specifications listed
in section II.D.1 .2 of this recovery plan,3)a barrier will be constructed along the
gatedclosure on Palm Canyon Drive (also known asDunn Road)to reduce
unauthorized vehicular use,and 4)guidelines for management of hiking,biking,
and equestrian trails (e.g.,seasonal closures)will follow recommendations
outlined in section II.D.1.2 of this recovery plan.
Additional actions recommended in the San Bernardino National Forest
Biological Assessment include:1)the Forest Service should not authorize forage
use by domestic livestock where they currently do not graze in bighorn sheep
habitat,2)other existing grazing allotments on the San Jacinto RangerDistrict
should not be converted from cattle to domestic sheep or goat use,and 3)the
minimum buffer distance between domestic sheep grazing and bighorn sheep
habitat should be increased from 3.2 kilometers (2 miles)(the current Forest Plan
standard)to 14.5 kilometers (9 miles)throughoutthe Forest.
2.STATE AGENCIES
2.1 Catfornia Department of Fish and Game.To designate areas important to
bighorn sheep conservation in the Santa Rosa Mountains,the Department of Fish
and Game established a State Game Refuge pursuant to Fish and Game Code
section 10837.State lands administeredby the Department of Fish and Game
total about 3 percent of bighorn habitat in the Peninsular Ranges (Figure 4).To
furtheridentify and implement management needs,the Department of Fish and
Gamecoordinated with the Bureau of Land Management in the completion of the
SantaRosa Mountains Wildlife Habitat Management Plan (Bureau of Land
Management 1980).Currently, the Department of Fish and Game’s management
activities for bighorn sheep are atthe highest level in the State’s history.Funds
providedthrough the sale of Environmental License Plates and through the
auction of special fund-raising permits have enabled the Department of Fish and
Game to support a number of important research efforts concentrating primarily
on population characteristics and the disease status of bighorn sheep.The
Department of Fishand Game cooperates with several universities,agencies,and
non-profit organizations in support of bighorn sheep research and conservation in
California.Conservation goals for bighorn sheep,as published in the Statewide
Plan forBighorn Sheep (California Department of Fish and Game 1983),are as
follows:
49
1.Maintain,improve,and expand bighorn sheep habitat where possible or
feasible.
2.Reestablish bighorn sheep populations on historic ranges where
feasible.
3.Increase bighorn sheep populations so that all races become numerous
enough to no longerrequire classification asrare or fullyprotected.
4.Provide for aesthetic,educational,and recreational uses of bighorn
sheep.
The California Department of Fish and Game’s Bighorn Sheep Management
Program maintains an inventory of the distribution of bighorn sheep in California.
This assessment of bighorn sheep populations has been conducted as part of a
long-term management plan for mountain sheep in California.The populations of
bighorn sheep in California are grouped into metapopulations,or ‘systems’of
populations,that best represent logical regions to manage for the long-term
viability of the species.This regional approach recognizes the importance of
inter-mountain areas that allow movement and exchange of individuals between
populations, the re-colonization of vacant habitats,and the interagency
coordination of land management.The program’s definition of regional
populations considers not only vegetative and geographic boundaries, but also
man-made barriers that define distributions and have resulted in the fragmentation
of habitat.Given the need to understand the status and dynamics of regional
populations of bighorn sheep,this type of inventory should provide an index for
documenting regional population changes over time,and help evaluate the success
or failure of management actions at a meaningful level.Further,this approach
mayhelp identify the“missing pieces ofthe puzzle” foroptimizing future
reintroduction and management efforts to ensure population viability.
Although a metapopulation approach is an important biological principle for long-
term survival of bighorn sheep populations,it is equally important as a
management concept that prioritizes regional coordination for bighorn sheep
population and habitat management.For example,data regarding extinction and
recolonization are limited,and the biological justification for considering some
regions as true metapopulations is therefore incomplete.Nevertheless,given the
need for regional management of bighorn sheep populations,metapopulations
have beendefined based on the best understanding of the regions.Several
51
investigations have postulated the importance of population size and genetic
diversity to the long-term viability of bighorn sheep populations.
California State law (Assembly Bill 560), which was enacted under an emergency
provision in September 1999,allows control ofmountain lions to protect
threatened,endangered,fully protected,and candidate sheep species.In these
cases,selective removal of lions is an alternative short-term emergency measure
to facilitate recovery of vulnerable sheep populations,such as in the Peninsular
Ranges (refer to section II.D.1.3).
2.2 Catfornia Department of Parks and Recreation.Two State parks are within
the range of thePeninsular bighorn sheep:Auza-Borrego Desert State Park and
Mount San Jacinto State Wilderness.Anza-Borrego Desert State Park comprises
243,000 hectares (600,000 acres)alongthe backbone of the PeninsularRanges,
encompassing approximately 47 percent of this species’ existing habitat within the
United States (Figure 4).The park also supports a majority of the rangewide
sheep population (Rubin et at.1998).Therefore,recovery of the species hinges
greatly on the successful management of bighorn sheep habitat in this State park.
Anza-Borrego Desert State Park has been actively involved in the conservation of
bighorn sheep for 30 years (Table 9).
2.3 Coachetta Vattey Mountains C~onservancy.The Conservancy wasestablished
by California State legislation in 1990 to “acquire and hold,in perpetual open
space,mountainous lands surrounding the Coachella Valley and to provide for the
public’s enjoyment of and the enhancement of their recreational and educational
expenences on those lands in a manner consistent with the protection of the lands
and the resource values specified in Section 33500 [PublicResources Code]”.
The Conservancy has acquired either fee title or a conservation easement on 973
hectares (2,405 acres)in the San Jacinto and Santa Rosa Mountains,and has
assisted other entities with additional acquisitions.The Conservancy is preparing
the Coachella ValleyMultiple Species Habitat Conservation Plan under contract
to the Coachella Valley Association of Governments (refer to section I.E.3.2).
3.LOCAL ORGANIZATIONS AND AGENCIES
3.1 Bighorn Institute.The Bighorn Institute is a nonprofit,tax-exempt
organization that was formed in 1982 to investigate the causes of bighorn sheep
52
declines,particularly Peninsular bighorn sheep.The Institute is located in
Riverside County,California,adjacent to the City of Palm Desert.Its facilities,
which include an office,laboratory,staff residence,and pens for a captive
breeding herd of Peninsular bighorn sheep,are located on 120 hectares (297 acres)
of land at the base of the Santa Rosa Mountains.
The Institute began monitoring radio-collared bighorn sheep in the northern Santa
Rosa Mountains and the San Jacinto Mountains in 1982 and 1992,respectively.
Long-term studies of the population characteristics,distribution,reproductive
success,nutrition,movements,and general ecology of these bighorn sheep are
ongoing.In the spring of 1998, the Institute initiated a multi-year study of cause-
specific mortality of radio-collared lambs in the northern Santa Rosa Mountains.
The Bighorn Institute has conducted annual helicopter surveys of bighorn sheep in
the Santa Rosa Mountains since 1982 and in the San Jacinto Mountains since
1987,and has also surveyed bighorn sheep throughout the Peninsular Ranges in
Mexico.Since 1982,39 sick lambs have been captured from the U.S.Peninsular
Ranges for disease research and rehabilitation at the Institute.In 1985,the
Institute began a Captive Breeding and Population Augmentation Program.
Although this program began as a by-product of disease research on causes of low
lamb survival (DeForge et at.1982,DeForge and Scott 1982),in 1995 it was
redirected as a formal captive breeding program with the primary goals of
producing stock for augmenting and re-establishing wild populations,and
conducting a research program in the Santa Rosa and San Jacinto Mountains.
Captive bighorn are maintained in 12-hectare and 3-hectare enclosures
encompassing rugged hilltops.Rams and ewes are selectively combined for the
breeding season and the parentage of all captive-born animals is recorded.
Captive animals are not available for public viewing and a standardized feeding
and observation routine is used to limit exposure to humans (Ostermann et at.in
press).
Before release,all bighorn are health-tested,eartagged,and fitted with mortality-
sensing radiocollars.Within the northern Santa Rosa Mountains,bighorn have
been released in Bradley Canyon (n equals 60), east Magnesia Canyon (n equals
6),and west Magnesia Canyon (n equals 8).Of the 74 captive-reared bighorn
released into the northern Santa Rosa Mountains,49 (22 males,27 females)were
captive-born and 25 (12 males,13 females)were wild-born lambs brought into
captivity for research and rehabilitation at I to 5 months of age (Ostermann et at.
53
Table 9.Past and present conservation activities in Anza-Borrego Desert State
Park.
Year Description of activities
1968 Field studies were conducted in Anza-Borrego as part of a statewide
status report on bighorn sheep (Weaver 1972,1975,1989;Weaver et at.
1968;Weaver and Mensch 1970).
circa 1970 Construction of Blue Spring guzzler in Vallecito Mountains with the
Society for the Conservation of Bighorn Sheep.
1971 The annual Anza-Borrego Bighorn Sheep Count began with about 25
volunteers.A waterhole count has been conducted every summer since
this time and now involves about 75 volunteers counting 24 watering
sites.Over 2,000 volunteers have donated over 60,000 hours to date.
1972-1975 Jorgensen and Turner (1973,1975)conducted 4 summers of bighorn
sheep research and documented over 100 water sources used by bighorn
sheep.Russi (1978)continued this work in 1976.
1973-
present
Tamarisk removed from riparian areas within bighorn sheep habitat to
enhance water availability and native plant community regeneration.
Currently,a Riparian Restoration Team works full time to remove
tamarisk and other exotic plants.Approximately 208 kilometers (120
miles)of canyons and stream courses have been treated by the team to
date.
1975 A seasonal closure ofbighorn sheep watering areas in Coyote Canyon
during June 15 to September 15 was implemented.This closure was
expanded in 1996 from June 1 to October 1.
1982 A bighorn sheep guzzler was constructed in collaboration with
California Department of Fish and Game at Limestone Spring in the
Santa Rosa Mountains.
1982 163,085 hectares (403,000 acres)of Anza-Borrego Desert State Park
were designated as State Wilderness Areas,setting aside a large area of
1983-
present
Park staff assisted in annual helicopter surveys of the entire Santa Rosa
andSan Jacinto Mountain ranges (DeForge e at.1995,1997).
1983-1992 Parkstaff assisted the Bighorn Institute with disease research.
1987 Feral cattle (117)were removed from bighorn sheep habitat by
helicopter at a cost of $70,000,culminating 16 years of effort to remove
domestic cattle from park lands.
1987 Six bighorn sheep guzzlers were constructed in the Vallecito Mountains
to provide water where natural springs and streams had been usurped by
human activity. Over 200 volunteers and$30,000 were used and
expended respectively,in the project.
54
Table 9.Continued
1987-1988 Gap fencing [22.5kilometers (14 miles)]was constructed in the upper
elevations of the park to keep stray cattle from entering from
neighboring lands.A special Senate appropriation ($200,000)was
obtained forthis project.
1992-
present
Cooperated on Peninsular Ranges Bighorn SheepPopulation Health
Study with University of California (Davis) and the Zoological Society
of San Diego.
1994-1998 Helicopter surveys were conducted in Anza-Borrego Desert State Park,
in collaboration with the University of California -Davis and California
Dept._of Fish_and_Game_(Rubin_et_al._1998,1999).
A 15-minute movie “The Bighorn of Anza-Borrego”was produced.
This movie is seen by thousands of park visitors each season in the
Anza-Borrego Visitor Center.
1995-1996
1996 The Coyote Canyon Public Use Plan was implemented,calling for the
closure of Middle Willows andUpper Willows to motor vehicular
traffic.This trail segment is 5 kilometers (3.1-miles)long.
in press).In 1997,three captive-reared ewes were released into Tahquitz Canyon
in the San Jacinto Mountains.Two of these females were captive-born,and the
third was a wild-born ewe captured as a lamb from the northern Santa Rosa
Mountains (Ostermann and DeForge 1996,Bighorn Institute 1997).
3.2 Coachetta Va itey Mutu~te Species Habitat Conservation Plan.This ongoing
planning effort is sponsored by the CoachellaValley Association of Governments,
with the cooperation of the Fish and Wildlife Service and California Department
ofFish and Game, and has been in preparation since 1996.Within the areas at
issue in this plan,the Association’s membership includes the County of Riverside
and all nine cities in the Coachella Valley,as well as the Agua Caliente Band of
Cahuilla Indians.Though the plan is not yet complete,it currently proposes to
address the conservation needs of bighorn sheep.Lands in the San Jacinto and
Santa Rosa Mountains set aside in the past and future by the cities and Riverside
County as open space will provide important contributions to bighorn sheep
recovery and completion of the habitat conservation plan if those lands are
managed appropriately.If the plan is adopted,participating Federal, State,and
local governments will cooperate in implementing an agreed upon conservation
strategy for bighorn sheep and other species over a large area of the San Jacinto
and Santa Rosa Mountains in Riverside County.
55
4.INDIAN TRIBES
4.1.Agua Catiente Band of Cahuitta Indians.The Agua Caliente Band of
Cahuilla Indians (Tribe)is a federally recognized Indian Tribe whose reservation
was established in 1876 by Executive Order.TheAgua Caliente Indian
Reservation encompasses 13,000 hectares (32,000 acres)of land in the western
Coachella Valley and is encompassedwithin a checkerboard ownership pattern
that supports a significant amount of bighorn sheep habitat.
TheTribe has a long and rich history of land stewardship,particularly in the
foothills of the San Jacinto and Santa RosaMountain ranges.For decades,the
Tribe has managed the areaknown as the Indian Canyons for cultural resource
protection and useby the public as a Tribal park.Protection of the natural
resources of the reservation and Indian Canyons has beenthe foremost priority of
theTribe and has been acknowledged by the Secretary of the Interior.
Currently,the Tribe is preparing a comprehensive Resource Management Plan for
thereservation that will protect cultural,wetland, land use,and wildlife resources.
The Tribe actively participates and holds seats on the Coachella Valley
Association of Governments,CoachellaValley Mountains Conservancy,and
Planning Advisory Group of the Coachella Valley Multiple Species Habitat
Conservation Plan.
The Tribe’s Planning and Environmental Department presently consists of 10
professionals and technicians who,atthe direction of the Tribal Council,oversee
all land management issues.The Tribal ResourceManagement Plan will address
the management and protection of endangered species,including bighorn sheep.
To the extent feasible,the Tribe intends to cooperatewith interested and affected
agencies who share in the implementation of this recovery plan.
4.2.Torres-Martinez Desert Cahuitta Indians.This federally recognized tribe
supportsapproximately six sections (1,554 hectares or 3,840 acres)of bighorn
habitat in the extreme southern Santa Rosa Mountains.
4.3.Morongo Band of MissionIndians.This federallyrecognized tribe supports
one irregularly shaped section (about 280 hectares or 700 acres)of bighorn habitat
at the extreme north end of the San Jacinto Mountains.
56
II.RECOVERY
A.CONSERVATION PRINCIPLES USED IN THIS RECOVERY PLAN
The following sections discuss general conservation principles in the context of
our current knowledge regarding Peninsular bighorn sheep,and outline the
relationship of these principles to the recoverycriteria for this species.
Conservation theory recognizes that population and genetic issues need to be
addressed in species conservation (Lande 1988),although population threats pose
a greater short-term risk to Peninsular bighorn sheep.The conservation of
Peninsularbighorn sheep requires an understanding of habitat use,population
dynamics,behavior,and spatial population structure,as well.Ecosystem
protectionprovides an additional important tool in speciesconservation. The use
of models in conservation decision-making forthe recovery of bighorn sheep in
the PeninsularRanges also is discussed below.
I.POPULATION CONSIDERATIONS
Population parametersare important to the viability of all populations; however,
theyare an especially important consideration in the conservation of small
populations (Gilpin and Soul~ 1986).Variation in population parameters (birth,
death,immigration,and emigration rates,as wellas population age and sex
structure) can cause fluctuations in population size that make small populations
especially vulnerable to extinction.Lande (1988)noted that a shortcoming of
some past recoveryplans has been an inadequate emphasis on factors related to
population characteristics,and cautioned that formany wild populations,risks
related to population parameters are of more immediate importance than genetic
concerns.
The small number of Peninsular bighorn sheep (334 adults estimated in 1998)
mandates that population dynamics be of concern in their conservation.
Furthermore,Peninsular bighorn sheep occur in discrete ewe groups that have
ecological significance relative to the genetic and distributional structure of the
population (Rubin et at.1998,Boyce et at.1999),and therefore represent an
important management and conservation unit (Bleich et at.1996).The
persistence of such subgroups areimportant to the viability of the entire
57
population (Soul~1987).Some of these groups include less than 20 ewes,making
them highly vulnerable to chance variation in birth and death events.The high
male to female sexratio in the San Jacinto Mountains (DeForge et at.1997)
provides an example.
Because ewe groups are connected by movements of rams and rarerdispersal by
ewes,Peninsular bighorn sheep are considered to comprise a metapopulation
(Torres et at.1994,Bleich et at.1996,Boyce et at.1997).Metapopulations
typically are assumed to exist in a state of balance between population extinctions
and colonizations (Hanski and Gilpin 1991).However,in the case of Peninsular
bighorn sheep, the use of a metapopulation approach should not diminish the
importance of individual ewe group viability for the following reasons.Bighorn
sheep are relatively slow colonizers (Geist 1967, 1971;Bleich et at.1996)and
therefore metapopulation extinction-colonization processes would have to
function over a very long time period.Recent abandonment of habitat and a lack
of known colonizations suggest that Peninsular bighorn sheep comprise a
nonequilibrium metapopulation”(i.e.,extinctions are occurring ata fasterrate
than colonizations)(Harrison 1994,Hanski and Simberloff 1997).Hanski and
Gilpin(1991) cautioned that such systems must be managed carefullybecause
they maynot necessarily function as a metapopulation.Therefore,extirpations of
existing ewe groups should be avoided,while colonization of habitat should be
promoted.
Inthe Peninsular Ranges,a variety of factors have reduced bighorn sheep numbers
to levels where random variations in population characteristics and environmental
factors have become serious threats.Therefore,this recovery effort should strive
to increase the overall population of bighorn sheep by addressing and,where
possible, reversing processes that caused thepast population decline.This effort
will entail implementing actions that increase the size of individual ewe groups by
reducing mortality rates,increasing recruitment,and allowing inter-group
movements to occur.
2.GENETIC CONSIDERATIONS
Maintaining genetic variation is an important conservation goal because loss of
genetic variability can result in inbreeding depression (a loss of fitness)and the
inability of populations to respond to long-term environmental changes (Gilpin
58
and Sould 1986,Ralls ei’at.1988,Lande 1988,Meffe and Carroll 1994,
FitzSimmons et at.1995). By reducing the fitness of individuals,loss of genetic
variation also can reduce the growthrates and resilience of populations (Lacy
1997).Loss of genetic variation is a special concern when dealing with small
populations because heterozygosity is lost (through the processes of founder
effects,population bottlenecks,genetic drift,and the effects of inbreeding)more
quickly in small populations than in large ones (Meffe and Carroll 1994).Inthe
Peninsular Ranges, movement of males apparently has maintained gene flow
between ewe groups,resulting in a relatively high level of genetic diversity
(Boyce et at.1997).However,increased habitat fragmentation could reduce the
connectivity among groups.If ewe groups become isolated, they will face an
increased risk of losing genetic variability in addition to vulnerability to natural
random fluctuations in the population.
Even if gene flow is maintained among ewe groups in the Peninsular Ranges,the
overall population size (approximately 334 adults)is small enough to cause
concern.The effective population size (N)(Crow and Kimura 1970),which
e
determines the rate at which heterozygosity is lost,is even smaller than thecensus
size.Au effective population size of 500 individuals has been suggested as the
minimum recommended for maintenance of genetic variation for future
evolutionary change (Franklin 1980,Lande and Barrowclough 1987,Franklin and
Frankham 1998),while Lande(1995)suggested that this number should be even
higher.The current censussize of Peninsular bighorn sheep falls far below even
the lower recommendation. Becausereduced population levels may place
Peninsular bighorn sheep at risk,important goals of this recovery effort are to
increase theabundance of Peninsularbighorn sheep and maintain as much genetic
variation aspossible.This recoveryplan recommends maintenance of
connectivity with populations in Baja California and itmay be deemed
appropriate in the future to recreate connectivity or induce genemigration with the
Mojave Desert metapopulation.
Although the observed genetic variation among ewe groups in the Peninsular
Ranges is not known to confer adaptive advantage to local environments,genetic
theory holds that existing genetic variation should be maintained “in as near a
natural geographic distribution as possible,so that evolutionary and ecological
processes maybe allowed to continue”(Meffe and Carroll 1994).In Peninsular
bighorn sheep, as in many taxa,genetic variation is partitioned among and within
59
subunits or ewe groups (Meffe and Carroll 1994,Boyce et at.1999,refer to
section I.A.3).Although there is no evidence to suggest that bighorn sheep in the
Peninsular Ranges lack genetic diversity,a conservative approach to genetic
conservation suggests that recovery tasks should recognize and attempt to
preserve existing genetic structure whenever possible.This approach will require
preservation of multiple ewe groups,maintenance of movement opportunities
between groups (Schwartz et at.1986),and judicious protocols for population
augmentation,reintroduction,and captive breeding programs (Ryman and Laikre
1991,Elliott and Boyce 1992,see Appendix C).Becausethe major problems
facing bighom sheep in the Peninsular Ranges relate to population dynamics and
viability,genetic theory should not over-ride management objectives to maintain
and expandthe number and size of ewe groups throughout the Peninsular Ranges.
This objective can be accomplished by selecting augmentation and reintroduction
stock from the closest available populations (Wehausen 1991,Ramey 1993,
Wehausen and Ramey 1993,Gutierrez-Espeleta et at.1998).
3.ECOSYSTEM PROTECTION
Loss of habitat is recognized as theleading cause of species endangerment and the
leading threat to global biodiversity (Groombridge 1992,Noss and Murphy 1995).
It is also considered the most significant threat to the viability of bighorn sheep
populations (Bleich et at.1996).Thepotentially negative impacts that habitat loss
and degradationhave on bighorn sheep arepresented in section I.D.Although
habitat lossmay not directly cause mortality in bighorn sheep,loss of important
resources (e.g.,water,forage,escape terrain, lambing areas,movement linkages)
ultimatelyreduces carrying capacity,which can affect survival and recruitment
rates.Insome cases,the cause of death maybe documented as disease,
malnutrition,or predation, etc., when in fact habitat loss wasthe underlying cause
that resulted in death.In addition,altered land uses that support larger human
populations introduce increased levels of anthropogenic disturbance in adjoining
habitat.The decline or extirpation of bighorn populations near other metropolitan
areas such as Tucson near the Santa Catalina Mountains and Albuquerque near the
Sandia Mountains (Krausman et at.in prep.),provide case history examples of
apparent vulnerability of bighorn to urban influences.This recovery plan will
attempt to avoid repeatingthese scenarios,and accordingly adopts theapproach of
conserving the larger ecosystem upon which bighorn sheep in the Peninsular
Ranges depend, as afforded under section 2(b)of the Endangered Species Act.
60
Such an ecosystem approach also will benefit numerous other common and
uncommon species.
4.THE USE OF POPULATION MODELS TO HELP GUIDE RECOVERY
ACTIONS
Models have become an important tool to scientists attempting to understand
complex processes because intuition is often not reliable (National Research
Council 1995).Conservation biologists frequently use models to gain a better
understanding of the many interacting factors (environmental, population,and
genetic)that place a species or population at risk.The comprehensive modeling
of these factors was christened “population vulnerability analysis”by Gilpin and
Sou1~(1986).Typically, the goal of a population vulnerability or “viability”
analysis is to evaluate the risk of extinction, either in terms of estimated time to
extinction or the probability of extinction in a given time interval (Boyce 1992).
As such,a population viability analysis is similar,in concept,to risk analyses used
to understand issues of public health and safety (Ginzburg et at.1982).
Population viability analyses,like other forms of risk analysis,contain a degree of
uncertainty because they attempt to determine the likelihood of future events
based on past and present patterns (ofpopulation dynamics,environmental
conditions,etc.).All models are inherently dependent on underlying assumptions
(Starfield and Bleloch 1991)and on the quality of data entered into the model.
Therefore,the results of a population viability analysis must be interpreted with
caution (Caughley 1994, Beissinger and Westphal 1998).Inclusive population
viability analyses may not be appropriate when data are limited (Beissinger and
Westphal 1998).This limitation does not mean that the use of models should be
discouraged (Ak~akaya and Burgman 1995,Starfield 1997,Beissinger and
Westphal 1998).
Au additional role of modeling in conservation biology is as a decision making
tool (Starfield and Bleloch 1991,Walsh 1995,Starfield 1997).Models can be
used to compare therelative effects (rather thanthe absolute outcome)of
alternative management strategies or environmental scenarios (Starfield and
Bleloch 1991,National Research Council 1995,Walsh 1995,Starfield 1997,
Beissinger and Westphal 1998)and canhelp guidemanagement strategies or
61
focusfuture research efforts.Smaller,focused models have greatpotential in
guidingconservation decisions (Starfield and Bleloch 1991,Starfield 1997).
Use of modeling can help to elucidate several issues related to the recovery of
Peninsularbighorn sheep (refer to section ll.D.2.2).Models should be designed to
ask specific questions (Starfield 1997)that increase our understanding of the
ecological processes in the Peninsular Ranges,and should be coupled with field
studies of thebighorn sheep (Beissinger and Westphal 1998).It may be useful to
simulate shorter time periods, as well asthe 100 to 200 year intervals typically
used in population viability analyses,so that model predictions (as well as model
assumptions)canbe evaluatedwith theuse of field study results (Beissinger and
Westphal 1998).This type of approachwill allow conservation biologists to learn
from themodels and field studies,and will allow conservation efforts to be
adaptive (Minta and Kareiva 1994).
B.OBJECTIVES AND CRITERIA
1.RECOVERY OBJECTIVE
Theultimate objective ofthis recoveryplan is to protect and maintain sufficient
individuals and habitat of bighorn sheep in the Peninsular Ranges to eventually
delist this species.The recovery of Peninsularbighorn sheep will involve a two-
stageprocess, beginning with an interimgoal of downlisting of the species from
endangered to threatened status,followed by long-term recoveryand removal of
threatened status.As new information becomes available,the downlisting and
delisting criteriamay warrant modification through future revisions to the
recoveryplan.
2.DOWNLISTING CRITERIA
As an interim management goal,Peninsular bighorn sheep may be considered for
downlisting (reclassification to threatened status)when all of the following
objective, measurablecriteria are met:
Downtisting Criterion 1:As determinedby a scientifically credible
monitoring plan, at least 25 adult ewes arepresent in each of the following
9 geographic regions (Figure 5)during each of 6 consecutive years
62
(equivalent to approximately one bighom sheep generation),without
continued population augmentation:
1.San Jacinto Mountains
2.SantaRosa Mountains--North of Highway 74
3.SantaRosa Mountains--South ofHighway 74 through Martinez
Canyon
4.Santa Rosa Mountains--South of Martinez Canyon
5.Coyote Canyon
6.North San Ysidro Mountains (Henderson Canyon to County
Road S-22)
7.South San Ysidro Mountains (County Road S-22 to State
Highway78)
8.Vallecito Mountains
9.Carrizo Canyon/TierraBlanca Mountains/Coyote Mountains
Area
Justification:The nine regions were selected on thebasis of maintaining:
(1) historical distribution,(2)home range herd memory,and (3)
connectivity among ewe groups to facilitate re-colonization in the event of
localized extirpations.Recovery Team members with knowledge of
current and historical conditions judged that each areawas capable of
supporting at least 25 ewes with associated subadults and rams.Within
each of thenine regions,fluctuationin thenumber of ewe groups,
including re-colonization of former habitats,is expected under the
metapopulation model.As such,ewe groups maymerge, split,and
redistribute themselves over time.Although the 9 areas support respective
carrying capacities well in excess of 25 adult ewes,a downlisting objective
based on maximum attainable population sizewas not selectedbecause
static population levels at full range capacitycannot be maintained in
naturallyvariable environments,even assuming intensive management
capability.Theminimum group size of 25 adult females was selected by
Recovery Team consensus because it:
1.would reduce risk of extirpation from random naturally
occurring events to an acceptable level;
64
2.should be achievable with prudent,population and land
management practices;
3.is consistent with management objectives for bighorn sheep in
other metapopulations;
4.should maintain ewe group knowledge of a largehome range
that will minimize the extent of geographic gaps between ewe
groups,thereby facilitating interchange of genes and populations
within the metapopulation;
5.falls wellwithin known or estimated historical population
levels;and
6.should provide,in all but the most catastrophic scenarios,
sufficient time for management intervention to prevent extirpation.
Downtisting Criterion 2:Regulatory mechanisms and landmanagement
commitments have been established that provide for long-term protection
of Peninsular bighorn sheep and all essential habitat as described in
section II.D.l of this plan.
Justification:Given the major threat of fragmentation to species with
metapopulation structures, connectivity among all portions of habitat must
be established and assured through land management commitments, such
that bighorn sheep areable to move freelythroughout all habitat. In
preparation for delisting,protectionby means otherthan the Endangered
Species Act must be assured.Such protection should include alternative
regulatory mechanisms by Federal,State,and local governments,and land
management commitments that would provide theprotection needed for
continued population stability.
3.DELISTING CRITERIA
As a long-term management goal of thePeninsular bighorn sheep,three delisting
criteria are proposed;
Detisting Criterion I:As determined by a scientifically credible
monitoring plan,at least 25 ewes must be present in each of the 9 regions
(Figure 5)listed under Downlisting Criterion #1 above,during each of 12
consecutive years (approximately 2 bighorn sheep generations),including
65
the 6 years under Downlisting Criterion HI,without continued population
augmentation.
Detisting Criterion 2:The rangewide population must average 750
individuals (adults and yearlings)with a stable or increasing population
trend over 12 consecutive years (same time period as Delisting Criterion
#1 above).
Justification:Recovery Team members with knowledge of historic and
current population levels evaluated the condition of existing habitat and
determined a carryingcapacity of approximately 1,000 bighorn sheep in
the Peninsular Ranges, which approaches historical population estimates.
The required 12-year average population estimate of 750 animals is based
on the assumption that achieving theobjectives in Downlisting Criterion
#1 of at least 25 females in each of the 9 geographic areas likely will result
in some areas supporting substantially morethan 25 ewes and other sheep.
This scenario likely willresult in an overall metapopulation size that
fluctuates between 600 and 1,000 sheep,averaging about 750 sheep with a
normal sex ratio,or approximately 75 percent of estimated carrying
capacity. An average population level would allow for natural population
fluctuations in a random environment and is believed to be reasonably
attainable assuming implementation of themanagement measures
prescribed in this recovery plan.
Detisting Criterion 3:Regulatory mechanisms and land management
commitments have been established that provide for long-term protection
of Peninsular bighorn sheep and all essential habitat as described in
section II.D.I of this recovery plan.Protection considered long-term can
be provided through appropriate institutional practices, such as State Park
General Plans,an amended California Desert Conservation Act Plan,an
amended Forest Plan,a completed Coachella Valley Multispecies Habitat
Conservation Plan,and natural resourcemanagement plans on Tribal
lands.In addition,connectivity among all portions of habitat must be
established and assured through land management commitments such that
bighorn sheep areable to move freely throughout the Peninsular Ranges.
Delisting would result in loss of protection under the Endangered Species
Act;therefore continued protection by othermeans must be assured.
66
Justification:This protection should include alternative regulatory
mechanisms, land management commitments,or conservation programs
that would provide the long-term protection needed for continued
population viability.
Recovery of Peninsular bighorn sheep likely will take severaldecades or longer
due to a low reproductive rate (e.g.,only one offspring per female per year and
reproduction starting usually at 2 years of age).The above criteria will be revised
asnecessary through a recovery plan amendment or revision if new information
becomes available,or if these criteria no longerpass scientific muster or otherwise
meet the conservation needs of this species based on the best available
information.
C.RECOVERY STRATEGY
This recovery plan describes a strategyto recover and delist bighorn sheep in the
Peninsular Ranges.The strategy consists of taking necessary actionsto: (1)
improvepopulation variables (reproduction,recruitment,survivorship),and (2)
secure and effectively manage habitat,including linkages between ewe group
home ranges.The recovery actions to implement this strategy are organized in the
narrativeoutline below.This recovery strategy is a synthesis of knowledge
accumulated on bighorn sheep in desert environments and elsewhere in North
America.Four biological principles of bighorn biologyare evident from past
research and have been incorporated into management guidelines by various
agencies (e.g.,McQuivey 1978,Wilson et at.1980,Smith and Krausman 1988,
Bureau of Land Management 1996,NewMexico Department of Game and Fish
1995):
1.Bighorn sheep are wide-ranging animals that arespatially dependent on
large tracts of habitat that provide a diversity of resources needed to offset
seasonal, annual, and longer termcycles of environmental variability and
scarcity;
2.Metapopulation structure requires habitatcontiguity between/among
constituent demes (ewe groups)to allow for long-term shifts in
distribution and genetic interchange;
67
3.Bighorn sheep appear to lack natural or acquired resistance to some
diseases and remain highly vulnerable to diseases introduced by domestic
sheep;and
4.Behavioralresponses to human-related activities can be variable among
individuals and populations, which can adversely affect habitatuse
patterns and population persistence.
