Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Peninsular Bighorn Sheep and Determination of a Distinct Population Segment of Desert Bighorn Sheep (Ovis canadensis nelsoni)
Federal RegisterApr 14, 2009
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
FWS-R8-ES-2007-0005; 92210-1117-0000-B4
RIN 1018-AV09
Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Peninsular Bighorn Sheep and Determination of a Distinct Population Segment of Desert Bighorn Sheep (
Ovis canadensis nelsoni
)
AGENCY:
Fish and Wildlife Service, Interior.
ACTION:
Final rule.
SUMMARY:
We, the U.S. Fish and Wildlife Service (Service), designate revised critical habitat for the Peninsular bighorn sheep, a distinct population segment (DPS) of desert bighorn sheep (
Ovis canadensis nelsoni
) occupying the Peninsular Ranges of Southern California, under the Endangered Species Act of 1973, as amended (Act). In total, approximately 376,938 acres (ac) (152,542 hectares (ha)) fall within the boundaries of the critical habitat designation. This revised designation of critical habitat for Peninsular bighorn sheep reduces the 2001 designation by approximately 467,959 ac (189,377 ha). The revised critical habitat is located in Riverside, San Diego, and Imperial Counties, California.
DATES:
This rule becomes effective on May 14, 2009.
ADDRESSES:
The final rule, final economic analysis, and map of critical habitat will be available on the Internet at
http://www.regulations.gov
. Supporting documentation we used in preparing this final rule will be available for public inspection, by appointment, during normal business hours, at the U.S. Fish and Wildlife Service, Carlsbad Fish and Wildlife Office, 6010 Hidden Valley Road, Suite #101, Carlsbad, CA 92011; telephone 760-431-9440; facsimile 760-431-5901.
FOR FURTHER INFORMATION CONTACT:
Jim Bartel, Field Supervisor, U.S. Fish and Wildlife Service, Carlsbad Fish and Wildlife Office (see
ADDRESSES
section). If you use a telecommunications device for the deaf (TDD), call the Federal Information Relay Service (FIRS) at 800-877-8339.
SUPPLEMENTARY INFORMATION:
Background
It is our intent to discuss only those topics directly relevant to the designation of critical habitat for Peninsular bighorn sheep in this final rule. For more information on the taxonomy, biology, and ecology of Peninsular bighorn sheep, refer to the final listing rule published in the
Federal Register
on March 18, 1998 (63 FR 13134), the original final critical habitat rule published in the
Federal Register
on February 1, 2001 (66 FR 8650), the proposed rule to revise critical habitat published in the
Federal Register
on October 10, 2007 (72 FR 57740), and the August 26, 2008 (73 FR 50498), notice of availability of the draft economic analysis (DEA) that announced revisions to the proposed critical habitat designation.
The listed entity treated in this rule is a DPS of desert bighorn sheep (
Ovis canadensis nelsoni
). We will refer to this entity as Peninsular bighorn sheep, or as a DPS (not species or subspecies).
As stated in the October 10, 2007, proposed critical habitat rule, we are formally recognizing the listed entity as Peninsular bighorn sheep, a DPS of the desert bighorn sheep (
Ovis canadensis nelsoni
). This is the currently accepted taxonomic placement of these animals. We submitted this as a change for inclusion in the Code of Federal Regulations (CFR). The taxonomic revision does not affect discreteness and significance of Peninsular bighorn sheep as a DPS. In the 1998 final listing rule, Peninsular bighorn sheep were listed as a DPS of the species
Ovis canadensis
. At the time of listing at least six subspecies of bighorn sheep (
Ovis canadensis
) were named, including
Ovis
canadensis
cremnobates
, which is a name that previously had been applied to the Peninsular bighorn sheep. However, because of ongoing questions regarding the distinctiveness of the subspecific taxa at that time, the Peninsular Ranges population was considered a distinct population segment (DPS) of the species
O. canadensis
rather than as a subspecies or a DPS of a particular subspecies.
Relevant information regarding the systematic relationships of the infraspecific (below species rank) taxa of bighorn sheep at or near the time of listing was based on morphometric (variation in size and shape) assessments, as well as molecular analyses, such as mitochondrial DNA (mtDNA) assessments (Wehausen and Ramey 1993; Ramey 1993; Ramey 1995; Boyce
et al.
1999) and microsatellite and histocompatibility complex loci analysis (Boyce
et al.
1997; Gutierrez-Espeleta
et al.
1998). While the discriminatory value of these various approaches was not addressed in the recovery plan (USFWS 2000), the Service concluded in the morphology and taxonomy section of the Recovery Plan (USFWS 2000, p. 3) that the currently recognized subspecies for desert bighorn sheep,
Ovis canadensis nelsoni
, includes the Peninsular bighorn sheep. This taxonomic placement was recognized in the final critical habitat designation for the Peninsular bighorn sheep published in 2001 (USFWS 2001, p. 8650). In that rule, we described the range of the DPS as coincident with the U.S. portion of the formerly recognized
Ovis canadensis cremnobates
. The current known range for the Peninsular bighorn sheep remains the same, as does its status as a DPS of the desert bighorn sheep (
Ovis canadensis nelsoni
).
Regardless of its systematic affiliation, the Peninsular bighorn sheep continues to meet the criteria for consideration as a DPS. Within this document, we refer to the listed entity as a distinct population segment (DPS) of desert bighorn sheep (
Ovis canadensis nelsoni
), not as a subspecies as we did within the discussion portion of the October 10, 2007, proposed critical habitat rule. We will continue to use the common name Peninsular bighorn sheep when referring to this DPS. No discussions or references to the Peninsular bighorn sheep DPS are intended to apply to any other portions of the range (
e.g
., San Bernardino Mountains, Joshua Tree National Park, the desert mountains of southwestern Nevada and northwestern Arizona) of the desert bighorn sheep (
Ovis
canadensis nelsoni
). For a detailed discussion of the DPS analysis for Peninsular bighorn sheep, see the Distinct Vertebrate Population Segment section of the 1998 final listing rule (March 18, 1998, 63 FR 13134). Therefore, we are changing the listed entity from a DPS of the species
Ovis
canadensis
, to a DPS of the subspecies
Ovis
canadensis
nelsoni
. This final rule includes a change to the List of Endangered and Threatened Wildlife at 50 CFR 17.11(h) to reflect this change.
DPS Description, Life History, Distribution, Ecology, and Habitat
No new substantial information pertaining to the DPS description, life history, ecology, or habitat of Peninsular bighorn sheep was received following the 2007 proposed rule to revise critical habitat for this DPS. Therefore, please refer to the final listing rule published in the
Federal Register
on March 18, 1998 (63 FR 13134), and the proposed rule to revise critical habitat published in the
Federal Register
on October 10, 2007 (72 FR 57740), for a discussion of the DPS's description, life history, ecology, and habitat.
DPS Distribution
During the first public comment period for the proposed rule, we received new information regarding occurrence data that had been collected within the past year. The areas in which new sheep occurrence data was received include the South Santa Rosa Mountains along Grave Wash and the Jacumba Mountains near Interstate 8. The occurrence data received falls within the boundary of the 2001 critical habitat designation and the 2000 Recovery Plan area; therefore, we do not believe this new information markedly affects the known distribution of Peninsular bighorn sheep. However, we considered this new occurrence data and revised our proposed designation to include these areas recently used by Peninsular bighorn sheep (see the Notice of Availability (NOA), August 26, 2008, 73 FR 50498). The areas represented by the new occurrence data are included in this final designation (see the “Summary of Changes From the 2007 Proposed Rule To Revise Critical Habitat to This Final Rule to Revise Critical Habitat” section of this final rule).
Previous Federal Actions
As discussed in the proposed rule to revise critical habitat for this DPS, a July 31, 2006, court-approved consent decree enacted a limited partial vacatur of tribal, mining, and Desert Riders lands and remanded the critical habitat designation back to the Service for new rulemaking. The Service was obligated under the consent decree to submit a proposed revised critical habitat designation to the
Federal Register
on or before September 30, 2007, and a final revised critical habitat designation on or before September 30, 2008. We published a proposed revised critical habitat designation in the
Federal Register
on October 10, 2007 (72 FR 57740), and accepted public comments on the proposed revised designation for 60 days, ending December 10, 2007. Because significant new information was received, the parties agreed to extend the due date to the
Federal Register
of the final revised critical habitat rule to March 30, 2009. On August 26, 2008 (73 FR 50498), we opened a second public comment period on the proposed revised critical habitat designation and announced our intention to hold two public hearings on the proposed rule that were held in Palm Desert, California, on September 10, 2008. In the same
Federal Register
notice we announced the availability of our Draft Economic Analysis (DEA) (dated June 9, 2008) and announced changes to the proposed rule. We accepted public comments during the second open comment period for 60 days, ending October 27, 2008. For more information on previous Federal actions concerning Peninsular bighorn sheep, refer to the final listing rule published in the
Federal Register
on March 18, 1998 (63 FR 13134), the final critical habitat designation published in the
Federal Register
on February 1, 2001 (66 FR 8650), and the proposed rule to revise critical habitat published in the
Federal Register
on October 10, 2007 (72 FR 57740).
Summary of Comments and Recommendations
We requested written comments from the public during two comment periods on the proposed rule to revise critical habitat for Peninsular bighorn sheep. The first comment period opened October 10, 2007 (72 FR 57740), and closed December 10, 2007, and was associated with the publication of the proposed rule. We received several requests for a public hearing during this comment period. The second comment period opened August 26, 2008 (73 FR 50498), and closed October 27, 2008, and was associated with the notice of availability of the DEA, announcement of revisions to the proposed critical habitat, and a notice of public hearings that were held September 10, 2008. During these two public comment periods, we contacted appropriate Federal, State, and local agencies; scientific organizations; and other interested parties and invited them to comment on the proposed rule to revise critical habitat for this DPS and the associated DEA.
During the first comment period, we received 212 public comments directly addressing the proposed revision of critical habitat: 1 from a Federal agency, 2 from State agencies, 1 from an elected official, and 208 from organizations and individuals. During the second comment period and the September 10, 2008, public hearings, we received 5,092 comments directly addressing the proposed revision of critical habitat for this DPS or the DEA: 1 from an elected official, 2 from State agencies, 3 from local governments, and 5,086 from organizations and individuals.
Peer Review
In accordance with our policy on peer review published in the
Federal Register
on July 1, 1994 (59 FR 34270), we solicited expert opinions from five knowledgeable individuals with scientific expertise that included familiarity with the DPS, the geographic region in which it occurs, and conservation biology principles. We received responses from all five of the peer reviewers.
We reviewed all comments received from the peer reviewers and the public for substantive issues and new information regarding critical habitat for Peninsular bighorn sheep. These comments are addressed below and incorporated into the final rule as appropriate.
Peer Reviewer Comments
Comment 1:
Several peer reviewers stated the proposed critical habitat is flawed because it does not provide for connectivity. One peer reviewer stated further that the proposal fragments the habitat available to the Peninsular bighorn sheep. Several peer reviewers asserted that, although essential habitat (as identified by the Peninsular bighorn sheep Recovery Team and depicted in the 2000 Peninsular bighorn sheep Recovery Plan) and critical habitat originally designated in 2001 promoted habitat connectivity among all subpopulations, the proposed critical habitat essentially severs the San Jacinto Mountains subpopulation (Unit 1) and the Carrizo Canyon subpopulation (Unit 3) from the remainder of the range (Units 2A and 2B). One peer reviewer also noted that movement of Peninsular bighorn sheep has been documented between these areas. According to the same peer reviewer, a collared ram from the San Jacinto Mountains was observed during July and August 2008 on several different occasions in the northern Santa Rosa Mountains with other bighorn sheep there. The peer reviewer concluded that not including these areas as critical habitat incorrectly suggests that these areas are not critical to the long-term recovery or survival of the population.
Another peer reviewer stated that movement between Units l, 2A, 2B, and 3 is important and that critical habitat should be extended to protect corridors connecting the units. The same peer reviewer maintained that if any unit is isolated, the subpopulation may not be viable and that critical habitat should be expanded to include corridors for movement between units. One peer reviewer noted an extensive and irrefutable body of scientific literature that illustrates the importance of habitat connectivity. Two peer reviewers stated that, despite the acknowledgement in the proposed rule that connectivity is vital for this species' recovery, the revised critical habitat designation decreases connectivity or does not include corridors for movement. One peer reviewer asserted that habitat fragmentation will only promote the
decline of this DPS and goes directly against the recommendations of the Recovery Plan that the Service adopted.
Our Response:
We agree with the peer reviewers that habitat connectivity is important to allow for movement between ewe groups and to maintain genetic variation. We also agree with the peer reviewer that an extensive amount of scientific evidence illustrates the importance of habitat connectivity, and we considered this information during the development of this critical habitat designation. We acknowledge that areas potentially providing connectivity between Units 1 and 2A and between Units 2B and 3 were included in the 2001 critical habitat designation; however, based on our reevaluation of the data available at the time of the 2001 designation, data obtained since, and our revised methodology for delineating critical habitat, we find that those areas do not meet the definition of critical habitat because the available data do not identify specific areas between these units that contain the physical or biological features essential to the conservation of the DPS.
The best available data do not provide any information indicating what areas, if any, Peninsular bighorn sheep use as connectivity corridors within the expansive areas between Units 1 and 2A and Units 2B and 3. Although the peer reviewers presented data showing that at least one collared ram has moved between Units 1 and 2A, we do not have occurrence data suggesting a specific corridor between these units. In addition, we have no data documenting natural sheep movement between Units 3 and 2B. As such we have not included specific corridors between Units 1 and 2A or between Units 3 and 2B in the designation. However, we will continue to monitor movement between these units to determine if specific movement corridors exist. In contrast, where the available data do support the identification of specific areas utilized by the DPS as movement corridors, such as between the ewe groups in the Santa Rosa Mountains and the Vallecito Mountains ewe group, those areas are included in the critical habitat designation.
We recognize this finding is different than what is outlined as essential habitat in the 2000 Recovery Plan and what was designated as critical habitat in the 2001 designation (which largely adopted the boundary delineated in the Recovery Plan). The Recovery Plan and 2001 critical habitat rule note that allowing for ram movement between ewe groups is important for maintaining genetic variation in the Peninsular bighorn sheep metapopulation. While we believe connectivity areas are important for the Peninsular bighorn sheep's recovery, we have significantly more data available today than when the Recovery Plan and 2001 critical habitat were finalized. We have utilized the currently available data to more precisely identify areas meeting the definition of critical habitat; in particular, areas related to connectivity. Such areas are included in this designation where the data support the determination that such areas contain the physical and biological features essential to the conservation of the DPS. For other potential connectivity areas that were included in the 2001 designation, the available movement and occurrence data we have for those areas do not support the identification of specific areas that provide a movement corridor that is essential for the conservation of the DPS.
We believe it is important to note that critical habitat designation is a different process than development of a recovery plan. A critical habitat designation is a specific regulatory action that defines specific areas as critical habitat in accordance with the statutory definition. A recovery plan is a guidance document developed in cooperation with partners, which provides a roadmap with detailed site-specific management actions to help conserve listed species and their ecosystems. The term “essential,” as used in the recovery plan, is not necessarily used in the same manner as it is used in the definition of critical habitat. The recovery plan provides important information about the species and the actions that are needed to bring about its recovery, while critical habitat identifies specific areas that are essential for the species' conservation.
The deviation from the Peninsular bighorn sheep Recovery Plan boundary and the 2001 final critical habitat designation is primarily the result of using a revised methodology to delineate critical habitat. Our revised methodology incorporates new information to best identify areas that meet the definition of critical habitat (see “Summary of Changes From the 2001 Critical Habitat Designation To the 2007 Proposed Rule To Revise Critical Habitat” section for more discussion). As a result, the final revised critical habitat boundary does not include areas the Recovery Plan identified as necessary for the conservation of the Peninsular bighorn sheep that we since determined (based on the best available data at this time) are not essential for the conservation of this DPS. Therefore, we believe the final revised critical habitat boundary more precisely maps the physical and biological features that occur within the geographical area occupied by the Peninsular bighorn sheep at the time of listing, which includes those areas containing preferred habitat for sheep use.
There are likely additional areas outside of the final revised critical habitat boundary that contain some of the PCEs, including areas identified in the Recovery Plan and 2001 critical habitat. We recognize that areas outside of the critical habitat boundary are likely utilized by Peninsular bighorn sheep (primarily for movement of rams between ewe groups). However, as stated above, the data available at this time do not support the identification of specific areas containing the essential features that provide a movement corridor between Units 1 and 2A or between Units 2B and 3. Additionally, Unit 2A is continuous with Unit 2B and these units contain a large contiguous portion of the Peninsular Ranges allowing for movement between six ewe groups with these units. Furthermore, although we do not have information to identify specific movement corridors, the areas between Units 1 and 2A or between Units 2B and are steep, rugged, and remote and there are no perceived threats in these areas. Therefore, we are confident that these areas will still be available for any natural sheep movements between units allowing for genetic connectivity.
We recognize that the designation of critical habitat may not include all of the habitat that may eventually be determined to be necessary for the recovery of Peninsular bighorn sheep, and critical habitat designations do not signal that habitat outside the designation is unimportant or may not contribute to recovery. Areas outside the final revised critical habitat designation will continue to be subject to conservation actions implemented under section 7(a)(1) of the Act and regulatory protections afforded by the section 7(a)(2) jeopardy standard and the prohibitions of section 9 of the Act if actions occurring in these areas may affect sheep; these protections and conservation tools will continue to contribute to recovery of the DPS.
Please see the “Criteria Used To Identify Critical Habitat” and “Summary of Changes From the 2001 Critical Habitat Designation To the 2007 Proposed Rule To Revise Critical Habitat” sections of this final rule for further discussion of this topic.
Comment 2:
Two peer reviewers stated that exclusion of areas under the Agua Caliente Band of Cahuilla Indians Tribal Habitat Conservation Plan (Tribal HCP) and Coachella Valley Multiple
Species Habitat Conservation Plan (Coachella Valley MSHCP) is inappropriate because the Coachella Valley MSHCP and the Tribal HCP are not yet approved, and therefore provide absolutely no protection to Peninsular bighorn sheep or their habitat at this time. One peer reviewer stated it would be pre-decisional to exclude critical habitat based on these plans. Another peer reviewer suggested that managers and those making policy decisions should have solid documentation that the Peninsular bighorn sheep will receive the same level of enforceable protection from the Tribal HCP and the Coachella Valley MSHCP as provided by the Endangered Species Act. One peer reviewer stated that the proposed exclusion of tribal lands and lands covered by the Coachella Valley MSHCP are not supported by the best available science and that removal of these areas from critical habitat will increase the threats to the persistence and recovery of Peninsular bighorn sheep.
Our Response:
We believe the exclusion of the identified tribal lands and the lands covered by the Coachella Valley MSHCP, which is now final, is appropriate based on the potential impacts associated with designating these areas as critical habitat. Section 4(b)(2) of the Act states that the “Secretary shall designate critical habitat, and make revisions thereto, on the basis of the best scientific data available and after taking into consideration the economic impact, the impact on national security, and any other relevant impact, of specifying any particular area as critical habitat.” The Act further states that the Secretary may exclude any 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 and commercial data available, that the failure to designate such area as critical habitat will result in the extinction of the species concerned.
We believe that critical habitat designation would negatively impact the working relationships and conservation partnerships we have formed with permittees, the Tribe, and other private landowners (
i.e.
, other relevant impacts), and could result in decreased voluntary conservation efforts to benefit the Peninsular bighorn sheep. Additionally, as explained in detail in the “Application of Section 4(b)(2)—Other Relevant Impacts—Conservation Partnerships” section of this final rule, we believe these conservation partnerships will provide as much or more benefit than consultation under section 7(a)(2) related to the critical habitat designation (the primary benefit of a designation).
The exclusion of Agua Caliente Band of Cahuilla Indians lands is not based on the 2007 draft Tribal HCP, but is primarily based on the importance of our government-to-government relationship with the Agua Caliente Band of Cahuilla Indians, our conservation partnership with the Tribe, and their current management of tribal lands as described in the 2001 Tribal Conservation Strategy (adopted by the Tribe on November 12, 2002, and implemented since its adoption). Furthermore, 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 goal of managing for healthy ecosystems upon which the viability of threatened and endangered species populations depend. As an indication of the success of our partnership with the Agua Caliente Band of Cahuilla Indians and their commitment to natural resources management, a regional HCP is being developed, which incorporates protections and management of this DPS's essential physical and biological features.
The protections provided by the Coachella Valley MSHCP and the Tribe's resource management are consistent with the mandates under section 7 of the Act to avoid destruction or adverse modification of critical habitat and go beyond that prohibition by including active management and protection of essential habitat areas. These established partnerships demonstrate a continued commitment to conservation and aid in fostering additional partnerships for the benefit of all sensitive species on tribally-owned or controlled lands, Coachella Valley MSHCP permittee-owned/controlled lands, and other private lands. Finally, we determined that the Tribe's management of its resources provides protection and management, in perpetuity, of lands that meet the definition of critical habitat for Peninsular bighorn sheep in Units 1 and 2A, and the Coachella Valley MSHCP provides further evidence of this partnership and continued protection of these features. Furthermore, we determined that the routine implementation of conservation measures in these units, combined with protections provided under the jeopardy standard of section 7 of the Act in these two occupied units, provide assurances that the DPS will not go extinct as a result of these exclusions.
Please see the “Application of Section 4(b)(2)—Other Relevant Impacts—Conservation Partnerships” section of this final rule for additional discussion of the Coachella Valley MSHCP and tribal conservation strategies and the benefits provided to Peninsular bighorn sheep.
Comment 3:
Several peer reviewers stated that alluvial fans and low-elevation habitat provide important resources for Peninsular bighorn sheep and noted that the proposed critical habitat does not include extensive areas of alluvial fans and other low-elevation habitat that were included in the 2001 critical habitat designation. Two peer reviewers stated that, based on a geographic information systems (GIS) evaluation of proposed critical habitat by California Department of Parks and Recreation staff, nearly 250,000 ac (101,172 ha) of habitat have been removed from the eastern side of critical habitat, as compared to critical habitat designated in 2001. The peer reviewers further stated this area includes alluvial fans, washes, bajadas (
i.e.
, converging alluvial fans), canyon bottoms, and open playas, which provide important forage resources and which are used during movement between more mountainous terrain. One peer reviewer stated that the fact that bighorn sheep use gentle terrain, such as alluvial fans and washes, despite potentially increasing their risk of predation, provides strong evidence that these areas provide critically important resources.
Another peer reviewer commented that the 2007 proposed revision eliminates key low-slope areas and raises the boundary upslope, which they assert is a contradiction to the best available science. One peer reviewer noted there are contradictions of slope
condition in the rule based on straight lines drawn on the critical habitat maps, even though the text in the proposed rule describes the importance of gentle slopes to bighorn sheep.
Our Response:
We agree that low-elevation habitat is important for Peninsular bighorn sheep because these areas can provide seasonal abundance of forage vegetation and water resources. In our August 26, 2008, NOA (73 FR 50498), we announced a revision to our criteria used to identify critical habitat to include occurrence data from 1988 to 2008. Because of comments received from peer reviewers and the public about low-elevation habitat and the revision of our criteria used to identify critical habitat to include a larger occurrence data set, we reevaluated and revised our proposed revised critical habitat boundary. In our August 26, 2008, NOA (73 FR 50498), we announced changes to the proposed critical habitat revision, including the addition of 36,240 ac (14,667 ha) of habitat for Peninsular bighorn sheep, the majority of which is low-elevation, low-slope, or alluvial-fan habitat on the eastern edge of the Peninsular Ranges. We acknowledge there are some low-elevation areas included in the 2001 designation of critical habitat that are not included in this final designation. However, currently available data do not support a determination that these areas outside the geographical area occupied by the species at the time of listing are essential for the conservation of the sheep; therefore these areas do not meet the definition of critical habitat.
Please see the “Criteria Used To Identify Critical Habitat,” the “Summary of Changes From the 2001 Critical Habitat Designation to the 2007 Proposed Rule To Revise Critical Habitat,” and the “Summary of Changes From the 2007 Proposed Rule To Revise Critical Habitat to This Final Rule To Revise Critical Habitat” sections of this final rule for further discussion of this topic.
Comment 4:
One peer reviewer objected to the statement in the proposed critical habitat rule that essential habitat delineated in the Recovery Plan (and in the 2001 critical habitat designation) included a “buffer” of 0.5 mile (mi) (0.8 kilometer (km)) around slopes greater than or equal to 20 percent. The peer reviewer stated that buffer areas identified in the Recovery Plan were added as “essential habitat” (as defined in the Recovery Plan) because these areas include important resources for bighorn sheep; they were not added as a buffer around essential habitat. The peer reviewer reiterated what was written in the Recovery Plan (
i.e.
, that bighorn sheep have been observed at great distances from slopes of greater than or equal to 20 percent, and the recovery team chose to define essential habitat as those areas within 800 m (2,625 ft) of slopes of greater than or equal to 20 percent). Additionally, the peer reviewer stated that the Peninsular bighorn sheep recovery team recognized that this area would capture the majority of Peninsular bighorn sheep use in these areas and that inclusion of these areas represented inclusion of important resources.
Our Response:
The Recovery Plan acknowledges that the 800-m (2,625-ft) area around slopes greater than or equal to 20 percent is a buffer. Page 157 of the Recovery Plan describes the process of delineating these areas as follows: “A buffer of 0.8 kilometer (0.5 mile) was then applied to the perimeter of all areas of slope [greater than or equal to 20 percent] in the derivative grid.” The inclusion of this area around 20 percent slopes adds expanses of land to the Recovery Plan area and the 2001 critical habitat designation, but we have relatively little to no occurrence data indicating that sheep use those areas. By including these 0.5-mi (0.8-km) buffers in the Recovery Plan, a boundary was developed that included almost any location that a Peninsular bighorn sheep could possibly roam, but such a buffer would not meet the statutory definition of “critical habitat,” because such areas are not essential for the conservation of the DPS. As stated in section 3(5)(C) of the Act, except in those circumstances determined by the Secretary, critical habitat shall not include the entire geographical area which can be occupied by the threatened or endangered species. Please see the “Criteria Used To Identify Critical Habitat,” and the “Summary of Changes From the 2001 Critical Habitat Designation To the 2007 Proposed Rule To Revise Critical Habitat” sections of this final rule for further discussion of this topic.
Comment 5:
One peer reviewer stated that the proposed delineation does not appear to be based on good science or conservation principles and that the major reduction in area (as compared to the original critical habitat delineated in 2001) will jeopardize the chances of recovery and survival of this population. A second peer reviewer stated that the proposal to remove over 50 percent of critical habitat is contrary to the PCEs as well as the Recovery Plan. A third peer reviewer believes the revised critical habitat is geared towards sustaining the current, low population level of Peninsular bighorn sheep, rather than planning for recovery. Finally, a fourth peer reviewer stated it is unclear what changed between the time of the 2000 Recovery Plan and today that would cause certain areas to be eliminated that were previously determined as essential for the DPS's recovery.