In the short term,acquisition and conservation of the relatively narrowband of
habitat that still remains is crucial to attaining the population recovery and
delisting objectives of this recoveryplan.Given the:(1)inability of bighorn
sheep to use higher elevation habitats because of excessive shrub and tree cover,
(2) incompatible land usesthat haveencroached into habitat along the lower
elevational slopes of the Peninsular Ranges,and (3) pervasive influence of human
activities throughoutbighorn habitat, the future ofbighorn sheep in the
Peninsular Ranges will depend on rapid and adequate protection of lower
elevational areas that provide critical resources, such as foraging,watering,
lambing,and rearing habitats. Short-term management actions to increase
population recruitment and adult survivorship are also necessary to effect
population increase.
Past studies on bighorn sheep in desertand mountain environments have amassed
a wealth of applicable knowledge that guides the management prescriptions of this
recovery plan.Much of this work applies to bighorn sheep in general and,
therefore,neednot be reexamined through further research in thePeninsular
Ranges.The monitoring and research tasks recommended in this recoveryplan
areintended to address the longer-term,more complex environmental
relationships that have posed management difficulties in the past.These tasks
willrequire substantial investment by numerous partners if they are to be
successfullyaccomplished. However,only through such a cooperative effortwill
it be likely that the knowledge requirements for effective management be met.
The success of this recovery plan will also depend on strong education and public
awareness programs.A number of recovery actions outlined in this plan will
directly affect the general public.Therefore,the general public needs information
and outreach on proposed actions being taken,especially in localized areas of
action.Programs that include comprehensive and accurate facts about the ecology
68
of Peninsular bighorn sheep and the threatsthat face them,will be crucial to
obtaining public support forconservation measures.
D.NARRATIVE OUTLINE FOR RECOVERY ACTIONS ADDRESSING
THREATS
Recovery actions are first described in general below, and then are identified as
site-specific tasks,with reference to their appropriate recovery regions, in section
ll.E. The following tasks consist of interim and long-term management goals and
activities that range from single event actions orstudies to continuous efforts
extending acrossthe entire recovery implementationtime line.The task
descriptions and theimplementation schedule (Part III of this recovery plan) help
frame the duration of therespective goals/actions and responsible entities for
taking the lead or assisting others in implementation responsibilities.
1.PROMOTE POPULATION NCREASE AND PROTECT HABITAT
1.1 Protect, acquire,enhance,andrestore habitat.The historic range of
Peninsular bighom sheep has been adverselyaffectedby urban
development, agriculture,mining activities,and highways that have ledto
the destruction,modification,and fragmentation of habitat. Further
development can be expectedin the future.As pointed out in section I.D
of this recoveryplan, the viability and,therefore,the recovery of
Peninsular bighom sheep arecriticallydependent on availability of habitat.
Consequently,an important part of this recovery effort is the protection
and restoration of remaininghabitat essential to Peninsular bighorn sheep
conservation.
1.1.1 Protect essential habitat.Essential habitat is that habitat
believed necessaryforrecovery and should,therefore,be protected
from furtherloss or degradation(Figures 2,4-9). It is likely that
the valley floor to the east and thenorth of the Peninsular Ranges
(e.g.,Coachella Valley,Imperial Valley) historically was used by
bighorn sheep,for example during long-distancemoves to and
from other mountain ranges.Exposure to the hazards ofhigh
densityurban development,major freeways,fences, agriculture,
and canals,now would be considered detrimental to bighorn sheep
69
recovery.Therefore,the vast majority of the valley floor to the
east of the PeninsularRanges is not considered essential habitat.
Consequently,“essential habitat”comprisesthose areas believed to
be necessary fora self-sustainingbighorn population with a high
probability for long-term survival (recovery)in the Peninsular
Ranges of the United States.Essential habitat, therefore, consists
of those physical and biological resources (space, food, water,
cover)needed for:(1) normal behavior and protection from
disturbance,and (2)individuaL/population growth and movement,
including dispersal necessary to support a future population
expansion to meet therecovery objective (delisting criteria of
approximately 750 animals).
Much of thehistorical range of the sheep is needed to sustain the
largerpopulation levels necessaryfor recoverybecause:
a.Habitat maybe colonized and inhabitedby future ewe
groups (Bleich et at.1996),if,for instance,population
spatial structure or environmental conditions change,or the
population grows as a result of recovery actions. The long-
term persistence of a metapopulation depends on the
number of habitat patches that are available for
colonization (Hanski 1989).An important phenomenon,
which is not intuitively obvious,is that destruction of only
a fraction of available habitat can drive a metapopulation to
extinction by disruptingthe balance between colonization
and extinction rates(May 1991).Even locally abundant
speciescan sometimes be very close to extinction if the
proportion of suitable habitat is near the extinction
threshold (Lande 1987).
b.Movement throughout therange is needed to sustain the
metapopulation (Bleich et at.1 990a).
70
c.The factors limiting the viability of Peninsular bighorn
sheep arenot yet fullyunderstood and,in general,bighorn
sheep habitatuse and selectionneed to be more thoroughly
examined(McCarty and Bailey 1994).It is therefore
necessaryto protect all remaining suitable habitat.
d.Thehabitat of Peninsularbighorn sheep is restricted to a
narrowband along thebase of the Peninsular Ranges,from
the San Jacinto Mountains south to Mexico. In some areas,
this band is less than 6 kilometers(4 miles)wide,so
essentially no true “core”habitat exists.Without
protection, connectivity couldbe severed at anypoint along
this narrow band of habitat.
e.Habitat near theeastern edge of this band often coincides
with alluvial fans and canyonwashes, which provide
Peninsularbighorn sheep with important resources (referto
section I.B.1).
f.Unpredictable changes in global climate warrant retention
of future options in habitat conservation strategies.
The delineation of essential habitat was based on habitat features
known to be importantto bighom sheep,rather thanbeing based
solely on current use patterns, becausepopulation numbers
currently are low and use patterns are knownonly for a recent short
time period.In addition,data collected on radio-collared animals
(a sample of the entire population) represent a subset of the total
area used.Methods used to delineate essential habitat are outlined
in Appendix B.Compiling historical data and conducting
recommended ecological research will further understanding of
how bighorn sheep use available habitat.See Figures 2,4-9 for
maps of essential habitat.
1.1.2.Secure habitat.Bighorn sheep habitat that is currently in
private ownership should be secured (e.g.,purchased or acquired
by exchange on a voluntarybasis) by State orFederal agencies and
75
managed compatibly through individual or regional habitat
conservation plans or programs (e.g.,Coachella Valley
Multispecies Habitat Conservation Plan, which will delineate these
lands in its planning area),so that proper protection,management,
and restoration measures canbe implemented.Interagency
conservation plans or otherpotential agreements made with local
governments and private land owners should assure:(1) long-term
protection of lands under city and county jurisdiction,and (2)
appropriate landuses adjoining bighom sheep habitat to prevent
indirect effectsfrom degradinghabitat value.Limited funds for
land acquisitionwill require prioritizing parcels; the value of each
tract of land should be evaluated according to the following
criteria,although not necessarily in the order listed below:
a.At the level of individual ewe groups:how important is
this landin supporting a ewe group in this area?
b.Doesthis land include particularly important resources
(e.g.,water sources,escape terrain,habitat for lambing,or
important forage resources)for the bighom sheep?
c.Does this landrepresent important habitat for movement
and dispersal necessaryforconnectivity among ewe groups
throughoutthe PeninsularRanges?
d.Has this ewe group already experienced habitat loss?
e.Would acquisition of this land reducethe cumulative
negative effects of urban growth?
f.Is the habitat imminently threatened?
A list of prioritized parcels should be prepared and updated
annually by land management agencies (Bureau of Land
Management,U.S.Forest Service,CaliforniaDepartment of Fish
and Game,Auza-Borrego Desert State Park,Coachella Valley
Mountains Conservancy)to facilitate acquisition when
76
opportunities arise.Methods to facilitate public and private
cooperation should be pursued, such as:(1)development of land
useplanning guidelines (e.g.the CoachellaValley Multiple
Species Habitat Conservation Plan,conservation guidelines in
Appendix F),(2)development of a public education and outreach
program (refer to II.D.3),and (3) development of supporting maps
that better identify and explain bighorn sheep ecology and
conservation requirements.
1.1.3 Maintain,manage,and restore habitat qualit’,.’and
connectivity.As mentioned in section I.D.of this recovery plan,
the recovery of Peninsular bighorn sheep is dependent on the
existence of adequate habitat.Maintenance, management,and
restoration of essential habitat will allowfor geographic expansion
when population numbers increase.Theability of bighorn sheep to
move freely throughout all parts of the range is critical to recovery
because it:(1)facilitates exchange of genes between ewe groups,
(2) allows habitat colonization,and (3)allows selection of
alternativehabitat in response to predation pressure or temporary
changesin habitat quality (Schwartz et al.1986,Bleich et al.1996)
or human-related disturbance.Shifts in habitat use occur more
readily within existing ewe group home ranges but homerange
boundaries themselves also can change,albeit less frequently and
more slowly over time.Therefore,in addition to protection of
designated essential habitat,the followingmeasures should be
taken to restore and maintain habitat quality and to assure
connectivity throughout the range:
1.1 .3.1 Remove exotic vegetation and preventfurther
invasion by exotic plants.This item refers primarily to
control of tamansk (Tamarix species)along stream courses
but also applies to other species such as fountain grass
(Pennisetum setaceum)in select regions.Additional
funding should be secured to continue and expand current
tamarisk removal programs throughoutthe Peninsular
Ranges.These programs should include,or be coordinated
with,efforts to eradicate tamarisk outside of bighorn sheep
77
habitat,as this will reduce future invasion into bighorn
sheep habitat.Tamarisk eradication,such as atThousand
Palms Oasis,can result in immediate reappearance of
surface water (Barrows 1994),which can helpexpand
sheep distribution.
1.1.3.2 Reduce or eliminate wild horsepopulations from
bighorn sheep habitat.Though burros and goats are
currently absent,they also should be eliminated if they
become established.The reduction or removal of non-
native ungulates would:(1) eliminate potential sources of
competition,(2) reduce potential destruction of water
sources and vegetation,and (3)benefit other riparian
dependant wildlife,such as least Bell’s vireo and
southwestern willow flycatcher.The involved State and
Federal agencies,along with the Agua Caliente Band of
Cahuilla Indians,should determine whether wild horse
management in Coyote Canyon (Anza-Borrego Desert State
Park)and Palm Canyon is consistent with bighorn recovery
objectives in these areas.Any continuation of feral horse
grazing should be contingent upon the demonstrated ability
to implement an effectivemanagement and monitoring
program to ensure against:(1) the possibility of
competition with sheep for food and water, (2) trespass
onto other land ownerships,and (3) risks to public safety.
1.1.3.3 Implement afire management plan that recognizes
fire as a natural disturbance in fire-adapted habitats of the
Peninsular Ranges ecosystem and as a process that helps
maintain bighorn sheep habitat.A wildland firepolicy
should establish fire management areas for natural and
management ignited prescribed fires.Further research on
the use of fire as a management tool should helpguide such
a plan (Smith and Krausman 1988,Krausman et al.1996;
78
and refer to section II.D.2.3).However, fire canrepresent a
serious threat to bighorn habitat quality in Sonoran scrub
plant communities,which unlike chaparral arenot well
adapted to fire disturbance.
1.1.3.4 Maintain existing water sources and consider
providing additional sources on public lands if water is
thought to be a limiting factor in particular areas.Water
development should be incorporated into research that
investigates the effect that the addition of water has on
bighorn sheep and other species (refer to section II.D.2).
1.1.3.5 Maintain and re-establish connectivity throughout
all habitat.Bamers to movement (roads,fences,increased
use of off-road vehicle areas,renewed railroad activity)
should be prevented.Potentialbighorn sheep crossing
areas should be identified and bridged or tunneled to
attempt reestablishing connectivity.Typical culverts are
not adequate becausebighorn sheep arenot known to move
through dark tunnels.Existing roads appear to represent
barriers between four current ewe groups (Rubin et al.
1998);solutions to promote connectivity should be
attempted. Another important recoverygoal is to
reestablish connectivity to habitat south of Interstate 8 and,
ultimately,to Mexico.This task willrequire the
cooperation of theCaliforniaDepartment of Transportation
to incorporate bighorn sheep movement opportunities into
their future construction plans.Coordination with Border
Patrol and the Mexican government willbe needed to
control human disturbance and the threat of disease
transmission from domestic sheep and goats while
reestablishing connectivity across theinternational border.
79
1.2 Reduce or eliminate direct and indirect human impacts.In addition to
habitat loss, habitat modification and human activities often directlyor
indirectly affect Peninsularbighorn sheep habitat use (refer to sections
I.B.5 and I..D.5).The following actions,which should all be accompanied
by strong educational and public awareness programs (refer to section
II.D.3),will reduce these impacts.
1.2.1 Reduce impacts from existing and future developments and
projects.These recommended actionspertain to any project
(residential, recreational,resort,commercial,agricultural,or
mining)that has been constructed withinbighorn sheep habitat,or
any project adjacent to bighorn sheep habitat. Though habitat and
opportunities for sheep movementthroughout all suitable habitat
should be maintained, habitatuse alongthe immediate urban
interface should not be encouraged because of risks associated with
behavioral habituation.
1.2.1.1 Constructfences to exclude bighorn sheep from
urban areaswhere theyhave begun or may begin using
urban sources offood and water.Fences serve several
functions including:(1)separating bighorn sheep from
potential threats of urbanization (e.g.,toxic plants,
parasites,accidents, vector-borne diseases,traffic,
herbicides,pesticides,behavioral habituation), (2)
controlling human and pet access to remainingbighorn
sheep habitat, (3)preventing bighorn sheep from becoming
habituated to and dependent upon artificial sources of food
and water,and (4)modifying habituatedbehaviors and
redirection into remainingnative habitat. Inthe northern
Santa Rosa Mountains, ongoing coordinationwith cities
and landowners on a regional fencing strategywill be
critical to the long-term health and maintenance of this ewe
group.Retrofitting existing developments with fences
where sheep currently exploit urban food and water sources
80
is particularly important;cooperation by residential
landowners will be critical to the success of excluding the
northern SantaRosa Mountains ewe group from urban
habitats.Along the remainder of the urban interface,where
sheep have not yet shown indications of habituation to
human habitats,future behavioral habituation also may
occur.Although fencing may be viewed as a last resort to
other potential forms of aversive conditioning,prudent
planning dictates that mitigation be required to offset the
likelihood of future adverse effects (behavioral habituation
and increased mortality rates) when newprojects are
approved along the urban interface. Though actual fence
construction could be contingent upon future use by sheep
and theineffectiveness of other potential deterrents,the
wherewithal,responsibilities,and easements for fences
should be determined and secured atthe time of project
approval.Fences should be 2.4 meters (8 feet)high, or
functionally equivalent,and should not contain gaps in
which bighorn sheep canbe entangled. Gaps should be 11
centimeters (4.3 inches)or less.This fence design should
only be usedat the urban interface.Refer to section
II.D.1.2.2 forguidelines for livestock fences within bighorn
sheep habitat.
1.2.1.2 Avoid non-native vegetation along unfenced habitat
interfuces where it may attract or concentrate bighorn
sheep.Along fenced sections of the urban interface,
ornamental and toxic plants should not extend over or
through fences where theymay be accessible to browsing
bighorn sheep.
1.2.1.3 Promote the use of native vegetation and limit the
planting of exotic species (including grass)in areas
accessible to bighorn sheep.A list of locally native plants
81
should be provided to developers,landscapers,and
homeowners.On Bureau of Land Management lands,
especially livestock grazing allotments in and near bighorn
sheep habitat,utilize only native vegetation in fire
rehabilitation and range improvement projects.
1.2.1.4 Prohibit the use of any known toxic plants where
they may be accessible to bighorn sheep or potentially
invade bighorn sheep habitat.A list of known toxic plants
should be provided to all developers, landscapers,and
homeowners.
1.2.1.5 Discourage the use ofplants known to invade and
degrade bighorn sheep habitat (e.g.,tamarisk,fountain
grass).
1.2.1.6 Prohibit intentional enticement of bighorn sheep
onto private property.This item includes, but is not
limited to,vegetation,mineral licks,or unfenced swimming
pools,ponds, or fountains upon which bighorn sheep may
become dependent for water.
1.2.1.7 In unfenced areas,monitor the use ofpesticides,
fungicides,herbicides,andfertilizers if sheep are using
urban landscapes.All products used should be warranted
by the manufacturer to not be harmful to wildlife when
applied at the label rate,and no applications should exceed
the label rate.Coordination with landowners and
homeowner groups is needed.
1.2.1.8 Regulate the diversion or procurement of water,
whetherfor human use or irrigation,and whether from
springs or aqu~fers,that would reducenatural water
sources used by bighorn sheep.Coordination with land
82
owners and the State Water Resources Control Board is
needed to redress potential water rights conflicts. The
Regional Water Quality Control Board’s Basin Plan should
recognize bighorn sheep as a beneficial use for perennial
and seasonal waters within essential habitat.
1.2.1.9 Prohibit the construction of water bodies in
developed areas adjoining sheep habitat that may promote
the breeding of midges (Culicoides sp.) and
monitor/control vectors in existing problematicponds.
Water features should be designed to eliminate blue-tongue
and other vector-borne diseases by providing deeper water
(over 0.9 meters [3 feet]),steeper slopes (greater than 30
degrees),and if possible,rapidly fluctuating water levels
(see Mullens 1989,Mullens and Rodriquez 1990).
Landowners and managers should coordinatewith local
mosquito and vector control districts to ensure management
of existing water bodies that harbor vector species.
1.2.1.10 Discourage the art~ficialfeeding of coyotes
because of the potentialfor increasing predator abundance
and consequentpredation on bighorn sheep.
1.2.1.11 Establish a method and secure funding to
consistentlymonitorand enforce all actions listed under
task 1.2.1.
1.2.2 Reduce or eliminatedetrimental human activities within
bighorn sheep habitat.A variety of human activities can affect
bighorn sheep (refer to section I.D).Bighorn sheep may react in
two ways (Papouchis et al.1999):(1) avoidance of disturbance or
human encounters (potentially including habitat abandonment),
and (2)habituation to sources of disturbance if they are sufficiently
predictable.Behavioral habituation can include adjustments to
83
timing of use in certain areas,such as by avoiding the area until the
disturbance is gone (Hamilton et al.1982)or fleeing the
disturbance and returning whenthe disturbance is absent.
Expansive urban development in and around bighorn sheep in
desert habitats has occurred in three metropolitan areas to date--
Albuquerque,Tucson,and Coachella Valley—and in all instances,
habitat abandonment and population decline has resulted
(Gionfriddo and Krausman 1986;Krausman,in litt.1998;
Krausman et al.In prep.).Bighorn sheep have demonstrated
greater resilience to human disturbance in more remote locales
such as Alberta (MacArthur et al.1982)and the Sierra Nevada
(Hicks and Elder 1979),though bighorn also are known to avoid
excessive human disturbance in areas well away from urban
centers (Papouchis et al.1999).
Given the potential behavioral vulnerabilities of bighorn sheep to
human disturbance (including dogs)and associated risks to the
persistence of currently depressed populations in the Coachella
Valley,a biologically conservative management approach is
appropriate in the Peninsular Ranges.The public should be
educated regardingproblems associated with human-sheep
relationships,and encouraged to continue supporting conservation
efforts (Smith and Krausman 1988).A trails management program
is currently in place on Anza-Borrego Desert State Park and
appears to be providing a level of management that is maintaining
relatively stablepopulation levels of bighorn sheep.The success of
this programmay be attributable to an intensive educational
program,along with prohibitions againstdogs(on trails) and other
disruptive activities,and a strong management presence to ensure
adequate compliance.In addition,the most heavily used areas
typically are located in steep terrain that limits the number and
location of trails to relatively fewnarrow canyon bottoms.Sheep
arebetter able to coexist with recreational use where human
84
disturbance typically occurs atelevations lower than where sheep
spend most of their time (Hicks 1977).
The following sectionprimarily focuses on the northern Coachella
Valley though the principles pertain rangewide. The relative
remoteness of the Anza-Borrego region renders comparisons with
the heavily populated Coachella Valley difficult,but recreation
activities could be viewed differently because they arepart of a
cumulative set of factors affectingthe sheep,some of which (e.g.,
development-related pressures in sheep habitat) are more intensein
the Coachella Valley. Though cause and effect relationships have
not been established,theproportionally larger population declines
in the northern Santa Rosa and San Jacinto Mountains than
elsewhere maybe related in part to the relatively higher levels of
human disturbance associated with the larger metropolitan area.
Other contributing factors may include the more extensive and
interconnected trail system that is not largely restricted to canyon
bottoms. Most of the trails head upslope and intersect other trails
athigher elevations,forming an extensive trail network throughout
ewe group home ranges,including lambing,rearing,and watering
habitat. The patchwork of differing land ownerships has
contributed to management difficulties. The types of trail use
activities,aswell asproliferation of new trails,also have gone
largely unregulated.The Dunn Road,constructed illegally in the
northern Santa Rosa Mountains in the I 970s, also is considered a
trail since much of the use is by recreational pedestrians and
bicycles and vehicular access is restricted.Travel in washes by
vehicles and on foot also should be considered trail use.
The Agua Caliente Band of Cahuilla Indians currently is preparing
a wildlife habitat management plan for the reservation,including a
trails management program,which should be coordinated with the
largerplanning effort to ensure attainment of regional objectives.
TheTribe recently banned dog use on its trails system,and will
85
coordinate its efforts with other agencies when a draftplan is
complete.
Research should focus on how different kinds and levels of
disturbance affect bighorn behavior and habitat use patterns.The
prevailing lack of baseline data on location,types,and extent of
trail use must be overcome as a prerequisite to studying and better
understanding these effects.
1.2.2.1 Develop and implement a trails management
program with affected land management agencies,
scientWc organizations,and usergroups.A trails program
in the San Jacinto and SantaRosa Mountains necessarily
will require interagency cooperation,with specific
responsibilities and levels of funding identified.The cities
and primary land management agencies,with the Bureau of
Land Management in a leadership role,should coordinate
with user groups in developing a plan with the Fish and
Wildlife Service and the Department of Fish and Gameso
that it can be effectively implemented on a regional basis.
Regular interagency meetings should be scheduled to
ensure effective coordination and implementation.The
program should consist of the following components:
a.Public education.Preparation of a public education and
outreach program is needed so that trail usersbetter
appreciate and understand bighorn sheep and other
biological values associated with the Peninsular Ranges.
Also see Section II.D.3.Most members of the public likely
will voluntarilyrefrain from recreating in sensitive habitats
during critical seasons if they understandthe effects of
human related disturbance on bighorn sheep.Nonetheless,
monitoring and enforcement will be necessaryto provide
effective management.
86
b.Prohibition of dogs in bighorn sheep habitat.Dogs
should remain in developed or designated areas
(campgrounds,picnic areas,on paved roads, etc.) under
restraint and prevented from roaming into bighorn sheep
habitat.
c.Lambing and rearing habitat.Seasonal restrictions are
needed on selected trails that bisect lambing habitat.In this
Recovery Plan,the lambing season is defined as January 1
to June 30,and lambing and rearing habitat is definedas
those areas in which ewes and lambs are observed during
this period.These definitions were chosen to provide
protection forthe majority of lambs during the first 3
months of life and to allow ewes undisturbed access to
lambing areas prior to the peak parturition months
(February through April).Trails that are currently known to
result in disturbance to lambing and rearing habitat are
listed in Table 10.
d.Watersources.Seasonal restrictions or trail relocations
maybe appropriate for selected trails that lead to water
sources.Trail use should be avoided near critical summer
water sources from June 1 through September 30,and other
times,as well,if water is scarce.Trail use is prohibited by
regulation[see California Government Code,Title 14,
Section 630(b)(l l)(A)and (30)(A)]at Magnesia Springs
and Carrizo Canyon Ecological Reserves.Trails that are
currently known to conflict with the summerwater
requirements are listed in Table 10.
e.Trail management.Trails that conflict with lambing,
rearing,and waterrequirements should be addressed
through management tools,such as seasonal restrictions or
87
Table 10.Trails and areas with potential conflicts that should be addressed in an
interagency trails management plan.*
Trail
Conflicts with
Lambing from
January 1
through June
30
Conflicts with
Water stress
from June 1
though
September 30
Comment
N.Lykken trail X X
Skyline trail X
Museum trail (Palm
Springs)
X X Applies above picnic
table at Desert Rider’s
Park.
South Lykken trail X
Picnic table trail
(south of Tahquitz
Canyon)
X Applies above picnic
table.
Tahguitz Canyon X X
Dunn Road X X
MurrayHill trail
complex
X X
Cathedral Canyon
trail
X X
Mirage trail (Bump
and Grind)
X Applies above the flat
overlook
Art Smith,Schey,
and connecting trails
X X
Carrizo Canyon trail X X
Bear Creek Canyon
trail
X X
Boo Hoff trail X X
Guadalupe trail X X
Morrow trail X X
This list of trails should be updated annually through the interagency trails program,
based on the most current information.
relocations. Permanent closures maybe necessary where
relocation is not possible and seasonal restrictions cannot
be effectively monitored or enforced.Trails should be used
as a tool to focus human activity away from areas of
concern.Newtrails in bighorn habitat should be avoided,
88
except in select areas along the urban edge, where they
could provide two benefits—alleviate pressure on trails that
intrude deeperinto sheep habitat,and provide a disturbance
barrier to discourage potential sheep attraction to urban
sources of food and water. Anynew trails should minimize
adverse impacts to alluvial fans,canyon bottoms,and other
areas that mayprovide essential seasonal forage conditions
while still accomplishing theobjective of routing use away
from the more sensitive areas.
f.Monitoring, enforcement,and research.A management
presence by uniformedpersonnel should be deployed
during peak use periods to educate the public,monitor
compliance with trails rules,and enforce rules against any
violations.Monitoring of bighom sheep habitat use
patterns should be designed to detect behavioral responses
that can adaptively feedback into revised management
measures.Experimental research to furtherour
understanding of human/sheep interactions also should be
conducted.See Section II.D.2.7.
1.2.2.2 Manage activities within bighorn sheep habitat that
fragment or interfere with bighorn sheep resource use
patterns or other behaviors to reduce or eliminate adverse
effects.This task includes but is not limited to road traffic,
trail use,off-trail activity,and aerial activities,such as hang
gliders and helicopters,which may have a negative effect
on bighorn sheep.For example,the U.S.Navy currently
implements a 457-meter (1,500-foot)minimum ceiling for
military flights above bighorn sheep habitat in the north end
of the Anza-Borrego Desert State Park and a 60-meter
(200-foot)minimum ceiling in the remainder of the park.
The 457-meter (1,500-foot) minimum ceiling should apply
to all flights over any bighorn sheep habitat.
89
1.2.2.3 Manage livestock grazing to reduce competition for
scarce resources and to minimize the potential for disease
transmission.Existing (Canebrake,with lambing and
watering habitat)and currently inactive (Vallecito and
Oriflamme) allotments should be evaluated and modified or
closed,if necessary to achieve recovery objectives.The
McCain Valley allotment should also be assessed to ensure
compatibility with adjoining sheep habitat.If the closure of
one or more livestock grazing allotments is determined
necessary to remove the impediments to recovery described
above in Section I.B.6 concerning competition or in Section
I.B.7 concerning disease transmission,the Bureau of Land
Management should develop proposed land use plan
amendments to effect such closure(s).Until decisions are
made regarding potential allotment modifications or
closures,the current allotment boundaries should be fenced
according to Bureau of Land Management fence
specifications for cattle and bighorn sheep (Bureau of Land
Management 1989).If any allotments,or portions thereof,
that overlap with bighorn sheep habitat are subsequently
closed through land use plan amendments,the fences
around such allotments should be removed following the
cessation of livestock grazing.
1.2.2.4 Prohibit the grazing of domestic sheep within 14.5
kilometers (9 miles,)of bighorn sheep habitat to prevent
disease transmission.
1.2.2.5 Require all cattle grazing allotments adjacent to
bighorn sheep habitat to be fenced where cattle straying
into bighorn sheep habitat degrades forage or water
resources.Fences should comply with Bureau of Land
Management specifications for cattle fences in bighom
sheep habitat (Bureau of Land Management 1989).
90
1.2.2.6 Prohibit the use ofgoats as pack animals in
bighorn sheep habitat.Goats are known to transmit
diseases to bighorn sheep.Other pack animals,such as
llamas and camels, should be assessed for potential disease
risk and prohibited if a risk exists.
1.2.2.7 Establish a methodand secure funding to
consistentlymonitorand enforce all actions listed under
task 1.2.2.
1.3 Reduce mortality rates.Low survivorship of adult Peninsular bighorn
sheep currently threatens population viability (refer to section I.B.4).
Measures to improve survivorship are fundamental to this recovery effort.
1.3.1 Reduce mortality due to unnatural causes.A number of
mortalities of Peninsular bighorn sheep have been caused directly
or indirectly by human activities.Some mortality factors,such as
poisoning by plants and vehicular collisions,are a byproduct of
urban developments built within or adjoining bighorn sheep
habitat,or human presence in bighorn sheep habitat (refer to
section II.D.1.2).Additional causes of mortality should be reduced
with the following actions:
1.3.1.1 Prohibitfences in which bighorn sheep may
become entangled orstrangled, or that interrupt habitat
connectivity or block movement of bighorn sheep within
remaining habitat.At the urban interface,fences should
not contain gapslarger than 11 centimeters (4.3 inches)
(refer to section II.D.1.2.1 .1).All other fences should
comply with Bureau of LandManagement specifications
for fences withinbighorn sheep habitat (Bureau of Land
Management 1989).
91
1.3.1.2 Post all movement areas or areas of bighorn sheep
concentration near highways with bighorn sheep crossing
signs to warn motorists.Post informational warning signs
at the entrance to blind curves.Solutions need to be
identified and implemented to reduce the extent of
vehicular related mortality along problematic road
segments such as Highway 74 above Palm Desert,S-22
west of Borrego Springs,and Highway 78 south of Borrego
Springs.If monitoring indicates that more effective
warning systems areneeded, flashing yellow lights and
intensified signage,etc.,should be phased in.Coordination
with Caltrans and the counties will be required.
1.3.2 Reduce mortality due to natural causes.Predation by
mountain lions represents a threat to the viability of bighorn sheep
in the Peninsular Ranges (refer to sections I.B.4,I.B.5,and I.D).
Selective removal of lions may therefore be necessary to facilitate
recovery.The goals of reducing predation pressure are to protect
small subpopulations from extinction and to stimulate population
increases.The following guidelines for implementing predator
management were designed to facilitate recovery of Peninsular
bighorn sheep in accordance with the recovery criteria established
in this recovery plan.The first level of predator control is
essentially an emergency action to protect small subpopulations
from extinction.This level of management was identified to help
the population meet downlisting criterion #1 (the presence of 25
ewes in each of the 9 recovery regions),while the second level of
lion control will be conducted,if necessary,to facilitate
achievement of delisting criterion #2.
Removal of mountain lions should be selective and only target
individual lions known to be,or suspected of,preying on bighorn
sheep.Predator management should not be implemented as a
mitigation measure for habitat loss because it is a temporary
92
remedy for a potential short-term problem and does not offset the
permanent impact of habitat loss.Lion removal must be
accompanied by careful monitoring to determine if predator control
achieves the desired protection of bighorn sheep (referto section
II.D.2.5).Theeffects of predatormanagement should be
incorporated into ecosystem level research on the predator/prey
relationships among bighorn sheep,lions,and deer(refer to section
ll.D.2.3). Thecriteria for implementing predator control may need
to be changed as knowledge regarding this predator-prey
relationship and the balance between predation and population
viability are better understood (refer to section II.D.2).The
ultimate goal is to restore an ecological system that includes viable
predator/prey systems in which no predator removal is necessary.
Predator Removal Level I.Predator removal should be
implemented if there are fewer than 15 adult femalebighorn sheep
in a givenrecoveryregion (refer to the 9 regions in section II.B)
and predation is a known mortality factor.Inthis circumstance,
protection of individual bighorn sheep is critical for ensuring
bighorn population survival and persistence in the recovery region.
Lion removal should be implemented solely in the recovery region
of concern,and continue until population growth is reestablished to
a trajectory expected to achieve the downlisting threshold of 25
adult ewes in the region.