Our Response:
The designation of critical habitat for Peninsular bighorn sheep is based on the best scientific data available regarding the DPS, including: (1) A compilation of data from peer-reviewed, published literature; (2) unpublished or non-peer reviewed survey and research reports; and (3) opinions of biologists knowledgeable about Peninsular bighorn sheep and their habitat. Consequently, the PCEs, as described in this final rule, represent our best assessment of what habitat components are essential for the conservation of Peninsular bighorn sheep, and we believe that our final revised designation is adequate to ensure the conservation of this DPS throughout its extant range.
The Act defines critical habitat as (1) the specific areas within the geographical area occupied by the species at the time it is listed on which are found those physical or biological features (a) essential to the conservation of the species, and (b) which may require special management considerations or protection, and (2) specific areas outside the geographical area occupied by the species at the time it is listed upon a determination by the Secretary that such areas are essential for the conservation of the species. Consistent with section 3(5)(C) of the Act, the designation does not include the entire geographical area which can be occupied by Peninsular bighorn sheep, but is limited to those areas that we determined meet the definition of critical habitat. The reduction in total area from what was identified as important for the Peninsular bighorn sheep in the Recovery Plan and designated in 2001 is primarily the result of: (1) Exclusions of habitat under section 4(b)(2) of the Act; (2) revision of the primary constituent elements; (3) revision of our criteria used to identify critical habitat; (4) removal of lands within the geographical area occupied by the DPS at the time it was listed that do not contain the physical or biological features as identified by the PCEs in the appropriate quantity and spatial arrangement essential to the conservation of the DPS; and (5) removal of lands outside the geographical area occupied by the DPS at the time it was listed that are not
essential for the conservation of the DPS.
The 2001 critical habitat designation was predominantly based on the 2000 Recovery Plan, and we used the best available scientific information at that time to delineate critical habitat. Since 2001, we received significant additional occurrence data and formulated a better understanding about specific habitat requirements of this DPS that was not known when we first designated critical habitat for the Peninsular bighorn sheep. We utilized this new information to appropriately revise the PCEs and criteria used to identify critical habitat, consistent with the Act. Additionally, case law has developed since 2001 regarding the Act's requirements and the definition of critical habitat (
e.g.
,
The Cape Hatteras Access Preservation Alliance
v.
U.S. Dep't of the Interior
, 344 F. Supp. 2d 108 (D.D.C. 2004);
Home Builders Ass'n of N. Cal
. v.
U.S. Fish and Wildlife Service
, U.S. Dist. LEXIS 80255 (E.D. Cal. 2006); and
Arizona Cattle Growers' Ass'n
v.
Kempthorne
, 534 F. Supp. 2d 1013 (D. Ariz. 2008)).
Therefore, we refined our approach to this critical habitat designation, including identification of the geographical areas occupied by the DPS at the time of listing, identification of physical or biological features essential to the conservation of the DPS, determination of any areas outside the geographical area occupied by the DPS at the time of listing that are essential for the conservation of the DPS, and appropriate exclusions under section 4(b)(2) of the Act. A complete discussion of how data collected since the 2001 designation were utilized to refine the proposed designation can be found in the “Summary of Changes From the 2001 Critical Habitat Designation To the 2007 Proposed Rule To Revise Critical Habitat” and “Summary of Changes From the 2007 Proposed Rule To Revise Critical Habitat To This Final Rule To Revise Critical Habitat” sections of this final rule.
We delineated critical habitat for the Peninsular bighorn sheep using the criteria presented in the “Criteria Used To Identify Critical Habitat” section of this final rule. Application of these criteria results in the determination of the physical and biological features that are essential to the conservation of this DPS, identified as the DPS's PCEs laid out in the appropriate quantity and spatial arrangement essential to the conservation of the DPS. Therefore, not all areas supporting the identified PCEs will meet the definition of critical habitat.
Refer to our response to Comment 1 for a discussion on the difference between critical habitat designation and development of a Recovery Plan.
Our proposed designation, in combination with our August 26, 2008, NOA, which announced the addition of areas to the proposed designation, and this final designation accurately describe all specific areas meeting the statutory definition of critical habitat for Peninsular bighorn sheep. See the “Summary of Changes From the 2001 Critical Habitat Designation To the 2007 Proposed Rule To Revise Critical Habitat” and “Summary of Changes From the 2007 Proposed Rule To Revise Critical Habitat To This Final Rule To Revise Critical Habitat” sections of this final rule for more information.
Comment 6:
Two peer reviewers pointed out that the proposed critical habitat rule states that researchers have documented movement of rams “between up to three ewe groups.” The peer reviewers suggested this statement incorrectly cites Rubin
et al.
(1998), which documented male movement among at least six groups, and the proposed rule therefore underestimates the importance of connectivity throughout the range. The peer reviewers stated that researchers have documented movement of radio collared males and females among all eight subpopulations, demonstrating that these subpopulations are currently linked via animal movement. One peer reviewer stated that historic ram movement data between the northern Santa Rosa Mountains and the San Jacinto Mountains was not used in delineating proposed critical habitat. The peer reviewer further stated that they believe the Service has had this data for years and, if used, they believe the Service would not have developed a critical habitat designation lacking connectivity between critical habitat units.
Our Response:
We corrected the section of the critical habitat designation involving the Rubin
et al.
(1998) citation mentioned above and included the additional information on the metapopulation structure of Peninsular bighorn sheep into the PCEs discussion in this rule. With regard to historic ram movement data and connectivity, see our response to Comment 1 and the “Criteria Used To Identify Critical Habitat” and “Summary of Changes From the 2001 Critical Habitat Designation To the 2007 Proposed Rule To Revise Critical Habitat” sections of this final rule for further discussion.
Comment 7:
One peer reviewer believes that the critical habitat designation should encompass areas of historical occupancy if it is intended to aid in the recovery of the Peninsular bighorn sheep.
Our Response:
Please refer to our response to Comment 5 for the statutory definition of critical habitat. The Service may designate as critical habitat areas outside the geographical area occupied by a species at the time it was listed (
i.e.,
historical habitat) only when we can determine that those areas are essential for the conservation of the species (section 3(5)(A)(ii) of the Act). We have determined that designating critical habitat solely within the geographical area occupied by the DPS at the time it was listed will provide for the conservation of the Peninsular bighorn sheep. We, therefore, did not include areas of historical occupancy that were outside of these areas. As previously mentioned in this final rule, critical habitat designations do not signal that habitat outside the designation is unimportant or may not contribute to a species' recovery. See our response to Comment 5 above and the “Criteria Used To Identify Critical Habitat” section of this final rule for more information.
Comment 8:
One peer reviewer had concerns about designating critical habitat based on occupancy at the time of listing. The peer reviewer identified what the peer reviewer believed to be two shortcomings of this approach, as follows: (1) Critical habitat is designated based on the distribution of a species at its lowest abundance level, and most likely its most limited spatial distribution, thereby reducing the probability of encompassing areas required for full recovery; and (2) designated critical habitat assumes that all areas have been sufficiently surveyed to document occupancy and doesn't address false absences. Another peer reviewer believes that the Service failed to recognize false absences as a result of this approach, and that this is a grave error because the peer reviewer believes many important areas may not be included in the critical habitat designation.
Our Response:
In response to the peer reviewer's comment and other public comments related to the delineation of critical habitat based on occupancy at the time of listing, we revised our criteria used to delineate critical habitat as announced in the NOA published in the
Federal Register
on August 25, 2008 (73 FR 50498). As a revision to our criteria, we included areas with occupancy data indicating they are currently occupied or areas with occupancy data indicating they were occupied at some point between 2008
(present time) and 1988 (
i.e.,
the time of listing (1998) less 10 years, which is the average lifespan of Peninsular bighorn sheep). Use of a data set that considers a larger time-span of occurrence data accounts for the large fluctuations in Peninsular bighorn sheep population levels over the last two decades, and provides a reasonable delineation of the geographical area occupied by the species at the time of listing. After rangewide estimates were made in the 1970s, the population was estimated as high as 1,171 in 1974 (Weaver 1974, p. 5). The population was estimated at 570 individuals in 1988 (Weaver 1989, p. 11). We reported in the final listing rule for Peninsular bighorn sheep that the population at that time (1998) was approximately 280 individuals (March 18, 1998, 63 FR 13134). The most recent estimate from 2006 puts the population at approximately 800 individuals (Torres 2007, p. 1). By considering occurrence data between 1988 and the present, we are not designating critical habitat based on the distribution of the DPS at its lowest abundance level, nor its most limited spatial distribution as the peer reviewer suggested.
We realize that false absences can result from rangewide surveys for Peninsular bighorn sheep. Additionally, we are aware that not all areas within the range of the DPS have been surveyed or studied equally. For example, there is a disproportionate amount of data from the northern half of the Peninsular Ranges in the United States, compared to the southern half that has not been studied as thoroughly. Regardless, we used the best available scientific information and occurrence data in determining areas occupied by Peninsular bighorn sheep. No information is available to indicate which portions of the DPS's range might include false absences.
Comment 9:
One peer reviewer believes that delineation of critical habitat must not rely on simple occurrence data alone, but should also rely on robust methods of identifying and mapping critical habitat based on habitat features.
Our Response:
We agree with the peer reviewer's statement. We delineated critical habitat based on occurrence data and a combination of habitat features. We designated critical habitat for the Peninsular bighorn sheep within areas that we determined were occupied at the time of listing and that contain the physical and biological features essential to the conservation of the DPS. Lands were designated based on sufficient essential features being present to support the life processes. Please see our response to Comment 5 and the “Criteria Used To Identify Critical Habitat” section of this final rule for detailed discussions.
Comment 10:
One peer reviewer noted a large number of known Peninsular bighorn sheep locations (documented post-listing) that were not included in the proposed revised critical habitat and further stated that it was unclear why these areas were not included. Another peer reviewer listed multiple areas that are documented as occupied at or since the time of listing but were not included in the proposed critical habitat designation. The peer reviewer indicated that occurrence data documenting occupancy were provided to the Service prior to the delineation of proposed critical habitat, and further stated that these areas provide lambing habitat, foraging areas, connectivity between mountainous areas, and important water sources. The peer reviewer determined that nearly 1,000 of these locations were not included in the proposed critical habitat following an examination of occurrence data collected during 2001 to 2003 with the use of Global Positioning System (GPS) collars in areas between Highway 74 and the southern edge of the Vallecito Mountains. Finally, another peer reviewer believes there are large areas without location data of Peninsular bighorn sheep that are included as critical habitat and areas with bighorn sheep location data that are not included as critical habitat.
Our Response:
Upon receiving the peer reviewers' comments, we examined the occurrence data considered in the delineation of the proposed revised critical habitat and found that a set of data was missing from our GIS database. Subsequently, we included that occurrence data into our GIS database and double-checked to ensure that all occurrence records submitted to the Service were included for our analyses. In light of this data and our revised criteria used to identify critical habitat (
i.e.,
a data set that includes data since 1988), we revised our proposed critical habitat boundary, as reported in the NOA, to include the areas represented by the location data (August 26, 2008, 73 FR 50498).
Comment 11:
One peer reviewer suggested the proposed revised critical habitat could have been improved had it been an “open process” that included the expertise of biologists on the Recovery Team, as well as others who have worked with bighorn sheep for decades, like what was done for the Peninsular bighorn sheep Recovery Plan. The peer reviewer believes that the resulting proposed critical habitat designation reflects a hurried process that used arbitrary decision-making, is not scientifically based, and contradicts the Services' Recovery Plan for the DPS.
Our Response:
Contrary to the opinion of the peer reviewer, designating critical habitat is an open process. We solicited additional expert opinion and public comment through publication of our proposed revised rule that was developed using the best scientific data available at that point in time. As stated in the proposed rule, comments and materials received, as well as supporting documentation used in the preparation of the proposed rule, are available for public inspection at the Carlsbad Fish and Wildlife Office. In accordance with section 4(5)(A) of the Act and the regulations at 50 CFR 424.16(c)(1), the Secretary shall—
(i) Publish notice of the proposal in the
Federal Register;
(ii) Give actual notice of the proposed regulation (including the complete text of the regulation) to the State agency in each State in which the species is believed to occur, and to each county or equivalent jurisdiction therein in which the species is believed to occur, and invite the comment of each such agency and jurisdiction;
(iii) Give notice of the proposed regulation to any Federal agencies, local authorities, or private individuals or organizations known to be affected by the rule;
(iv) Insofar as practical, and in cooperation with the Secretary of State, give notice of the proposed regulation to list, delist, or reclassify a species to each foreign nation in which the species is believed to occur or whose citizens harvest the species on the high seas, and invite the comment of such nation;
(v) Give notice of the proposed regulation to such professional scientific organizations as the Secretary deems appropriate; and
(vi) Publish a summary of the proposed regulation in a newspaper of general circulation in each area of the United States in which the species is believed to occur. Further, the regulations at 50 CFR 424.16(c)(2) state that at least 60 days shall be allowed for public comment following publication in the
Federal Register
of a rule proposing the listing, delisting, or reclassification of a species, or the designation or revision of critical habitat.
On May 14, 2007, representatives from the Carlsbad Fish and Wildlife Office and the Regional Office, including the Regional Director, met with recovery team members in part to inform members that we were initiating work to propose revisions to designated critical habitat for the Peninsular
bighorn sheep. At that meeting, we requested that recovery team members submit any data they wanted us to consider in our proposed revision. We received data from one recovery team member in response to this request.
During the development of this revision to critical habitat for the Peninsular bighorn sheep, we followed the appropriate guidance and regulations regarding inclusion of expert biologists and other appropriate entities, including the general public. In accordance with our policy on peer review published in the
Federal Register
on July 1, 1994 (59 FR 34270), we solicited expert opinions from five knowledgeable individuals with scientific expertise that included familiarity with the DPS, the geographic region in which it occurs, and conservation biology principles. We reviewed all comments received from the peer reviewers and the public for substantive issues and new information regarding the designation of critical habitat for Peninsular bighorn sheep.
Under section 4(f)(2) of the Act, the Secretary may procure the services of appropriate public and private agencies and institutions and other qualified persons in developing and implementing recovery plans. However, the Act limits the use of recovery teams appointed under this subsection to the development and implementation of recovery plans. The Act does not contain a provision for development of critical habitat teams. However, the Service could set up a critical habitat team, but it would be subject to the Federal Advisory Committee Act (FACA), unlike a recovery team that is exempt from FACA. Since the Act contains specific timeframes for completion of critical habitat designations, creating a critical habitat team would slow the process of designation of critical habitat causing us to be out of compliance with the statutory requirements of the Act. However, consistent with our peer review policy and the Act's standard of using the best available scientific data, we openly and publically solicited information for consideration in rule development and solicited peer review of our proposal.
In total, we received comments from all five peer reviewers that we solicited comments from, and we received 5,299 comments from the general public during two public comment periods and two public hearings. Therefore, we believe we followed an open process during development of the Peninsular bighorn sheep revised critical habitat designation.
Regarding the peer reviewer's beliefs that the proposed critical habitat designation reflects a hurried process that used arbitrary decision-making and was not scientifically based, we disagree with this comment. As noted above, we solicited information from the entire Peninsular bighorn sheep recovery team prior to the proposed revisions to the designation. We also solicited expert opinions from five knowledgeable individuals with scientific expertise that included familiarity with the DPS, the geographic region in which it occurs, and conservation biology principles. Additionally, the designation of critical habitat for Peninsular bighorn sheep is based on the best scientific data available regarding the DPS, including: (1) A compilation of data from peer-reviewed, published literature; (2) unpublished or non-peer reviewed survey and research reports; and (3) opinions of biologists knowledgeable about Peninsular bighorn sheep and their habitat (see our response to Comment 5 and the “Criteria Used To Identify Critical Habitat” section for additional discussion on use of available scientific data and how this data was used to develop criteria for identifying critical habitat).
Comment 12:
One peer reviewer believes it is impossible to duplicate the delineation of the revised critical habitat based on the Service's poorly described methods and an inadequate explanation of how the PCEs were used to delineate critical habitat. Another peer reviewer believes the proposed rule does not provide specifics on how proposed revised critical habitat was delineated, nor does it include discussion of the actual methods of identifying and mapping the PCEs. The same peer reviewer stated that along several sections of the proposed revised critical habitat boundary, the boundary line follows a perfectly straight course, which does not appear to conform to (or follow) any obvious biological or topographical feature; therefore, the peer reviewer questioned how this boundary line was placed. Another peer reviewer could not identify the specific methods used to create the revised boundary of the proposed rule and further stated that the boundary lines give the appearance of being hand-drawn, rather than based on a scientific method.
Our Response:
As discussed in our response to Comment 5 above and the “Criteria Used To Identify Critical Habitat” section of this final rule, we delineated critical habitat for the Peninsular bighorn sheep using the following criteria: (1) Areas that contain the PCEs required by the DPS as determined from aerial imagery and GIS data on vegetation, elevation, and slope; (2) areas within the ewe group distribution (
i.e.,
subpopulations) boundaries identified by Rubin
et al.
(1998); (3) areas occupied by the subspecies between 2008 (present time) and 1988; and (4) areas where occupancy data points indicate repeated Peninsular bighorn sheep use, but which were not captured within the ewe group distribution boundaries identified by Rubin
et al.
(1998). Application of these criteria results in the determination of the physical and biological features that are essential to the conservation of this DPS, identified as the DPS's PCEs laid out in the appropriate quantity and spatial arrangement essential to the conservation of the DPS. Since the 2007 proposed rule, we revised the “Criteria Used To Identify Critical Habitat” section of this rule to provide more detail and description of the stepwise process used, data considered, habitat features mapped, and method used to delineate critical habitat boundaries. The boundaries were drawn with GIS software using detailed aerial imagery maps and data layers of occurrences and habitat information. Any straight lines along the boundary of critical habitat are the result of following habitat features that are naturally straight in appearance.
Comment 13:
One peer reviewer asked if a model was employed, and if so, describe the type and state whether it was based on expert opinion.
Our Response:
We did not use a model to delineate critical habitat for the Peninsular bighorn sheep. For more information on how we delineated critical habitat, see the “Criteria Used To Identify Critical Habitat” section of this final rule.
Comment 14:
One peer reviewer inquired as to whether or not PCEs were weighted in the process of revising critical habitat.
Our Response:
The PCEs were not weighted in the process of revising critical habitat.
Comment 15:
One peer reviewer expressed concern that Anza Borrego Desert State Park's vegetation maps were not utilized in the critical habitat revision. The peer reviewer believes that vegetation has a critical influence on what type of habitat the Peninsular bighorn sheep use; therefore, he asserts that this information would have been instrumental in delineating a more accurate critical habitat boundary. Another peer reviewer asked which vegetation layer was used in delineating critical habitat.
Our Response:
We believed it was important to use a GIS vegetation data
layer that provided a consistent analysis over the entire extent of the Peninsular bighorn sheep range. Any vegetation layers that were prepared for a specific entity, including a park (such as Anza Borrego Desert State Park) or individual county, were not all-encompassing and therefore inappropriate for the analysis. The proposed and final revised critical habitat includes land in three separate counties (Imperial, Riverside, and San Diego). Therefore, the GIS layer that we used for the vegetation analysis portion of defining proposed critical habitat for the Peninsular bighorn sheep was the Fire and Resource Assessment Program layer created by the California Department of Forestry and Fire Protection. For further information on this vegetation data, see their Web site at:
http://frap/cdf/ca/gov
. This vegetation layer was most appropriate because it extended over the entire area of the Peninsular Ranges and allowed for consistency in our analysis of vegetation across the range of this DPS.
Comment 16:
One peer reviewer was concerned that our methodology included an elevation cut-off of 4,600 ft (1,400 m) to guide the critical habitat boundary line. The peer reviewer stated that, at times, Peninsular bighorn sheep rely on areas higher than this, especially on the western side of the Santa Rosa Mountains.
Our Response:
We acknowledge that Peninsular bighorn sheep have occasionally been observed above 4,600 ft (1,400 m) elevation; however, it is commonly accepted that sheep within the Peninsular Ranges are primarily restricted to lower elevations (see the “Primary Constituent Elements (PCEs)” section for more information). We do not have evidence to suggest that areas above 4,600 ft (1,400 m) elevation are essential for the conservation of this DPS, and the commenter did not provide information to support the assertion that sheep rely on higher elevations. As previously mentioned in this final rule, critical habitat designations do not signal that habitat outside of the designation is unimportant or may not contribute to recovery (see our response to Comment 1 above).
Comment 17:
One peer reviewer stated that the rule indicates that areas with canopy cover greater than 30 percent were not included as critical habitat. The peer reviewer asked what information was used to determine this cut-off point and what GIS data layer was used to identify these areas.
Our Response:
Generally, bighorn sheep primarily rely on their sense of sight to detect predators. Research shows that bighorn sheep will avoid habitat where dense vegetation reduces visibility and, instead, prefer to 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 denser vegetation (i.e., chaparral and conifer woodland) found at higher elevations (Service 2000, p. 10).
The GIS layer that was used for the vegetation analysis for the proposed revised critical habitat designation for the Peninsular bighorn sheep was the Fire and Resource Assessment Program layer created by the California Department of Forestry and Fire Protection. With this layer, we were able to highlight areas likely to have vegetative canopy cover over 30 percent (
i.e
., chaparral and conifer woodland). Subsequently, we used detailed aerial imagery to focus on those areas and visually confirm whether or not those areas had canopy cover above 30 percent. If areas appeared to have canopy cover over 30 percent, those areas were removed from the critical habitat delineation. Therefore, vegetated areas within the final revised critical habitat designation include only those areas that provide lower density vegetation and better visibility to detect potential predators.
Comment 18:
One peer reviewer inquired as to how we identified areas unlikely to be used by Peninsular bighorn sheep.
Our Response:
As required by section 4(b)(2) of the Act, we used the best scientific data available in designating critical habitat, and more specifically (as per section 3(5)(A) of the Act), in determining the specific areas within the geographical area occupied by the DPS at the time of listing that contain the physical or biological features essential to the conservation of the DPS which may require special management considerations or protection, as well as in determining if any specific areas outside the geographical area occupied by the DPS at the time of listing are essential for the conservation of the DPS. Areas unlikely to be used by Peninsular bighorn sheep were identified by Service biologists using detailed aerial imagery maps of the Peninsular Ranges with GIS information on vegetation, elevation, slope, and sheep occurrence data from 1988 to 2008. Please see our responses to Comments 5, 16, and 17 and the “Criteria Used To Identify Critical Habitat” section for additional information related to how we used the data to delineate critical habitat.
Comment 19:
One peer reviewer noted that the proposed rule (72 FR 57740, October 10, 2007) includes language describing how the delineation of critical habitat is supported by a draft habitat model provided to the Service by Peninsular bighorn sheep biologists, because areas designated as critical habitat “roughly fall within the upper level habitat suitability classes derived from the preliminary model.” The peer reviewer believes the Service incorrectly interpreted the draft model, suggesting that the Service did not understand the model results. The peer reviewer also stated that although the recent models are based on two years of GPS data from a subset of the total population, and may therefore underestimate use of some areas, they provide support for the essential habitat line and the original (2001) critical habitat line. The peer reviewer believes that the models do not provide support for the currently proposed revised critical habitat delineation.
Our Response:
As stated in the proposed rule, we did not adopt the above mentioned predictive habitat model in our critical habitat delineation process because: (1) It was in draft form and had not been peer reviewed; and (2) it was based on only two years of GPS data from a subset of the Peninsular bighorn sheep population. In response to comments received from peer reviewers and the public, we reanalyzed the draft predictive habitat model. However, we continue to believe it is inappropriate to draw conclusions on whether the model supports or does not support our revised critical habitat designation for this DPS because there are limitations in the data set used to create the model (
i.e
., only two years of GPS data), the model is in draft form, and has not been peer reviewed.
Comment 20:
One peer reviewer believes that the proposed rule (as written) suggests that the proposed critical habitat delineation was based partially on ewe group delineations in Rubin
et al.
(1998). The peer reviewer noted that the Rubin
et al.
(1998) ewe group delineation was intended to document the approximate known distribution of ewe groups at that time. The peer reviewer further stated the ewe group delineation was not intended to represent essential habitat, it does not include additional areas used by rams, and it does not represent areas of connectivity. The peer reviewer clarified that the ewe group delineation in Rubin
et al.
(1998) was based on a small number of radiocollared sheep
(GPS collars had not been used in the study at that time), it did not include locational information on sheep in the San Jacinto Mountains, and it was based on data collected in the mid-1990s when the population of Peninsular bighorn sheep was at its smallest known size. Finally, the peer reviewer contends that the proposed rule is implying that ewe-group delineations in Rubin
et al.
(1998) were based on animal locations collected during 1971-1996 (p. 57747). However, the peer reviewer stated that ewe-group delineations were actually based on data collected during 1993-1996; Rubin
et al.
(1998) did use data collected since 1971, but those data were only represented by water-hole count data (used to examine long-term abundance trends). Therefore, the peer reviewer believes that the ewe group delineations in Rubin
et al.
(1998) present a minimum distribution of bighorn sheep in the Peninsular Ranges.
Our Response:
As stated in this final rule and the “Criteria Used To Identify Critical Habitat” section of the NOA (73 FR 50498, August 26, 2008), 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 as an initial step in the delineation process. We consider Rubin
et al.
(1998) to be the best available data on Peninsular bighorn sheep ewe group distribution. The ewe group delineations presented in Rubin
et al.
(1998) were based on data collected during 1993 to 1996 (not 1971 to 1996 as incorrectly stated in the proposed rule (72 FR 57740, October 10, 2007)), when the population of Peninsular bighorn sheep was at historically low levels. Therefore, the ewe group delineations present a minimum distribution of bighorn sheep in the Peninsular Ranges. However, this is the only data we are aware of that identifies the distribution of ewe groups and subgroups within the Peninsular Ranges. Furthermore, we believe that the ewe groups presented in Rubin
et al.
(1998) accurately depict the general locations of the known ewe groups in these ranges and provide a logical starting point for the delineation of critical habitat.
Comment 21:
One peer reviewer believes that climate change will undoubtedly have an effect on habitat, and changes in temperature and precipitation will likely increase the importance of upper elevation habitats. Additionally, the peer reviewer believes the proposed revision to critical habitat excludes some high elevation areas currently occupied by bighorn sheep and reduces the protection of habitat that will be essential for conservation of the Peninsular bighorn sheep in the future.
Our Response:
Peninsular bighorn sheep generally do not use the upper elevation habitats of the Peninsular Ranges at this time because those areas are more densely vegetated and provide conditions of poor visibility. For further discussion, see our responses to Comments 16 and 17.
We acknowledge that climate change could result in changes in the resources and habitat condition along an elevational gradient in the Peninsular Ranges. However, the scientific evidence available at this time does not suggest that upper elevation habitats in the Peninsular Ranges will become more visually open (
i.e
., more suitable for Peninsular bighorn sheep) as a result of a climate change scenario like that described by the peer reviewer. The peer reviewer did not submit any specific data supporting the contention for the need to expand critical habitat to include currently unoccupied upper elevation habitat. We are unaware of any studies or data that would indicate this request is appropriate. In fact, Epps
et al.