Predator Removal Level 2.Predatorremoval may also be
implemented if there are greater than 25 ewes in each of the 9
recovery regions,to furtherfacilitatethe long-term goals of
population recovery.Lion removal should only occur if lion
predation is the primary cause of mortality and low survivorship is
determined to be limiting population recovery.Careful
monitoring,habitat evaluation,and possibly computer simulations
should be used to determine if,when, and where predator removal
should occur.Predator removal should be discontinued if available
93
evidence indicates that:(1)lion predation no longer limits bighorn
sheep population growth,and (2) continued removal would no
longerresult in a population expansion within the recovery region
necessary forthe overall recovery of the metapopulation.
1 .4 Develop a long-term strategy and maintain the current capability for
captive breeding,reintroduction,and augmentation programs.A small
captive breeding herd (14 animals in 1998) exists at the Bighorn Institute
(refer to sections I.C.1 and I.E.3)and is managed according to the
guidelines outlined in Appendix C.This herd was established in 1984 to
facilitatethe study of low lamb survival.Animalsborn or rehabilitated at
the facilityhavebeenreleased into thenorthern SantaRosa Mountains (n
equals 74)or the San Jacinto Mountains (n equals 3),typically as small
groups of yearlings,since 1985 (Ostermann et al.in press).
The Recovery Team should develop a long-term strategy that identifies the
process and circumstances under which captive breeding,reintroductions,
and augmentations may be appropriate and carried out,including the
potential introduction of animals from adjoining metapopulations.
Reintroduction and augmentation are potential tools to (re)establish ewe
groups and restore connectivity among neighboring groups.Augmentation
of dwindling groups mayserve as a “rescue effect”(Brown and Kodric-
Brown 1977),thereby reducing the risks associated with naturally
occurring random variations in populations.Augmentation may also play
an important role in the conservation of bighorn sheep because habitat use
patterns are learned from experienced animals.Once use of a particular
area is discontinued by females,it maybe more difficult forinexperienced
sheep to become established in this area (refer to section I.B.2).Finally,
augmentation can be of value to address genetic concerns.
Reintroduction and augmentation programs are recognized conservation
tools and have been used extensively to manage bighorn sheep populations
(Bleich et al.1990b,Ramey 1993);however,theycome with a set of
potential problems (Campbell 1980,Kleiman 1989,National Research
94
Council 1995).Reintroductions and augmentations also must be
coordinated with other recovery efforts.That is,they are meant to play
supportive roles to other measures that protect Peninsular bighorn sheep
and their habitat, they should be supported through public relations and
education programs (Kleiman 1989,National Research Council 1995),and
they should be preceded or accompanied by otherconservation measures
to restore population viability (Stanley Price 1991).Finally,decisions
regarding reintroductions and augmentation need to consider the genetic,
disease,and population structure consequences of such actions.
Although there are advantages to using free-ranging animals in
augmentations and reintroductions,captive breeding also can provide
animals for releases.In addition,captive propagation can be used as a
recovery tool to:1)conduct recovery related research,2)maintain genetic
diversity or genetic lineages,and 3)maintain refugial populations.
The long-term strategy should specify the goals of reintroduction and
augmentation activities,and describe the steps that will be followed to
reach these goals.The strategy should be consistent with the guidelines
adopted by the Conservation Breeding Specialist and the Reintroduction
Specialist Groups of the Species Survival Commission of the International
Union for the Conservation of Nature and Natural Resources,The World
Conservation Union,and those of the American Zoo and Aquarium
Association’s Caprinae Taxon Advisory Group.Appendix C outlines
additional considerations and a protocol for captive breeding and release
of captive animals.
2.INITIATE OR CONTINUE RESEARCH PROGRAMS NECESSARY TO
MONITOR AND GUIDE RECOVERY EFFORTS.
This section focuses on research topics with management applicability needed for
recovery.The approach is to design management actions so that:(1) results can
be measured, (2) efficacycanbe evaluated as testable hypotheses,and (3)
alternative or refined actions can be formulated and tested again (adaptive
95
management,as defined by Holling 1978).However,adoption of this approach
for bighorn sheep recovery likely will be more problematic than for most species.
Manyresults will not become apparent for many years because sheep are long-
lived and behavior can be slow to change and difficult to document.
2.1 Monitor population status.The status,population dynamics,and
population trends of Peninsular bighorn sheep should be monitored so that
the success of this recovery effortcanbe evaluated.Consistent long-term
monitoring will allow use of adaptive management approaches that would
increase the effectiveness of recovery efforts.Continued monitoring is
also a necessary component of future research. Population monitoring
(abundance,distribution,recruitment)should be coordinated with other
research (e.g.,survivorship,habitat selection)to maximize cost efficiency
and the data collected per animal collared,as well as to minimize handling
and marking animals.
2.1.1 Monitor abundance.All bighorn sheep habitat in the
Peninsular Ranges should be surveyed by helicopter at least every
other year to generate population estimates.Initially,this will
require that a known number of radio-collared animals are
distributed throughout the range so that mark-recapture abundance
estimations can be generated.The number of collared animals
should be sufficient to achieve an accuracy of plus or minus 25
percent with a probability of 0.05,following the methods described
in Krebs (1989)and Robson and Regier (1964),or approximately
30 percent of the estimated ewe population should be radio-
collared. However, a “sightability”estimate maybe generated
after additional surveys are conducted,thereby eliminating the
need to maintain this percentage of radio-collared animals.This
approach would be especially beneficial if/when population
numbers become large.Where ewe group delineations are known,
estimates of abundance should be generated for individual ewe
groups as well as for the entire range.Annual waterhole counts
should be continued in Anza-Borrego Desert State Park and
96
perhaps reinitiated in the Santa Rosa and San Jacinto Mountains.
Data from waterhole counts can be used to potentially provide
important information about population characteristics (e.g.,lamb
to ewe ratios and/or ram to ewe ratios)and to index abundance.
Continuation of waterhole counts concurrent with helicopter
surveys (for 5 to 10 years)may reveal a relationship between
abundance indices and population estimates.This relationship may
allow biologists to use historical waterhole count data (collected
over 28 years)to estimate historical abundance patterns.Aerial
surveys and waterhole counts should be conducted according to the
protocols in Appendix E.
2.1.2 Monitor distribution.Further data should be collected on
distribution of Peninsular bighorn sheep.Ground surveys for
bighorn sign should supplement aerial surveys and telemetry
studies to further define habitat use patterns.Questions regarding
distribution include but are not limited to:(I)how many ewe
groups are currently found in the Santa Rosa Mountains and
Vallecito Mountains,(2)if augmentation or reintroductions are
necessary, where should these occur,and (3) how do the number
and distribution of ewe groups change over time as conditions or
population numbers change?
Abundance monitoring (see task 2.2.1.1)will initially require that
radio-collared animals be distributed throughout the range.The
location of each animal should be obtained via visual location or
fixed wing aircraft telemetry surveys,at least biweekly.In
addition,the locations of all observed animals without collars
should be recorded during biennial helicopter surveys.
2.1.3 Monitor recruitment.Reproductive success,which includes
lamb production and recruitment,should be monitored on a yearly
basis in all ewe groups.Tracking and observing individually
marked ewes generates the most useful data because lamb survival
97
to specific ages can be determined,and the reproductive success of
individualewes can be tracked.Alternatively,the lamb to ewe
ratio of each ewe group couldbe measured atvarious times of the
year (e.g.,during waterhole counts or helicopter surveys).Ground
surveys should be organized if feasible.If lamb mortality is found
to be high in specific ewe groups,the radio-collaring of lambs may
be necessary to identify causes ofmortality.Recruitment should
be compared among ewe groups,years,and management strategies.
2.1.4 Monitor survivorship and cause-speqfic mortality.Adult
survivorship should be monitored annually in all ewe groups.This
monitoring would require that radio-collared rams and ewes are
present in each area and telemetry signals are monitored on a
regular (at least biweekly)basis.It is important that all mortalities
be investigated promptly so that cause specific mortality rates can
be calculated.Astandardized mortality siteinvestigation protocol
should be established.Whenever possible,fresh carcasses or tissue
samples should be collected and submitted to the California
Veterinary Diagnostic Laboratory for pathological examination.
Survivorship and cause-specific mortality should be compared
among ewe groups,years,and management strategies.
2.2 Develop population models.Although a substantial amount of
knowledge exists regarding bighorn sheep in the Peninsular Ranges and
elsewhere,there is a need for further research regarding their ecology and
the factors that influence population viability.Incorporating existing
knowledge into models may provide insight into the ecology of Peninsular
bighorn sheep and the system to which they belong.Rather than using the
absolute results of models to make policy or management decisions,
however,the relative outcomes of alternative models should be used to
guide management decisions (Beissinger and Westphal 1998)and future
research efforts.Models uncover knowledge gaps and thereby guide
future research and generate hypotheses that would not otherwise be
addressed.The recovery of Peninsular bighom sheep will benefit from
98
answers to a number of questions.These questions include,but are not
limited to:(1) how do the number of ewe groups,size of groups,and level
of connectivity among groups affect persistence probabilities of the
metapopulation,and (2)what are the relative long-term effects of various
levels of adult and juvenile mortality on population viability?
Although the above questions pertain primarily to viability from the
perspective of population numbers,future models could also incorporate
data to assess genetic diversity.Additional models should explore habitat
selection versus availability.
2.3 Research the relationships between bighorn sheep,mountain lions,
mule deer,and habitat.In thePeninsular Ranges,mountain lions and
mule deer are found within bighorn sheep habitat,and are important
variables affectingthis ecosystem (Hayes et al.2000). To increase our
knowledge of the ecology of Peninsularbighorn sheep,a better
understanding of predation,interspecies relationships,and habitat
selection is needed.Information regarding the relationships will be
valuable in making future management decisions to facilitate population
recovery,including decisions regarding habitat management,reduction of
mortality due to predation,and whether other species should be managed
to achieve recovery of Peninsular bighorn sheep.Pertinent research goals
include,but are not limited to:
a.Estimate the number of mountain lions preying on bighorn sheep.
b.Examine movement patterns of mountain lions within and adjacent
to bighorn sheep habitat,and attempt to identify influencing
factors.
c.Examine the spatial and temporal patterns of mountain lion
predation on bighorn sheep and mule deer in relation to the
distribution of both prey species, season,climate patterns,and
habitat characteristics.
99
d.Describe the habitat use patterns and distribution of mule deer in
and near bighorn habitat.
Answering some of these questions requires long-term study (perhaps 10
ormore years).Such a study would requireextensive monitoring and
habitat study of all three species.Experimental approaches involving
removal of mountain lions and manipulation of mule deer populations and
habitat should be designed to test the outcome in terms of predation rates
on bighorn sheep.
2.4 Investigate the relationships between bighorn sheep and coyotes and
bobcats.Although mountain lions appear to be the primary predator of
adult bighorn sheep,predation by coyotes or bobcats also may affect the
viability of bighorn sheep populations,primarily through predation on
lambs. Factors that put bighorn sheep at risk from these predators should
be investigated.Studies should examine what impact expanding
urbanization, the use of urban environments,and artificial water sources
may have on the relationship between these three species.
2.5 Investigate the efficacy of temporarysuppression of natural
predation.Mountain lion predation currently is the primary cause of death
of adult radio-collared bighorn sheep in most ewe groups in the Peninsular
Ranges,and threatens population viability (refer to sections I.B.4 and
I.B.5).Any measures to intervene should be designed sothat the
effectiveness of various techniques canbe evaluated. The presence of
lions and otherpredators in the area of interest should be monitored as part
of the investigation.Because mortality and mountain lion predation rates
fluctuate across years (refer to sections I.B.4 and 1.B.5),it will be
important to evaluate the effectiveness of these actions over multiple
years.
2.6 Research habitat use/selection and dispersal behavior.Habitat use by
sheep has been studied by a number of researchers (refer to section I.B.l),
but manyquestions remain.In thePeninsular Ranges, as in many other
100
bighorn sheep habitats,the specific factors that limit populations are not
well understood.Abetter understanding of habitat use patterns and factors
underlying habitatselection will aid our understanding of resource
requirements and promote informed management decisions.Selected
topics for future research include:(1)water and nutritional requirements
and how these factors affect population characteristics and distribution,(2)
how and where habitat use and movement are influenced by disturbance
barriers and sources of fragmentation,(3)habitat use and how it relates to
predator evasion,(4)how habitat quality influences dispersal behavior,
and (5)how human disturbance affects habitat use patterns.
Documentation of habitatuse for essential life functions,such as lambing,
rutting,summer water stress,and dispersal,is needed.A detailed
vegetation map with sources of fragmentation for the entire Peninsular
Ranges would facilitate analyses of these variables on habitat usepatterns.
A number of questions exist regarding dispersal behavior.For example,
how often do ewes move between groups?Although preliminary data
suggest it occurs at a low rate,long-term monitoring (two or morebighorn
sheep generations)may be necessary to more accurately estimate the
frequency of such moves.Other questions include,but are not limited to:
(1)what conditions (population density,forage quality,time of year)are
associated with movement of animals between ewe groups;(2)what
habitat featuresare associated with movement paths; (3) how does range
expansion occur;and (4) how far (and among howmany ewe groups)do
rams typically move? The frequency and duration of monitoring will
depend on the specific research questions.For example,long-term studies
are needed to document dispersal behavior,while frequent or nearly
continuous monitoring may be necessary for studying habitat selection and
use patterns (Laundre et al.1987).The use of Global Positioning System
collars mayprovide a valuabletool in such studies.
2.7 Evaluate the effect of human activities on bighorn sheep.Given the
history of bighorn sheep population declines and extirpations in other
areas near urban centers,information is needed on how to manage
101
recreational activity in a manner that does not interfere with bighorn
habitat use.Because knowledge of the location and extent of human
activity is a prerequisite to conducting research and making informed
management decisions,responsible land management agencies should
place a high priority on obtaining this information.Avariety of study
designs maybe appropriate, such as:(1)experimentally prescribing
different management techniques and measuring results,(2)measuring
physiological changes in individuals in response to different disturbance
regimens, (3)determining the effects of human activities on bighorn
population characteristics (e.g.,reproduction and recruitment rates),and
(4) determining the effects of human activity on bighorn behavioral
patterns or activity cycles.It is critical that studies seeking to detectthe
effects of human disturbance have sufficient sample sizes and statistical
power to avoid type II statistical errors (accepting a falsenull hypothesis).
2.8 Research disease and preventive measures.There is a need to provide
ongoing screening for pathogens and exposure to infectious diseases to
detect and mitigate emerging epizootics. Although infectious diseases do
not currently appear to play an important role in population dynamics of
bighorn sheep in most of the Peninsular Ranges,it will be important to
continue monitoring the presence and impact of infectious diseases in ewe
groups because outbreaks could occur at any time.Since it will be
essential to radio-collar animals to monitor ewe groups,biological samples
should be collected atthe time of capture and tested for presence of
infectious disease.In particular,whole blood and serum should be
analyzed for the presence of specific pathogens and antibodies to those
pathogens. A standardized sampling protocol should be developed and the
laboratories used by researchers should be identified in all reports so that
testing can also be standardized. When feasible,fresh carcasses should be
taken immediately to theCalifornia Veterinary Diagnostic Laboratory in
San Bernardino for necropsy.A standardized necropsy protocol should be
developed,and necropsy reports made available to all agencies and
researchers.
102
At this time,preventive measures such as vaccination or anthelmintic
treatments do not appear to be warranted in any of the ewe groups with the
exception of thenorthern SantaRosa Mountains ewe group.Nematode
parasites have been documented in this group and nematode treatment may
be appropriate. Treatment schemes should be designed so that the
effectiveness of each treatment can be evaluated (control animals or
groups should be used).Infectious disease data should be re-evaluated
periodically or continuously,and recommendations regarding treatment
and preventive strategies based on research findings.
Pathogen monitoring should be extended to cattle and mule deer in the
Peninsular Ranges.Other ungulates may serve as reservoirs for cross
transmission of bluetongue to bighorn sheep.
2.9 Research genetics of bighorn sheep in the Peninsular Ranges.
Genetic issues should be considered and re-evaluated during the recovery
process,especially as new methods become available.Samples should be
used in association with those already collected to more clearly delineate
population structure,to estimate gene flow,to identify themost
appropriate source stock (free ranging and captive) for translocation,to
assess the risk of inbreeding and outbreeding depression,to test if there
has been a recent population bottleneck within a subpopulation,and to
monitor loss of variation due to changes in breeding structure.Research
directed towards the estimation of the effective population size (N)shoulde
be a priority,and genetic variability should be directly monitored (Lande
and Barrowclough 1987).In addition,analyses of samples collected from
bighorn sheep within and outside of the Peninsular Ranges would be
useful to better estimate the phylogeographic structure of desert bighorn
sheep and to further identify management units.DNA samples should be
collected from every animal captured in the Peninsular Ranges and from
adjacent populations,using a standardized sampling protocol. A DNA
bank has been established at the University of California at Davis that
consists of over 700 samples from bighorn sheep in the Southwest,
including over 100 samples from the Peninsular Ranges. Given recent and
103
anticipated technological advancements,collection and long-term storage
of germinaland somatic cells from captured animals should be initiated
for future use.
3.DEVELOP AND IMPLEMENT EDUCATION AND PUBLIC AWARENESS
PROGRAMS.
Conservation efforts have a higher chance of success if they are supported by the
local community.A number of recoveryactions outlined in this recovery plan
will directly affect the general public.It is therefore imperative that strong public
education and awareness programs be implemented. The public needs to be
informed ofthe reasons why specific recovery actions are being taken. This task
will require an educationprogram on the ecology of Peninsular bighorn sheep,
what threats this species is currently facing,and how recovery actions will reduce
thesethreats. Coordination with thepublic and interest groups will be particularly
important for controversial issues,such as trails and predator management.This
knowledge should translate into a respect and concern for this species,leading to
support forconservation measures.
Several programs and sources of informationpertaining specifically to Peninsular
bighorn sheep already exist.Interpretive displays and materials arefound at the
Visitor Center in Anza-Borrego Desert State Park, the Bureau of Land
Management Visitor Center in Palm Desert,Bighorn Institute,Living Desert in
Palm Desert,and Palm Springs Desert Museum.In addition,local interest groups
have hosted guest talks by biologists studying bighorn sheep.These programs
should be continued and additional programs established, such as information
provided to the public through the tourist industry and ecotourism operators.The
effectiveness of educational programs would be increased if a higher degree of
coordinationexisted among individual programs and other recovery activities.
This coordination would not only allow each program to present the most accurate
and updated information,but would also let the general public see that the
recovery of Peninsular bighorn sheep is a collaborative effort supported by
multiple agencies,organizations,and individuals.Specific recovery actions are:
104
3.1 Distribute information related to recovery efforts.Updated and
accurateinformation should be available to interested individuals, groups,
or local governments.This material should be provided by the key
agencies involved in therecovery effort and should include information on
theecology of Peninsularbighorn sheep,currentthreats to population
viability,and explain recovery actions.Information dissemination should
coordinatewith the Coachella Valley Multiple Species Habitat
Conservation Plan.
The need for specific recovery actions should be explained to the general
public.For example,home owners, landmanagers,and developers should
be provided with information that explains:(1)why restrictions on toxic
plants,fences,and pesticides are needed,and (2)why artificial feeding of
coyotes could adverselyaffect bighorn sheep.Recreation groups should
be providedwith information that explainswhy certain trail closures are
necessary.Interpretive signs should be posted at all trailheads that enter
bighorn sheep habitat.Trained docents could be present at popular
trailheads during high trail usage periods and during periods of trail
closures to provide additional information and answer questions.
3.2 Continue,update,and coordinate existing education programs.
Existing programs should be expanded and regularly updated to provide an
accurate view of our currentknowledge regarding Peninsular bighorn
sheep.Dynamic displays that feature up-to-date population status and
monitoring activities,current researchprojects,and conservation activities
likely will be most effective.Eachprogram should highlight not only how
its agency’s or organization’s activities contributeto the recovery of
Peninsular bighorn sheep,but howthese activities complement those of
other agencies/organizations.Au annual meeting of government officials
including the Fish and Wildlife Service,the Bureau of Land Management,
CaliforniaDepartment of Fish and Game,California Department of Parks
and Recreation,U.S.Forest Service,researchers from the University of
California at Davis, Bighorn Institute,and others,as appropriate (e.g.
educational facilityrepresentatives or public relations directors),should be
105
heldto facilitatethe exchange of information and ideas for improving and
updating education programs.
3.3 Develop additional educational programs.An educational program
targeting local schools should be developed.This program might include
a teachingpacket that school teachers can use to introduce their students to
Peninsular bighorn sheep and the desert ecosystem in general.Classroom
activities could be combined with visits from biologists or tours of bighorn
sheep habitat,possibly in conjunction with existing programs (e.g.,at
Auza-Borrego Desert State Park and The Living Desert).Current
conservation issues,population monitoring,and research projects could be
incorporated intothis type of program,possibly through the use of
informative videos orweb sites.Cunningham (1993) outlined the use of
such an interactiveprogram in Arizona.
The feasibility of additional educational programs should be investigated.
Possible sites/organizers are the Zoological Society of San Diego,the Los
Angeles Zoo,and museums within Riverside and San Diego Counties.
Additional goals of existing and newly developed programs should be to:
a.Reach people who would not typically be exposed to traditional
programs (i.e.,individuals who might not frequent visitor centers
orwho do not have school-aged children).This goal might be
accomplished by promoting informative presentations atsenior
citizen centers,home owner group meetings, tourist centers,or golf
clubs.In addition,local and nationaltelevision programs featuring
the Peninsularbighorn sheep should be developed,and press
releases should be encouraged.
b.Stress an ecosystem approach in which habitat protection is an
integral part of the recovery of Peninsular bighorn sheep.
106
c.Encourage the public to takepart in conservation activities. A
prime example is 28 years of waterhole count data that have been
collected byvolunteer counters in Anza-Borrego Desert State Park.
Habitat restoration,such as tamarisk removal or water
development also represent ideal volunteer projects. An
observation logbook might be established at visitorcenters to allow
visitors to recordbighorn sheep and other species they observed.
d.Conduct public attitude assessments to determine the effectiveness
of specific programs and guide future activities.
3.4 Distribute a protocol to select law enforcement,public health,and
safety off cialsfor the humane treatment of injured bighorn sheep.Injured
bighorn sheep are sometimes found by motorists, pedestrians,or hikers
who thenreport the situation to public officials in a variety of agencies.
Personnel of these agencies often are not knowledgeable about medical or
humane treatment procedures for injured animals.A protocol needs to be
developed and distributed to city,county,State,and Federal agencies that
are likely to receive reports of injured animals that provides information
on appropriate contacts who are qualified to diagnose and treat injured
animals. Information from such cases should be collected and maintained
by one agency so that a complete database is available for researchers and
managers.
E.SITE SPECIFIC RECOVERY TASKS.
In this section, the recoveryactions described in section II.D are further identified
as site specific recovery tasks.They are matched with the nine recovery regions
listed under the recoverycriteria (Table 11).Site specific tasks for each of these
areas are indicated in Table 12.
107
Table 11.Recovery criteriaregions.
RECOVERY REGIONS
1.San Jacinto Mountains
2.Santa Rosa Mountains--North of
State Highway 74
3.Santa Rosa Mountains--South of Highway 74
through Martinez Canyon
4. SantaRosa Mountains--South of Martinez
Canyon to slopes west of Village Peak
5.Coyote Canyon--east and west sides
6.North San Ysidro Mountains--Henderson
Canyon to County Road S-22
7.South San Ysidro Mountains--County Road S-22
to State Highway 78
8.Vallecito Mountains/Fish Creek Mountains
9.Carrizo Canyon/TierraBlanca
Mountains/Coyote Mountains A/south of Interstate 8
108
Table 12.Site specific tasks recommended for each recovery region. Refer to the narrative outline (section II.D)for a
complete description of recovery actions.
Recovery Action
(abbreviated)
Recovery Region
SR-
N74
SY-S VM/
EC
SJ
——
x x
SR-
S74
—
x
SR-
MCS
a
x
CC
—
x
SY-
N
———
x x x
CC/TB!
CM
—
x1.1.1 Protectessentialhabitat
1.1.2 Secure habitat x x x x x x x x x
1.1.3.1 Remove exotic vegetation X X X X X X X X X
1.1.3.2 Reduce/eliminate wild horses x x
1.1.3.3 Implement fire management plan x x x x x x x x x
1.1.3.4 Maintain/provide water sources x x x x x x
1.1.3.5 Maintain/reestablish habitat connectivity x x x x x x x x x
1.2.1.1 Constmct fences (at urban interface)x x x
1.2.1.2 Avoid non-native vegetation x x x
1.2.1.3 Promote native plants, limit exotic plants x x x
1.2.1.4 Prohibit use of toxic plants x x x
1.2.1.5 Discourage use of exotic invasive plants x x x
1.2.1.6 Prohibit enticement onto private property x x x
1.2.1.7 Monitor use of pesticide,herbicides,etc.x x x
1.2.1.8 Regulate water diversion/procurement x x x x x x x x x
1.2.1.9 Prohibit artificial water sources (Culicoides)X X X
1.2.1.10 Discourage feeding coyotes x x x
1.2.1.11 Secure funds/methods to monitor x x x x x x x x x
1.2.2.1 Develop trails management program x x x x
1.2.2.2 Prohibit activities withnegative impacts x x x x x x x x x
1.2.2.3 Minimize livestock grazing impacts x x x
1.2.2.4 Prohibit domestic sheep grazing x x x x x x x x x
1.2.2.5 Fence neighboring cattle allotments x x x
1.2.2.6 Prohibit goats as pack animals x x x x x x x x x
1.2.2.7 Secure funds/methods tomonitor x x x x x x x x x
Table 12.Continued.
Recovery Action
(abbreviated)
Recovery Region
SJ SR-
N74
SR-
574
SR-
MCS
CC SY-
N
SY-S VM/
FC
CC/TB!
CM
1.3.1.1 Regulate fence construction and design x x x x x
1.3.1.2 Postlmonitor highway crossing areas x x x x x x
1.3.2 Reduce mortality due to natural causes x x x x x x
1.4 Develop reintro/augment.strategy x x X
2.1.1 Monitorabundance x x x x x x x x x
2.1.2 Monitordistribution x x x x x x x x x
2.1.3 Monitorrecruitnient x x x x x x x x x
2.1.4 Monitor survivorship/causes of mortality x x x x x x x x x
2.2 Developpopulation models x x x x x x x x x
2.3 Research bighom/lions/deer/habitat x x x x x x
2.4 Research impact of coyotes/bobcats x x x x x x x
2.5 Research methods to decrease predation x x x x x x
2.6 Research habitat use/dispersal x x x x x x x x x
2.7 Monitor human impacts x x x x x x x x
2.8 Research disease/prevention x x x x x x x x x
2.9 Research genetics x x x x x x x x x
3.1 Distributerecoveryinforniation x x x x x x x x x
3.2 Cont./update public education programs x x x x x x x x x
3.3 Develop new public education programs x x x x x x x x x
3.4 Distribute protocol for injured sheep treatment x x x x x x x x x
SI:San Jacinto Mountains
SR-N74:Santa Rosa Mountains -north of Highway 74
SR-574:Santa Rosa Mountains -south of highway 74
SR-MCS:Santa Rosa Mountains--South of Martinez Canyon
CC:Coyote Canyon--east and west side
SY-N:
SY-S:
North San Ysidro Mountains
South San Ysidro Mountains
VM/FC:Vallecito/Fish Creek Mountains
CC/TB/CM:Carrizo Canyon/Tierra Blanca
Mountains/Coyote Mountains
III.IMPLEMENTATION SCHEDULE
The ImplementationSchedule that follows outlines actions and estimated costs for
the Peninsularbighorn sheep recovery program,as set forth in this recovery plan.
It is a guide for meetingthe objectivesdiscussed in part II of this plan.This
schedule indicates task priority,task numbers,task descriptions,duration of tasks,
responsible agencies,and estimated costs.The agencies responsible for
committing funds are not necessarily theentities that will carryout the tasks.The
agency or agencies with leadresponsibility for each task are indicated in the table.
Initiation of these actions is subject to the availability of funds.
The Implementation Scheduleindicates speculative,future costs (preparation of
additional plans,or research programs, etc.) as “to be determined”.Some costs
appear as zerobecause indirect costs,such as those incurred by:(1) contributions
of time and materials by agencies and other groups, and (2) administrative or
regulatory costs by public agencies,arenot included in cost totals.Costs of
continuous tasks are estimated assuming a25-year time to recovery.Though the
Implementation Scheduledoes not distinguish between public and private costs,
no identifiableor specific expenditures are likely to be needed by the private
sector,other than voluntary efforts contributed by nonprofit organizations and
citizen groups.Priorities (Column 1 of the following table)areassigned as
follows:
Priority I -An action that must be taken to prevent extinction or to prevent the
species from declining irreversibly.
Priority 2 -An action that must be taken to prevent a significant decline in
species population/habitat quality or some othersignificant
negative impact short of extinction.
Priority 3 -All other actions necessary to provide for full recovery of the
species.
111
Abbreviations used in the Implementation Schedule:
To be determined
Continuous
Coachella ValleyMultiple SpeciesHabitat Conservation Plan,
which includesparticipating cities,County of Riverside, and
landowners
Palm Springs,Cathedral City,Rancho Mirage,Palm Desert,Indian
Wells,and La Quinta
San Diego,Imperial,and Riverside Counties
ACBCI
BI
BLM
CALTRANS
CDFG
CDPR
CVMVCD
CVMC
CVWD
DoD
FWS
RWQCB
RC
RCFCWCD
SDZS
UCD
USFS
*
Agua Caliente Band of Cahuilla Indians
Bighorn Institute
Bureau of Land Management
CaliforniaDepartment of Transportation
CaliforniaDepartment of Fish and Game
CaliforniaDepartment of Parks and Recreation
CoachellaValley Mosquito and Vector Control District
Coachella ValleyMountains Conservancy
CoachellaValleyWater District
Department of Defense
U.S.Fish and Wildlife Service
Regional Water Quality Control Board
Riverside County
Riverside County Flood Control and Water Conservation District
San Diego Zoological Society
University of California -Davis
U.S.Forest Service
Lead Agency
TBD
cont.
MSHCP
Cities
Counties
AGENCIES AND ORGANIZATIONS
112
RECOVERY PLAN IMPLEMENTATION SCHEDULE FOR PENINSULAR BIGHORN SHEEP
Responsible
Agencies
Cost (SI ,000s)
jFYj F’i’
Priority
—
I
Task Task Description
Task
Duration
(Years)
—____
cont.ACBCI*, BLM*,
FWS*,CVMC*,
MSHCP*,
CDFG*,CDPR*,
CVWD*
Total
Estimated
Cost
(SI ,OOOs)
~L2il22L2LIJL
0 0 0 0 0 0
FY FY FY
I
I I
Protect essential habitat
1.1.2 Secure habitat cont.BLM*,CDFG*,
CVMC*,CDPR*,
MSHCP*
70,000 TBD TBD TBD TI3D TBD
I 1 3 1 Remove exotic vegetation and prevent
invasion by exotic plants
cont.ACBCI*, BLM*,
CDFG*,CDPR*,
CVWD*,
RCFCWCD*
250 10 10 10 10 10
1 1.1.3.2 Reduce/eliminate wild horses 5 ACBCI*,BLM*,
CDPR*
TBD TBD TBD TBD TBD TBD
I 1.1.3.4 Maintain/provide water sources 5 13LM~,CDFG*,
CDPR*
50 20 20 10 0 0
1 1.1.3.5 Maintain/re-establish habitat
connectivity
cont.BLM*,FWS*,
CDFG*,CDPR*,
Caltrans*,MSHCP*
TBD TBD TBD TBD TBD TBD
1 1.2.1.1 Construct fences to exclude bighom
sheep from urban areas
5 MSHCP*,CDFG,FWS 500 100 100 100 100 100
I 1.2.1.4 Prohibit use of toxic plants cont.MSHCP*0 0 0 0 0 0
I 1 2 1 8 Regulate water diversion/procurement cont.RWQCB*,CVWD*0 0 0 0 (1 0
RECOVERY PLAN IMPLEMENTATION SCHEDULE FOR PENINSULAR BIGHORN SHEEP
Responsible
Agencies
Priority
—I
Task Task Description
Task
Duration
(Years)
—cont.