(2004, p. 111) applied a climate change model that assumed an increase in temperature of 2 degrees Celsius and a decrease in precipitation of 12 percent and found no change in the probability of extinction for sheep in those ranges supporting the Peninsular bighorn sheep. Should additional data become available, we may revise this final critical habitat designation, subject to available funding and other conservation priorities.
Comment 22:
One peer reviewer agreed with the Service regarding correction of an earlier error to recognize this listed entity as a DPS of the subspecies
Ovis canadensis nelsoni
. The peer reviewer also stated that no attempt was made by the Service in the proposed rule to give the reader a full geographic picture of how this DPS fits into the larger distribution of that subspecies. The peer reviewer believes that this animal should be referred to as a DPS, avoiding the term subspecies. The peer reviewer believes that if Peninsular bighorn sheep is defined as simply “bighorn sheep in the Peninsular Ranges,” then the word Peninsular in that phrase is redundant and unnecessary. The peer reviewer believes the problem is that the use of Peninsular bighorn sheep in this context gives the reader a false impression that there is something unique and different about this subspecies. The peer reviewer suggested this could be avoided by referring to the animal as “bighorn sheep in the Peninsular Ranges.” Another peer reviewer stated that the commonly accepted vernacular name for
Ovis canadensis nelsoni
is Nelson's bighorn sheep and not Peninsular bighorn sheep. The peer reviewer suggested the Service refer to this DPS throughout the rule as “Nelson's bighorn sheep in the Peninsular Ranges.”
Our Response:
As discussed in the Background section of this final rule, we are formally changing the listed entity as a DPS of the desert bighorn sheep,
Ovis canadensis nelsoni
, and this final rule includes such change to the list of Endangered and Threatened Wildlife at 50 CFR 17.11(h). Within this final rule, we believe it is appropriate to continue to refer to these sheep with the common name Peninsular bighorn sheep. Further, we will refer to this listed entity as a DPS, not a species or subspecies as we have in previous
Federal Register
publications. We also have included information on the geographic distribution of the desert bighorn sheep subspecies, of which Peninsular bighorn sheep are a DPS, in the “Background” section of this final rule.
Comment 23:
One peer reviewer noted that in the proposed rule the Service stated it “has been hypothesized that desert bighorn sheep can survive without a permanent water source,” although the Service did not provide a citation. The peer reviewer believes the most appropriate citation should have been Krausman
et al.
(1985), which demonstrated this to be true for a Sonoran Desert population. The peer reviewer further believes that more meaningful discussion would have compared high temperatures for the population studied by Krausman
et al.
(1985) with those in the Peninsular Ranges, from which a greater need for water could be surmised. The same peer reviewer noted that the Service also did not provide a citation in the proposed rule when referring to water as “especially important to lactating ewes. * * *” The peer reviewer believes that Bleich
et al.
(1997) refuted this as a myth.
Our Response:
In light of the peer reviewer's comment, we included the citation of Krausman
et al.
(1985) into our discussion of water in the “Primary Constituent Elements (PCEs)” section of this final rule. All other variables (
e.g
., vegetation, elevation, climate, terrain) being the same, we agree with the peer reviewer that it could be assumed that sheep living in ranges with higher temperatures would have a greater need for water. However, we are not aware of an analysis comparing the Peninsular Ranges to the Little Harquahalas studied
by Krausman
et al.
(1985, p. 26). Regarding the peer reviewer's comment regarding Bleich
et al.
(1997), we reevaluated the available literature on the importance of water to lactating ewes. As a result, we revised the discussion of water in the “Primary Constituent Elements (PCEs)” section of this final rule.
Comment 24:
One peer reviewer stated the proposed rule lists sites for breeding and space for mating as key habitat elements, but the peer reviewer believes there is no evidence to suggest that lack of breeding is a limiting factor for these sheep. The peer reviewer also believes there is no evidence that breeding takes place in any habitat other than where normal activities occur during the months in which breeding and mating take place.
Our Response:
We acknowledge the peer reviewer's concerns regarding Peninsular bighorn sheep breeding habitat. We did not suggest in the proposed rule that lack of breeding is a limiting factor for Peninsular bighorn sheep or that breeding occurs exclusively in a specific type of habitat. Rather, our intention was to highlight the importance of maintaining space for individual and population growth and normal behavior, which includes breeding.
Comment 25:
One peer reviewer believes the document could be strengthened by using primary literature (versus grey literature) and citing original sources.
Our Response:
Consistent with section 4(b)(2) of the Act, the Secretary shall use the best scientific data available when making critical habitat determinations. Data reviewed by the Secretary may include, but are not limited to, scientific or commercial publications, administrative reports, maps or other graphic materials, information received from experts on the subject, and comments from interested parties. Designation of critical habitat for Peninsular bighorn sheep includes a compilation of data from peer-reviewed, published literature; unpublished or non-peer reviewed survey and research reports; and opinions of biologists knowledgeable about Peninsular bighorn sheep and their habitat. We use primary literature whenever possible, although in some cases grey literature provides timely and detailed information that may otherwise not be available. Therefore, in this final revised critical habitat designation we have used the best scientific information available at this time, including updated information provided by peer reviewers and commenters, which is incorporated into this rule where appropriate.
Comment 26:
One peer reviewer believes the distribution of critical habitat could be more exact (and defensible) based on locations of sheep. The peer reviewer further stated that the Service should consider documented sheep locations approximately 500-1,000 m (1,640-3,280 ft) in any direction as the boundary of critical habitat, because the peer reviewer believes this would be defensible given the accuracy of the radio and GPS collar generated locations. Finally, the peer reviewer suggested other defensible options for a more exact critical habitat delineation, including the use of minimum convex polygons or 95 percent adaptive kernel techniques (and the connectivity between them).
Our Response:
Consistent with 50 CFR 424.12(b), when considering the designation of critical habitat, the Secretary shall focus on the principal biological or physical constituent elements within the defined area that are essential to the conservation of a given species and that may require special management considerations or protection. Additionally, as per section 3(5)(A)(ii) of the Act, critical habitat also includes specific areas outside the geographical area occupied by the species at the time it is listed if such areas are essential for the conservation of the species. While delineating critical habitat, we not only considered Peninsular bighorn sheep locations, but also a combination of habitat features. We believe that drawing circles around occurrence points as the commenter has suggested (by delineating the critical habitat boundary as 500-1,000 m (1,640-3,280 ft) in any direction of a sheep location) would not accurately reflect essential habitat for this DPS because collared sheep represent a subset of the total number of sheep in the Peninsular Ranges. Additionally, there are a disproportionate number of collared animals in the northern extent of the DPS's range compared to the southern extent of its range. Therefore, we believe basing critical habitat only on occurrence data would lead to an underrepresentation of the habitat essential to the whole population.
Both the minimum convex polygons or 95 percent adaptive kernel techniques could be valid options for determining a species' habitat or home range; however, we believe our criteria used to identify critical habitat gives a more precise delineation of essential habitat based on occurrence data and the physical or biological features essential to the conservation of Peninsular bighorn sheep (see “Criteria Used To Identify Critical Habitat”). We did consider the use of other techniques to delineate critical habitat, including minimum convex polygons or 95 percent adaptive kernel techniques such as the peer reviewer suggested. However, those techniques can yield broad and irregularly shaped polygons of habitat inclusive of expanses of areas that lack occurrence data.
We delineated critical habitat boundaries as described in the “Criteria Used To Identify Critical Habitat” section of this final rule. Please see this section for a detailed discussion of the delineation process used for this rule.
Comment 27:
One peer reviewer stated it was not clear in the proposed rule how the distribution of bighorn sheep and occupied areas were determined. The peer reviewer believes the “Methods” section does not define occupied habitat. The peer reviewer believes that if sheep are regularly using an area, it is important for the Service to define occupied habitat. However, if sheep have not used an area in more than 5 to 10 years and there is no suitable habitat adjacent to that area, the peer reviewer believes it would be difficult to defend this area as critical. The peer reviewer suggested an in-depth cumulative effects examination to address this issue.
Our Response:
We agree with the peer reviewer that areas of regular, repeated sheep use are important to this DPS; however, we disagree with the peer reviewer's assertion that areas not used by sheep in more than 5 to 10 years will be difficult to defend as critical habitat. Section 3(5)(A)(i) of the Act defines critical habitat as the geographical area occupied by the species, at the time it is listed in accordance with the provisions of section 4 of the Act, on which are found those physical or biological features (a) essential to the conservation of the species and (b) which may require special management considerations or protection. As a revision to our criteria announced in the NOA (73 FR 50498, August 26, 2008), we included areas with occupancy data indicating they are currently occupied or areas with occupancy data indicating they were occupied at some point between 2008 (present time) and 1988 (i.e., the time of listing (1998) less 10 years, which is the average lifespan of Peninsular bighorn sheep).
Use of a data set that considers a larger time-span of occurrence data accounts for the large fluctuations in Peninsular bighorn sheep population levels over the last two decades. Because the average lifespan of sheep is approximately 10 years (Botta 2008a, p. 1), areas occupied 10 years prior to listing should be considered occupied at listing. Therefore, we appropriately
included areas supporting the essential physical and biological features that may require special management considerations or protection that are within areas occupied at the time of listing. We did not include areas that were unsuitable or otherwise did not support physical and biological features essential to the conservation of the species. Please see our response to Comment 8 and “Criteria Used To Identify Critical Habitat” section of this rule for additional discussion on occupancy and methodology used to develop critical habitat.
With regard to the assertions about a cumulative effects analysis, the peer reviewer may be confusing a cumulative effects analysis under section 7 of the Act or NEPA with the process for designating critical habitat. A “cumulative effects” analysis is not required under section 4 of the Act. Under section 4(b)(2) of the Act, we did consider the economic, national security, and other relevant impacts of designating critical habitat.
Comment 28:
One peer reviewer believes that bighorn sheep habitat along the border could be altered by illegal immigrants and the Border Patrol (or other agents that pursue illegal immigrants). The peer reviewer also believes that future economic growth could further infringe on the bighorn sheep's habitat in the southern part of its range as it has in the northern part of its range. The peer reviewer believes that these issues should be addressed in a cumulative effects analysis.
Our Response:
When delineating critical habitat for Peninsular bighorn sheep, we used the best available scientific information to determine those areas that meet the definition of critical habitat. We do not have any data indicating that activities associated with the Border Patrol activities or illegal immigration threaten Peninsular bighorn sheep habitat along the border, nor did the peer reviewer supply data to support this assumption. The DEA analyzed projected economic growth and associated economic impacts, and the majority of projected growth is expected to occur in the northern part of the range. We recognize the potential threat of development in the “Special Management Considerations or Protection” section of this final rule. Again, the peer reviewer may be confusing a cumulative effects analysis under section 7 of the Act or NEPA with the process for designating critical habitat.
Comment 29:
One peer reviewer did not agree with our discussion of the potential negative effects of roads to Peninsular bighorn sheep as stated in the 2007 proposed rule. The peer reviewer believes that the citation of Epps
et al.
(2005, p. 1035) in the proposed rule is inappropriate to this DPS because that study was concerned with the effects of major fenced highways, and the roads in question in the Peninsular Ranges are smaller two-lane roads that Peninsular bighorn sheep cross regularly.
Our Response:
In light of the above comment, we revised our discussion of the effects of roads on Peninsular bighorn sheep and revised our citation of Epps
et al.
(2005). Please see the “Special Management Considerations or Protection” section of this final rule.
Comment 30:
One peer reviewer believes that the discussion in the 2007 proposed rule of behavioral interactions between humans and bighorn sheep is not objective and lacks a real analysis of the problem as its basis. The peer reviewer believes that an analysis is required regarding our statement that “disturbance could modify the sheep's behavior or cause bighorn sheep to flee an area.” The peer reviewer believes this statement falsely implies that such an incident is detrimental to the conservation of this animal. Additionally, the peer reviewer suggested we provide an alternative statement indicating that bighorn sheep in the Peninsular Ranges are a good example of a DPS that can readily habituate to human activities that are non-threatening and geographically predictable.
Our Response:
The opening paragraphs of our proposed revised critical habitat designation clearly state that the rule is not intended to serve as a comprehensive review of desert bighorn sheep ecology and conservation, and such reviews can be found elsewhere. The proposed rule briefly discusses the natural history and management of bighorn sheep, and then concentrates upon the methodology used to designate critical habitat. The effects of human activities on bighorn sheep have been discussed and debated by many biologists and managers for decades; thus, we included a brief synopsis of the topic. We recognized there were differences of opinion, and thus we were careful to include words such as “potential.” It should be noted that we were discussing human activity in a general sense, and we listed a variety of activities as examples.
A careful review of the literature reveals that bighorn sheep group or individual responses to human activity are highly variable and influenced by local factors and local history. Therefore, generalized statements extending to all bighorn sheep are inappropriate. An overwhelming majority of biologists have expressed concern and have recommended limiting or managing human activities in bighorn sheep habitat. The peer reviewer is correct in asserting that much of the literature consists of opinions and that there is a need for additional well-designed studies that provide stronger inferences. However, considering the volume of opinions on the potential impacts that human activities may have on bighorn sheep, it was appropriate to include discussion of these potential impacts when considering if the physical or biological features essential to the conservation of the Peninsular bighorn sheep may require special management considerations or protection.
Comment 31:
One peer reviewer made the following statement: “Conspicuous by its absence in this proposal is any reference to the recent Turner
et al.
[2004] published habitat analysis of bighorn sheep in the northern Peninsular Ranges, the Ostermann
et al.
[2005] rebuttal to that, and the response by Turner
et al.