Total
Estimated
Cost
($1,000’s)
1...............MSI~1CP*0
Cost (S 1,000’s)
IFYI FY
..2L 02 03 I...~2LI2~————0 0 0 0 0
FY FY
02
FY
03III.2 I.Secure funding to implement measures
I 1.2.2.1 Develop and implement a trails
management program
cont.RLM*,CDFG,USFS,
FWS,MSHCP
TBD TBD TBD TBD TBD TI3D
I I 2 2 2 Prohibit fragmenting and interfering
activities
cont.BLM*,USFS*,FWS*,
DoD*,CDFG*,CDPR*
Counties*,Cities*
TBD TBD TBD TBD TBD TBD
I 1.2.2.3 Minimize livestock grazing impacts 5 BLM¶USFS*25 5 5 5 5 5
1.2.2.4 Prohibit grazing bydomestic sheep 5 BLM*,USFS*0 0 0 0 0 0
I 1.2.2.7 Secure funding to implement measures cont.BLM*,IJSFS*,FWS*,0 0 0 0 0 0
1.3.2 Reduce mortality due to natural causes cont.CDFG*,CDPR,FWS,
BLM
TBD TBD TI3D TBD TBD TBD
I 2 11 Monitor abundance cont.CDFG*,CDPR,BLM,
FWS,BI
323 11 15 11 15 11
I 2 I 2 Monitor distribution cont.CDFG*,CDPR,I3LM,
FWS,BI
323 II 15 11 15 II
I 2.1.3 Monitor recruitment cont.CDFG*,CDPR,BLM,
FWS,RI
323 11 15 11 15 II
I 2.1.4 Monitor survivorship and cause-specific
mortality
cont.CDFG*,CDPR,BLM,
FWS,BE
125 5 5 5 5 5
2 1.1.3.3 Implement fire management plan 5 USFS*,BLM,CDFG,
CDPR
TBD TI3D TBD TBD TBD TBD
2 1.2.1.2 Avoid non-native vegetation cont.MSHCP*0 0 0 0 0 0
I;RECOVERY PLAN IMPLEMENTATION SCHEDULE FOR PENINSULAR BIGHORN SHEEP
Priority Task
—
I 2 1 9
Task Description
Task
Duration
(Years)
—
cont.
Responsible
Agencies
Total
Estimated
Cost
(SI,000’s)
Cost (S 1,000’s)
}FYj FY
K2LL2L————
0 0 0 0 0
FY[FY IFY
Oil 02103
2
2 Prohibit (7ulicoides water sources MSHCP*0
2 1.2.2.5 Fence cattle allotments adjoining habitat 3 BLM*TBD TBD TBD TBD 0 0
2 1.2.2.6 Prohibit goats as pack animals cont.BLM*,USFS*,
CDFG*,CDPR*
0 0 0 0 0 0
2 1.3.1.1 Regulate fence design/construction cont.BLM*,USFS*,
MSHCP*
0 0 0 0 0 0
2 1.4 Develop captive breeding,
reintroduction,augmentation strategy
cont.BI,*CDFG,*FWS*TBD TBD TBD TBD TBD TBD
2 2.2 Develop population models 3 TBD 30 10 10 10
2 2.3 Research the relationships between
bighorn,mountain lions,mule deer,and
habitat characteristics
5 FWS,*CDFG,*
CDPR*,SDZS*,UCD*
650 130 130 130 130 130
2 2.5 Investigate the efficacy of temporary
suppression of natural predation
5 CDFG*,FWS,CDPR 150 30 30 30 30 30
2 2.6 Research habitat use/selection and
dispersal behavior
10 TBD ISO 15 15 15 15 IS
2 2.7 Monitor the effects of human
disturbance
3 CDFG*,BLM,CDPR,
USFS,FWS
TBD TBD TBD TBD
2 2.8 Research disease and preventive
measures
3 TBD TBD TBD TBD TBD
2 2.9 Research genetics 3 TBD TBD TBD TBD TBD
RECOVERY PLAN IMPLEMENTATION SCHEDULE FOR PENINSULAR BIGHORN SHEEP
Priority Task Task Description
Task
Duration
(Years)
Responsible
Agencies
Total
Estimated
Cost
($l,OOO’s)
Cost (51,000’s)
—1~
FY FY FY FY FY
01J02j03j04J05
—————
2 2 2 2 2
2
2 3.1 Distribute information on recovery
efforts
cont.FWS*,BLM,CDFG,
BI,MSHCP,CDPR,
USFS
5
50
2 3.2 Continue,update,and coordinate
existing programs
cont.FWS*,BLM,USFS,
CDFG,BI,CDPR,
MSHCP
50 2 2 2 2 2
2 3.3 Develop educational programs cont.FWS*,BLM,USFS,
CDFG,MSHCP,CDPR,
BI
50 2 2 2 2 2
3 1.2.1.3 Promote native plants cont.MSHCP*29 5 I I I I
3 1.2.1.5 Discourage use of exotic invasive plants cont.MSHCP*0 0 0 0 0 0
3 1.2.1.6 Prohibit enticement on private property cont.MSHCP*25 I I I I I
3 1.2.1.7 Monitor use of pesticide,herbicides 5 MSHCP*25 5 5 5 5 5
3 1.2.1.10 Discourage feeding coyotes cont.MSI~1CP*0 0 0 0 0 0
3 1.3.1.2 Post/monitor highway crossing areas cont.Caltrans*,BLM,
CDPR,CDFG
25 TI3D TBD TBD TBD TBD
3 2.4 Investigate the relationships between
bighorn,coyote,and bobcat
10 TBD 100 10 10 10 10 10
3 3 4 Injured sheep treatment protocol cont.CDFG*,FWS,I3LM,
MSHCP
0 0 0 0 0 0
Total estimated cost of recovery:$73,253,000 +
ON
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Wilson,L.0.,J. Blaisdell,G.Walsh,R.Weaver,R.Brigham,W.Kelly, J.
Yoakum,M.Hinks, J.Turner,and J.DeForge.1980.Desert bighorn
habitat requirements and management recommendations.Desert bighorn
Council Transactions 24:3-7.
Wilson,D.E.and D.M. Reeder, eds.1993.Mammal species of the world: a
taxonomic and geographic reference,2nd edition.Smithsonian Institution
Press.Pp.408-409.
Wootton,J.T.and D.A.Bell.1992.Ametapopulation model of the Peregrine
falcon in California:viability and management strategies.Ecological
Applications 2(3):307-321.
B.Personal Communications
Bleich,V. C.CaliforniaDepartment of Fish and Game, Bishop,Calif.
Boyce,W.M.University of California,Davis,Calif.
Correll,T.The Living Desert Museum,Palm Desert,Calif.
DeForge,J.R.Bighorn Institute,Palm Desert,Calif.
Jorgensen,M.C.California State Parks,Colorado Desert Dist.,Borrego Springs.
Calif.
Krausman,P.R.University of Arizona,Tucson,Arizona
146
Rubin,E.S.University of California, Davis,Calif.
Weaver,R.A.California Department of Fish and Game,retired
Wehausen,J.D.University of California,White Mountain Research Station,
Bishop,California
C.In Lift.References
DeForge,J.R.1997.Letterto Gavin Wright, Bureau of LandManagement,
North Palm Springs,California.Oct.22,1997.Bighorn Institute,Palm
Desert Calif.2pp.
Jessup,D. A.1999.Letter to Sheryl Barrett,U.S.Fish and Wildlife Service,
Carlsbad,Calif.Aug.28,1999.Calif.Dept.of Fish and Game, Santa
Cruz.2pp.
Jessup,D. A.2000.Letterto Scott McCarthy,U.S.Fish and Wildlife Service,
Carlsbad,Calif.June 23,2000. Calif. Dept.of Fish and Game,Santa
Cruz.Ip.
Krausman,P.R.1998.E-mail to Esther Rubin.Oct.19,1998.Univ.of
Arizona,Tucson.ip.
147
V.APPENDICES
APPENDIX A.AN OVERVIEW OF THE PENINSULAR RANGES
ThePeninsular Ranges are located in southern California and Mexico,in the
ColoradoDesert division of the Sonoran Desert (Ryan 1968).On the north,the
Peninsular Ranges arebordered by the Transverse Ranges.From this point, they
extend south into Mexico,forming the backbone of Baja California.In
California,the ranges form a prominent natural province (Sharp 1976)that is
bounded on theeastby the Salton Trough.To thewest, the province extends to
the Pacific Ocean,as a 130-kilometer-wide (80-mile-wide)series of northwesterly
trending basins and ranges.The basins form channels below sea level and the
ranges form the islands of San Nicolas, SantaBarbara, Santa Catalina,and San
Clemente.
Thehighest peak in the San Jacinto Mountains is the3,292-meter (10,800-foot)
high San Jacinto Peak.Toro Peak,at 2,655 meters (8,700 feet),is thehighest
peak in the SantaRosa Mountains (Oakeshott 1978).The Salton Sea,located to
the east of thePeninsular Ranges,is found in the largest land mass below sea level
in the Western Hemisphere (Ting and Jennings 1976).Historically,the Salton
Sea has alternated between a freshwater lake fed with waters from the Colorado
River,and a dying brackishpond when the waters of the Colorado River flowed
instead to the Gulf of Mexico.When filled,the Salton Sea lapped at the foothills
of theSanta Rosa Mountains.Since approximately 1907,however,the sea has
been an increasinglysaltydepository for agricultural wastes of the Coachella and
Imperial Valleys (Ting and Jennings 1976).
Bighorn sheep inhabit the eastern slopes of the Peninsular Ranges in habitat
characterized by steep slopes and cliffs,canyons,washes,and alluvial fans. The
remainder of this appendix will, therefore, provide an overview of theeastern
slopes of the Peninsular Ranges.
Within bighorn sheep habitat,annual rainfall is variable with maxima of 35 to 470
millimeters (1.3 to 18.5 inches)during thepast 36 years (National Oceanic and
148
Atmospheric Administration,1962 to 1997).Rainfall exhibits a bimodal
distribution pattern with most (approximately 70 percent)occurring in the winter
months and a lesser amount in the late summer months.Winter rains are of the
Pacific marine type,characterized by steady long rain showers,which promote the
spring peak in plant productivity.Summer showers are of the Gulf marine type,
which result in localized and sometimes fierce thunderstorms (Lindsay and
Lindsay 1991).Maximum temperature in bighorn sheep habitat oftenreaches 46
degrees Celsius (115 degrees Fahrenheit)in summer,while winters are mild,with
temperatures occasionally reaching freezing (National Oceanic and Atmospheric
Administration,1962 to 1997).
Onthe eastern slopes of the Peninsular ranges,vegetation associations are
coniferous forest,primarily ponderosa pine (Pinus ponderosa),Jeffrey pine (Pin us
jeffreyi),Coulter pine (Pinus coulteri),and white fir (Abies concolor)above
approximately 1,800 meters (5,905 feet),chaparral above approximately 1,500
meters (4,920 feet),and pinyon pine (P.monophylla)-juniper (Jun iperus
cal~fornica)above approximately 1,200 meters(3940 feet).Lower elevations are
dominated by agave (Agave deserti),ocotillo (Fouquieria splendens),cholla
(Opuntia spp.) and palo verde (Cercidiumfioridurn),creosote (Larrea tridentata),
palo verde-mesquite (Prosopis spp.) associations (Ryan 1968).Bighorn sheep
typically are found at elevations less than 1,400 meters (4,600 feet) (Jorgensen
and Turner 1975),usually stayingat elevations below the chaparral and pinyon
pine-juniper vegetation associations.These associations canrepresent visual
obstruction because of denser and taller structures,and therefore make bighorn
sheep more susceptible to predation (refer to section I.B.I and I.B.2).
The Peninsular Ranges are inhabited by a large number of mammalian species
(reviewed by Ryan 1968).The only native sympatric ungulate is themule deer
(Odocoileus hernionus).Bighorn sheep and deer distributions overlap at the upper
elevations of bighorn sheep habitat, with possible geographic and seasonal
differences in the degree of overlap. Deer are observed more frequently at lower
elevations during the winter months.Potential native predators of bighorn sheep
aremountain lions (Puma con co1or~,bobcats ~Lvnxrufus),coyotes (C’anis
latrans),and golden eagles (Aquila chrvsaetos).These species are found
throughout bighorn sheep habitat in the Peninsular Ranges.
149
References
Bolton,H.E.1930.Anza’s California expeditions.Vol.IV.Fonts complete
diary of the second Anza expedition. University of California Press,
Berkeley.SS2pp.
Brigandi,P. 1995.The livestock industry on the Anza-Borrego desert.A report
for the Anza-Borrego Desert State Park. Contract No.C4532007.
Cunningham,S.C.and R.D.Ohmart.1986.Aspects of the ecology of desert
bighorn sheep in Carrizo Canyon, California.Desert Bighom Council
Transactions 30:14-19.
Jorgensen,M.C.and R.E.Turner.1975.Desert bighorn of the Anza-Borrego
Desert State Park.Desert Bighorn Council Transactions 19:51-53.
Lindsay,L.and D.Lindsay.1991.The Anza-Borrego Desert Region.Third
Edition.Wilderness Press,Berkeley, California.l’79pp.
National Oceanic and Atmospheric Administration.1962-1997.Climatological
data:California. National Climate DataCenter, Asheville, North Carolina.
Oakeshott,G.B.1978.California’s changing landscape:a guide to the geology
of the state.McGraw-Hill,New York,New York.1379pp.
Reed,L.1986.Old Time Cattlemen and Other Pioneers of the Anza-Borrego
Area. Third Edition.Anza-Borrego Desert Natural History Association,
Borrego Springs,California.l4.6pp.
Ryan,R.M.1968.Mammals of Deep Canyon.TheDesert Museum,Palm
Springs,California.
Sharp,R.P. 1976.A field guide to southern California. Kendall/Hunt
Publishing Company,Dubuque,Iowa.L3Olpp.
151
References
Bolton,H.E.1930.Anza’s California expeditions.Vol.IV.Fonts complete
diary of the second Anza expedition. University of California Press,
Berkeley.SS2pp.
Brigandi,P.1995.The livestock industry on the Anza-Borrego desert.A report
for the Anza-Borrego Desert State Park.Contract No.C4532007.
Cunningham,S.C.and R.D.Obmart.1986.Aspects of the ecology of desert
bighorn sheep in Carrizo Canyon, California.Desert Bighorn Council
Transactions 30:14-19.
Jorgensen,M.C.and R.E.Turner.1975.Desert bighorn of the Anza-Borrego
Desert State Park.Desert Bighorn Council Transactions 19:51-53.
Lindsay,L.and D.Lindsay.1991.The Anza-Borrego Desert Region.Third
Edition.Wilderness Press,Berkeley, California.l79pp.
National Oceanic and Atmospheric Administration.1962-1997.Climatological
data:California. National Climate DataCenter, Asheville, North Carolina.
Oakeshott,G.B.1978.California’s changing landscape:a guide to the geology
of the state.McGraw-Hill,New York,New York.Y79pp.
Reed,L.1986.Old Time Cattlemen and Other Pioneers of the Anza-Borrego
Area.Third Edition.Anza-Borrego Desert Natural History Association,
Borrego Springs,California.l4eSpp.
Ryan,R.M.1968.Mammals of Deep Canyon.The Desert Museum,Palm
Springs,California.
Sharp,R.P. 1976.A field guide to southern California.Kendall/Hunt
Publishing Company,Dubuque,Iowa.3Olpp.
151
Ting,I.P.and B.Jennings.1976.Deep Canyon’s past.Pages 1-6 in Deep
Canyon,a desert wilderness for science.I.P.Ting and B.Jennings,eds.
University of California,Riverside.177pp.
Turner, J.C.1976.Bighorns.Pages 167-173 in Deep Canyon,a desert
wilderness for science.I.P.Ting and B.Jennings,eds.Univ.of
California, Riverside. lT7pp.
152
APPENDIX B.DELINEATION OF ESSENTIAL HABITAT FOR
BIGHORN SHEEP IN THE PENINSULAR RANGES
Intended use of the map(Figures 2,4-9)
A number of habitatmodels havebeen developed to rate bighorn sheep habitat
(e.g.,Hansen 198Gb,Holl 1982,Armentrout and Brigham 1988,Cunningham
1989,Dunn 1996)and components of bighorn sheep habitat have been examined
or discussed by numerous researchers (e.g.,Hansen 1980a,McCarty and Bailey
1994).It has been suggested that some of these modelsbe used to rate bighorn
habitat in the Peninsular Ranges.However,application of these models here is
inappropriate because theywere developed in other areas and life zones where
bighorn sheep exhibit different habitat requirements.For example,the Hansen
model hasbeen shown to be of limited value in measuring habitat quality in areas
outside the habitats in which itwas derived (Andrew and Bleich 1999)and is no
longerused by the CaliforniaDepartment of Fish and Game (S.Torres,California
Department of Fishand Game, pers.comm.).Cunningham (1989) suggested that
such habitat modelsneed to be modified before being applied to novel bighorn
sheep habitat.
The purpose of mapping bighorn sheep habitat in this recoveryplan is not to rate
the relative value of habitat types and areas within the Peninsular Ranges,but to
identifythose lands in need of protection,restoration,and management that are
essential to bighorn sheep recovery (refer to section I1.D.1).Rating the quality of
sheep habitat would require a more thorough understanding of habitat selection
versus habitat availability;studies that address this topic in the Peninsular Ranges
havenot been conducted to date but are recommended under section II.D.2.6.
Though bighorn sheep habitat sometimes canbe describedby its function (e.g.,
habitat for escape or lambing),Wilson et al.(1980)and Bleich et al.(1996)
concluded that all habitat types used by bighorn sheep in desertenvironments are
necessary fortheir population viability.TheSanta Rosa Mountains Wildlife
Habitat Management Plan (Bureau of Land Management 1980),a long-standing
plan developed and implemented under the Sikes Act (16 USC 670a et seq.,
Public Law 86-797)also recognized this,stating “(e)ach acre of bighorn habitat is
important in maintaining thepresent population”.
153
The purpose of this mapping effort is to delineate those areasbelieved to be
necessaryfor a self-sustaining bighorn population with a high probability for long-
term survival and recovery in thePeninsular Ranges of the UnitedStates.
“Essential habitat”,therefore,consists ofthose areas that provide bighorn sheep
with the various physical and biological resources (e.g.,space,food,water,cover)
potentially needed for:(1)individual/population growth and movement,and (2)
normal behavior with protection from disturbance. Essential habitat should be
protected from further loss or degradation (refer to section II.D.1.1).The valley
floor to the eastand the north of the Peninsular Ranges (e.g.,Coachella Valley,
Imperial Valley) likelywas used historically by bighorn sheep during rare,long-
distance moves to and from othermountain ranges.However,no suchmoves
have been documented. Furthermore,the chance of such moves has essentially
been eliminatedby high density urban development, major freeways,fences,and
canals.Consequently,the vast majority of the valley floor to the east of the
Peninsular Ranges is not included as essential habitat and is now detrimental to
future use by sheep.
Approach used
The delineation of essential habitatwas based on physical and biological features
known to be important to bighorn sheep.These features were identified by
reviewing pertinent literature and by drawing on thecollective knowledge and
experience of theRecovery Team and other biologists whohave studiedbighorn
sheep in the Peninsular Ranges.The knowledge of such biologists played an
important role in the mapping exercise because Peninsular bighorn sheep occupy a
habitat that has marked climate and vegetational differences compared to habitat
of most otherbighorn sheep populations.The Peninsular Ranges arelocated in
the Colorado Desert,a division of the Sonoran Desert,which experiences
different precipitation patterns(timing and intensity of rainfall)than the Mojave
or other Sonorandeserts and contains a somewhat different flora (Jaeger 1957,
MacMahon 1985).These differences appear to cause Peninsularbighorn sheep to
use habitat differentlythan bighorn sheep in other areas.For example,dense
vegetation at higher elevations of the Peninsular Ranges restricts bighorn sheep to
the more open desert slopes at lower elevations.For this reason,researchers
familiar with bighorn sheep in the Peninsular Ranges have referred to these
154
mountains as the“upside-down mountain ranges”(R.Weaver,California
Department of Fish and Game retired,pers. comm.).Therefore,published
information regardinghabitat use patterns of bighorn sheep,in general,was
supplemented with knowledge regarding habitat use patterns of Peninsular
bighorn sheep,to identify habitat features that determine the distribution of
bighorn sheep in these ranges.
Delineation of essential habitat is not based solely on known use patterns because:
(1)population numbers currently are low and small populations use less habitat
than larger populations,such as will be needed for recovery;(2) bighorn sheep are
difficult to detect; (3)use patterns are only known for a recent short time period;
(4) telemetry data on radio-collared animals (a sampled subset of the entire
population) represents only the areaused by marked animals,not the entire herd;
and (5)habitat loss and human disturbance likely inhibits use of some lower
elevation habitat. However, the delineated habitat boundarieswere reviewedby
Recovery Team biologists studying bighorn sheep in the Peninsular Ranges to
verifythat the mapped habitat encompassed most areas known to be usedby
animals currently or in the recent (25 to 30-year)past.However,numerous
documented locations of sheep fell outsidethe essential habitat boundaries (Figure
6). The resulting map also was compared against a previous modeling effort
(Bureau of LandManagement 1980)as part of the validation and refinement
process (see below).
Choice of habitat components
Habitat requirements have been examined by numerous researchers in the past
(e.g.,Cunningham 1989,McCartyand Bailey 1994).Topographic cover,water,
and forage appear to be the most consistently recognizedhabitat requirements,
although other components such asmineral availability,thermal cover,as well as
absence of competition with otherungulates and disturbance from human
activities also havebeen suggested to be important (Cunningham 1989,McCarty
and Bailey 1994).
Because these habitat components and characteristics largely determine how
bighorn sheep use their habitat in the Peninsular Ranges,information available on
155
these potential model parameters were compiled for analysis.Data that are
available consisted of:(1) a fairlycomprehensive inventory of water sources for
Anza-Borrego Desert State Park, (2) a water source surveyby the Bureau of Land
Management for the northern parts of therange, (3)vegetation community maps,
and (4)topographic relief.
In desert environments,water is a known limiting factor for many species of
plants and wildlife.However,some populations of bighorn sheep are known to
exist in areas without sources of perennial water (summarized in Broyles 1995),as
is known to be the case in parts of the Peninsular Ranges for at least some parts of
the year(refer to section lB.1).In the Peninsular Ranges, the presence of
perennial water is known to be a limiting factor only during prolonged droughts or
summers without significant thunderstorm activity.However, given the numerous
dependable water sources in the San Jacinto Mountains and other portions of the
range (e.g.central Santa Rosa Mountains), water likely does not limit sheep
distribution in these regions,evenunder drought conditions.The variable quality
and lack of reliable water source data in some portions of the Peninsular Ranges,
and the fact that water availability does not limit habitat use in much of these
ranges,resulted in thedecision to not use water sources to delineate bighorn sheep
habitat.Available observational records (Figure 6) indicate that sheep range at
least 16 kilometers (10 miles)from known perennial water sources. Given the
existing distribution of water,sheep are capable of using, and therefore can be
expected to use,all areasmapped as essential habitat.
Generalized plant community mapping has been completed within bighorn habitat
throughout Riverside County,and detailed mapping has been completed in Anza-
Borrego Desert State Park. However, bighorn sheep are generalist foragers and
plants known to be eaten arebroadlydistributed acrosshabitat types in the
Peninsular Ranges.Extreme topographic relief provides a diversity of
interdigitatedhabitats and plant communities across the mountainous slopes,
canyons,washes,and alluvial fans within the home range of each ewe group.
Consequently,the distribution of forageplants does not appear to limit sheep
distribution,though it can influence seasonal habitat use patterns.
156
Theprimary habitat components that limit thedistribution of bighorn sheep in the
PeninsularRanges maybe those associated with predator evasion.Unobstructed
visibility is recognized as an important habitat characteristic by many researchers
(e.g.,Geist 1971,Risenhoover and Bailey 1985,Fairbanks et at.1987,Etchberger
et at.1989).Bighorn sheep rely on their keen vision and climbing ability to detect
and evade their predators (Geist 1971).Thepresence of escape terrain and an
unobstructed view are,therefore, key habitat requirements(Geist 1971).
All bighorn sheep habitatmodels recognizeescape terrain asa key habitat
component.However, the definition of “escape terrain” varieswidely (McCarty
and Bailey 1994).Some researchers defined itby a minimum slope (e.g.,Andrew
et at.1999,Dunn 1996)or slope plus a qualitative measure of ruggedness (e.g.,
Holl 1982,Risenhooverand Bailey 1985,Armentrout and Brigham 1988),while
others havedescribed escapeterrain with word models that incorporate a
qualitativedescription of slope and ruggedness (e.g.,Hansen 1 980b,Elenowitz
1983,Gionfriddo and Krausman 1986,Fairbanks et at.1987,Cunningham 1989).
Thedifficulty in determining a universal definitionmay be because bighorn sheep
in different mountain ranges have access to different habitat (in terms of slope and
ruggedness),and/or because use of escape terrain varies with group size
(Risenhoover and Bailey 1985),group composition,and season (Cunningham and
Ohmart 1986,Bleich et a!.1997).Furthermore, escape terrain has been described
ashabitat used “for escape from perceived danger”(Van Dyke et at.1983).This
definition recognizes that escape terrain is based on a bighorn sheep’s perception,
something that apparently differs among individuals and populations. Desert
bighorn sheep frequently have been found at slopes of 21 to 50 percent (Elenowitz
1983), slopes greater than or equal to 20 percent (Andrew et at.1999),and slopes
averaging 13 to 34 percent (Bleich et at.1997).A minimum slope of 20 percent
wasused (in combination with canopy cover)to definebighorn sheep habitat in
NewMexico (Dunn 1996).A slope of greater than or equal to 20 percent was
adopted asthe minimum required as escape terrain forbighorn sheep in the
Peninsular Ranges.The first step of the habitat mapping process was,therefore,
to identify all patches of land having a slope of greater than orequal to 20 percent
(see following methods).
157
Bighorn sheep areclosely associated with mountainous habitat and often are
hesitant to venture far from escapeterrain (Geist 1971).Although they have been
documented to move great distances from escape terrain on rare occasions
(Schwartz et at.1986),it is not uncommon to observe animals moving a short
distance from escape terrain in search of forage or water sources,or moving
between neighboring mountain masses. Washes and alluvial fans often support a
higher diversity,quality,and quantity of forage species than less productive rocky
slopes (Leslie and Douglas 1979),seasonal and perennial watersources (Wilson
et al.1980,Holland and Keil 1989),bedding and thermal cover (Andrew 1994),
alternative forage sources in times of drought,resource scarcity,and stress (Leslie
and Douglas 1979,Bleich et a!.1997),and a source of forage with higher
nutritional value during thelambing and rearing season (Hansen and Deming
1980).Also refer to section I.B.1.Since temperature varies inversely with
elevation, the earliest winter forage growthoccurs at lower elevations (Wehausen
1980,1983),and sheep often seek this early source of nutrients.The critical
importance to bighorn of access to a variety of feeding habitats was demonstrated
in the Whipple Mountains when reintroduced sheep were confinedto an enclosure
containingwhat was consideredample forage.At lambing time,both ewes and
theirnew lambs began dying of malnutrition (Berbach 1987),apparently because
theywere not free to seek out habitats containing more nutritious forage.
Researchers have documentedanimals ranging at a variety of distances from
mountainous terrain,e.g.,1.6 kilometers (0.80 mile)(Denniston 1965),0.8
kilometer (0.50 mile)(MeQuivey 1978),1.3 kilometers (0.70 mile)(Leslie and
Douglas 1979),greater than 1 kilometer (1.6 miles)(Burger 1985),greater than
1.6 kilometers (1 mile)(Bleich eta!.1992),and greater than 2.5 kilometers (1.6
miles)(Andrew eta!.1997).Jones et at.(1957) reported bighorn sheep foraging
as far as 2 kilometers (1.2 miles)from thebase of the SantaRosa Mountains.
Elsewhere in thePeninsular Ranges,bighorn sheep were frequently observed
within 0.8 kilometer (0.5 mile)from mountainous habitat feeding in or moving
across washes and alluvial fans (DeForge and Scott 1982;E.Rubin and M.
Jorgensen, pers. comm.).Accordingly,the second step of the mapping process
was to include habitat within 0.8 kilometers (0.50 mile)of slopes greater than or
equal to 20 percent.
158
To identify slopes of 20 percent or greater,7.5’digital elevation models (DEMs)
were merged together over the entire study area. These digital elevation models
are 30-meter by 30-meter (98-foot by 98-foot)cell grids with avertical accuracy
of 7 meters (23 feet).All grid cellswere then aggregated intoslope classes.Next,
the slope classes were analyzed to select habitat within 0.8 kilometer (0.5 mile)of
slopes of greater than or equal to 20 percent.This selectionwas accomplishedby
first lumping slopes greater than or equal to 20 percent into one class in a
derivative grid.A buffer of 0.8 kilometer (0.5 mile) wasthen applied to the
perimeter of all areas of slope in the derivative grid.
Inthe Peninsular Ranges,bighorn sheep habitat is delimited atupper boundaries
by dense vegetation associations (primarily chaparral)that reduce visibility and
likely increase susceptibility to mountain lionpredation. Measuring visibility (by
actual field measurements)to delineate theupper boundary of habitat would
require study because it is currently not known what visibility threshold is
acceptable to bighorn sheep in the Peninsular Ranges.Fire frequencyand its
effect on plant succession changes visibilitythresholds over time (refer to section
I.D).Therefore, to determinethe upper boundary of bighorn sheep habitat, the
westernmost areas used by bighorn sheep withinthe past 25 to 30 years were
identified and the vegetation associations in these areas were applied rangewide
where detailed vegetation analyses were available.Because a detailed vegetation
map was not available rangewide, a team of biologists experienced with
Peninsular bighorn sheep flew the entire upper/western boundary line in a
helicopter and visually assessed vegetation associations.The path of the flight
was determined by consensus among the biologists and was recorded via a Global
Positioning System (GPS).The antenna of a Trimble Navigation,LTD.,Global
Positioning System was mounted in the helicopter and position data were
recorded every 10 seconds. A total of 228 kilometers (142 miles)were flown.A
base station Global Positioning System,located in the Anza-Borrego Desert State
Park, was run during the entire flight.Trimble Navigation Pathfinder Office
software was used to post process the collected GlobalPositioning System data
using base station information.Trimble Navigation Pathfinder Office (IM) was
then used to exportthe data as an ESRI NRC/INFO Geographic Information
Systems (GIS)readable file.Only corrected data were used to build theresulting
Geographic Information System layer.Because this line is dynamic in response to
159
fire frequency and likely has shifted to a lower elevation with the advent of fire
suppression, a 0.8 kilometer (0.5 mile) extension was added to the west side of
this line.
The resulting line in Anza-Borrego Desert State Park waschecked against detailed
Geographic Information System mapping of vegetation associations within the
park (Keeler-Wolf et at.1998).Vegetation associations not typically used by
bighorn sheep in the Peninsular Ranges were excluded from essential habitat.
These associations primarily included Muller’s oak (Quercus cornelius-rn utteri),
sugarbush (Rh us ovata),chamise (Adenostomafascicutatum),and manzanita
(Arctostaphvlos spp.)associations. Associations encompassed within bighorn
sheep habitat included brittlebush (Encetiafarinosa),desert lavender (Hyptis
emo,yi),cholla (Opuntia spp.),burro-weed (Ambrosia dumosa)and creosote
(Larrea tridentata),and other creosote associations.The resulting line supported
the habitat boundary that was derived during the helicopter flight alongthe
western margin of current bighorn sheep habitat.
To validate the choice of greater than or equal to 20 percent slope and 0.8
kilometer (0.5 mile) distance from this slope as model parameters,Recovery
Team members experienced with Peninsularbighorn sheep flew theeasternmost
line of bighorn sheep habitat in a northern portion of the range (San Jacinto
Mountains and SantaRosa Mountains).The path of this flight was determined by
consensus among the team members, based on their observations of bighorn sheep
in these ranges,and was believed to represent the low elevation (easternmost)
boundary of habitat commonly used by Peninsularbighorn sheep.The path of this
flight,which was recorded via Global Positioning System,supported the choice of
the greater than or equal to 20 percent slope plus 0.8 kilometer (0.5 mile)distance
from this slope as the eastern,lower elevation habitat boundary.
The resulting habitat boundarieswere reviewed by RecoveryTeam members who
have studiedbighorn sheep in the Peninsular Ranges to verify whether those areas
known to be used by sheep in therecent past (within the past 25 to 30 years)were
included within the modeled habitat boundaries.This reviewincluded a
comparison of bighorn sheep sighting locations againstthe map and verified that
160
most areas used by sheep within the past 25 to 30 years were included within the
modeled habitat boundaries (Figure 6).
Mapping Refinement
Upon furtherreview by Recovery Team members, it wasdetermined that the
modeled habitat included a habitat type not likely to be used by Peninsular
bighorn sheep.This habitat type,classified as mud hills (Augustine and Ward
1995)was found in the Borrego Badlands and Camzo Badlands of Anza-Borrego
Desert State Park. Much ofthis soil type was removed from the delineated map
because it did not correspond with knownbighorn sheep habitat usepatterns.