[2005].” The peer reviewer further stated that a subsequent unpublished preliminary habitat analysis by Rubin
et al.
was referenced in the proposed rule instead, with a statement that it was not adopted because of its preliminary nature; yet it was used as validation of the critical habitat boundaries, which effectively is stating that it was adopted. The peer reviewer pointed out that in discussing why the new proposal includes much less habitat, the Service stated that many areas in the original critical habitat did not support features essential for the conservation of the Peninsular bighorn sheep or otherwise contain suitable habitat for the DPS. The peer reviewer stated this is the same point made by Turner
et al.
(2004), and regardless of whether the Service accepts the details of their habitat modeling, the peer reviewer believes it would be appropriate to cite them as having arrived at the same conclusion. Finally, the peer reviewer stated that, without advocating one study over the other, this is not objective, and there should be a discussion addressing why the Turner
et al.
analysis was not used, while an unpublished preliminary analysis was used.
Our Response:
We considered the papers cited above (Turner
et al.
2004; 2005; and Ostermann
et al.
2005), but they did not play a role in the development of the critical habitat designation. Therefore, they were not cited and discussed in the proposed rule. Turner
et al.
(2004) based their model primarily upon data collected
from a subpopulation that exhibited atypical habitat selection patterns. Approximately 90 percent of the data points utilized were collected from a group of bighorn sheep that frequented urban areas in the vicinity of Rancho Mirage. Furthermore, 79 percent of the data points utilized were collected over only a seven-year period when bighorn sheep use of urban areas was most pronounced. This fact also biased the data from a spatial standpoint because point locations were much easier to collect in urban settings. Approximately 80 percent of the point locations utilized were obtained within 1.9 mi (3 km) of an artificial water source, which was located next to a residential community. Additionally, Turner
et al.
(2004) assumed that the density of bighorn sheep point locations in a given area accurately reflected habitat quality, and they did not account for variations in sampling effort and detection. Finally, the Turner
et al.
(2004) model utilized a subset of the available data. Only a small amount of the data utilized was collected from other bighorn sheep groups that exhibited behavior and habitat use patterns typical of bighorn sheep inhabiting the remainder of the Peninsular Ranges.
For the reasons stated above, the Turner
et al.
(2004) model should not be considered a general model for identifying or ranking bighorn sheep habitat in the Peninsular Ranges. Its validity is specific to the small group of sheep that frequented urban areas in Rancho Mirage from 1994-2000. The Turner
et al.
(2005) rebuttal to Ostermann
et al.
(2005) did not fully address the above issues, but instead aired past grievances with the Service and addressed aspects of Peninsular bighorn sheep recovery that were not specific to their model or Ostermann
et al.
(2005).
The preliminary habitat analysis conducted by Rubin
et al.
(2007) utilized point locations collected from bighorn sheep not closely associated with urban areas, and their efforts utilized different and recently developed methodology. The preliminary results were presented by Rubin
et al.
to our office and examined. However, the Rubin
et al.
(2007) preliminary results were not used to adjust the boundaries of the proposed critical habitat designation (see our response to Comment 20 above). The peer reviewer is justified in asserting that if the preliminary results of Rubin
et al.
(2007) were mentioned in the proposed rule, then the Turner
et al.
(2004) model, plus rebuttals, also should have been discussed. However; since neither model was used to designate the proposed critical habitat, we removed further discussion of the models (e.g., Rubin
et al.
2007; Turner
et al.
2004) from this final rule.
Public Comments
Comments Related to Criteria Used To Identify Critical Habitat
Comment 32:
Two commenters stated that upon examination of occurrence data and the original critical habitat (2001), they believe that the original critical habitat was overdrawn. The commenters further believe that the original critical habitat contains large areas of land that have no evidence of current or historic bighorn sheep activity or that have had only a handful of observations over the past 30 years. The commenters noted that the Service's attempt to base the proposed critical habitat on more technical, state-of-the-art distributional information appears to be a step toward resolving some of these issues. The commenters believe the methodology used in the proposed rule is vague, and the sources of information do not appear to be publicly available. For example, one commenter questioned how the ewe group delineation from Rubin
et al.
(1998) was compared to all occupancy data collected since the time of listing on GIS imagery maps. Both commenters also questioned how ewe group delineation was expanded to include areas where occupancy data points indicate repeated Peninsular bighorn sheep use and recent sheep movements.
Our Response:
We acknowledge that the 2001 critical habitat designation contains large areas of land that have no evidence of current or historic bighorn sheep activity or have had only a handful of observations over the past 30 years. A complete discussion of how information and data collected since the 2001 designation was utilized to refine the proposed designation and the steps used in the delineation process (
i.e
., methodology) can be found in the “Criteria Used To Identify Critical Habitat,” “Summary of Changes From the 2001 Critical Habitat Designation To the 2007 Proposed Rule To Revise Critical Habitat,” and “Summary of Changes From the 2007 Proposed Rule To Revise Critical Habitat To This Final Rule To Revise Critical Habitat” sections of this final rule.
Comment 33:
Two commenters believe it is disconcerting that the proposed rule expands areas of occupancy (from E. Rubin's ewe group determination) to include areas where there are only a handful of sightings, where sighting data are unverifiable, and where bighorn sheep have been recently released. The commenters believe this suggests that critical habitat can be “created” by releasing bighorn sheep into previously unoccupied areas. The commenters further stated that the expansion of the northernmost ewe group delineation in the San Jacinto Mountains could be justifiable; however, they believe there is no way to objectively evaluate the information used in support of this expansion. The commenters provided the example that several bighorn sheep sightings in Chino Canyon were the result of helicopter pursuits driving animals onto the valley floor. The commenters questioned if these coerced observations were included in the database. Additionally, the commenters believe the proposed rule expanded the southernmost ewe group delineation near Interstate 8 based on consistent, recent sightings of uncollared Peninsular bighorn sheep and asked the Service if this includes ewes, lambs, and rams. The commenters stated that their understanding was that California Department of Fish and Game (CDFG) personnel suggest these are occasional sightings of rams. The commenters believe that since these are uncollared animals, it is unknown if these “consistent sightings” are of one or a few individuals being repeatedly seen or from multiple groups colonizing the area and further indicated that subjective statements such as this by the Service are unacceptable in a final rule.
Our Response:
We believe it was necessary and justifiable to explore and consider additional available scientific information because the ewe group delineations from Rubin
et al.
(1998) were intended to document the approximate known distribution of ewe groups at that time and were based on only a few years of data. Using the ewe group delineations as a starting point, we expanded our proposed critical habitat boundary from the ewe group delineations using a much larger set of occurrence data from 1988 to 2008 and information on essential habitat features. See our response to Comment 20 and the “Criteria Used To Identify Critical Habitat” section of this final rule for more discussion on the methodology and expanded critical habitat boundary.
In response to the commenters' assertion that we included areas where there are only a handful of sightings, where sighting data are unverifiable, and where bighorn sheep have been recently released, we used the best available scientific data in determining whether the areas in question meet the definition of critical habitat. A captive breeding program has been maintained by the Bighorn Institute since 1984 in
cooperation with CDFG and the Bureau of Land Management (BLM). 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) solely into areas currently and historically occupied by the DPS. We recognize that a small percentage of data points considered may be those of released sheep from the captive breeding program; however, we do not suggest that critical habitat can be created by releasing sheep into previously unoccupied areas, as the commenters have asserted. Furthermore, all areas included in the designation contain data points from non-captive-bred sheep. In regard to the commenters' concerns and assertions about the data considered, we are not aware of any “coerced” observations in our database. Finally, the recent bighorn sheep sightings near Interstate 8 include multiple ewes and lambs in groups of varying sizes.
Comment 34:
Several commenters expressed concern about the draft habitat model mentioned in the proposed rule.
Our Response:
We did not use the draft habitat model in our critical habitat delineation for the proposed rule or this final rule. See our response to Comment 19 above.
Comment 35:
Two commenters questioned why the Service does not mention in the proposed rule the three current peer reviewed papers on bighorn sheep critical habitat in the northern Peninsular Ranges (i.e., Turner
et al.
2004; 2005; Ostermann
et al.
2005). The commenters believe this is incongruous, as the critical habitat delineated in the proposed rule most closely approximates the conclusions of Turner
et al.
(2004).
Our Response:
Please see our response to Comment 31 for a discussion of these papers.
Comment 36:
Several commenters believe that the proposed revised critical habitat is flawed because it fails to consider historic and recent known Peninsular bighorn sheep locations. One commenter believes the current proposal fails to include and adequately consider the vast majority of known Peninsular bighorn sheep locations prior to the listing of the DPS as endangered in 1998, when the Peninsular bighorn sheep population was at a historic low point and their range was severely constricted. The commenter also believes that omitting historic locations of Peninsular bighorn sheep from critical habitat designation ensures that the distribution of the DPS will remain severely limited in relation to its historic distribution and is contrary to the Act. The commenter suggested that to promote recovery of the DPS, it is essential that Peninsular bighorn sheep be able to re-inhabit their historic range which, given the rapid expansion of human development in the area, will be impossible if sufficient historic habitat is not protected as critical habitat.
Additionally, one commenter believes the critical habitat designation in the proposed rule does not accurately take into account multiple sheep locations recorded since Peninsular bighorn sheep were listed in 1998. The commenter noted that conservation groups have been informed by the Peninsular bighorn sheep recovery team members that the proposed revised critical habitat fails to consider known sheep locations that were made available to the Service by members of the Peninsular bighorn sheep recovery team. The commenter noted their belief that the consequence of this omission (whether purposeful or inadvertent) is that significant areas of currently occupied habitat essential to the DPS are omitted from the proposed rule.
Our Response:
Regarding the commenters' concern about a flawed proposal and assertions about historic and known sheep locations not considered in the proposed revised critical habitat designation, we revised our criteria in light of these concerns and similar comments from peer reviewers about the limited dataset used in the proposed rule. The revisions were announced in the NOA published in the
Federal Register
on August 26, 2008 (73 FR 50498). We revised our criteria to consider occurrence data between 2008 (present time) and 1988 (
i.e.
, the time of listing (1998) less 10 years, which is the average lifespan of Peninsular bighorn sheep). Use of a data set that considers a larger time-span of occurrence data accounts for the large fluctuations in Peninsular bighorn sheep population levels over the last two decades. See our response to Comment 8 above.
Regarding the concerns that critical habitat should include the historical range of the DPS, the Service may designate as critical habitat areas outside of the geographical area occupied by a species at the time it was listed (
i.e.
, historical habitat) only when we can demonstrate that those areas are essential for the conservation of the species (section 3(5)(A)(ii) of the Act). Likewise, we can designate as critical habitat areas outside the geographical area presently occupied by a species only when a designation limited to the species' present range would be inadequate to ensure the conservation of the species (50 CFR 424.12(e)). Refer to our response to Comment 7 for further discussion.
We believe that we considered a scope of occurrence data that is reflective of the large population fluctuations of Peninsular bighorn sheep over the past two decades, not just occurrence data from a “historic low point” when the range of this DPS was “severely constricted,” as the commenter suggests. See our response to Comment 8 above for a detailed discussion.
With regard to the commenter's concerns of the omission of occurrence data previously provided to the Service, we examined the occurrence data considered in the delineation of the proposed revised critical habitat and found that a set of data was missing from our GIS database. Subsequently, we included that occurrence data into our GIS database and double-checked to ensure that all occurrence records submitted to the Service were included for our analyses. Please see our response to Comment 10 above.
Comment 37:
One commenter asserted that instead of including the full catalogue of known locations, the Service's proposed revised critical habitat gives greater weight to occurrence data acquired remotely through radio telemetry and GPS. The commenter believes that this nonrandom sampling inevitably biases the assessment of habitat selection by Peninsular bighorn sheep towards more intensively studied groups and that it cannot be construed as representative of habitat use throughout the range.
Our Response:
We realize that much of the occurrence data for this DPS is based on data acquired remotely through radio telemetry and GPS. Additionally, we are aware that not all areas within the range of the DPS have been surveyed or studied equally (see our response to Comment 8). For example, the extreme southern portion of the Peninsular Ranges has not been studied as heavily with radio telemetry and GPS collar technology as in the north. Therefore, we use a variety of occurrence data such as photographic evidence, scat data, and field notes collected from Service biologists and other species experts to determine occupied habitat. The designation of critical habitat for Peninsular bighorn sheep is based on the best scientific data available regarding the DPS, including a compilation of data from peer-reviewed, published literature; unpublished or non-peer-reviewed survey and research reports; and opinions of biologists knowledgeable about Peninsular bighorn sheep and their habitat.
Comment 38:
One commenter believes the proposed rule is flawed because it uses uncertain and unclear methodology, and another commenter believes the Service failed to consider the best scientific and commercial data available. Additionally, one commenter believes that the failure to provide a clear and transparent methodology prevents independent validation of the proposed changes insofar as scientists and other members of the public are unable to conduct a comprehensive appraisal of the methods and determinations.
Several commenters stated that it is unclear how the Service utilized the PCEs identified in the proposed rule to ascertain whether specific habitat should be categorized as critical. One commenter stated that he was unable to assess how the Service derived the maps of critical habitat, as they contain features not consistent with known topography or known bighorn sheep locations. The commenter further noted that the critical habitat maps in the proposed rule show several lengthy and inexplicable straight line edges of habitat, notably adjacent to Borrego Springs and south of Route 78, which do not conform to the terrain and for which no biological explanation or justification is provided in the proposed rule; they added that bighorn sheep habitat does not naturally occur in such a linear fashion. The commenter had concerns that these boundaries may have been based on political and economic reasoning rather than sound science.