Conversely, the preliminaryhabitatboundaries excluded several small islands of
“nonhabitat” (defined by themodeling of slope and distance from slope).Because
Recovery Team members familiar with the areas considered theseislands to be
bighorn sheep habitat on the basis of known sightings in nearbyor comparable
areas,these islands were included in delineated habitat.
A small number of known observations fell outside the delineated boundaries at
lower elevations on relatively flat terrain,such as ClarkDry Lake and Coyote
Canyon.These observations support previouslypublished reports of bighorn
sheep occasionally moving away from mountainous areas.However, the relative
rarity of records beyond the 0.8 kilometer (0.5 mile)distance from slope was
judged to indicate that suchhabitat was not essential to population recovery if the
habitat delineated within the 0.8 kilometer (0.5mile)distance from slope were
protected. In other areas,the oppositeprocess was required to minimize the
habitat edge to area ratio consistent with sound tenets of resource management
and preserve design. Along some segments,the 0.8 kilometer (0.5 mile) distance
from slope was expanded slightly to capture “nonhabitat”areas that would have
represented deep but narrow intrusions into an otherwise stable and manageable
essential habitat boundary.
Further modifications were deemed necessaryalong the urban interface in the
Coachella Valley. The 0.8 kilometer (0.5 mile) distance from slope largely has
been lost to urban development.Much of the remaining valley floor and alluvial
habitat within the 0.8 kilometer (0.5 mile)distance is highly fragmented and
161
degraded with marginal or detrimental value to bighorn conservation (e.g.,vacant
lots along Highway 111,parcels bordered on three sides by urban development).
A series of meetings with affected jurisdictions and major land ownerswas
convened under the auspices of the Coachella Valleymultiple-species planning
effort to discuss and refine the delineation of essential habitat along theurban
interface.Lands without long-term conservation value were excluded from
essential habitat (Figures 7,8,9). The larger fragments that still remain were
included within essential habitat where they were contiguous with mountain slope
habitat and of a configuration amenable to effective management.Subject to
implementation of required conservation measures,theessential habitat boundary
does not include development projects previously reviewed and approved by us.
Finally,pursuant to Secretarial Order 3206 June 5,1997,we have entered into
government to government discussions with the various American Indian tribes
that possess lands in bighorn sheep habitat. Wecoordinated with the tribes to
encourage their participation in delineating essential habitat and developing the
Peninsular bighorn sheep RecoveryPlan in a waythat promotes recovery of the
species and minimizes the social,cultural,and economic impacts on tribal
communities.We worked with and supported the efforts of the Torres-Martinez
Desert Cahuilla Indians to obtain data on the value of Reservation lands to
bighorn sheep conservation but the Tribe has not agreed that sufficient
information is available to demonstrate that their lands are essential to recovery.
Based on coordination with theMorongo Band of Mission Indians,tribal lands
within the essential habitat boundary willbe included for sheep conservation.The
Agua Caliente Band of Cahuilla Indians has coordinated with us in the delineation
and have agreed that a reservation-wide habitat conservation planning effort will
determine appropriate land management issues at a finer scalewithin the essential
habitat boundary.
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167
APPENDIX C.GUIDELINES FOR DEVELOPING A LONG-TERM
STRATEGY FOR REINTRODUCTION,AUGMENTATION, AND
CAPTIVE BREEDING OF BIGHORN SHEEP IN THE PENINSULAR
RANGES
The purpose of this appendix is to provide guidelines for developing a long-term
strategy for reintroduction, augmentation,and captive breeding of bighorn sheep
in the Peninsular Ranges,as identified in the recoveryplan (task 1.4). This
appendix is organized into two sections.The first section outlines some of the
preliminary steps needed to identify cases in which reintroductions,
augmentations,and captive breeding maybe appropriate,and highlights some
important considerations in the development of a long-term strategy.The second
section presents protocols for captive breeding and release of captive animals,and
represents guidelines prepared by the Bighorn Institute for an existing captive
breeding and release program.This section addressesmany of the issues
identified in our Policy Regarding theControlled Propagation of Species Listed
Under the Endangered Species Act (65 FR 56916;September 20,2000).
I.Considerations in developing a long-term strategy for reintroductions and
augmentations
A number of decisions must be made when developing a long-term strategy for
augmentation and reintroduction ofbighorn sheep in the Peninsular Ranges.
Important preliminary steps are presented here in outline form:
1)Identifythe general goals of the long-term strategy in relation to the overall
recovery effort.These goals should consider the viability of thepopulation
with respect to population dynamics and genetics.
2) Determine if existing ewe groups should be augmented or new groups
established.A population model,using estimatedpopulation parameters (e.g.,
abundance,recruitment,survivorship,dispersal),should be used to evaluate
theeffectiveness of various options (including the option of no augmentation
or reintroductions)on the viability of the metapopulation.
168
3) Identify and prioritize sites for augmentations and reintroductions. This
assessment must evaluate not onlythe site’s importance to the viability of the
entire population, but also must address the following questions:
a)What is/was the cause of extinction or endangerment in this location?
b) Has this cause been minimized or removed?
c)Is reintroduction or augmentation thebest conservation option for this
particular situation?Have other necessary measures,such ashabitat
restoration or protection, been taken?
4)Determine augmentation and reintroduction techniques.The success of
previous bighorn sheep augmentation and reintroduction projects has been
mixed,and a number of questions remain (Desert Bighorn Council 1996).In
reintroducing or augmenting Peninsularbighorn sheep,the following issues
need to be evaluated:
a)Determine whether to use captive or free-ranging animals.For the
following reasons, caution should be exercised when using captive
animals:
i)If multiple,consecutive generations of animals are bred in captivity,
theymay undergo “domestication selection”;that is,captive
individuals may have behavioral or morphological phenotypes that
perform well in captivity but not in the wild.In addition, captive
animals may have been raised in an overly protective environment
where selection against deleterious genes was relaxed (Brambell 1977,
Campbell 1980,Elliott and Boyce 1992,Bush et a!.1993).
ii)Captive animals may be disease vectors to wild populations if they
have been exposed to novel diseases during exsitu (outside the
original site,or captive)propagation (Campbell 1980,Woodford and
Kock 1991,Bush et at.1993),or if theyhave continued to harbor
pathogens that have been “purged”from wild populations.
iii)The use of captive animals during augmentations can reduce or
increase theeffective population size of the wild population (Ryman
and Laikre 1990,Elliott and Boyce 1992).
Part 11 of this appendix provides protocols by which these concerns maybe
minimized. Releases of free-ranging animals are typically more successful
169
than are those of captive animals (Griffith eta!.1989,Gordon 1991,
Stanley Price 1991);however,an advantage of using captive animals is
that their genetic profiles typically areknown. In addition,the potential
effects on population (Stevens and Goodson 1993)and genetics of
removing animals from the wild population must be considered. Currently
the small size of ewe groups within the peninsular Ranges limits the
availability of free-ranging animals for translocation. Additional genetic
studies mayhelp identify sources withinthe PeninsularRanges or
elsewhere. Future projects could involve both captive and free-ranging
bighorn sheep.
b)If captive animals are to be used in reintroductions and augmentations,
determine thedesired size of the captive herd,and optimum facilities and
management techniques.One alternative is to establish a large captive
herd that is housed in a larger enclosure and managed less intensely than
theexisting captive herd.An approach similar to this is usedby the New
MexicoDepartment of Game and Fish (1997) at their Red Rock Wildlife
Area,where bighorn sheep are housed in a fencedarea of over 500
hectares (1,235 acres).Potential advantages of such a facility are that
released animals mayhave traits more characteristic of free-ranging
animals (as opposed to animals raised in a moreconfined environment),
and a larger captive population may lessen genetic concerns associated
with small founder populations. As with any captive breeding program,
however, the source of animals for this captive population would have to
be considered, and both population and genetic management guidelines
would have to be addressed (see part II of this appendix).
c)Determine thebest population composition of released groups.This
considerationapplies whether captive or free-ranging animals are used.
The number, age/sex composition,and experience of released animals are
important considerations (Lenarz and Conley 1980,Wilson and Douglas
1982,Kleiman 1989).The gregarious behavior of bighorn sheep suggests
that larger groupsare desirable (Wilson and Douglas 1982).However,
smaller group sizes more likely mimic natural re-colonization events.The
sex ratio should maximize the reproductive potential of the released group
170
or thewild population during reintroductions and augmentations
respectively.For bighorn sheep,this typically means a low ram to ewe
ratio (Lenarz and Conley 1980).Young animals have high reproductive
value (Gotelli 1995)and have a strong tendency to integrate with existing
herds when used as release stock (Ostermann et al,in press),anl thus are
desirable for augmentation programs.Lenarz and Conley (1980)
suggested that the optimum agefor released bighorn sheep is 3 years.
However, inclusion of a small number of older or free-ranging,and
presumablymore experienced,individuals increasesthe likelihood of
success of a reintroduction. The effect of these variables needs to be
considered not only with respectto howtheywill influence success of the
release,but also how the removal of these animals will affect the source
stock from which they came (Stevens and Goodson 1993).
d) Identify appropriaterelease animals based on pedigree and proximity to
the intended release area.Thoughbased solely on genetic theory, this
approach is conservatively designed to:(1)preserve the potential for
genetic adaptations to local conditions,(2) prevent outbreeding depression,
and (3)maintain the existing genetic structurecurrently found among
Peninsularbighorn ewe groups (Brambell 1977,Boyce et a!.1999).
However,other options are available to prevent loss of heterozygosity in
the wild population (May 1991).In general,thepreservation of the gene
pool of the entire metapopulation (wild and captivepopulations included)
should be the primary concern (Foose 1991).Therefore,when
reintroducing or augmenting animals,care must be taken to avoid genetic
swamping of native populations (Kleiman 1989,Ryman and Laikre 1991,
Foose 1991,Elliott and Boyce 1992).Furthermore, during any
reintroduction or augmentation,the number and sex ratio of released
animals must be considered, as it will affect effective population size
(Crow and Kimura 1970,FitzSimmons et at.1997).The second section of
this appendix discusses the genetic considerations of captive breeding and
release of captive animals in detail.
171
e)Determine the most effective means of releasing animals.These
considerations,which apply to both the release of captive and free-ranging
animals,should include:
i)Whether to use a ‘soft’or ‘hard’release (Berbach 1987,Moore and
Smith 1991).
ii)How far to move free-ranging animals during reintroductions and
augmentations.Thephilopatric behavior of bighorn sheep may result
in animals attempting to return to their natal home range.Research on
dispersal and movement patterns may guide these decisions (refer to
section II.D.2 of this recovery plan).
iii)During which time of year to conductreleases.
iv)What specific release site to use. For instance,how far should release
sites be from otherbighorn sheep (Bleich et at.1996)or from human
development?This questionmaybe assessed by releasing and
monitoring a small number of sentinel animals during a feasibility
study (Kleiman 1989,Chivers 1991).
5)Determine methods for monitoring and assessing the success of reintroduction
or augmentation programs,in relation to the goals of this recovery effort
(Stanley Price 1991),and identify a specific schedule for future review and
possible revision of the long-term strategy.
II.Captive breeding and release of captive bighorn sheep
While it is not a long-term solution (Snyder et a!.1996),captive breeding is a
powerful tool forrescuing species threatened with extinction (Caughley 1994,
Philippart 1995,Caughley and Gunn 1996).Captive breeding can also be used to
delay extinction while the agents of a decline are investigated (Caughley and
Gunn 1996).Other advantages of captive propagation include the ability to
moderate environmental variance,manage genetic diversity,increase the effective
population size,and expand animal numbers to provide stock for wild populations
(Foose et at.1995).Releasing captive-born animals intothe wild to support weak
populations is an increasingly common practice (Griffith et a!.1989,Kleiman
1989,Snyder etat.1996).
172
Although there are benefits of captive propagation programs for releasing animals
into the wild (Griffith et at.1989,Kleiman 1989,Caughley 1994,Foose et at.
1995),these programs can be costly,labor intensive,and their effectiveness has
been questioned (Campbell 1980,Philippart 1995,Caughley and Gunn 1996,
Snyder et a!.1996).Additionally,there are a number of potential risks associated
with captivebreeding and release programs.Our Policy Regarding Controlled
Propagation of Species Listed Underthe Endangered Species Act (65 FR 56916;
September 20,2000) identified thefollowing risks that must be addressed when
planning controlled propagation and reintroductionprograms: (1) removal of
natural parentalstock that mayresult in an increased risk of extinction by
reducing the abundance of wild individuals and reducing genetic variability within
naturally occurring populations; (2) catastrophicevents that can causethe loss of
some or all of the captivepopulation; (3)potential for inbreeding or other adverse
genetic effects that mayresult from increasing only a portion of the gene pool; (4)
potential erosion of genetic differences between populations;(5)exposure to new
selection regimes in controlled environments that may diminish capacity to
survive and reproduce in thewild; (6)genetic introgression;(7)increased
predation or competition for food,space,and/or mates;and (8) disease transfer.
Adhering to established criteria and upholding standardized protocols will
contribute to the success of reintroduction and augmentation programs and reduce
the accompanying risks.In this appendix, generalized criteria and guidelines for
reintroduction and augmentation programs are combined with knowledge of
desertbighorn sheep ecologyto create more specific guidelines for Peninsular
bighorn sheep captive breeding and release programs.
In this appendix, reintroduction is defined as themovement of wild or captive
animals intoformerly occupied habitat,while therelease of animals into currently
occupied habitat is termed “augmentation”or “restocking.” The ultimate
objective of these guidelines is to establish wild,free-ranging herds that no longer
rely on captivebreeding.Separate guidelines should be developed for captive
breeding programs with otherprimary goals.
173
Before commencing a captive breeding program,a feasibility study should be
conducted to determine its necessity and potential for success. The following
general criteria should be considered (Kleiman et a!.1994):the wild population’s
need for support with respect to genetic diversity and population structure, the
availability of stock,removal of the original cause of decline,protection of
sufficient habitat,local politics,governmental and nongovernmental agency
support,reintroduction/augmentation technology,knowledge of species biology,
and sufficient financial resources.A summary of these criteria, which are grouped
into four categories,is provided below.
Need for population and/orgenetic support
Because captive breeding and reintroduction/augmentationprograms
require large financial and logistical commitments,theneed for population
and/or genetic support must first be clearly established (Kleiman 1989,
Phillipart 1995,Snyder eta!.1996).The International Union for the
Conservation of Nature and Natural Resources (1995) guidelines for
reintroduction and augmentationsrecommendconducting a population and
habitat viability workshop before initiating a program.A population
viability analysis may also facilitate the design and objectives of the
programby providing direction on thenumber of animals needed, and
hence the size of the facilityneeded,and whether restocking (augmenting
populations)or reintroduction (establishing new groups)is preferred.
Captive breeding is often expensive and not always the most cost-efficient
conservation strategy (Kleiman 1989,Kleiman et at.1991,Snyder et at.
1996).It must be conducted in conjunctionwith other conservation
measures,and should be based on specific recommendations within a
recovery ormanagement plan so that it does not unjustly preempt other
recovery techniques (Snyder et a!.1996).
Environmental conditions
Captive breeding should only be undertaken if suitable, unsaturated habitat
is available (Brambell 1977,Kleiman 1989,Ounsted 1991)and release
sites have sufficient carryingcapacity to support theexpansion of the
reintroduced or augmented population.Ideally,release sites should be
174
legally protected (Kleiman et a!.1994).Removing or controlling the
original cause(s)of decline is an essential step,as failure to do so is a
primaryreason that reintroduction and augmentation efforts are
unsuccessful (Brambell 1977,Ounsted 1991,Kleiman et a!.1994).
However,in some situations,augmentinga population while investigating
the cause of decline is an acceptable practice (Caughleyand Gunn 1996).
Thephilopatric behavior of bighorn sheep (Geist 1971)suggests there are
advantages to augmenting a population to retain traditional herd
knowledge,rather than reintroducing animals after extirpation,particularly
if this would allow researchinto the cause of decline.
Biopolitical conditions andfunding
Although no breeding program canbe successful without knowledge of
the species’biology or reintroduction/augmentation technology,non-
biological factors such as long-term funding,project administration, and
communication amongparticipating organizations have been found to be
important determinants forprogram success (StanleyPrice 1991,Beck et
a!.1994,Kleiman et a!.1994).Feasibility studies should include
investigating prospects for long-term funding and obtaining the support of
all relevantgovernmental and non-governmental agencies.Inadequate
funding could severelylimitthe progress and success of the program.
Therefore, programs should not be initiated until funding is secured to
ensure that all phases (disease testing,research, post-release monitoring,
etc.) willbe accomplished.Because captive breedingprograms are a
multidisciplinary undertaking involving people drawn from a variety of
backgrounds (International Union forthe Conservation of Nature and
Natural Resources 1995),the decision making structure,as well as the
authority and responsibility of each group involved should be clearly
delineated (Kleiman et a!.1994).
Knowledge of the species and reintroduction/augmentation technology
Knowingthe ecological requirements of a species is necessary for a
successful breeding and release program.For many species, thelack of
basic information and release technology necessitates detailed studies
examining the species behavior and biological needs before establishing a
175
breeding program (Kleiman 1989,Stanley Price 1991).However, past and
ongoing captive propagation programs for desert bighorn sheep (Calkins
1993,New Mexico Department of Gameand Fish 1997,Ostermann et al.
in press)have demonstrated the potential for establishing self-sustaining
captivepopulations and the techniques developed for translocations
(Rowland and Schmidt 1981,Wilson and Douglas 1982)provide
information that canbe applied to releasing captive-reared animals into the
wild.
Husbandry
Large,predator-proof enclosures with native vegetation,natural habitat features,
and adequate food, salt, mineral,and waterresources are needed. Native
vegetation should be retained in the enclosure,and supplemental feedmay be
required to prevent over-browsing.Anenclosure that contains a variety of habitat
types and topographic relief will allow captive animals to exhibit natural behavior,
such as using escapeterrain in response to disturbance.Presumably, housing
captive animals in conditions as similar to therelease site as possible will ease
their transition to a wild environment.During the nonbreeding season,adult
males and females should be separated or have ample room to naturally segregate.
To reduce diseasetransmission risks,captivepopulations should be maintained
within the natural range of the animal,in single-species facilities that do not
regularly exchange stock (Snyder et a!.1996).The design of the enclosure should
allow for the safe capture of animals for sampling and/or release.Enclosure
fencing should be greater than or equal to 3 meters (10 feet)in height above
groundand extend aminimum of 0.61 meter (2 feet)underground,or employ
otheroptions to exclude predators.Mountain lions have entered enclosures and
killed captive bighorn sheep on several occasions(Blaisdell 1971,Sandovol 1979,
Winkler 1977).Monitoring consisting of at least dailychecks of the enclosure
and animals is necessary for detectinghealth concerns,causes of mortalities, and
disturbances.
Disease prevention and screening
Disease prevention is of primary importance for desert bighorn sheep captive
breeding programs.Of all North American wild ungulate species, wild sheep are
possibly the most sensitive to common livestock diseases and parasites (Jessup
176
1985). Disease outbreaksterminated reintroduction efforts at both the Lava Beds
National Monument in California (Blaisdell 1982)and the Sierra Diablo pens in
Texas (Brewer 1997),two initially successful desert bighorn sheep breeding
operations.Disease in the captive animals and poor reintroduction success led to
the release of all bighorn sheep from the ZionNational Park captive propagation
enclosure (McCutchen 1978).Outbreaks ofblue-tongue reducedthe Red Rock
population by approximately 18 animals in 1985 and 25 animals 1991 (New
Mexico Department of Game and Fish 1997).See section I.E.3 for information
on the captivepopulation atBighorn Institute.
Disease considerations for augmentation programs include the potential of
introducing disease to the wild population when releasing captive-reared stock
and theimpact of diseases endemic in the wild population on released animals
(Viggers eta!.1993).The prevalence of disease in the wild and captive
population will determine theneed to eradicate pathogens in animals brought into
or released from captivity and whether to release or breed certain animals.
Elimination of all pathogens from captive animals is not expectedor
recommended (Bush et a!.1993,Viggers et a!.1993),as this mayreduce their
immunity to disease and place them atrisk of diseases endemic in thewild
population.Regular,standardized disease monitoring of both the wild and captive
populations is stronglyrecommended.
Disease prevention measures
Captive breeding facilities should be closed to the public and the staff
should practice rigorous diseaseprevention measures, including avoidance
of potential disease transmission from other captive stocks as well as
between wild and captive bighorn sheep.All potential routes for disease
transmission from domestic livestock should be anticipated and avoided.
For example,when purchasing hay,care should be taken to avoid dealers
who rotate their crops with domestic livestock grazing.
Separate quarantinefacilities should be available to house incoming stock;
however,animals known to be sick should not be brought into captivity.It
is important to determine the cause of death for all animals that die in
captivity or soon after release into the wild. Fresh carcasses should be
177
refrigerated and transported to a veterinary diagnostic laboratory for full
necropsy.
Disease-free certification
Disease screening (hematology,serum chemistry, serology,virus isolation,
ova and parasite tests,and bacterial culture) should be performed on
greater than or equal to 25 percent of the captive animals at least annually,
and on all pre-release animals within 30 daysprior to their release into the
wild. Health screening of pre-release bighorn sheep helps prevent the
introduction of disease into the free-ranging population and optimize the
released animal’s chances for survival in the wild.Screening of wild-
caught breedstock reduces the chance of introducing disease to the captive
population.All bighorn sheep entering or leaving thecaptive breeding
program should be certified as “disease-free.” Disease-free certification
requires that within 30 days prior to release:(1) the animals appear
healthy and shows no signs of active infection upon visual examination by
an U.S.Department of Agriculture accredited veterinarian familiar with
bighorn sheep,(2)recent laboratory results (from testing described above)
do not indicate active infection or other health concerns,(3) the animal
tests negative for Ovine Progressive Pneumonia (AGlID test),and (4) the
animals have not been exposed to diseased animals in the captive breeding
facility.
Treatment of sick animals in captivity
Animals showing signs of illness (e.g.,drooping ears,nasal discharge,
coughing,lethargy,weight loss)should be closely observed and
biologically sampled to attempt to determine the cause of illness.Bighorn
sheep in poor condition,needing frequent treatment,or exhibitingsigns of
infectious orcontagious disease should be placed in quarantine.
Treatment should be provided under veterinary supervision if the
condition is lifethreatening,unless research needs dictate otherwise.
Principles guidinggenetic management
Genetic management strives to minimize the loss of naturallyoccurring genetic
variability by preserving genes of founderswho represent a gene pool of interest
178
(Ballou and Lacy 1995).Goals forthe genetic management of captive populations
usually include retaining genetic variation for future evolutionary potential,
minimizing genetic changes that may occur while a species is in captivity,and
avoiding inbreeding (Foose and Ballou 1988,Hedrick and Miller 1992,Foose
1991,Foose et a!.1995).Concerns about the fitness,evolutionary potential,and
locally adapted gene pools of natural populations require that conservation efforts
also consider intraspecific genetic variation (Soul~1986,Millar and Libby 1991,
Hedrick and Miller 1992,Cronin 1993).Molecular markers (allozymes,
restriction fragment length polymorphisms,microsatellites,mitochondrial DNA)
can aid in identifying current and historic levels of population subdivision,gene
flow, and population characteristics (Milligan et a!.1994,Avise 1995).However,
it is important to note that molecular markers identify only a small portion of the
genome and arenot specifically or necessarily tied to traits involved in either
adaptation or fitness.
Identifying the genetic structure of the population being augmented is considered
a first step towards assuring that appropriate subpopulations aretargeted for
propagation and release (Brambell 1977,Lyles and May 1987).Peninsular
bighorn sheep are distributed in a metapopulationcomprising approximately eight
subpopulations,although thedegree to which this structure reflects anthropogenic
forces is unknown (Torres et a!.1994,Boyce et a!.1997,Rubin et a!.1998,Boyce
eta!.1999).
The genetic effects of population subdivision are quantifiedby the fixation index
(F;Wright 1951),which describes theproportion of geneticvariation within
bighorn sheep subpopulations relative to the total variation in the population.The
fixation index can also be used as an index of geneticdifferentiation among
populations. Ahigh fixation index value indicates significant genetic
substructuring of the population.Moderatevalues (defined as F of 0.05 to 0.15,
ST
Wright 1978)formean F were foundfor six populations within thePeninsular
STRangesusingnuclear DNA markers (micro-satellite loci [F equals 0.113]and
the major histocompatibility complex loci [F equals0.120]). They suggest
ST
there are relatively high levels of male-mediated gene flow among populations
(Boyce et a!.1997).When managing a group of closely related subpopulations
migration should be maintained while also allowing for genetic differentiation
179
among demes in response to local selective pressure (Nelson and Soul~ 1987,
Ryman eta!.1995).
Other factors to considerin reintroduction or augmentation programs are effects to
the native gene pool,including introgression,and an increase in the variance in
family size or thenumber of offspringper individual (Ryman et a!.1995).
Introgression occurs when populations with different genetic characteristics are
mixed.It maycause the loss of locally adapted genes through interbreeding, loss
of entire gene pools as a result of displacement,and/or homogenization of a
previously geneticallystructuredpopulation through swamping with a common
genepool. Factors relating to introgression that should be considered include:the
amount of genetic divergence between the captive and wild populations, the
genetic population structure of the wild population, and the number of animals to
be released relative to the size of therecipient population (Ryman eta!.1995).
Without knowledge of the genetic characteristics of the natural population, it is
nearly impossible to predict the occurrence or importance of changes in the
genetic structure of the augmented population.Although problems with
outbreeding depression usually involve populations that are distinct subspecies,
the effects of genetic mixing are difficult to predict,ranging from no effect to
outbreeding depression even within the same species under similar circumstances
(Ryman et a!.1995).There are some circumstances when introgression canbe
beneficial, for example,when a natural population has been geneticallydepleted
over an extended period due to small population size (Ryman et al.1995).
A second problem with captive or supportive breeding programs is the potential to
increase the variance in family size or number of offspring produced per
individual (Ryman et a!.1995).Taking a fraction of the wild population into
captivity for enhanced reproduction and survivalmay increase population
numbers, but it canreduce genetic variation by inflatingthe variance in family
size,a parameter that is inversely related to the genetically effective size of the
population (Ryman and Laikre 1991).Pedigree analysis, rotation of breeding
stock,and genetic management of the captive and wild populations canhelp
lessen concerns associated with introgressionand variance in family size.For
example,in the northern SantaRosa Mountains, the origin (captive or wild-born)
of all animals in this herd is known and the sire and/or dam of most individuals is
180
known (Ostermann and DeForge 1996).Inthis case,particular wild-born bighorn
sheep native to the genepool can be targeted forcaptive propagation if necessary.
This situation presents a unique opportunity to usehigh intensity genetic
management (Lacy et a!.1995)to improve or maintain the genetic variability in a
free-ranging population.
Se!ection of breeding stock
Even when the main goal of an augmentation project is to provide population
support,Kleiman (1989) recommended first considering the genetic
characteristics of potential release animals.Animals released into the wild should
be similar to thenative animals of theregion because over evolutionary time,
successful populations are expected to become morphologically, physiologically,
and behaviorally adapted to the local environment (Brambell 1977,Kleiman 1989,
Lynch 1996).Obtaining locally adapted stock forcaptive breeding and release
into the wild is proposed as a method to approximate the correct,locally adapted
genotype, although this may add relatively little genetic variability to thewild
population (Lyles and May 1987).However, given thehabitat fragmentation and
small size of several demes in the Peninsular Ranges, genetic exchange to avoid
inbreeding depression should be considered.
Only bighorn sheep less than 1 year of age arerecommended for capture for
breedingstock if animals are to be placed in small enclosures (approximately less
than 2 hectares [5 acres])for quarantine.Young bighorn sheep adjust more
readily to a captive environment than adult bighorn sheep (J.DeForge, pers.
comm.), which havedied from colliding with fences while in captivity (Montoya
1973,Sandoval 1981).Larger enclosures would reduce this risk.
Mating strategies
Appropriate level of geneticmanagement of captive populations depends on the
information available,intended intensity of management,and goals of the
program (Lacy et a!.1995).Breeding programs for bighorn sheep vary from small
populations receiving high-intensity genetic management to large herds where
only low-intensity genetic management is possible.Several low-intensity mating
strategies based on maximizing the effectivepopulation size and maximum
avoidance of inbreeding have been developed (Princee 1995).This document
181
focuses on concepts for intensive genetic management,which applies mainly to
small captive populations.
The genetic importance of an animal is defined as a measure of the probability
that it carries founder genes that are currently at risk of being lost (MacCluer et al.
1986,Ballou and Lacy 1995,Thompson 1995),though this value may be
compromised by the presence of deleterious genes.Although animals with many
living relatives in a population may be less geneticallyvaluable than animals with
few relatives, this largergroup of relatives maybe more successful due to superior
fitness. “Mean kinship”,one of several methods used to identify genetically
important individuals,is defined as the average of thekinship coefficients
between an individualand all living individuals including itself (Ballou and Lacy
1995).Animals with low mean kinship valuesare geneticallyimportant. Because
mean kinship is insensitive to the age structure of apopulation, the concept of
kinship value was introduced.“Kinship value” considers theage and reproductive
value of animals when calculating mean kinship (Ballou and Lacy 1995).Kinship
valueswill exceed meankinship for animals whose relatives are of prime
reproductive age.
Both theory and computer simulation studies suggest that mating strategies based
on mean kinship (and therefore kinship value) retain the highest level of gene and
allele diversity (Ballou and Lacy 1995,Miller 1995).To theextent possible, a
strategybased on kinship value (Ballou and Lacy 1995)should be used to arrange
matings in the captive population, precluding matings between relatives. Target
founder representation and kinship value can be used to assess the genetic
importance of animals and help direct rotation ofbreeding stock.Rams will
generallycontribute genes faster than ewes and will therefore need to be rotated
more frequently than ewes.
Genetic evaluation
Captive breeding programs should include provisions for genetic testing,
including mitochondrial DNA sequence analysis and microsatellite typing on all
founders in the captive population.Genetic testing of captive-born offspring is
particularly important in populations with low intensity genetic management or in
cases where paternity is unknown. Molecular genetic analyses canbe used to
182
determine the genetic similarity between captive-reared and free-ranging sheep,as
wellas to constructpedigrees for captive or wild populations.
Population management
General objectives for population management of large captive populations with
multiple generations in captivity are:(1) establishment of a self-sustaining
captive population, (2)expansion of the population to a predetermined carrying
capacity as quickly as possible withingenetic management guidelines,(3)
stabilization of the population at a given capacity, with an age and sex ratio that
will achieve the goals of theprogram(such as production of surplus stock for
release) (Fooseand Ballou 1988).For small captive breeding programs,
population management is most relevant to thebehavioral stability of the captive
population and minimizing the impact of stock rotation.Inmost cases bighorn
sheep should be released intothewild by 10 years of age,to prevent an
accumulation of old-age animals.Ewes that fail to recruit a lamb for 3
consecutive years should be considered for release because they arenot
contributing to the goal of producing stock for release into thewild.
Surplus or unfit animals
Healthy animals displaying abnormal behavioral or physiological
characteristics should be evaluated. Preferably,if the characteristic has
potential to be altered to allow release intothe wild, the animal should be
retained in captivity until suitable for release.If an animal’s genetic
characteristics cause it to be unfit for release intotarget populations,that
animalcan be released intoa nontarget subpopulation so long as
deleterious traits arenot introduced to the wild.Because the primary goal
of captive propagation is reintroduction or augmentation, bighorn sheep
should be released into thewild whenever possible. As a lastresort,
animals may be transferred to a zoo facility in cooperation with the
American Zoological and Aquarium Association.
183
Release and Monitoring
Research and data collection on the captive population
Captive populations can providean ideal control population for
experimental or developmental studies.Data on thepopulation
characteristics, behavior,physiology, nutrition,and diseases of the captive
population should be collected to the extent possible without risking the
animals’survival or ability to be released into the wild.Handling or
continuous observation at closerange should be minimized to avoid
habituation.The captivepopulation at Bighorn Institute has been used in
severalstudies (Castro et al.1989,Jessup et al.1990,Borjesson et a!.
1996)that required little or no additional handling.
A SPARKS (Single Population Analysis and Records Keeping System;
International Species Information System [ISIS]1989)or similar format
studbook should be maintained to record the identification, sex,parentage,
date of birth, release date, release location,and dateas well as cause of
death for each individual born or brought into captivity.Marking of
animals to facilitate data collection may be necessaryin large captive
populations.Locations of births within enclosures and individual ewe
reproductivesuccess should also be recorded.Notes recording the feeding
rations, general health,and behavior of captive animals,and unusual
environmental conditions should be collected at least once daily.
Research and data collection on released bighorn sheep
Eachrelease should be designedas an experiment to test various
techniques related to factors such as release site and time (May 1991).
Monitoringpost-release animals is one of the most critical components of
a reintroduction or augmentation program because itallows for the
assessment of methods, use of adaptive management,and can provide a
framework for theoretical studies.All released bighorn sheep should be
fitted with a radiocollar and eartag and monitored as frequently as possible
(more than weekly)to record their integrationprocess, habitatuse,
behavior,health,survivorship,and reproductive success.At a minimum,
monitoring should be designed to document survival and reproductive
184
rates,cause-specific mortality,habitat use of released bighorn sheep
though their first year in the wild,and key biotic and abiotic factors,such
as habitat quality and weather.Most importantly,post-release studies
should provide data to evaluatethe success of theprogram.Long-term
(greater than or equal to 3 years)monitoring on at least amonthly basis of
greater than or equal to 50 percent of released animals in a subpopulation
should be included in all programs.Monitoring of post-release animals
should include planned studies comparing captive-reared and wild-reared
sheep (e.g.,reproductive success, survivorship,vigilance, maternal
behavior, reactions to disturbance,etc.),and theoretical studies (May
1991,Sarrazin and Barbault 1996).
Peer-reviewed Program Assessment
Guidelines for reintroductions (Kleiman 1989,Stanley Price 1991,Chivers 1991)
suggest an assessment phase in which the experiences,results,and conclusions of
a reintroduction or augmentation program would be published at intervals or at the
completion of the study.Short-termsuccess of suchprograms canbe evaluated
by:1)the survival and/or reproductive rates of released animals,or 2) the amount
of genetic diversity retained and/or habitat preserved,or 3)public education and
research interest generated,or 4) the time gained to allow continued research into
the problems suppressing the population (Kleiman 1989;Caughley and Gunn
1996).The multi-faceted nature of captivebreeding and release programs
requires that assessments examineboth the captive breeding and release phases, as
well as the indirect benefits generated from the program.Reporting failures
encountered in captive breeding and release programs is of equal or greater value
than reporting successes,although it is done much less frequently.
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Variability Within and Among NaturalPopulations.University of
Chicago Press,Chicago.
194
APPENDIX D.GUIDELINES FOR SAFELY CAPTURING. HANDLING,
AND MONITORING BIGHORN SHEEP
Standardresearch methods, including surveys (foot,helicopter,and fixedwing
aircraft),field capture,biological sampling,and radiotelemetry monitoring have
been used for assessing abundance and abundance trends (DeForge et a!.1995,
1997;Rubin et a!.1998),recruitment patterns (Wehausen et a!.1987,DeForge et
a!.1995,DeForge et a!.1997,Rubin et a!.2000,Ostermann et a!.in press), adult
survivorship and cause-specific mortality (Hayes et a!.2000,DeForge et a!.1997,
DeForge and Ostermann 1 998b,Ostermann et a!.in press), health status and
disease exposure (DeForge eta!.1982;Clark eta!.1985, 1993;Jessup and Boyce
1993;Elliott eta!.1994;Boyce 1995;Crosbie et a!.1997),genetic profiles
(Boyce eta!.1997,Boyce eta!.1999),and spatial distribution of the population
(Rubin et a!.1998)in specific subpopulations of bighorn sheep within the
Peninsular Ranges.Adaptive management (Holling 1978)will require the
continued use of thesefield research methods to achieve recovery of Peninsular
bighorn sheep.
As with any human intervention, theseresearch methods arenot without risks and
consequences for free ranging bighorn sheep.Low-level helicopter surveys
provide an effective method for estimating population sizeand distribution.
However, alterations in behavior,movement,and distribution of bighorn sheep
resulting from helicopter disturbance (Bleich et a!.1990a)could potentially
introduce bias into those estimates or adversely affect survivorship and
reproduction in bighorn sheep populations (Bleich eta!.1994).Jessup et a!.
(1984)compared the relative risks and benefits of different capture methods,
including drop-netting,drive-netting, darting from helicopters, stationary corral-
trapping and the use of a hand-held net gun operated from a helicopter. Some
methods were found to be inherentlysafer than others.All methods presented
some risk to individual animals,and no single method of capture was best for all
situations.Bleich et a!.(199Gb)documented chronic injuries to the mandibles
and necks of bighorn rams from ill-fitting radiotelemetry collars and proposed
potential adverse effects on foraging behavior and decreased fitness of these
otherwise dominant males.
195
Through constant critical re-assessment of research activities,risks canbe
recognized and addressed to minimize the impact of these activities on bighorn
sheep populations.Inthe past,epidemiological analysis of capture data
documented the relative safety of drop net and helicopternet gun capture of
bighorn sheep over other methods including drive-net, chemical immobilization,
and corral trapping (Jessup et a!.1988).Recommendations on collar tightness
(Bleich et a!.1 990b) havereduced jaw and neck injuries in bighorn rams in recent
years.Risks associated with future research activities can be minimized by
requiring:(1) adequate justification for the activity,(2)thorough planning,(3)
selection of appropriate survey and capture methods,experienced personnel,and
proper equipment for the activity,and (4) constant critical re-assessment of
research activities to recognize and address problemsarising from these activities.
Guidelines for specific research activities
Surveys
Fixed-wing aerial surveys have a very low probability of affecting bighorn sheep
because aircraft are typically flown at high altitude.During these flights,
telemetry locations of radio-collared animals are obtained but visual observations
arenot usually attempted.The risk of disturbance to bighorn sheep is greater
during helicopter and foot surveys.
Helicopter surveys may temporarily disrupt normal bighorn sheep behavior and
may negatively affect bighorn sheep if not conducted properly.Helicopter
surveys should be avoided during periods when bighorn sheep maybe especially
sensitive to disturbance.These periods include the late winter through early
summer months,when the majority of ewes give birth,and the summer months,
when bighorn sheep are dependent on scant water sources.During surveys,the
helicopter should only remain above a group of animals long enough to determine
group size and composition.If the group appears to be running excessively,if
terrain conditions arepotentially dangerous forthe animals,or if young lambs are
observed in a group, the safety of the animals should take priority over data
collection,and the surveycrew should continue moving to the next portion of the
survey area.During surveys,the location of roads should be considered, and
196
flight paths should proceed from roads into habitat,so as to avoid driving animals
towards automobile traffic.
Foot surveys are not typically considered a risky research activity but the
following considerations will further reduce any negative impact on bighorn
sheep.Bighorn sheep appear to be more comfortable when they areable to
remain higher than their human observers and watch them from a distance.
Observers should approach bighorn sheep from below and avoid approaching too
closely. Care should be taken to avoid startling bighorn sheep by appearing
suddenly around a corner or over a ridge. Time near springs and guzzlers should
be kept to a minimum to avoid displacement of animals from water sources,
especially during the summer.
Capture
The active management of bighorn sheep may require:(1)marking or tagging to
determine population numbers,range usage,movement patterns,behavior,
reproduction,survival,and cause-specific mortality;(2) treating or sampling
diseased individuals;(3)sampling of healthy bighorn sheep for research;and (4)
relocation (Jessup et al.1984).In skilled,experienced hands,the use of a net gun
from a helicopter has been shown to be a safe method of capture,with fewer stress
related complications and lower injury and mortality rates than other methods
(Jessup et a!.1988).Due to the steep,rough terrain and the scattered distribution
of bighorn sheep found in the Peninsular Ranges,net gun capture appears to be
the most practical and cost-effective capture technique.The use of drop nets and
tangle nets may also be necessary on the rareoccasionwhen an animal has to be
captured within or on the fringes of the urban environment.The safe use of these
techniques requires careful planning and adequate numbers of experienced
personnel trained in handling net-captured bighorn sheep.Thorough discussions
of capture methods and veterinarymedical concerns canbe found in The Wi!d!fe
Restraint Handbook (CaliforniaDepartment of Fish and Game 1996),and the
Wild!~fe Restraint Series (International Wildlife Veterinary Services 1996).
The most common veterinaryproblems occurringduring the helicopter net gun
capture of bighorn sheep are physical injury,capture stress/capture myopathy
(disorder of muscle tissue or muscles)and hyperthermia.Physical injurycan
197
occur when a netted animal tumbles on rough, rockyterrain, takes a fall down a
steep slope,or whenthe nettangles around theanimal’s neck and compromises
respiration.The risk of physical injurycanbe minimized by netting the animal as
it runs uphill or capturing animals on relatively flat saddles or in flat sandy canyon
bottoms. Capture stress/capture myopathy occurs when an animal severely
overexerts itself,resulting in pathologic metabolic changesand cellular damage in
muscle tissue and internal organs.Hyperthermia occurs when an animal’s heat
production from muscle activity exceeds its ability to dissipate that heat.Due to
the physical exertion experienced during helicopterpursuit, the rectal temperature
of most bighorn sheep at capture will be higherthan 38.9 degrees Celsius (102
degrees Fahrenheit),considered normal forresting domestic sheep (California
Department of Fish and Game 1996),and will often reach 39.4 to 40.6 degrees
Celsius (103 to 105 degrees Fahrenheit)or greater.These animals are susceptible
to hyperthermiaregardless of the ambient temperature.Dousing with water
around the flanks,inguinal region, thorax,head,and neck atcapture to cool the
animal should be routine during warm weather and anytime an animal shows an
increasing trend in rectal temperature. Animals with heavy winter pelage also
may havea problem dissipating heat even in cold weather and may require efforts
to cool them.Keeping chase times within conservative limits will prevent most
problems with capture stress/capture myopathy and hyperthermia. A “safe” chase
time will vary with the condition of the animal,terrain, environmental conditions,
and the intensity of pursuit. Most individual chase times during California
Department of Fish and Game bighorn sheep captures areunder 3 minutes.
Pursuit of a running animal should not exceed 5 minutes.Attention must be paid
to total chase time as animals in a group may be run repeatedly as individual herd
members are captured.Pursuit should be called off if the animal appears
disoriented,exhausted,or injured,or anytime a member of the capture crew
determines that there is excessive risk in continuing the capture effort.
Prolonged restraint can also contribute to capture stress/capture myopathy and
hyperthermia.Mostbighorn sheep cease struggling when eye covers and hobbles
are applied.Positioning the animal in a normal resting position with its head up
will allow the sheep to belch ruminal gas and minimize bloat and regurgitation.
Vital signs should be taken immediately and monitored continuously to monitor
the need/effectiveness of cooling treatment or to determine if a severely distressed
198
animal should be released.A severely compromised animal that is not ambulatory
requires aggressive therapy.Jessup (1999) recommended that wild sheep with
rectal temperaturesgreater than 41.7 degrees Celsius (107 degrees Fahrenheit),
respiration rates of 75 per minute, and/or heart rates greater than 200 per minute
receive intensive treatment for capture stress/myopathy including cooling baths,
balanced intravenous fluids,anti-inflammatory drugs (fast acting corticosteroids),
vitamin and mineral supplements,and possibly intraperitoneal bicarbonate.
Medical treatment of a moderately compromised animal that is ambulatory
involves the trade-off of continued stress during the treatment period with the
benefits of medication.Some medications themselves mayhave adverse effects
when administered.For example,pharmacologic doses of corticosteroids used in
treatingshock mayinduce parturition in ewes in late stages of pregnancy (Plumb
1995).In a field situation,the decision to treat or release is ajudgement call made
by capture personnelin consultation with an experiencedwildlife veterinarian.
Air transport ofbighorn sheep to base camps should be accomplished in “sheep
bags” (heavyweave plastic mesh bags custom designed forthis purpose), which
support the animal in a sternalposition. “Air transport of mountain sheep upside
downsuspended by their hobbled legs is inappropriate and unnecessary”
(Jessup 1999).During captures using base camp processing,the capture crew
should be prepared to process animals exhibiting capture stress at the capture site
to reduce the handling time.
Processing (application of tags and collars,collection of biological specimens,
administration ofprophylactic medications)should be carried out in a quick,
efficientmanner with minimal disturbance to the animal.Prior to release, the
animal should be positioned so that release occurs in the directionwith the fewest
physical hazards and that allows the animal to move toward the area from which it
was captured.
Other issues to consider when capturing and handling bighorn sheep include:
Pregnancy status -capture of ewes in thelast two months of pregnancy
should be avoided whenever possible (December through early summer).
199
Caution should be usedwhen capturing ewes with very young lambs
(spring through late summer)due to possible abandonment of the lamb or
exposure of the lamb to predation in the absence of the mother. These
ewes should be processed at thecapture site, and should not be transported
to a base camp.
Extreme caution should be used when capturing young lambs.Lambs
should be processed and released at thecapture site whenever possible.
Whenever possible,processing at the capture site is preferred to minimize
stress on the animal,However, for adult animals, the choice of processing
at the capture siteor transport to abase camp will varywith local
conditions.Very important for ewes and less so for rams,the location and
distance of base camps from the capture site should allowdirect access
back intothe area in which the animal was captured.A general guideline
is that the release site should be within the home range of the ewe group
and within 5 kilometers (3.1 miles)of the capture location with no
insurmountable or dangerous obstacles separating the animal from its
home range.
Capture personnel should be made aware of human safety and zoonotic
disease concerns.
Key points to consider before capture of bighorn sheep:
Adetailed capture plan must be prepared in advance of the capture that
outlines goals,methods,potential problems,personnel and safety
procedures (CaliforniaDepartment of Fish and Game 1988).
A pre-capturemeeting should be mandatory for all participating personnel.
All personnel must be trained in proper animal handling techniques.
Experienced veterinary assistance and emergency medical supplies and
equipment should be readily available to treat a physically distressed or
200
injured animal.Frequent post-capture monitoring of individual bighorn
sheep is mandatory to determine effects of capture,tags,and collars on
survivorship, reproduction,and well being.
A written report should be prepared after each capture that documents the
activity,provides a critical assessment of the capture,and suggests
improvements for future capture activities.
References
Bleich,V.C.,R.T.Bowyer,A.M.Pauli,R.L.Vernoy,R.W.Anthes.1990a.
Responses ofmountain sheep to helicopter surveys.California Fish and
Game 76(4):197-204.
Bleich,V.C.,J.D.Wehausen, J.A.Keay,J.G.Stahmann,M.W.Berbach.
1 990b.Radiotelemetry collars and mountain sheep:a cautionary note.
Desert Bighorn Council Transactions 34:6-8.
Bleich,V.C.,R.T.Bowyer,A.M.Paub,M.C.Nicholson and R.W.Anthes.
1994.Mountain sheep Ovis canadensis and helicopter surveys:
ramifications forthe conservation of large mammals.In:Biological
Conservation 70(1):1-7.
Boyce,W.M.1995.Peninsular bighorn sheep population health and demography
study.Final Progress Report -June 1,1995.California Department of
Fish and Game.Sacramento,California.
Boyce,W.M.,P.W.Hedrick,N.E.Muggli-Cockett,S.Kalinowski,M.C.T.
Penedo,and R. R.Ramey II.1997.Genetic variation of major
histocompatibility complex and microsatellite loci:a comparison in
bighorn sheep.Genetics 45 :421-433.
Boyce,W.M.,R. R.Ramey II, T.C.Rodwell,E.S.Rubin,and R.S.Singer.
1999.Population subdivision among desert bighorn sheep (Ovis
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canadensis)ewes revealedby mitochondrial DNA analysis.Molecular
Ecology 8:99-106.
CaliforniaDepartment of Fish and Game.1988.Capture and Relocation of
Wildlife.In:Fish and Game Operations Manual; Wildlife Management
Program,Sect.3620-3625.Sacramento,California.
CaliforniaDepartment of Fish and Game.1996.Medical Concerns.In:Wildlife
Restraint Handbook pp.9/1-9/14.Wildlife Investigations Laboratory,1701
Nimbus Rd.,Suite D.Rancho Cordova,Ca.95670.
Clark,R.K.,D. A.Jessup,M.D.Kock, and R. A.Weaver.1985.Survey of
desertbighorn sheep in California for exposure to selectedinfectious
diseases.Journal of the American Veterinary Medical Association
187:1175-1179.
Clark,R.K.,C. A.Whetstone,A.E.Castro,M.C.Jorgensen, J.F.Jensen, and D.
A.Jessup.1993.Restriction endonuclease analysis of herpes viruses
isolated from two Peninsularbighorn sheep (Ovis canadensis
cremnobates).Journal of Wildlife Diseases 29(1 ):50-56.
Crosbie,P.R., W.L.Hoff,D.Stiller,D. A.Jessup,and W.M.Boyce.1997.The
distribution of Dermacentor Iiunteri and Anap!asma sp.in desertbighorn
sheep (Ovis canadensis).Journal of Parasitology 83(1):31-37.
DeForge,J.R.,D. A.Jessup,C.W.Jenner,J.E.Scott.1982.Disease
investigations intohigh lamb mortality of desertbighorn in the Santa Rosa
mountains, California.Desert Bighorn Council Transactions 26:76-81.
DeForge,J.R.,E.M.Barrett,S.D.Ostermaun,M.C.Jorgensen, and S.G.
Torres.1995.Population dynamics of Peninsularbighorn sheep in the
Santa Rosa Mountains,California,1983-1994.Desert Bighorn Council
Transactions 39:50-67.
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DeForge, J.R.,S.D.Ostermann,C.W.Willmott,K. B.Brennan,and S.G.
Torres.1997.The ecology of Peninsular bighorn sheep in the San Jacinto
Mountains,California.Desert Bighorn Council Transactions 41:8-25.
DeForge,J.R.and S.D.Ostermann.1998b.The effects of urbanization on a
population of desertbighorn sheep.Abstract for the 5th Annual Conf.of
Wild.Soc.,Buffalo,NY.
Elliot,L.F.,W.M.Boyce,R. K.Clark,D. A.Jessup.1994.Geographic analysis
ofpathogen exposure in bighorn sheep (Ovis canadensis).Journal of
Wildlife Diseases,30(3):3 15-318.
Hayes,C.L.,E.S.Rubin,M.C.Jorgensen,R.A.Botta,and W.M.Boyce.2000.
Mountain lionpredation on bighorn sheep in the PeninsularRanges,
California.J.Wildl. Manag.64(4):954-9.
Holling,C.5.1978.Adaptive Environmental Management.Academic Press.
New York.
International Wildlife Veterinary Services.1996.Medical concerns.In:Wildlife
Restraint Series.Ed.R. K.Clark,D. A.Jessup.pp.8.1-8.15.IWVS,Inc.
Publications,P.0.Box 936, Fort Collins,Colorado 80522.
Jessup,D.A.,W.E.Clark,and R. C.Mohr.1984.Capture of bighorn sheep:
management recommendations.Wildlife Management Branch
Administrative Report 84-1. CaliforniaDepartment of Fish and Game.
Sacramento, California.
Jessup,D.A.,R. K.Clark,R.A.Weaver,M.D.Kock.1988.The safety and cost
effectiveness of net-gun capture of desert bighorn sheep (Ovis canadensis
ne!soni).Journal of Zoo Animal Medicine 19(4):208-2 13.
Jessup,D.A.,W.M.Boyce.1993.Diseases of wild sheep.In:Zoo and Wild
rd
Animal Medicine,3 Edition.Ed.M.E.Fowler.W.B.Saunders.pp.
554-560.
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Jessup,D.A..1999.Capture and handling of mountain sheep and goats.In:Zoo
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and Wild Animal Medicine,4 edition.Eds.M.E.Fowler,R.E.Miller.
W.B.Saunders Company.pp.681-687.
Ostermann,S.D.,J.R.DeForge,and W.D.Edge.Captive breeding and
reintroduction evaluation critena:a case study of Peninsular bighorn
sheep.Conservation Biology.In press.
Plumb,D.C.1995.Glucocorticoid agents, general information.In:Veterinary
Drug Handbook.Iowa State University Press,Ames,Iowa.pp.292-295.
Rubin,E.S.,W.M.Boyce,M.C.Jorgensen,S.G.Torres,C.L.Hayes,C.S.
O’Brien,and D.A.Jessup.1998.Distribution and abundance of bighorn
sheep in the Peninsular Ranges,California.Wildlife Society Bulletin
26(3):539-55 1.
Rubin,E.S.,W.M.Boyce, and V. C.Bleich.2000.Reproductive strategies of
desert bighorn sheep.J.of Mammalogy 81(3):769-786.
Wehausen, J.D.,V. C.Bleich,B.Blong,and T. L.Russi.1987.Recruitment
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Wildlife Management 51:86-98.
204
APPENDIX E.PROTOCOLS FOR MONITORING POPULATION
ABUNDANCE
This appendix presents protocols for two methods of monitoring the abundance
and population trends of Peninsularbighorn sheep.These two methods are:(1)
waterhole counts and (2)aerial helicopter surveys.For explanations of
terminology (e.g.,ewe group)or reference to specific names of locations,please
refer to themain body of therecoveryplan and papers cited therein.
Waterhole counts havebeen conducted in selected parts of Anza-Borrego Desert
State Park since 1971 (M.Jorgensen, pers. comm.)and havebeen used to assess
abundance trends of Peninsularbighorn sheep (Rubin et a!.1998).Prior to 1993,
no marked animals were present in the areas in which counts were conducted.
Count data were,therefore,only appropriate foruse as an index of abundance
rather than for calculation of an absolute population estimate.Since 1993,
however,collared animals have been present and waterhole count datacan be
used to generatepopulation estimates for some ewe groups in Anza-Borrego
Desert State Park.
Waterhole counts are organized and conducted by volunteers under thedirection
of Park staff.Although helicopter surveys provide a more comprehensive
population estimation tool,waterhole counts should be continued.Continuation
for atleast 10 more years willallow investigators to determine thecorrelation
between waterhole count and aerialsurvey population estimates,which maymake
it possible to generate historical population estimates using earlywaterhole count
data. In addition, waterhole counts provide data that are difficult to determine
from a helicopter (e.g.,reproductive status of individually marked ewes;refer to
section II.D.2.1 of therecoveryplan),and provide an opportunity forthe
communityto participate in Peninsular bighorn sheep conservation projects (refer
to section II.D.3).
Helicopter surveys havebeen conducted in the SantaRosa Mountains annually
since 1977 (Wehausen eta!.1987,DeForge eta!.1995),the San Jacinto
Mountains in 1983, 1984,and annually since 1987 (DeForge et a!.1997),and in
some parts of Anza-Borrego Desert State Park in the early 1980’s (M.Jorgensen,
205
pers. comm.).Radio-collared animals have been present in the northern Santa
Rosa Mountains sincethe early 1980’s (DeForge et a!.1995)and in the San
Jacinto Mountains since 1992 (DeForge et a!.1997).In 1994, 1996,and 1998,
radio-collared animals were present throughout thePeninsular Ranges and surveys
covered all parts of the ranges for the first time,making itpossible to generate
population estimates for the entire range as wellas for subregions (Rubin et a!.
1998).Currently, helicopter surveys in the San Jacinto Mountains and the Santa
Rosa Mountains are conducted by California Department of Fish and Game and
theBighorn Institute,while surveys of the remainder of the range areconducted
by California Department of Fish and Game and Anza-Borrego Desert State Park.
The following sections outline specific protocols for each monitoring technique.
Aerial Helicopter Surveys
Frequency of surveys
Helicopter surveys covering the entire range should be conducted at leastevery
other year.Recently, the San Jacinto Mountains and Santa Rosa Mountains have
been surveyed annually,while the remainder of therange has been surveyed every
other year (1994,1996, 1998).
Time of survey
Helicopter surveys should be conducted ideally between late September and early
November. This method reduces therisk to bighorn sheep by avoiding periods
when young lambsare present,periods when ewes reach late gestation,and
months of high summertemperatures. In addition,this time period coincides with
part of the rut,or breeding season.This approach allows themost accurate
estimate of the sex ratio because bighorn tend to congregateduring this time.
Areas to be surveyed
All bighorn sheep habitat in thePeninsular Ranges should be surveyed.For
consistency among years,the same predetermined areas should be flown every
year,with the same amount of time (effort) spent per area during each year.Flight
areas and associated approximate surveytimes are included in this appendix
(Tables E-l and E-2).Maps are not included here because the geographic
references in the Tablesbelow accurately describe the survey areas and this plan is
206
Table E-l.Approximate polygons flown byBighom Institute in annual helicopter surveys of the
San Jacinto and Santa Rosa Mountains.Topography and sheep sign influenced the amount of
time spent per area.Flight polygons were developed while the population was at a low,and some
areas where sheep sign (trailing,bed sites,etc.)has not been noted for several consecutive years
are flown less intensely than areas with sign.If the population increases, more time may be
needed to thoroughly survey areas that are only cursorily surveyed now.Flight times are actual
time within thepolygon.
Polygon Area/Canyons Notes
Number
San Jacinto Mountains:
west fork of Palm Canyon north to
Blaisdell Canyon
2 Santa Rosa Mountains:
Calcite Mine west to Rattlesnake
Canyon
3 SantaRosa Mountains:
western Santa Rosa Mountains,west of
Rattlesnake Canyon to Buck Ridge and
Rockhouse Canyon
4 Santa Rosa Mountains:
Big Wash north,Wonderstone Wash,
Travertine Palms, and Barton,Alamo,
and southern Sheep Canyons.
5 Santa Rosa Mountains:
north Sheep Canyon, Martinez Canyon
6 Santa Rosa Mountains:
Agua Alta and Toro Canyons
7 Santa Rosa Mountains:
Guadalupe,Devil, andBear Canyons
8 Santa Rosa Mountains:
Coyote,Sheep, Deep,Carrizo,and Dead
Indian Canyons.
9 Santa Rosa Mountains:
Magnesia,Bradley,and Cathedral
Canyons.
Approx.
flight time
(hours)
2.25
2.25
2.25
1.75
Areas south of Andreas and north
of Chino have been flown less
intensely in recent years due to
lack of bighorn sheep sign.It will
be necessary to add survey time if
distribution expands.
Buck Ridge flown cursorily.
Barton, Alamo, and Sheep
Canyons flown cursorily due to
lack of sign.
1.25
2.00
2.25
2.25
2.00
Polygon should include Indio and
Eisenhower Mountains.
Western Cathedral Canyon
appears to have been abandoned
recently —minimal flight time
spent west of Cathedral Canyon.
Surveys may need to intensify
west of Cathedral Canyon proper
if the population increases.
207
Table E-2.Survey polygons flown inbighorn sheep habitat outside of the Santa Rosa and San
Jacinto Mountains.Flight times are actual time within the polygon.
Polygon Area Polygon Description
Number
10
11
12
13
14
15
16
17
18
19
20
21 Carnzo Canyon area
22 ‘‘
23 ‘‘
24 ‘‘
25 Fish Creek
Mountains
26 Coyote Mountains
27 5.of Interstate 8
Coyote Peak
NE side of Coyote Canyon
SW side of Coyote Canyon
N of County Rd 22 (Montezuma Grade)
S of County Rd 22 and Yaqui Ridge
Pinyon Ridge and N side of Sentenac Canyon
Pinyon Mts to Pinyon Canyon
Sunset Mm,Harper Flats, to Harper Canyon
Harper Canyon to Hapaha Flats to Alma Canyon
Alma Canyon to Fish Creek Wash to Split Mm
Whale Peak (Fish Creek Wash to Smuggler
Cyn)
Tierra Blanca Mts to Rockhouse Canyon
W side Carrizo Wash (to Blackwater Canyon)
Camzo Gorge to Tule Cyn,E.to Dos Cabezas
E side of Carrizo Wash (N of railroad tracks)
Fish Creek Mountains
Coyote Mountains
Dos Cabezas to U.S.-Mexico border
Approx. flight
time (hours)
1.25
3.00
2.25
2.75
2.00
1.00
2.25
1.50
1.75
1.25
1.25
2.00
1.25
2.00
1.25
1.75
1.75
2.00
Coyote Canyon
N.San Ysidro Mts
S.San Ysidro Mis
Vallecito Mountains
not intended to represent a comprehensive compendium of information related to
bighorn conservation activities.
Survey techniques
The survey crew consists of three observers in addition to the pilot.When
possible,the samepilot and pool of experienced observers should be used each
year.Thedoors of the helicopter should be removed for optimum visibility.Each
polygon should be flownsystematically at 40 to 60 kilometers per hour (25 to 35
miles per hour), followingtopographic contours of 100 to 150-meter (330 to 490-
foot)intervals.Thepilot and the observers should not be aware of the locations
of radio-collared sheep,and telemetry should not be used to locate groups or
individuals.The number of radio-collared animals in each survey polygon should
be determined immediately before or during the helicopter survey,by additional
personnel,using aerial fixed-wing or ground monitoring.These animals serve as
“marked”animals in the calculation of abundance estimates using mark-recapture
methods (see below).The Global Positioning System base station at Anza-
Borrego Desert State Parkheadquarters should be run during the entire survey so
208
that Global Positioning System location data can be corrected by staff at their
General Plan office.All four individuals in the flight crew areconsidered
observers, and each of the three passengers is assigned one of the following
additional tasks:(1)to monitor theprogress of the flight on a topographical map,
advise thepilot of polygon boundaries,and record the location of each observed
sheep on the map, (2)maintain a data sheet onto which the date, time,elevation,
group size and composition,number of collared animals,and,possibly,
identification of collared animal is recorded for each group of animals,or (3)
record the flight of thesurveyand the location of each observed animal using a
Global Positioning System unit.All observed animals should be classified as
yearling ewe,adult ewe,yearling ram,Class II ram,Class III ram,Class TV ram,
or lamb (classifications modified slightly from those used by Geist 1971).When
possible, simultaneous double-counts should be conducted during each survey,
followingthe methods of Graham and Bell (1989), to provide an additional
abundance estimate. All sightings of feral animals and deer should be recorded
during surveys.The location and condition of springs,tinaj as, and otherwater
sources also should be recorded.
Data Ana!yses
Population estimates should be generated using estimators such as Chapman’s
(1951) modification of the Peterson estimator (Seber 1982),or the joint
hypergeometric estimator (e.g.,Neal et a!.1993).Estimates should be calculated
separately for each sex and for the total population (rams and ewes combined).In
the event that low numbers of collared rams prevent the estimation of ram
numbers,the ram to ewe ratio and the estimated number of ewes can be used to
generate an estimate of adult numbers.Confidence intervals (95 percent)should
be calculated using methods such as those of Seber (1982).Simultaneous double-
count data should be used to estimatethe number of groups missed and to
generate an additional estimate of the minimum number of animals presentwithin
the surveyed areas (Graham and Bell 1989).All reported results (e.g.,lamb to
ewe orram to ewe ratios) should clearlystate whether or not yearlings are
included.
209
Estimates should be generated forthe entire range,as well as for individual ewe
groups.It is important to note that ewe group distribution maychange slowly
over time.Monitoring of radio-collared ewes to determine ewe group structure
will therefore, have to be continued,and stratification of survey datamay have to
be modified slightly.Furthermore,ewe groupdelineations in the Santa Rosa
Mountains south of Highway 74 and in the Vallecito Mountains still need to be
more clearly resolved.
Further considerations
Initially,a sufficient number of active radio-collared animals must be present in
each portion of the range foruse in mark-recapture estimate calculations. The
number of collared animals should be sufficient to achieve an accuracy of plus or
minus 25 percent with probability of 0.05,following the methods described in
Krebs (1989)and Robson and Regier (1964),or approximately 30 percent of the
estimated ewe population should be radio-collared.However, a “sightability”
estimate maybe generated after additional multiple surveys are conducted,
thereby eliminating theneed to maintain this percentage of radio-collared animals.
This approach would be especially beneficial if/when population numbers become
large.
As batteries expire, collars become non-functional and the actual number of
marked animals present in thesurvey areabecomes difficult to know. Only those
bighorn sheep with functional collars should be usedas marked animals.This
approach will require that bighorn sheep with “functional”collars be
distinguishable from those with “nonfunctional”collars at a glance,from the
helicopter.Therefore,an accurate inventory of all collaredanimals must be
maintained and the choice of collar and eartag color combinations must be
considered during collaring efforts.No newly collared animal should match (in
collar and eartag color combination) an animal that is possibly still present in the
field.
Within a polygon,an attempt should be made to “sweep”across the survey area,
rather than flying over an areamore than once.This method will reduce the
chance of double counting animals. Helicopter activity at times cause bighorn
sheep to move (Bleich et a!.1994);therefore,adjacent polygons should,when
210
possible,be flownconsecutively so that groups canbe recognized and possible
double counts eliminated.The flight polygons delineated in this document were
chosen,in part, so that natural breaks in topography or roadways coincided with
polygon boundaries.
Data should be maintained in an electronic data set that canbe used by
investigators in the future.All raw data should be retained.That is,data should
not be summarized before being entered into a data set.
Waterhole Counts
Frequency of Counts
Waterhole counts should be conducted annually.