Our Response:
As discussed in our responses to Comments 5 and 12 above and the “Criteria Used To Identify Critical Habitat” section of this final rule, we delineated critical habitat for the Peninsular bighorn sheep using the following criteria: (1) Areas that contain the PCEs required by the DPS as determined from aerial imagery and GIS data on vegetation, elevation, and slope; (2) areas within the ewe group distribution (
i.e.
, subpopulations) boundaries identified by Rubin
et al.
(1998); (3) areas occupied by the DPS between 2008 (present time) and 1988; and (4) areas where occupancy data points indicate repeated Peninsular bighorn sheep use, but which were not captured within the ewe group distribution boundaries identified by Rubin
et al.
(1998). Application of these criteria results in the determination of the physical and biological features that are essential to the conservation of this DPS, identified as the DPS's PCEs laid out in the appropriate quantity and spatial arrangement essential to the conservation of the DPS. Since the 2007 proposed rule, we revised the “Criteria Used To Identify Critical Habitat” section of this rule to provide more detail and a description of the stepwise process used, data considered, habitat features mapped, and method used to delineate critical habitat boundaries. Any boundaries of the proposed critical habitat designation that seem straight in appearance are the result of our criteria used to identify critical habitat and are not the result of political or economic reasoning.
Comment 39:
Many commenters stated that the methods were not designed by or made in consultation with members of the Peninsular bighorn sheep recovery team who are most familiar with Peninsular bighorn sheep ecology and habitat and that they diverge significantly from those methods previously used in the Recovery Plan to determine critical habitat for the DPS.
Our Response:
In accordance with our policy on peer review published on July 1, 1994 (59 FR 34270), we solicited expert opinions from five knowledgeable individuals (some of which were on the recovery team) with scientific expertise that included familiarity with the DPS, the geographic region in which it occurs, and conservation biology principles. We reviewed all comments received from the peer reviewers and the public for substantive issues and new information regarding the designation of critical habitat for Peninsular bighorn sheep. Furthermore, on May 14, 2007, representatives from the Carlsbad Fish and Wildlife Office and the Regional Office, including the Regional Director, met with recovery team members in part to inform members that we were initiating work to propose revisions to designated critical habitat for the Peninsular bighorn sheep. At that meeting, we requested that recovery team members submit any data they wanted us to consider in our proposed revision. Therefore, we believe that we followed the appropriate guidance and regulations regarding inclusion of expert biologists and others during development of this critical habitat designation. See our response to Comment 11 above.
Comment 40:
One commenter believes that the 0.5-mi (0.8-km) buffer zone around slopes equal or greater than 20 percent as described in the Recovery Plan is not necessary, and they expressed support for the Service not to include this buffer in the final critical habitat designation.
Our Response:
The areas of the 0.5-mi (0.8-km) zone around 20 percent slopes were included in the Recovery Plan and 2001 final critical habitat designation because they may contain resources for the DPS, and bighorn sheep have on occasion been observed to wander great distances from areas of 20 percent slope. The inclusion of these areas resulted in the addition of large expanses of land to the Recovery Plan area and the 2001 critical habitat designation. However, based on the best scientific information currently available and our criteria used to identify critical habitat, those areas do not meet the definition of critical habitat. As a result, we are not including some areas that were previously designated as critical habitat that are within this 0.5-mi (0.8-km) zone around 20 percent slopes. See our response to Comment 4 above, and the “Criteria Used To Identify Critical Habitat” and “Summary of Changes From the 2001 Critical Habitat Designation To the 2007 Proposed Rule To Revise Critical Habitat” sections of this final rule for further discussion.
Comment 41:
One commenter had concerns about the occurrence data considered in our criteria used to identify critical habitat. The commenter stated that no scientifically based reason is identified for why occurrence data from 1988 to present is used. The commenter followed that Peninsular bighorn sheep occurred in the area for millennia prior to 1988 and were in decline by the 1970's. The commenter was also concerned that our use of occupancy data points was restricted to those indicating repeated Peninsular bighorn sheep use. The commenter stated that given the incomplete records for the location of all bighorn sheep at all times, especially in the southern part of the range, they believe it is unreasonable that only the repeated occupancy data points were used for the designation.
Our Response:
As stated in our response to Comment 27 above, we considered areas with occupancy data indicating that they are currently occupied or areas with occupancy data indicating they were occupied at some point between 2008 and 1988 (
i.e.
, the time of listing (1998) less 10 years, which is the average lifespan of Peninsular bighorn sheep). Use of a data set that considers this time span of occurrence data accounts for the large fluctuations in Peninsular bighorn sheep population levels over the last two decades. Because the average lifespan of sheep is approximately 10 years (Botta 2008a, p. 1), areas occupied 10 years prior to listing should be considered occupied at listing. Regarding the concerns over using repeated occupancy data given the incomplete records in the southern part
of the range, we are aware that not all areas within the range of the DPS have been surveyed or studied equally (see our response to Comment 8 above). Regardless, we used the best available scientific information and occurrence data in determining areas occupied by Peninsular bighorn sheep. Please see the “Criteria Used To Identify Critical Habitat” section of this rule for more information.
Comment 42:
In response to our August 26, 2008, NOA announcing changes to the proposed rule, one commenter wrote; “The proposed expansion of critical habitat beyond the boundaries, beyond those in the October 2007 critical habitat proposed rule, relies on essentially the same qualitative, opinion-based approach that led to the remand of critical habitat for new rulemaking by the Court (
Agua Caliente
v.
Scarlett
).”
Our Response:
The commenter implies that the consent decree and associated remand of critical habitat reflect a court judgment supporting their opinion that the methodology used in delineating critical habitat is inappropriate. However, the court order upholding the approval of the consent decree states, “It is also well established that in approving a consent decree, the Court does not delve into the merits of the case, but rather limits its review to determine if the settlement is fair, reasonable, and equitable.” There was no court “ruling” that the methodology used to designate the critical habitat boundary was inappropriate. The parties agreed to a settlement to avoid the mutual risks and expenses of protracted litigation. Additionally, issues other than the methodology for delineating critical habitat, such as the economic analysis and tribal sovereignty, played important roles in the case.
Comments Related to the Primary Constituent Elements
Comment 43:
One commenter believes that information about how PCEs are quantified, the models used for their application, and the methods applied to point-by-point determination of exclusion from critical habitat are not described in the proposed rule and are arbitrary. The commenter noted that some critical habitat was added in comparison to the critical habitat identified based on essential habitat designation in the Recovery Plan, and much habitat was deleted. The commenter inquired if there is a difference in the PCEs of these two groups (
i.e.
, areas added and areas deleted).
Our Response:
In our responses to Comments 5, 12, and 38 and in the “Criteria Used To Identify Critical Habitat” section of this final revised rule, we explain how we delineated critical habitat for the Peninsular bighorn sheep. In response to the commenter's inquiry if PCEs were different for areas added than for those deleted from critical habitat, the same set of PCEs for Peninsular bighorn sheep were used in the process of determining areas to include and not include as critical habitat in this designation.
Comment 44:
One commenter believes the PCEs set forth an almost unlimited area, confined only by certain upper-level altitudes.
Our Response:
Some PCEs may extend beyond the boundary of critical habitat; however, we used ewe group delineations, occurrence data, and habitat features, in addition to the PCEs, to delineate the boundary of critical habitat. We believe that this process has resulted in critical habitat units that contain the PCEs laid out in the appropriate quantity and spatial arrangement essential to the conservation of the DPS. See the “Criteria Used To Identify Critical Habitat” section of this final rule for further discussion of the use of PCEs to delineate critical habitat.
Comments Related to DPS Biological Information
Comment 45:
Two commenters believe the proposed rule gives a false impression that this population is a unique species or subspecies through weak use of nomenclature and erroneous information. The commenters also stated that in numerous places, the proposed rule refers to this DPS as if it were a subspecies or species. The commenters believe that the proposed rule incorrectly refers to this DPS as “Peninsular bighorn sheep (
Ovis canadensis nelsoni
)” in the title and body of the text; however,
Ovis canadensis nelsoni
is the Latin trinomial for “desert bighorn sheep” and the term “Peninsular bighorn sheep” was the common name for the now synonymized subspecies;
Ovis canadensis cremnobates
. The commenters believe this is a matter of peer-reviewed scientific literature and the proposed rule should use correct terminology and refer to this DPS as desert bighorn sheep (
Ovis canadensis nelsoni
) in the Peninsular Ranges of California (Wehausen and Ramey 1993; Ramey 1995).
Our Response:
See our response to Comment 22 above. We are updating the listed entity to a DPS of desert bighorn sheep (
Ovis canadensis nelsoni
). However, we believe it is appropriate to continue to refer to these sheep with the common name Peninsular bighorn sheep within this rule. Additionally, we revised our discussion of the taxonomy of the listed entity in the “Background” section of this final rule.
Comment 46:
Two commenters believe the proposed critical habitat rule includes overstatements that have little or no basis in fact about the negative impacts of human disturbance on bighorn sheep.
Our Response:
Please see our response to Comment 30 above. We do not believe that the discussion in the proposed rule overstates impacts, and we based our discussion on a variety of widely discussed and debated impacts.
Comment 47:
Two commenters stated that while it is important to minimize the effects or impacts of any construction project on bighorn sheep habitat, they believe the assertions in the proposed rule about power lines degrading and fragmenting habitat are without factual substantiation. The commenters also stated that once constructed, power lines and support structures are inanimate objects in the environment, and they believe there is no empirical evidence that power lines fragment bighorn sheep habitat or preclude movements under the power line.
Our Response:
We agree with the commenters that it is important to minimize the effects or impacts of any construction project on bighorn sheep habitat. Our discussion of power lines in the proposed rule in relation to the threat of disturbance to Peninsular bighorn sheep and their habitat was limited to disturbance that would occur during power line construction. Once constructed, power lines become part of the inanimate landscape and may not impede sheep movement. Contrary to the commenters' assertions, we did not suggest or state in the proposed rule that sheep movement is precluded by power lines once constructed.
Comment 48:
Two commenters noted the discussion in the proposed rule of roads fragmenting bighorn sheep habitat in which Epps
et al.
(2005) is cited as “showing that nuclear genetic diversity of desert bighorn sheep populations was negatively correlated with the presence of human-made barriers (highways), which essentially eliminated dispersal.” The commenters believe this is incorrect, stating that the study found there was a negative effect with fenced highways (
e.g.
, Interstates 10, 15, and 40; and State Highway 62), not roads in general.
Our Response:
In light of the above comment, we revised our discussion of
the effects of roads on Peninsular bighorn sheep and revised our citation of Epps
et al.
(2005) to reflect that the study was of fenced highways, not roads in general. Please see the “Special Management Considerations or Protection” section of this final rule.
Comment 49:
One commenter believes the proposed critical habitat designation does not take into consideration the effects of either natural or anthropogenic environmental variations and perturbations on the habitat requirements and utilization of Peninsular bighorn sheep, including changes due to development, fire and fire management, exotic species infestations, and climate change. The commenter asserted that the Service should revise and re-analyze the proposed critical habitat designation, taking into account these factors and ensuring that any new designation includes sufficient critical habitat to allow for Peninsular bighorn sheep recovery in light of the changes brought by climate change and other natural and anthropogenic alterations to sheep habitat across its range.
Our Response:
As discussed in the “Special Management Considerations or Protection” section of this rule, when designating critical habitat, we assessed whether the geographical area occupied at the time of listing contains features that are essential to the conservation of the DPS and that may require special management considerations or protection. We considered the effects of anthropogenic factors (
i.e.
, development and expansion of urban areas, human disturbance related to recreation, construction of roadways and power lines, and mineral extraction and mining operations) on the essential features in the delineation of critical habitat. Additionally, we discussed the issue of climate change in our response to Comment 21 above. At this time, the available scientific evidence regarding potential effects of climate change on Peninsular bighorn sheep habitat does not warrant modification of this critical habitat delineation. We recognize that the threats faced by Peninsular bighorn sheep (including climate change and anthropogenic effects) may change in the future; however, we base our critical habitat designations on the best scientific information available at the time of the designation and do not speculate as to what areas may be found essential if better information becomes available or what areas may become essential over time.
Conservation (
i.e.
, recovery) is achieved when a five-factor analysis performed pursuant to section 4(a)(1) of the Act indicates that current and future threats have been minimized to an extent that the species is no longer threatened with extinction in the foreseeable future. Recovery is a dynamic process requiring adaptive management of threats, and there are many paths to accomplishing recovery of a species. We recognize that recovery efforts will occur both within and outside the boundaries of this final critical habitat designation. However, we believe that conservation of Peninsular bighorn sheep would be achieved if threats to this DPS, as described in the “Special Management Considerations or Protection” section of this rule, were reduced or removed due to management and protection of those areas.
Comment 50:
One commenter stated that in recent years, climate science has advanced considerably, and the Service should take into account the current predictions for impacts to Peninsular bighorn sheep habitat based on global climate change, which includes dramatic vegetation shifts, significantly altered fire regimes, and effects on precipitation (California Climate Change Center 2006). The commenter believes that each of these climate change elements may adversely impact Peninsular bighorn sheep and its existing habitat. The commenter cited a study by Kelly and Goulden (2008) showing that the average elevation of the dominant plant species increased by 65 meters between the surveys of 1977 and 2006-2007 (a 30-year interval) in the Santa Rosa Mountains; this elevational shift in vegetation is attributable to global climate change. The commenter believes that this significant distributional movement of plant species in a relatively short time period indicates that a very dynamic change is occurring in Peninsular bighorn sheep habitat. The commenter also cited a study by Seeger
et al.
(2007) that concluded a broad consensus among climate models indicates that southwestern North America will become more arid in the 21st century due to global climate change. The commenter believes that as a result of these data, the Service should require additional areas and a robust critical habitat designation to provide refuge for Peninsular bighorn sheep during these changing times.