Time of Counts
Counts should be conducted at the same time every year so that yearly
comparisons of ram:ewe ratios,lamb:ewe ratios, group size,and number of sheep
observed at water sources are most meaningful.In addition,counts should be
conducted during the hottest and driest time of the year to maximize the number
of animals coming to drink atwater sources. Counts have typically been
conducted during the July 4th weekend,and should continue to be held between
mid June and the first week of July.
Areas to be Counted
Annual counts have been conducted in thesouthern part of the park (Carrizo
Canyon area) during 1973 to 1982,and in thenorthern part of the park (San
Ysidro Mountains, Coyote Canyon,and one site in the south SantaRosa
Mountains) since 1971.Counts in the southern portion of the park were
discontinued after 1982 because of the largenumber of volunteers that were
needed to conduct counts atboth ends of theState park,and thecomplex logistics
of organizing and getting teams set up in fairly remote count sites.
Inthe past,the number of sites counted in each area has varied slightly across
years because of variation in the number of available volunteers or unexpected
problems (for example,a firenear count sites).Thenumber of sites did not
211
significantly influencethe number of sheep counted in each portion of the range
(Rubin et a!.1998).However,an attempt should be made to keep the number and
locations of count sites constant during future years.Prioritysites should be those
that havebeen counted most consistently in the past.Additional or “secondary”
sites should be counted when additional volunteers are available.Data analyses
can then focus on data collected at “priority” sites,while “secondary” sites canbe
used for more cursory monitoring of sheep presence.
Count Techniques
Teams of three to five observers should be assigned to each count site.Each team
should include atleast two individuals who areexperienced at classifying bighorn
sheep by ageand sex.At each count site,the entire team should be stationed at a
location that allows observation of animals coming to a water source,while
minimizing disturbance of the animals or interference with their use of the water
source.These locations have been identified by Anza-Borrego Desert State Park
personnel.While at these sites, observers should minimize noise and movement.
Observations should be made during 7 a.m.to 5 p.m.on 2 consecutive days and 7
a.m.to 2 p.m. on the third day.During these periods,observers should
systematicallyscan all areas within view and record all sheep observations on the
supplied data sheet.Data to be recorded include date,time,temperature,group
size and composition, the presence of collared animals,and,if possible, the
identification of collared animals. Additionally,interactions among individuals
(e.g.,breeding behavior,lamb nursing bouts)and observations of other species
(e.g.,deer,coyotes, birds) should be recorded.The location of each group of
bighorn sheep should be noted on a topographic map.
Repeat sightings of individual sheep should be recorded as such,but they should
not be counted.At the end of each day,each team should review and discuss their
observations with neighboring teams so that repeat observationscan be identified
and eliminated from the final tally.
Data Analysis
Theprimary use of data collected during waterhole counts is to monitor
abundance trends.Rubin et a!.(1998) used count data to assess long-term trends.
In this case,linear regression analysis wasused to determine if the number of
212
ewes observed per day showed an increasing or decreasing trendover a period of
10 to 26 years.If a sufficient number of collared animals are present in each ewe
group area, abundance estimates can be generated for some ewe groups,using
mark-recapture techniques.Lamb to ewe ratios can be calculated to monitor
reproductive success of ewe groups.Most lambs are 3 to 5 months old during
waterhole counts and these ratioswill not be directlycomparable to ratios
generated from helicopter surveys,which represent lamb recruitment to an older
(approximately 6 to 8 months)age.The reproductive status (lamb present versus
not present)of individual radio-collared ewes can supplement observationaldata
collected by biologists monitoring reproductive patterns of Peninsular bighorn
sheep.Ram to ewe ratios should be generated for comparison among years.The
rut typically peaks after July,so these ratios may underestimate the actual ram to
ewe ratios since some rams maynot have joined ewe groups yet.
Further Considerations
To make waterhole count data as useful as possible for future investigators,it is
important for teams to determine the composition of eachgroup as accurately as
possible. Given the great distances sometimes involved,an effort should be made
to equip each team with a spotting scope and at least one individual should be
experienced at using it to observe and classify bighorn sheep.
All new observers must complete a one dayorientation and training session ledby
Anza-Borrego Desert State Park personnel.In addition,all new observers must be
paired with individuals experienced at classifying bighorn sheep in the Peninsular
Ranges (Bleich 1998).
Data should be maintained in an electronic dataset for use in the future.All raw
data should be retained. That is,data should not be summarized before being
entered into a primary data set.
Reinitiation of waterhole counts in the Santa Rosa Mountains should be
considered. This approach may enhance theprobability of detecting relationships
between aerial helicopter data and waterhole count data, thereby facilitating a
retrospective interpretation of numbers of sheep in the Santa Rosa Mountains in
the past.
213
References
Bleich,V.C.,R.T.Bowyer,A.M.Pauli,M.C.Nicholson,and R.W.Anthes.
1994.Mountain sheep Ovis canadensis and helicopter surveys:
ramifications for conservation of large mammals.Biological Conservation
70:1-7.
Bleich,V. C.1998.Importance of observer experience in classifying mountain
sheep.Wildlife Society Bulletin.In press.
Chapman,D. G.1951.Some properties of thehypergeometric distribution with
applications to zoological samplecensuses.University of California
Publication in Statistics 1(7):131-160.
DeForge, J.R.,E.M.Barrett,S.D.Ostermann,M.C.Jorgensen, and S.G.
Torres.1995.Population dynamics of Peninsular bighorn sheep in the
Santa Rosa Mountains,California, 1983-1994.Desert Bighorn council
transactions 39:50-67.
DeForge,J.R.,S.D.Ostermann,C.W.Willmott,K.B.Brennan, and S.G.
Torres.1997.The ecology of Peninsularbighorn sheep in the San
Jacinto Mountains,California.Desert Bighorn Council Transactions 41:8-
25.
Geist,V.1971.Mountain sheep:a study in behavior and evolution.University
of Chicago Press,Chicago.383pp.
Graham,A.and R. B.Bell.1989.Investigating observer bias in aerial survey by
simultaneous double-counts.Journal of Wildlife Management
53(4):1009-1016.
Jorgensen, M. pers.comm.Calif Dept.Parks and Recreation.
Krebs,C.J.1989.Ecological Methodology.Harper Collins Publishers. New
York, N.Y.6S4pp.
214
Neal,A.K.,G. C.White,R.BruceGill,D.F.Reed,and J. H.Olterman.1993.
Evaluation of mark-resight model assumptions for estimating mountain
sheep numbers.J.Wildl.Manage.57:436-450.
Robson,D.S.and H. A.Regier.1964.Sample size in Peterson mark-recapture
experiments.Transactions of the American Fisheries Society 93 :215-226.
Rubin,E.S.,W.M.Boyce,M.C.Jorgensen,S.G.Torres,C.L.Hayes,C.S.
O’Brien,and D. A.Jessup.1998.Distribution and abundance of bighorn
sheep in the Peninsular Ranges,California.Wildlife Society Bulletin
26(3):539-551.
Seber,G. A.F. 1982.The Estimation of Animal Abundance.Charles Griffin
and Company,Limited, London,England.
Wehausen,J.D.,V. C.Bleich,B.Blong,and T. L.Russi.1987.Recruitment
dynamics in a southern Californiamountain sheep population. Journal of
Wildlife Management 51(1):86-98.
215
APPENDIX F.RECOMMENDED CONSERVATION GUIDELINES
BACKGROUND
Bighorn sheep in thePeninsular Ranges are afforded protection pursuant to the
CaliforniaFish and Game Code (sections 4700 as a fully protected species and
2050 asa threatened species).Section 4700 of the Fish and Game Code does not
allowfor issuance of permits or licenses to take fully protected mammals,except
for scientific research,notwithstanding any other provision of law;therefore, a
CaliforniaEndangered Species Act section 2081 permit that would authorize
incidental take of Peninsularbighorn sheep cannot be issued.This take
prohibition in turn limits the type of mitigation that canbe required pursuant to
the California Environmental Quality Act.The sheep also is listed at 50 CFR §
17.11 by the U.S. Fish and Wildlife Serviceas an endangered species and
protected against take at 50 CFR §17.21.Regulations that authorize take under
prescribed circumstances arefound at 50 CFRParts 17 and 402.
The California Environmental Quality Act requires that mitigation measures be
identified and implemented for any significant impacts unless a finding of over-
riding considerations is adopted.Section 15370 of the California Environmental
Quality Act Guidelines provide five categories of mitigation measures: “...avoid,
minimize,rectify,reduce or compensate.”These forms of mitigation are
appropriate for bighorn sheep only to the extent that they avoid take of the
species,pursuant to Section 4700 of the Fish and Game Code,and avoid take
under 50 CFR §17.21,unless otherwise authorizedby the U.S.Fish and Wildlife
Service under 50 CFR §17.22.Accordingly,the Fish and Wildlife Service and
California Department of Fish and Game work with lead agencies and project
proponents on a case by case basis to identify which forms of mitigation would be
appropnate.
OBJECTIVES
The objective of these guidelines is to provide a set of consistent mitigation
measuresfor project proposals that do not otherwise threaten sustainable bighorn
sheep populations needed for recovery.Thesemitigation measures are not
216
intended for projects proposed in locations that would fragment habitat or
preclude effectivereserve design and management of the species because those
adverse effects cannot be offset.In such instances, theFish and Wildlife Service
and California Department of Fish and Gamemay recommend additional
avoidance,minimization,and mitigation measures to ensure against the likelihood
of significantadverse effects that would impinge on take and jeopardy thresholds.
Through proper coordination, our agencies will assist local, State,and Federal
governments in identifying whether the adverse effects ofproject proposals can be
mitigated to a level of insignificance,based on project location,size,and potential
for indirect effects, which typically arethe primary criteriainfluencing the type
and severity of impact.These guidelines mayrequire future modification based
on the availability of new information on threats,ecological requirements, species
status,etc.
CONSERVATION MEASURES
I.HABITAT COMPENSATION:Acquisition of off-site habitat maybe
appropriateto offset any residual effects after application of appropriate avoidance
and minimization measures.For projects adjacent to bighorn sheep habitat that
provide infrastructure to support larger human populations,habitat compensation
is generallyappropriate because of the consequent increased levels of human-
related disturbance in adjoining open space.The cumulative effects of human
disturbance maybe mitigated by acquisition of sheep habitat that would otherwise
be vulnerable to future development. Projects adjacent to sheep habitat that do
not result in indirect effects to adjoining sheep habitat generallylack a mitigation
nexus.
To maintain sustainable subpopulations (ewe groups),compensation habitat
should be acquired within the range of the affected ewe group and at an elevation
comparable to the impact.Bighorn sheep in the Peninsular Ranges are mainly
threatened by habitat loss atlower elevations that provide unique resources
unavailable farther up themountain slopes.Therefore,loss of unique or limiting
resources at lower elevations cannot be offset by conservation of different
resources associated with habitats at higher elevations.
217
Habitat acquisition promotes survival and recoveryby reducing the potential
futureloss of bighorn sheep habitat through permanent protection of land
currently available for development.Amount of compensation will be determined
on a case by case basis becausethe effects of individual projects arevariable. A
management endowment should accompany all acquired lands so that the
responsible public agencyhas the ability to effectively manage conserved lands.
II.FENCING:Fencing along the urban interface provides a barrier that separates
bighorn sheep from urbanization threats (e.g.,disease and mortality associated
with toxic plants,traffic,parasites,irrigated landscapes, pesticides, etc.). Fencing
also can help mitigate the adverse effects of incompatible land uses adjoining
sheep habitat.For example,fencing controls human access into habitat that may
otherwise conflictwith management objectives to minimize human disturbance,
especially during sensitive time periods,such as lambing.Landuses along the
habitat edge should be designed to not introduce additional human disturbance.
Recreational access should be provided only where access is coordinated with
natural resource agencies and is consistent with management objectives in the
regional trails plan. Fencing does not offset the effects of habitat loss and should
be located alongthe edge and not within sheep habitat.
A.Fencing should be mandatory for any new development in or
adjacent to sheep habitat,where bighorn sheep havebegun or may
begin using urban sources of food and water.
B.Fences should be 2.4 meters (8 feet) high, chain-link or functional
equivalent.
C.Fences should not contain gaps in which sheep can be entangled
[gaps should not be largerthan 11 centimeters (4.3 inches)].
III.TOXIC PLANTS: Landscape plants cancause sickness or death.Only local
native plants should be used along the wildland interface.Known and potential
toxic plants should not be used in areas accessible to bighorn sheep.Ornamental
plants currently known to be toxic to sheep include oleander,Prunus species,and
plants in the nightshade (Solanaceae)family.
218
IV.LAMBING SEASONAND HABITAT RESTRICTIONS:Seasonal
restrictions during this period minimize impacts to bighorn sheep ata critical
stage of their life cycle.Lambing habitat is often emphasizedbecause of the
sensitive nature and behavior of ewes and lambs.Lambing habitat comprises
those areas used for breeding,sheltering,and nurturing of lambs up to the time of
weaning, including those areas occupied by ewes 1 monthbefore giving birth.
Though the lambing seasoncan span themajority of the calendar year--from late
winter through summer, January 1 through June 30 encompasses themajority of
the lambing season.Trails that traverse lambing habitat should be managed during
this period orrelocated outside of sensitive habitat areas.
V.SUMMER WATER SEASON:Availablewater sources during summer
months are highlyrestricted and bighorn sheep are vulnerable to disturbance in
these areas.If summerrains fail,water mayremain scarce until the first winter
rains.Accordingly, interagency cooperation willbe needed to adapt trails
management prescriptions to the water requirements of bighorn sheep.Public
education,signage, rangers,and other forms of management should be provided at
appropriate locations to control access during this period.
Title 14 of the Public Resources Code,Section 550(b)(1)and Sections 630(b)(l I)
and (30) restricts access to waterholes on State lands in the SantaRosa
Mountains. Closure periods are from June 15 to September 15.
VI.WATER FEATURE DESIGN SPECIFICATIONS:Any artificial water
features (e.g.ponds,lakes)in areas adjoining bighorn habitat should be designed
to preclude shallow,vegetated edges that provide breeding habitat for Cu!icoides
midges, an invertebrate disease vector forbluetongue virus.Water bodies should
be designed with steep sides and depths at least 0.6 to 0.9 meters (2 to 3 feet)
alongthe edge [see: Mullens,B.A.1989.A quantitative survey of Cu!icoides
variipennis (Diptera:Ceratopogonidae)in dairy wastewater ponds in southern
California. J.of Medical Entomology 26(6):559-565;and Mullens,B. A.and J.
L.Rodriquez.1990.Cultural management of bluetongue virus vectors.Calif.
Agriculture 44(l):30-32].
219
WILDLIFE AGENCY RECOVERY AND MANAGEMENT
RESPONSIBILITIES
AUGMENTATION: Augmentation is a potential recoverytool that is addressed
within the context of the recoveryplan and would be used until a self-sustaining
population is established.The release of captive reared or translocated wild
animals to establish new populations or supplement small populations are not
acceptable mitigation measuresbecause they do not compensate for thepermanent
loss of habitat or ensure the continued viability of habitat to support self-
sustaining, wild populations.
PREDATOR CONTROL:Predator control is a potential management tool
available to the Fish and Wildlife Service and CaliforniaDepartment of Fish and
Game to address specific situations.Bighorn sheep are adapted to survive natural
levels of predation,drought,disease,competition,etc., which do not pose
problems in properly functioning ecosystems.Because predator control is a
temporary solution to remedy a short-termproblem, it does not constitute
mitigation for the permanent loss of sheep habitat.
220
APPENDIX G.RESPONSE TO COMMENTS
The following issues are a compilation of all substantive comments received by
the Fish and Wildlife Service from technical reviewers, agencies,and the public,
which were not otherwise responded to by directly incorporating changes intothe
text of the final recovery plan.The issues are organized by general subject matter.
LEGAL ISSUES
Issue.~Designation of essentia!habitat i!lega!lv usurps authority over local !and
use p!anning by imposing prohibitions on private property and mandating
erection offences.Ident~fying private !ands for protection without committing
Federa!funding orconservation incentives exposes !oca!government to property
taking lawsuits because cities and counties lack thewherewithal to cooperate in
implementation of theplan.To avoidrepresenting a moratorium on future
deve!opment,can some deve!opment in essentia!habitat go forward if adequately
mitigated,and fso,what criteria or standards would be used?
Response:Essential habitat (in contrast to critical habitat,discussed below)is a
nonregulatory indication of those areas we believe to be important to the
conservation of bighorn sheep.The map is intended to provide information that
can advance conservation efforts through theactivities of other agencies and the
public.By sharing biological information,we intend to promote public policy
decisions that balance the conservation needs of bighorn sheep with other
competing land uses.As such,the designation of essential habitat does not affect
the discretion of local and State governments or private landowners over land use
decisions.Given the biological importance of the habitat to recovery,limited
development could occur in essential habitat if adequatelymitigated and designed
to be compatible with bighorn sheep recovery.Furthermore, the identification of
areas with biological importance can provide a wider range of potential landuses
that generateeconomic opportunity.For example,local governments and private
landowners can structure economic incentives to conserve bighorn habitat by
creating programs whereby developments in other areascan provide a source of
income to land owners with habitat of higherconservation value.This mitigation
bank concept has gained widespread acceptance in numerous other areas where
221
local government has created a mitigation nexus that avoids property taking
lawsuits and promotes regional habitat conservation planning.
Issue:Membership of theRecovery Team and peer review team consists of
individuals whose livelihood depends on funding,permits, and recommendations
from the State and Federal government.Therefore,these individua!s are
reluctant to voice criticisms with the recovery planning process forfear of
retribution.In addition,authors of thedraft recovery plan stand to gain
financially by creating an open checkbook/cash cow with questionable research
projects having no accountability.
Response:At our invitation,members agreed to participate on the Recovery
Team for the purpose of providing scientific advice to the Fish and Wildlife
Service and cooperating agencies, including assistance in developing and
implementing the recoveryplan. The draft recovery plan was largely written by
team members who provided theinformation and opinions needed to complete a
draft plan.Though consensus was achieved on most issues addressed by the team,
we and cooperating agencies judged howbest to incorporate various views where
full agreement was not reached.Many of the research topics recommended in the
recovery plan are a reflection of scientific questions that remain unresolved.Any
funding to address these researchneeds willbe directed on a competitive basis to
the best qualified individuals available.Funding and permitting actions by us and
cooperating agencies have and will follow applicable laws and regulations that
ensure against preferential treatment and capricious behavior.Recovery Team
members are not dependent upon the Fish and Wildlife Service or the listing of
bighorn sheep for their continued livelihood.Members are under no obligation
whatsoever and do not enjoy economic benefit for their voluntary participation on
the Recovery Team.
Issue:Undue reliance on unpublished information fails to justify thespending of
$16M every 5 years for several decades.The conclusions,recovery criteria,and
habitat mapping lack credibility due to theirreliance on over 100 unsupported
citations and that underlying data were intentional4’withheld from public review.
The public has a right to inspect all the unpublished information cited in the draft
plan as an aid to provide informed comments; therefore, the public comment
222
period should be extended untilafter these data havebeen made available.
Following the response to all commentsand correction of many deficiencies,the
draft recoveryplan should be circulated again for public review.
Response:The draft recovery plan wasbased on thebest available data,which
includespersonal experience of credible researchers.Unpublished information
cited in the draft recoveryplan wasdocumented and compiled prior to completion
of thefinal recovery plan and has been available along with published papers,for
public inspection. Any facts or interpretations based on unpublished information
cited in the draft recoveryplan for which documentation could not be obtained
havenot been included in the finalrecoveryplan.Justification for research
recommended in the recoveryplan was not based on cited unpublished
information but on consensus recommendations of the Recovery Team and
concurrence bythe cooperating agencies.Upon reassessing the relative
importance of the unpublished information cited in thedraft recovery plan to the
findings and conclusions in therecoveryplan, we have determined that the
unpublished information unavailable forreview in thedraft recovery plan did not
materially affect any significant findings or recommendations in the final recovery
plan. As a result, we elected to not reopen the public comment period. In
response to any substantive comments received after review of the unpublished
information, the recoveryplan may be appended, revised orupdated.
Issue:The recovery plan is too general to meet thespec~ficcriteria at 16 U S.C.
1533(1).The unusable scale of the essential habitat map was intentionally vague
and fails to meet the site speqfic standards for describing management actions
necessary for recovery.
Response:Section 4(f)of the Act requiresthat recovery criteria be measurable
and site specific,with estimates of associated time frames and costs.We believe
that these requirementshave been satisfied.The scale of the draft essential habitat
map in the draft recovery plan wasdesigned to portray a specific concept outside
and alongthe urban interface based on bighorn habitat requirements and
principles of conservation biology.The draftmap was designed to elicit input
from interested parties sothat the final map couldbest reflect the concerns of
local interests. Weelected not to depict draft essential habitat in the draft
223
recovery plan at aparcel specific scale because it would have engendered
unnecessary and unproductive controversy and suggested a predetermined
outcome.We scheduled numerous meetings with all local jurisdictions and major
landowners to refine the boundaries along the urban interface.As described
below under the Essential/Critical Habitat section, consensus amongFederal,
State,and local governments was achieved alongthemajority of the urban
boundary.
Issue: A recovery plan is unnecessary ~fbighorn sheep in the Peninsular Ranges
are synonymous with the Nelson ‘s subspecies.
Response:Section 4(f)of theAct requires preparation of recoveryplans for listed
species wheneverprudent. This comment implies that bighorn sheep in the
PeninsularRanges do not comprise an entitythat canbe listed under the Act.
Pleaserefer to the Federal Register Notice,dated March 18,1998,aswell as
section l.A.1.of the recovery plan, for a discussion of the applicability of our
policy on implementing the Act’s provisions for listing distinct vertebrate
population segments.
Issue:The Fish and Wildlfe Service ‘s authority and intended use of the
“Recommended Conservation Guidelines”in Appendix F is not apparent.
Furthermore,the guidelines appear intended to restrictthe power and override
thelegislative authority of lead agencies.
Response:The Fish and Wildlife Service and Department of Fish and Game
prepared these guidelines to assist local governments in their implementation of
the California Environmental Quality Act and landuse decision making,not to
usurp the discretion of other governmental agencies.It is our intention to provide
consistent guidance as early as possible in the decisionmaking process sothat (1)
our recommendations do not come as a surprise later on in the planning process,
and (2)projects canbe designed to accommodatethe habitat requirements of
bighorn sheep.
224
PROCEDURAL IS SUES
Issue:The bibliograpiw contains many blanks for theauthors names,indicating
that such information cannot be relied upon.
Response:The blank lines in place of thename of an author is a bibliographic
convention that indicates thesame author asfor thepreceding reference.In the
final plan the bibliographic format has beenrevised to show full references.
Issue.The recovery plan should describe how the public will track agency
implementation of recovery tasks,be involved in prioritizing lands to be acquired,
be involved in future modifications to recovery criteria,comment on land
exchanges,etc.Similarly,thedraft recovery plan did not ident~fr how entities,
such as local government,were expected to fulfil!assigned task responsibilities in
theImplementation Schedule.The recovery tasks often lack site spec~city and do
not ident~fy applicable mechanisms or responsible entitiesfor implementing the
tasks.For example,the habitat protection objective for task 1.1 does not describe
who,how,or where the action would be completed.As a result,affectedparties
have been prevented from providing meaningful review of the recoveryplan.
Response:Thepublic can track implementation by communicating directly with
the agencies assigned to implement specific tasks.Progress and updates should
be incorporated into the public education and outreach programs recommended in
the recovery plan. The public may also track the extent of appropriations
allocated by legislative bodies as an indication of agencycapability for
implementing the recovery plan.Local governments should interpretthe recovery
plan as guidance for contributing to the recoveryprocess. Many of the provisions
in the recovery plan should be implemented through the regional habitat
conservation plan sponsored by the CoachellaValley Association of
Governments. This plan represents a stakeholders group that provides an
opportunity for involvement by all interests.Any of the recovery tasks that apply
to respective jurisdictions should be viewedas an opportunity to cooperatively
participate with other agencies in the common goal of bighorn sheep recovery.
We encourage local governments to use their applicable authorities for
conservation/management of open space in the furtherance of bighorn recovery.
225
Participating agencies canprovide moredetailed guidance on theroles and
responsibilities of local government as case specific questions arise.If the
recoveryplan is updated or revised in the future,the public will be given another
opportunity to comment on the plan.
Issue:The recovery plan should contain an economic impact analysis to estimate
the costs of recovery.The total estimatedcosts of recovery implementation
should be determinedand provided to the public for comment beforethe recovery
plan is approved.Projected funding levels for monitoring appear inadequate;~fa
long-term monitoringprogram is needed,why are costs projectedfor only 5
years.
Response:Though an economic impact analysis is not required by law or
regulation, section 4(f)of the Act requires an estimate of costs to achieve
recovery.We haveprojected total costs based on a rough estimate of 25 years to
recovery,with moredetailed cost estimates for the first five years.Certain costs
aredifficult to estimate accurately without detailed scopes of work,real estate
appraisals,etc.As a result,cost estimates in the Implementation Schedule should
be viewed asapproximations that inform the public and participating agencies
about the resourceestimates necessary to achieve the recovery objectives of the
recovery plan.
Issue:The recovery plan should describe thestudy areasfor all research
conducted in the Peninsular Ranges.
Response:The reader should refer to the references cited to obtain more detailed
information on the study methods of literature cited in the recovery plan. The
purpose of this recoveryplan is not to compile and summarize all research
conducted in the areaat issue.
Issue:Reliance upon forthcoming planning efforts,such as the Coachella Valley
multispecies plan to address immediate bighorn sheep conservation needs,
unnecessarily defers actions needed to avertthe near-term risk of extinction.
226
Response:We are not aware of any suchdeferrals and intend to use our legal
authorities under sections 4 (designation of critical habitat),7 (interagency
consultation),and 10 (habitat conservation planning)whenever appropriate during
the interim period while theCoachella Valleyplan is in preparation.
Issue:The recovery plan should critically examine past management mistakes so
that they are not repeated in the future.
Response:Much of therecovery plan reflects on thepast (e.g.,section I.D)and
looks to the future (e.g.,section II.D).Many of the Recovery Team members
havemany years of experience in the PeninsularRanges and,therefore,have a
solid historical perspective.A focused,intensive historical inquiry likely would
result in arguable conclusions of dubious merit that could adversely affect current
interagency cooperation.The purpose ofrecovery plans is to assess the current
situation with a view towards future feasibility of implementing needed
conservation actions.
Issue:Many of the tables were not as descriptive as they could havebeen
because (1)thetables excluded potentially available data,such as from years
before orafter those presented in the tables,and (2)statistical analyses were not
conducted.
Response:In some instances,more recent datawere not available;in other cases,
data from earlier years were not comparable because of different data collection
methodologies;and in othercircumstances,available data have not yetbeen
compiled and analyzed.Inmost instances,statistical analyseswere not included
because this information wasprovided in the references cited and because the
purpose of recoveryplans is more informative and prescriptive than analytical and
quantitative.
Issue:The recovery plan should discuss the financial situation of the Bighorn
Institute,along with a detailed critique of overall operations.
Response:Financial issues associated with the Bighorn Institute are not a concern
of theFish and Wildlife Service or cooperating agencies.Overall operations
227
regarding research and captiverearing have beenthe subject of annual reviews by
the California Department of Fish and Game prior to Federal listing and now fall
under thepurview of section 10(a)(1)(A),not section 4(f)of the Act.
Issue: A repositoryfor all data collected on bighorn sheep should be created and
made available to the public at large.
Response:Creation of such a repository would not be possible unless agencies
and researchers donated proprietary information and personal property.The
concept poses numerous legal,economic,and administrative issues that exceed
our authorities and those of cooperating agencies.
Issue:Numerous comments requested theFish and Wildl~fe Service and
cooperating agencies to conduct additional research and further analyze data not
in their possession before issuing a recoveryplan.
Response:The Act’s mandate to use the best available informationdoes not
require us to conduct additional research or obtain unavailable data as a
prerequisite to preparing and completing recovery plans.A court stipulated
settlement agreement requiredcompletion of the recovery plan under an
established schedule.
Issue:The draft recoveryplan focuses excessively on habitat conservation
insteadofpopu!ation recovery;the various problems should be dealt with in
order of importance.
Response:As described in thedraft and final recoveryplans,multiple,apparently
cumulative factors are depressing population levels, with contributingcauses
differing among ewe groups.The relative importance of factors affecting
reproduction,recruitment,and adult survival arepoorly understood in some ewe
groups, though intensively studied in others.These complexities make itdifficult
to determine relative importance and management priority.Therefore,we have
and will address concurrently all probable factors affecting individual ewe groups
to the extent possible.If thehabitat base upon which bighorn sheep depend is not
228
protected,sufficient space willnot be available to support “recovered” population
levels.
Issue:The Fish and Wildlife Service should list credentials of Recovery Team
members.
Response:By practice and for consistency,we do not provide this information
regardingteam members. Members were selected for a variety of skills and
experiences that may not be apparent from brief synopses.
Issue:The Fish and Wildl~fe Service rejected,without explanation,many
comments provided by Recovery Team members themselves.Disagreements
within the team should be discussed in the recoveryplan.
Response:The various views heldby members of the team were discussed openly
at team meetings until a consensus emerged.Various iterations,including the
final recoveryplan, havebeen reviewed multiple times by team members,and all
comments have been incorporated intotherecoveryplan directly or after group
discussion where furtherconsideration was warranted.We are unaware of any
significant scientific disagreement within the team regarding the content of the
recoveryplan. Regardless, the Fish and Wildlife Service and cooperating
agencies assume ultimate responsibility fortherecovery plan,inasmuch as
Recovery Teams function asexpert advisors to theFish and Wildlife Service.
Issue:The peer review process of thedraft recovery plan was flawed,failed to
address all the issuesraised and to follow academic protocol,and therefore,
should not be referred to as peer review.The draft recovery plan misleads the
public into thinking that the peer reviewers endorse the draftplan.
Response:Thepeer review process referred to in the draft recovery plan
represented separate technical and agency reviews prior to public release and was
not intended to follow academic protocols.Though most of the comments
received by the technical (peer)reviewers were addressed in the draft recovery
plan, thedraft recoveryplan did not claim that the reviewers necessarily agreed
with or endorsed the plan.The Recovery Team and Fish and Wildlife Service
229
have included and addressed in this list of issues and responses all substantive
comments submitted by technical reviewers not otherwise incorporated into the
draft or final recovery plans.
Issue:Research tasks in the recovery plan should identify testable hypotheses.
Response:The Recovery Team is not a research team;therefore,this recovery
planrepresents a general strategy for recovery that identifies major research topics
that should be pursued.It would not be appropriate to propose various
experimental designs and hypotheses at this time because the additional level of
analysis required should more properly occur whendetailed research proposals by
individual researchers are prepared.
Issue:The Recovery Team should include a trained land use planner to improve
the effectiveness of coordinating conservation activities with localjurisdictions,
such as the cities and counties.
Response:One of the current Recovery Team members has an extensive
backgroundin land use planning,havingworked in that capacity fornumerous
jurisdictions for many years.In addition,several other members workroutinely
with local government in land useplanning matters and have a thorough
understanding of legal and procedural requirements needed to coordinate effective
interagency conservation programs.
ESSENTIAL/CRITICAL HABITAT ISSUES
Issue:All localjurisdictions should be extendedthesame opportunity asthe
Indian tribes in determining essential habitat boundaries.Failure to do so will
doom the recovery planning effort.
Response:Federally recognized Indiantribes enjoy a special relationship and trust
privileges under numerous executive,legislative,and judicial mandates not
extended to non-Tribal entities.Nonetheless,withinthe context of the Coachella
Valley multispecies planning program, the Fish and Wildlife Service and
California Department of Fish and Game convenednumerous meetings with city
230
and county governments to discuss and refine essential habitat boundaries in a
process similar to that used with the tribes. TheFish and Wildlife Service,
Department of Fish and Game, and local jurisdictions achievedagreement along
virtually the entire urban boundary except for about six proposed project sites.
TheFish and Wildlife Service and Department of Fish and Gamewill attempt to
resolveresidual differences for each of the proposed developments through
individual regulatory actions.
Issue:The suggested 20 percent slope delimiting lower elevational boundaries in
most cases liesbelow the 213-meter (700-foot)lower elevation limit described
elsewhere in the recovery plan as the lower elevational limit ofsheep distribution.
The essential habitat line should be set along the 213-meter (700-foot)elevation
contour from Palm Springs to La Quinta,which would avoid lambing and
wateringareas and provide opportunities for unrestricted hiking.Essential
habitat should not extend onto the valleyfloor farther than existing wilderness or
the proposed National Monument boundary.The map appears to represent a no
growth effort that would extort extreme mitigation from developers.
Response:The213-meter (700-foot) lower elevational limit of sheep distribution
typically corresponds to the urban interface atthe northern end of the Coachella
Valley,whereas in the southern end of the valley,the urban interface occurs along
lower elevational contours.As described elsewhere,sheep in the Peninsular
Ranges are adapted to survive at lower elevations and depend on lower elevational
slopes and alluvial habitats for important resources.The extent of suitable habitat
is influenced by soils,aspect, and other topographic features that do not
necessarily correspond with fixed elevation contour lines,or wilderness and
proposed monument boundaries,which were established for a variety of reasons
apart from the habitatneeds of bighorn sheep.
Issue. Habitat compensation should not be required for development adjacent to
sheep habitat because development of thesefragmented areas would not affect
sheep.
Response:Most of the proposed development alongthe urban interface occurs
within, rather than adjacent to, sheep habitat. As discussed in therecovery plan,
231
bighorn sheep in thePeninsular Ranges spend much of their time at lower
elevations, where otherwise scarce resources,such as food and water, commonly
occur. Flatter topographycontainsmore productive alluvial soils that support
more diverse and nutritional foodsources than occurs on steeper, rockier slopes.
Though alluvial habitats are more fragmented by urban development,these
smaller patches still support habitat value,though much reduced from historical
conditions.Development of habitat fragmentsalso indirectly affects sheep by
supporting a largerhuman population that increases the amount of disturbance in
adjoining sheep habitat.As long as suitable habitat conditions exist within the
historical range of the species and development results in indirect adverse effects
to sheep in nearby habitat,local governments have a mitigation nexus under the
California Environmental Quality Act.Mitigationmeasures can be designed to
conserve larger patches of comparable value habitatby requiring offsite habitat
replacement, thereby contributing to theconservation of sheep even if smaller
habitat fragments arepermitted for development. To contribute to recovery,we
recommend that local governments consideroffsite habitat replacement for
permitted development of residual habitats between the essential habitatboundary
and 800 meters (2,624 feet)from toe of 20 percent slope.
Issue:Proposed designation of essential habitat requires adequate legal notice to
landowners in the vicinity of ha bitat proposed for conservation so that an
opportunity to comment on the proposal is provided.The public comment period
should be opened indefinitely until essential habitat is displayed on detailed
aerialphotography and has been made available for public comment.A more
detailed map of essential habitat then should be provided for public comment
before the recovery plan is completed.
Response:TheFish and Wildlife Service broadly announced a 45-day public
comment period on the draft recoveryplan (64 FR 73057; December 29,1999),
which was extended an additional week as a convenience to the public.This
noticing process fulfilled all legal requirements.As described above,the Fish and
Wildlife Service coordinatedwith affected interests in soliciting input and
promoting discussion to achieve consensus on the essential habitat boundary.
232
Issue.The draft recovery plan does not adequately describe theimportance of the
Mount San Jacinto State Park to sheep recovery.
Response:The park is largely located above the elevationwhere bighorn sheep
normally occur.
Issue.~The essential habitat map should model food and water resourcesas was
done for physiography.
Response:Food and water resources generally are too dynamic to quantify
because their distribution is a function of unpredictablyvariable rainfall patterns.
For example,randomly occurring thunderstorms do not provide uniformly
distributed moisture regimens throughout sheep habitat but ratherresult in
localized green-up followinghigh intensity,short durationprecipitation events.
Sheep typically respond to these sporadic events by exploitingephemeral sources
of food and water.Patterns of sheep distribution relative to perennial water
sources havebeen analyzed and discussed in Appendix B.
Issue:The draft recovery plan did not identify the spec~fic projects previously
approved by the Fish and Wildl~fe Service that would be excluded from areas
mapped as essential habitat.Essential habitat should be designated on areas
previously approved by theFish and Wildl~fe Service for development Wscient~fic
data indicatethese areas should be part of critical habitatfor recovery.Essential
habitat should include not yet constructed projects thathave been previously
approved by the Fish and WiIdl~fe Service because these areas are neededfor
sheep recovery.
Response:TheFish and Wildlife Service completed section 7 consultation on the
Ritz-Carlton Golf Course and Mirada development prior to release of the draft
recoveryplan,and completed section 7 conferences on the Jimenez Pit,Cahuilla
Zone Reservoir,and Shadowrock projects prior to listing.TheFish and Wildlife
Service and project proponents agreed to reconfiguration ofproject designs and
other conservation measures on the former four projects.Agreement on the latter
project has not been achieved and the affected area is considered essential habitat
233
unless theproject is reconfigured to be consistent with the section 7 conference
opinion.
Issue:Critical habitat should be designated even fit divulges locations and
consequently exposes sheep to harm.
Response:On July 5,2000,theFish and Wildlife Service published a proposed
rule (65 FR 41405)to designate critical habitat under a separate process pursuant
to a recent settlement agreement with theplaintiffs who challenged our not
prudent finding that accompanied the listing.This topic wasdiscussed in the
proposed rule.
Issue.The recovery plan should describe therelationship of essential habitat and
critical habitat from a regulatoryand procedural perspective.
Response:Though the two designations are similar in their focus on defining
future survivaland recovery needs,they differ significantly from a regulatory
perspective. Forpurposes of this plan,essential habitat is an informative
designation intended to provide scientificguidance to cooperating agencies and
the public,while critical habitat is statutorily defined with implementing
regulations that govern Federal agency activity.Critical habitat receives
protection under the Act through the prohibition against destruction or adverse
modification of critical habitat as set forth under section 7 of the Act with regard
to actions carried out,funded,or authorizedby a Federal agency.Aside from the
protection that maybe providedunder section 7,the Act does not provide other
forms of protection to lands designated as critical habitat.Critical habitat
designation does not impose any restrictions to activities on private or othernon-
Federal lands that do not involve aFederal permit,authorization,or funding.The
process for designating critical habitat is distinct from the process forcompleting
the recoveryplan. A proposal to designate critical habitat for thePeninsular
bighorn sheep was published in the Federal Register on July 5,2000 (65 FR
41405). The essential habitat mapped in the recovery planhas the same boundary
as the proposed critical habitat,with slightdiscrepancies introduced by a legal
description for critical habitat along boundaries imposed by a
township/range/section coordinate grid.
234
Issue: Undeveloped but fenced property should not be mapped as essential
habitat.
Response:Areas that can be enhanced or restored areincluded as essential habitat
if theyare necessaryfor recovery.Fencing often does not establish an effective
movement barrier to sheep, though it can cause entanglement,injury,and death.
The Fish and Wildlife Service advises that fences constructed to exclude bighorn
sheep couldresult in take if built atthe wrong location or improperly designed.
Issue:The recoveryplan should provide more spec{fic guidelines to local
jurisdictions for conserving habitat and reducing the effects of urbanization.For
essential habitat to be effective,therecovery plan should provide guidance on
future regulation of take undersections 7 and 10 of the Act,which should
spec (17cally prohibit authorization offuture take f ewe group population levels
drop below predetermined thresholds and/or populations increase to a point
suggesting progress towards recovery.For example,the threshold approach used
for predator management also could be applied to habitat loss.
Response:Appendix Fwas designed to provide general guidelines that would fit
most projects in or adjacent to sheep habitat.More specific guidelines would be
difficultwithout a caseby case analysis of individual projects. The Fish and
Wildlife Service cannot use recoveryplans to predetermine future regulatory
decisions under sections 7 and 10 because the Act did not envision recovery plans
as a regulatory mechanism.
Issue:The draft recovery plan places inordinate importance on land use controls
and too little emphasis on reducing predation pressure. By failing to manage
threats under its control,such as predation, theFish and Wildl~fe Service unfairli’
shqis onerous regulatory impositions onto private property owners.Another
commenter claimed that theacknowledged lack of understanding concerning
factors limiting population viability undermines the credibility of the proposed
land use controls,and that theuncertaintyover adverse effects of urban
development eliminates any nexus for governmental regulation.
235
Response:The Fish and Wildlife Service intends on concurrent implementation
of numerous recovery tasks commensuratewith available funding.Completion of
the recovery plan provides a basis for increased funding allocations to cooperating
agencies.Because numerous factors are depressing population growth, it would
not be appropriate for theFish and Wildlife Service and cooperating agencies to
attempt to prioritize threats and address only one at a time. Focusing solely on
predator control and allowing continued loss of valuable habitat would be based
on a theory that habitatlossdoes not adversely affect bighorn sheep.The
available evidence suggests the opposite.The ewe groups adjoining metropolitan
areas historicallyhave declinedto a greater degree and currently are more severely
threatened with extirpationthan more southerlyand remote ewe groups that have
not sustained substantial loss of habitat in the past.
Issue:The draft recovery plan does not adequately identify the specific lands
mapped as essential habitat and targets all available habitat without scientflcalh’
analyzing whetherportions of the area support any suitable habitat at all.
Response:Appendix B presents a habitat model that analyzed a variety of habitat
characteristics based on information in the scientific literature and distributional
data throughout thePeninsular Ranges.Areas with unsuitable soils and
topography were excluded,as were areasgreater than 800 meters (2,624 feet)
from toe of 20 percent slope,though sheep are known to use these areas.Based
on the wide-ranging movements of sheep in the Peninsular and other ranges
throughout the desert southwest, sheep are known to use a broad range of habitats
in desert environments.None of the areas mapped as essential habitat contains
soils,vegetation,or topography that is unsuitable for use by sheep.Though sheep
maynot use or occur in certain areas as frequently when population sizes are
small and distribution is more constrained,it is sometimes difficult to track sheep
movements, especiallywhen only a small percentage of certain subpopulations
have radio collars.Thus,theknown distribution is always an underestimate of
actual distribution.
Issue:The designation of “essential habitat”is an illegal subterfugefor avoiding
the statutory requirementfor designating critical habitat and analyzing
consequent economic effects.
236
Response:Aproposal to designate critical habitat for thePeninsular bighorn
sheep waspublished in the Federal Register on July 5,2000 (65 FR 41405),under
terms of the settlement agreement referenced above.A notice of availability for
the drafteconomic analysison proposed critical habitat designation was published
in the Federal Register on October 19,2000 (65 FR 62691).
Issue:Numerous land owners requested that their lands be specifically removed
from areas designated as essential habitat because ofthe significant social and
economic impacts that should be minimized per existing Fish and Wildlife Service
policy on recovery planning.
Response:As discussed above, the Fish and Wildlife Service has met with many
landowners and agencies in an effort to refine the essential habitatboundary so
that social and economicimpacts are minimized to the extent that thepotential for
recovery is not compromised.These discussions resulted in substantial agreement
with all parties involved over the vast majority of the urban interface. The
resulting essential habitat boundary was designed to minimize economicconflict
to the extent consistent with maintaining the likelihood of future recovery.
Essential habitat differs significantly from critical habitat.Under critical habitat,
exclusions are a procedural outcome of applying section 4(b)(2) and/or “special
management”under the Endangered Species Act.Under 4(b)(2), economicand
social impacts are evaluated. However, there is no such process identified for
exclusions for essential habitatbecause recovery plans arenonregulatory
documents designed to guide, not dictate,recovery of the species.
Issue:The draft recovery plan was deficient because it did not quant~fy the
acreage ofdiferent landownerships,historical distribution,and extent of
proposed essential habitat.
Response:Acreages were not calculated in the draftrecoveryplan because an
updated landownership mapwas not available and aprecise boundary along the
urban interfacewas not delineated. In the finalrecovery plan,land ownership is
delineated with respect to essential habitat in Figure 4;however,the land
ownership map is somewhat outdated and any acreage figures would be
approximate.Approximate land ownershippercentages aresummarized in
237
Section I.E.of the plan.Historical trends along theurban interfaces are
summarized in Section D.1.
Issue:Lands that historicallynever were used by sheep should be identified.The
term “unoccupied habitat”is scient~ficallv undefined and inappropriately used to
describe unsuitable habitat from which bighorn sheep are absent.
Response:Historical information prior to the use of aerial surveys and radio
telemetry is of limited utility because the rugged topography and lack of roads
throughoutthe Peninsular Ranges greatly restrictedthe extent of access on the
ground.Therefore, it is not possible to reliablyconclude that certain areas were
not used historically. Similarly,given the relatively small sample size of radio-
collared sheep at present,especially rams (which are far more wide ranging than
ewes), more recent data cannot be properly interpreted to conclude that sheep are
absent from certain areas.Therefore,the remaining undeveloped portions of
historical range constitutethe current distribution of bighorn sheep in the
Peninsular Ranges.Use of theterms “occupied~~, “unoccupied~~,“suitable”,and
“unsuitable”, aremore conceptual than empirical.Thus,theseterms add little to
our understanding of sheep biology,and as aresult, the final recovery plan avoids
use of this terminology.
Issue: Given the tendency of sheep to not venturefar from escape terrain,
justification in the recovery plan is not adequate to support the need for habitat
up to 0.8 kilometer (0.S mile)from toe of 20 percent slope.Twenty percent slope
does not represent effective escape terrain;therefore,a steeper slope should be
usedfor ident{fying habitat in need of conservation.The recoveryplan does not
adequately describe what constitutes a movement corridor on thedesert floor.If
sheep avoid human disturbance,thefragmented habitat patches on the desert
floor within the urban matrix would appear to have low habitat valuefor sheep.
Response:Though sheep typically are found in steeper terrain,numerous records
exist in the Peninsular Ranges and elsewhere of occurrences over 0.8 kilometer
(0.5 mile)from escape terrain.The 0.8 kilometer (0.5-mile)distance was selected
to capture the more typical movements onto the alluvial slopes.The 20 percent
slope forescape terrain was takenfrom thepublished literature.As discussed in
238
Appendix B,a range of slopes have been recognized by various authors as escape
habitat. Flatter topography encompasses moreproductive soils that support more
diverse and nutritious forage that is seasonallycritical to sheep.Flatter
topography also canbe importantfor dispersal and for sources of seasonal water.
Sheep in other areas of the desert southwest have been knownto movemany
kilometers across the desert floor to reach neighboringmountain ranges.Given
the limited number of documented movements of this kind,not enough is known
to delimit linkage dimensions.Rams are especially prone to use flatterareas
farther removed from escape terrain.Ruggedness on flattertopographycan
function as escapehabitatbut hasbeen difficult to measure and account for in
studies published to date.The essential habitat map excludes the less frequently
used and lower value habitats characterized by small patch size and proximity to
human disturbance.
Issue: Designation of essential habitat as proposed would restrict access for
construction and maintenance of infrastructural facilities like flood control and
water supply.Flood controlfacilities should not be included in essential habitat
because any use by sheep is incidental to the primary purpose of these lands.
Response:Case by case project reviews under the regulatory provisions of
sections 7 and 10 of theAct will detennine whether construction of infrastructural
facilities are compatible with sheep survival and recovery.Based on discussions
with Riverside County Flood Control and Water Conservation District and
Coachella Valley Water District,normal operations and maintenance of existing
facilities would not conflictwith themanagement objectives for essential habitat.
Flood control facilities typically occur in washes and alluvial habitat that have
been most affected by historical habitat losses and often still support the same
important habitat values as the surrounding areas.As such, these facilities are not
defacto unsuitable or detrimental to sheep use.If reasonably managed,these
areas can fulfill their intended function while atthe same time not conflicting with
sheep use in the area.
Issue:The recoveryplan does not discuss the possibility that past habitat loss
from urbanization in the San Jacinto and northern Santa Rosa Mountains may
239
have resulted in irreversible population declines,rendering essential habitat
designation in this area potentially useless.
Response:The recovery plan strives to intensify management efforts to offset the
loss ofhistoric habitat,and thereby maintain functional population levels in the
future.If populations become extirpated and theRecovery Team and cooperating
agencies determine that habitat areas are no longer capable of supporting self-
sustaining populations, future revisions of the recovery plan maydelete essential
habitat and management objectives for those areas.
BIOLOGICAL ISSUES
Issue: One commenter thought that the eyesight of bighorn equaling that of
humans aided by 8-power binoculars should be emphasized.
Response:According to Geist (1971),scientific evidence is not available to
support this popular myth, which probablyoriginatedwith the experiences of
hunters with the species.
Issue:The regular sightings of bighorn sheep in Chino Canyon and Tachevah
Canyon alleged by Fish and Wildlife Service biologists appear inconsistent with
portions of the draft recovery plan that state bighorn sheep vanished from the
northern San Jacinto Mountains after construction of the Palm Springs Aerial
Tramway.
Response:Though rams still rangenorth of Chino Canyon,ewes havenot been
documented in the northern San Jacintos (north of Chino Canyon) since the late
1980’s.The tramway was constructed in the earlyto mid-1960’s.
Issue:The high number of undetermined causes of death indicates that a better
explanation is needed of how the deaths were discovered and how thecauses were
diagnosed.
Response:Most deaths were discovered from radiocollared animals because the
fate of uncollared animals is far more difficult to ascertain.When dead animals
240
are found, the cause of death is sometimes difficult to determine because in many
cases,coyotes and other scavengers have consumed the carcass so thoroughlythat
the original cause of death (whether predation or not) cannot be determined.
Issue: Some commenters thoughtthe recovery criteria of 25 ewes per 9 ident~fied
regions and an average of 750 adults for delisting is too low to assure survival
and recovery,and that theestimated rangewide carrying capacity of 1,000 sheep
appears low.Another commenter thought the criteria requiring a minimum of 25
ewes in each ewe group would be too dfftcult to achieve.
Response:The team and agencies decided that it would be difficult to justify a
higher population level than wasknown historically,especially giventhe
extensive habitat loss and fragmentation,and other factors that likely have
reduced carryingcapacity over time.Team members most familiarwith the
Peninsular Ranges assessed current and historic habitat quality,and made regional
comparisons with otherbighorn sheep habitats in estimating current conditions
and carrying capacity.The 9 regions were deemed capable of supporting in
excess of 25 ewes, with the carryingcapacityin most of theregions substantially
exceeding the minimum.Because 750 is an average figure,it would be necessary
for thepopulation to rise above that level forsome period of time,likely in
response to changingcarrying capacity.The averaging criterionwas selected
because it allows natural population fluctuations and management flexibility.If
the long-term carrying capacityexceeds 750 animals, the population likely would
exceed the 750 minimum established in the recovery plan.
Issue:The operations by theBighorn Institute are contributing to thedecline
instead ofthe recovery of bighorn sheep.Alternative methods,such ason-the-
ground surveys,should be used for estimating population size and distribution,
instead of more highly disruptive helicopter flights.Helicopter censuses and
captures arefar morestressful to sheep than researchers,hikers, and riders
quietly moving through sheep habitat.
Response:The Bighorn Institute conductshundreds of days of on-the-ground
work and only about 6 days of helicopter work each year.Conducting on-the-
ground studies is often not feasible on private property and could result in
241
significant disruption to sheep if implemented at a level needed to estimate
population distribution and abundance at precision levels comparable to aerial
techniques. Even at current levels,on-the-ground disturbance associated with
research activities could be detrimental if not for rigorous safeguards.For
example,Bighorn Institute biologistsregularly document through radio telemetry
that their presence “bumps”or “pushes”sheep in flight away from them,atwhich
point the field methodology requires backing off, which often prevents the
recording of field data.
Issue.Why is agricultural useadjoining bighorn sheep habitat considered a
more compatible use,whereasresidential and resort developments are not?
Response:Agricultural activities do not generate thehigh levels of secondary
impacts,such as humanrecreation in adjoining habitat, as is typically associated
with urban land uses.In addition,agricultural lands can be restored to sheep
habitat,whereas urban land uses can not.Though agricultural lands were
excluded from delineated essential habitat, several Recovery Team members
recommended they be included because of their restoration potential.
Issue: Numerous commenters inquired whether studies have been conducted and
evidence exists for the presence of bighorn sheep on their lands.
Response:We have included a mapwith known locality records to providea
better indication ofbighorn sheep distribution. References cited throughout the
recovery plan should be perused to determine study areas and methods. The lack
of records for certain areas doesnot necessarily indicate that sheep are absent,
only that their presencehas not been documented.
Issue:The slow reproductive rate and long-term estimates for recoveryshould be
accelerated by importing sheep to increase population levels.
Response:Unless the factors that limit population growth in the Peninsular
Ranges are addressed,it is unlikely that a program to introduce animals from
outside areas would be successful.However, alleviating in situ decimating factors
would allow theresident population to expand on its own, which would forego the
242
need for translocation.Importing animals also poses risks of disease
transmission. Regardless,bighorn sheep populations throughout the Mojave
Desert arecurrently depressed to the extent that surplus animals are not available
for importation.
Issue:Given the history ofpopulation declines in regions adjoining urban areas,
it does not seem plausible for therecovery plan to claim that Peninsular bighorn
sheep have a high potentialfor recovery.
Response:The recovery plan attempts to build on past examples and taking
action soon enough to reversethe decline of sheep in our mountains.The
Recovery Team and cooperating agencies believethat the recovery potential is
high if themanagement recommendations in the recovery plan are implemented.
Issue:The further research and planning required through the captive rearing
and augmentation guidelines in Appendix C does not recognize or expedite the
immediaterecovery needs and issues thatmust be addressed in theshort-term.
After many years of operation,these issues should already have been addressed
and a plan ready to implement.
Response:The existing operations of the Bighorn Institute are reviewed annually
by the agencies and adjustments made if needed.Captive breeding forpopulation
augmentation,population monitoring,and research have been and continue to be
the primary emphases until changes in direction are agreed to by the Institute,
agencies,and Recovery Team.
Issue:One commenter suggested that thedraft recovery plan was deficient
because a recent discovery of a desert bighorn sheep population in Ventura
Countywas not addressed.
Response:Sheep populations in Ventura County arenot included in the distinct
population segment listed in the Peninsular Ranges and, therefore, arenot relevant
to the recoveryplan.
243
Issue:Because bighorn sheep are wilderness animals,moreemphasis should be
place on conservation efforts in Anza-Borrego Desert State Park,instead of
urbanizing Coachella Valley,where prospects for success are less than in more
remote areas.
Response:Numerous subpopulations arenecessary to maintain the larger
Peninsular Ranges metapopulation.Therefore, recoverywill require protection of
all areas needed to maintain theconstituent subpopulations.This protection will
require increased management emphasis and cooperation among land managers in
urbanized areas.
Issue:The limited dispersal and colonization capabilities contradict statements
elsewhere in the recovery plan that bighorn sheep are wideranging animals
dependant upon large tracks of habitat.
Response:True,each individual is a wide-ranging animal with a relatively large
home range.This behavior and knowledge of these areas is learned by the
offspring, which is transmitted across generations.Though colonizations of new
habitat are known to occur,theyare not a common event.Rams are more wide-
ranging than ewes and areknown to move between mountain ranges and ewe
groups.
Issue:The draft recoveryplan does not clearly indicate how or whether models
would be used to assist in gaining a better understanding of the interacting
factors that place sheep at risk.
Response:Models are a tool that help assimilate knowledge and understand
factors that place bighorn sheep at risk,for later application through management
prescriptions.Models should be used anytime theycan helpus to better
understand bighorn sheep population dynamics,genetics,or ecosystems.Though
the recovery plan provides examples of high priority issues that should be
examined with models, the points atwhich a model would be appropriate are
difficult to predict.Modeling is included in the section on research because it is
an ongoing process that willhave to be applied and modified as questions arise
and more data become available.
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Issue:The recovery plan is biologically inconsistent,arguing on the one hand
that human disturbance in wild areas causes them to avoid otherwise important
habitat but on the hand arguing thatfences are needed to prevent sheep from
being attracted to urban areas.
Response:Bighorn sheep reactdifferently to various kinds of disturbance
dependingon numerous factors,including location.The northern Santa Rosa
Mountains ewe group is the only herd that has habituated to using the urban
interface, yet when in wild habitat distant from theurban edge, these same sheep
react similarly to nonhabituated herds—that is,individuals revert to normal wild
behavior when away from the urban edge.Thereaction is perhaps most
pronounced during the lambing season,when ewes with lambsare frequently
displaced by human disturbance.This effect has been repeatedlydocumented
through radio telemetry research,where sheep are sometimes inadvertently
“bumped”or “pushed”fartheraway by researchers,even though the sheep are still
hundreds of meters distant and not visible to theresearchers. In other words,
behavioral reactions often depend on geographical and seasonal context,with the
spectrum of contrasting responses to human stimuli most clearly evident within
this ewe group.
PREDATOR CONTROL ISSUES
Issue:Radiocollars may render sheep morevulnerable to predation and
therefore should not be used as prevalently as they are today.
Response:We are not aware of data that indicates radiocollared animals are at
greater risk of predation than uncollared animals.Nonetheless,cooperating
agencies have attempted to balance the number of radiocollarsto minimize
potential risk without compromising information needed to achieve population
recovery.
Issue:Whereas one commenter asserted that the proposed predator management
measures were too laxand should be more aggressive in termns of moving
predators from the area before they become an issue,another commenter claimed
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that scientflc evidence was sufficient to indicate that mountain lion predation was
not a problem and that management measures,therefore,were not warranted.
Response:This issue was discussed vigorouslyby the team and agencies.
Because documented mortalities were particularly high in certain ewe groups, the
team and agencies decided the prudent course of action dictated a measured
management response,which would be modified as more data became available.
Issue.Predator management should be given higher priority than land
management restriction because mortality to predators is the more likely limiting
factor on bighorn populations.
Response:The draft recovery plan and available evidence indicate that individual
subpopulations are affectedby a variety of influences that affect population levels
and that the combinations and relative strength ofthese influences typically differ
among ewe groups and change over time.Therefore,the recovery plan focuses on
the range of threats facing bighorn sheep.The recoveryplanprescribes
predetermined criteria for initiating predator management and recognizes the
importance of habitat protection so that recovered populations havesufficient
space to inhabit.
Issue:The long-term decline in habitat quality and deer populations in the Santa
Rosa Mountains should be identified as a cause of high levels of mountain lion
predation on bighorn sheep,with a strategy to reverse the situation.The recovery
plan should more clearly establish the relationship of bighorn sheep to mule deer
by superimposing a deer distribution map.
Response:Mule deer typically occur athigherelevations thanbighorn sheep,
though ranges may overlap regionally and seasonally,such as during the winter
when deer in some areasmove to lower elevations.Traditional predator/prey
theory holds that predator populations increase and decrease in response to
fluctuatingprey populations. However, there are no data indicating that high
levels of predation are due to declines in habitatquality or deerpopulations, or
whetherprey switching maybe occurring in the Peninsular Ranges.Because data
on habitat quality,as well as deer and mountain lion populations in the Peninsular
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Ranges arenot sufficiently robust to provideinsight into these questions,the draft
and finalrecoveryplans propose focused research to address this ecological issue.
Issue:The recovery plan does not provide compelling evidence thatthe
predator/prey system is not viable,and therefore,predators should not be
managed unless a cause and effect relationship with bighorn population declines
is established.
Response:The high incidence of predation,comparatively lower adult
survivorship ratesthan in other regions,and long-term population declines
suggest to land managers that predation is a limiting factorto population growth
in some areas of the Peninsular Ranges.The cooperating agencies haveagreed
that this evidence is sufficient to promptresponsible but cautious management
intervention.
Issue:One commenter argued that counter to claims in the draft recoveryplan,
the onlyavailable scientflc evidence indicates a declining trend in statewide
mountain lionpopulations.
Response:The evidence presented bythe commenter lacked associated statistical
analysis; therefore,the statistical resolution of the data cannotbe evaluated and no
-conclusion on population trend is possible.
TRAIL ISSUES
Issue:The constant presence of bighorn sheep along Highway 111 in Rancho
Mirage indicates human activities, such as hiking and jeep use,may not create
movement barriers,as suggested in the draft recoveryplan.Further information
is requested to support why back roads and trails are detrimental to sheep when
they are known to cross 6-lane highways (e.g.Highway 111 in RanchoMirage).
Response:The recoveryplan cites numerous studies that have documented
avoidancebehavior to human related disturbance (see Papouchis et al.1999 for
example).Numerous records of vehicular related mortality provide further
evidence of adverse effects.The recoveryplan seeks to remedythe maladaptive
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behavior of habituation to urban sources of food and water so that sheep arebetter
able to survive in thewild.
Issue: A trails map to clarfy and accompany Table 10 is needed.
Response:Though a good idea,an accurate trails map is not currently available.
The cooperating agencies arepursing the development of such a map.
Issue: Detailedmaps of lambing,rearing,and watering habitat are needed to
just~fyany decisions to close trails.
Response:The distribution of lambing,rearing,and watering habitat is
incompletelyknown and,therefore,cannot be accurately mapped. The final
recovery plan has been modified to include a more complete set of information
upon which trails decisions should be based.
Issue.’A permit system should be usedfor controlling trail use on all trails for
which conflicts were identified in the recovery plan.
Response:The cooperating agencies are working with interest groups in the
formulation of a range of alternative trails strategies that include this option.
Issue:The recovery plan should consider that in the San Jacinto Mountains,the
existing trails network appearsto provide a passive disturbance boundary that
may control sheep access to the urban interface and prevent exposure to the
urban hazards experienced in the northern Santa Rosa Mountains.Consequently,
seasonal or permanent trail closures could have unintended adverse effects.
Response:A trails management plan prepared by the land management agencies
and interest groups will considerthe merits of this comment.Certain adjustments
to the existing trails network and associated monitoring could be implemented to
improve upon this concept.
Issue: More specificity is needed in describing where human disturbance and
other indirect effects of urbanization is conflicting with sheep conservation.
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Response:Human intrusion and associated disturbance has the potential to extend
whereveraccess into habitat is provided.Though lambing and watering habitats
areparticularly vulnerable, excessive human use throughouttheyear may also
affect bighorn persistence.
Issue.’Will mitigation credits be given for the eradication of invasive non-native
plants?
Response:Conservation measures for proposedprojects will be determined on a
caseby casebasis through regulatory processes of local,State,and Federal
agencies.
Issue:The January through June trail conflicts in the San Jacinto Mountains
appear excessive if the lambing season there extendsonly through mid-March.
Response:The draft recovery plan stated on page 12 that DeForge et a!.(1997)
found a similar onset to the lambing season in February in the San Jacintos.
Cunningham found that lambing in CarrizoGorge extended only to mid-March.
Lambs are critically dependent upon their mothers for severalmonths after birth.
Issue:Rather than monitoring to ensure compliance withseasonal trail closures
before allowing construction of trail reroutes out of lambing habitat,the recovery
plan should allow simultaneous construction of alternative trail routes to enhance
the effectiveness of seasonal closures on existing trails in lam bing habitat.
Response:The final recovery plan has been modified to incorporate flexible
approaches that will be provided in more detail in the trails management plan
prepared by the cooperating agencies and interests.Without adequate
management and monitoring, this approach could result in more trails and no
reduction in use of problematic trails.
FENCING ISSUES
Issue:The draft recovery plan does not provide evidence for the effectiveness of
the proposed fencing as a mitigation measure and fails to address the associated
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financial and visual burdens.Except in areas with vehicular related mortalities,
the needfor fencing is questionable,consideringthe potentially detrimental
effects of severing habitat,restricting sheep movement,and rendering sheep more
vulnerable to predation against fences.Alternatives to fences,such as
nonmotorized trails adjoining development,which would provide a deterrent to
sheep movement into urban areas,warrant more analysis.By imposing the
mandate for fencing on private property without adequate justification,the draft
recovery plan acted in an arbitrary manner in excess of statutory authority.
Response:The cooperating agencies are open to alternativemeans of controlling
sheep movements into urban areas.However,some landowners and jurisdictions
have chosen fencingas an affordable and reliable solution to the problem of
behavioral habituation.When installed,fences haveproven effective and
aesthetic concernshavebeen addressed through alternative designs and
alignments.Fencing alongthe urban interface is intended to benefit sheep by
curtailing movementinto areas with unnatural sources of mortality and help
reduce herd mortality rates to sustainable levels.The demonstrated loss of
animals to vehicularrelated mortality,poisoning from landscaping plants,
drownings, etc.,establish a legal nexus to warrantmeasures to prevent these
adverse effects.
NON-NATIVE ANIMAL ISSUES
Issue:The recovery plan needs to establish a buffer zone between bighorn sheep
habitat and cattle grazing,as was done for domesticsheep grazing, so that the
risk of disease transmission is minimized.
Response:There is no conclusive evidence to support a buffer zone for disease
protection from cattle as there is for domestic sheep.The recovery plan
recommends research on disease transmissionbetween livestock and bighorn,and
if a buffer zone is shown to be warranted,future iterations of the recovery plan
willbe amended accordingly.
Issue:Cattle grazing and associatedfencing should not be allowed for various
reasons,including disease hazards and risk ofphysical injury to bighorn sheep.
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Response:Weagree that fencing should be minimized and eliminated if possible.
If fencing is necessary,design guidelines have beendeveloped that minimize and
prevent the risk of injury.Therecoveryplan establishes theneed to thoroughly
review theappropriateness of cattle grazing in sheep habitat and take action if
prudent.
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Region 1
U.S.Fish and Wildlife Service
Ecological Services
911 N.E.11th Avenue
Portland,Oregon 97232-4181
October 2000