According to the commenter, a study on the effects of climate change on desert bighorn sheep in California by Epps
et al.
(2004, p. 110) concluded that “global warming could have serious consequences for desert bighorn sheep, particularly if coupled with decreases in precipitation.” The commenter further stated that the Epps
et al.
(2004) study found that an average increase of 3.6 degrees Fahrenheit combined with a 12 percent decrease in precipitation increased the likelihood of extinction in desert sheep from 20 percent to 30 percent over the next 60 years. Therefore, the commenter believes that the Service should revise and re-analyze the proposed critical habitat designation, while taking into account these climate change factors, to ensure that any new designation includes sufficient critical habitat that provides for bighorn recovery.
Our Response:
We acknowledge that recent data indicate that plant distributional changes may be occurring in the Peninsular Ranges; however, we are unaware of data indicating a shift in the resource use and distribution of sheep in the Peninsular Ranges that would correlate with the change in plant distribution. By considering sheep occurrence data over the past 20 years, we are likely capturing recent shifts in sheep distribution that may have resulted from changes in plant distribution in the Peninsular Ranges. Additionally, we acknowledge that recent climate studies indicate that the Southwestern United States may experience decreases in precipitation and increases in temperature in the coming years. If in the future, data reveal that sheep are experiencing a shift in distribution to areas outside of the critical habitat designation, in association with changing plant distribution resulting from climate change, we may revise the critical habitat designation at that time, subject to available funding and other conservation priorities.
With regard to the citation of Epps
et al.
(2004), we agree that the study concluded that global warming could have serious consequences for desert bighorn sheep populations. Here, we would like to expand on the commenter's shortened description of Epps
et al.
(2004). The modeled 2.0 degree Celsius temperature increase, combined with a 12 percent precipitation decrease, resulted in an average increased extinction risk of 0.21 to 0.30 for desert bighorn sheep across California; however, the modeled climate scenario did not appear to markedly change the extinction probability for sheep occupying the Peninsular Ranges. Epps
et al.
(2004, p. 111) reported a 0-0.2 extinction probability for sheep in the Peninsular Ranges over the next 60 years under two scenarios, one being no further climate change and the other being the 2 degree temperature increase combined with the 12 percent precipitation decrease (see also our response to Comment 21
above). We cannot conclude from Epps
et al.
(2004) that the Peninsular bighorn sheep population will be under a greater risk of extinction from the modeled climate change scenario, and we do not believe it appropriate to revise and reanalyze our critical habitat designation at this time. Critical habitat designations do not signal that habitat outside of the designation is unimportant or may not contribute to recovery in the future. Should additional data become available, we may revise this critical habitat designation, subject to available funding and other conservation priorities.
Comment 51:
A number of commenters believe that the proposed revision of critical habitat will have a negative impact on sheep recovery because it excludes habitat that supports processes essential to metapopulation survival. One commenter believes that maintaining and reestablishing habitat connectivity to provide long-term genetic and demographic connection between ewe groups is crucial to recovering the Peninsular bighorn sheep and notes that it is a Priority 1 strategy in the Recovery Plan (Service 2000, p. 113). Several commenters noted that connectivity of habitat, as well as the resulting facilitation of animal movements and gene flow among metapopulations, are recognized as crucial elements for recovery by the Service. Several commenters further stated that they believe the proposed rule fails to identify critical habitat in regions that are confirmed linkages between metapopulation subsegments, based on data and materials provided to the Service by the Bighorn Institute and by bighorn sheep researchers, such as Dr. Esther Rubin. Several commenters believe that the proposal would eliminate critical habitat crucial for maintaining connectivity between Unit 1 and Unit 2A (thereby isolating the Peninsular bighorn sheep population in the San Jacinto Mountains) and between Units 2B and 3 (thereby isolating the Carrizo Canyon population).
One commenter believes that connectivity between bighorn population sub-segments in the Peninsular Ranges has been predicted from preliminary genetic studies and verified by both radio tracking and GPS collar data. The commenter also stated that failure to identify critical habitat between the Northern Santa Rosa Mountains (Unit 2A) and the San Jacinto Mountains (Unit 1) and between the Fish Creek Mountains (Unit 2B) and Coyote Mountains (Unit 3) would result in a failure to apply the protections that the Service is required to afford to a recovering endangered species through the designation of essential habitat and critical habitat. The commenter further believes that such a failure would be especially pronounced in the case of the bighorn sheep, when the Recovery Plan and the best available science indicate that the protection of Peninsular bighorn sheep critical habitat connectivity is a crucial element for recovery to allow for its downlisting or delisting. Another commenter believes that failing to maintain critical habitat in these areas is a serious flaw of the proposed revised critical habitat designation and could jeopardize the persistence of isolated herds and preclude recovery of the Peninsular bighorn sheep.
Our Response:
We agree with the commenters that habitat connectivity is important to allow for movement between ewe groups and to maintain genetic variation; however, we do not have occurrence data suggesting specific travel corridors connecting the units discussed by the commenters, and we are unable to identify specific areas containing physical or biological features essential to the conservation of the DPS. Please see our responses to Comments 1, 5, and 7 and the “Criteria Used To Identify Critical Habitat” section of this final rule for further discussion.
Comment 52:
One commenter indicated that the population of Peninsular bighorn sheep dropped from possibly two million in 1800 to about 1,200 in the 1970s, and then to about 300 at the time of listing in 1998. The commenter believes that limiting Peninsular bighorn sheep habitat to 420,487 ac (170,166 ha) (as stated in the proposed rule) would not protect the entire range of the species.
Our Response:
Our understanding is that the commenter may be confusing a possible estimate of all bighorn sheep in North America in 1800 with the Peninsular bighorn sheep DPS. As we stated in our response to Comment 8 above, when rangewide estimates were made in the 1970's, the population was estimated as high as 1,171 in 1974 (Weaver 1974, p. 5). At no point in history was the population of Peninsular bighorn sheep near two million. In this rulemaking, we are designating critical habitat for the Peninsular bighorn sheep and not the entire population of bighorn sheep that exists in various parts of North America. We believe the acreage we are designating in this final rule (376,938 ac (152,542 ha)) is adequate to provide for the conservation of the Peninsular bighorn sheep DPS.
Comments Related to Proposed Exclusions Under Section 4(B)(2) of the Act
Comment 53:
One commenter stated that conservation groups disagree with the Service's assertion that it is appropriate to exclude some habitats from critical habitat designation because those areas are encompassed by the Coachella Valley MSHCP and draft Agua Caliente Band of Cahuilla Indians Tribal HCP. The commenter also believes that tribal lands should be retained in critical habitat for many reasons, including that the Tribal HCP is in draft form and not yet approved, nor is it found to adequately conserve the DPS. The commenter asserted that critical habitat should be designated even in areas where these plans may overlap to some degree in order to provide a safety net for habitat conservation for this endangered DPS. Several additional commenters also questioned the proposed exclusion of lands owned by the Agua Caliente Band of Cahuilla Indians Tribe.
One commenter noted that the proposed rule states (as reason for excluding critical habitat encompassed by the Agua Caliente HCP), “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 intrusion into tribal natural resource programs (October 10, 2007, 72 FR 57750).” The commenter believes this argument is not acceptable because it fails to take the conservation and recovery goals of the Act adequately into account.
Our Response:
We believe the exclusion of lands under the Coachella Valley MSHCP and Agua Caliente Band of Cahuilla Indians' lands is appropriate based on the potential impacts associated with designating these areas as critical habitat (see “Exclusions Under Section 4(b)(2) of the Act” section of this final rule for a detailed discussion). Section 4(b)(2) of the Act allows the Secretary to exclude areas from critical habitat if he determines that the benefits of such exclusion outweigh the benefits of specifying such area as part of 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. We believe that critical habitat designation could negatively impact the working relationships and conservation partnerships we have formed with the
Coachella Valley MSHCP permittees, the Tribe, and other private landowners.
This belief is supported by the following statement from the Tribe received during the comment period for the proposed rule, “Contrary to the requirements of the ESA, Executive Order 13175, and the Secretarial Order, the proposed rule fails to defer to the tribe's own established standards, it discourages the Tribe from developing its own policies, and it intrudes on tribal management of its lands. Designation of critical habitat could delay approval of the 2007 draft Tribal HCP, thus adding to the costs of preparing the Tribal HCP and undermining significant protections for the bighorn sheep. Designation of critical habitat also can be expected to increase the amount of time and financial resources necessary to undertake covered activities described in the Tribal HCP, yet it is unlikely to yield material benefits for the bighorn sheep.”
Additionally, as explained in detail in the “Application of Section 4(b)(2)—Other Relevant Impacts—Conservation Partnerships” section of this final rule, we believe these conservation partnerships through the Coachella Valley MSHCP and tribal conservation programs will provide as much or more benefit than consultation under section 7(a)(2) related to the critical habitat designation (the primary benefit of a designation). See our response to Comment 2 above for additional discussion. With regard to the commenter's assertion that this argument is not acceptable because it fails to take the conservation and recovery goals of the Act adequately into account, we take conservation into account when determining areas that meet the definition of critical habitat and in considering the benefits of specifying any particular area as critical habitat. After weighing the benefits of excluding a particular area against the benefits of including such area as critical habitat, the Secretary may exclude the area from critical habitat if he determines that the benefits of exclusion outweigh the benefits of inclusion and that the failure to designate such area as critical habitat will not result in the extinction of the species concerned. Thus, at the end of the analysis under section 4(b)(2) of the Act, we consider whether an exclusion will result in extinction of the species, not whether the exclusion could impact recovery goals.
Comment 54:
One commenter stated opposition to the Service's policy of relying on section 4(b)(2) of the Act to exclude habitat that may be covered by management plans or conservation plans under the logic that these areas do not need “special management” pursuant to section 3(5)(A) of the Act. The commenter referred to this approach as “belt and suspenders” and reminded the Service that the district court of Arizona struck down this approach in
Center for Biological Diversity
,
et al.
v.
Norton
(D. Ariz. 2003). The commenter believes that all Peninsular bighorn sheep essential habitat needs special management because of the variety of impacts to its habitat (
e.g
., impacts from development, grazing, fire management activities, and off-road vehicle use). The commenter believes that current or future management actions provided for the Peninsular bighorn sheep or its habitat by management plans or conservation plans are not a reasonable justification for excluding these areas from the protection that a designation of critical habitat provides. The commenter further stated that the Act defines critical habitat as an area that may need special management, and therefore areas that are receiving management under a management plan or conservation plan meet the definition of critical habitat and should not be excluded if the necessary management is being provided under a plan. The commenter concluded that the Service should include in the final critical habitat designation all areas within the boundaries of conservation or management plans for Peninsular bighorn sheep because these areas meet the definition of critical habitat by nature of their need for special management.
Our Response:
The commenter appears to be confusing the purposes of sections 3(5)(A) and 4(b)(2) of the Act. Section 3(5)(A) provides the requirements for identifying critical habitat, while section 4(b)(2) directs the Secretary to consider the impacts of designating such areas as critical habitat and provides the Secretary with discretion to exclude particular areas if the benefits of exclusion outweigh the benefits of inclusion. In this final revised rule, we did not state that areas do not meet the definition of critical habitat under 3(5)(A) of the Act because they are being adequately managed. However, we consider the management of particular areas that do meet the definition of critical habitat in our analyses under section 4(b)(2) of the Act.
We explain our criteria for designating critical habitat in our response to Comment 6 above, as well as the “Criteria Used To Designate Critical Habitat” section below. We believe our criteria captures all areas that meet the definition of critical habitat under section 3(5)(A) of the Act, in particular those areas that were occupied at the time of listing, and contain the physical and biological features essential to the conservation of the DPS that may require special management considerations or protection. We will focus our response to this comment on our exclusion of lands under section 4(b)(2) of the Act that we determined met the definition of critical habitat under section 3(5)(A) of the Act.
Section 4(b)(2) of the Act states that the Secretary shall designate critical habitat, and make revisions thereto, under subsection (a)(3) on the basis of the best scientific data available and after taking into consideration the economic impact, the impact to national security, and any other relevant impact, of specifying any particular area as critical habitat. The Secretary may exclude any 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 and commercial data available, that the failure to designate such area as critical habitat will result in the extinction of the species concerned. Therefore, consistent with the Act, we must consider the relevant impacts of designating areas that meet the definition of critical habitat using the best available scientific data prior to finalizing a critical habitat designation.
After determining the areas that meet the definition of critical habitat under section 3(5)(A) of the Act as described above, we took into consideration the economic impact, the impact on national security, and other relevant impacts of specifying any particular area as critical habitat for Peninsular bighorn sheep. In this final revised designation, we recognize that designating critical habitat in areas where we have partnerships with landowners that have led to conservation or management of listed species on non-Federal lands has a relevant perceived impact to landowners and a relevant impact to future partnerships and conservation efforts on non-Federal lands. These impacts are described in detail in the “Conservation Partnerships on Non-Federal Lands” section below. Based on these relevant impacts, we weighed the benefits of designating areas as critical habitat against the benefits of excluding these areas from the critical habitat designation. Please see the “Application of Section 4(b)(2) of the Act” and “Exclusions Under Section 4(b)(2) of the
Act” sections of this final revised rule for a detailed discussion of the benefits of excluding lands covered by management plans versus the benefits of including these areas in a critical habitat designation.
Upon weighing the specific benefits of inclusion against specific benefits of exclusion, we determined that the benefits of excluding a portion of Units 1 and 2A outweigh the benefits of including these areas in the final critical habitat designation. When weighing the benefits of including an area in the critical habitat designation, we fully consider the regulatory benefits provided to the species under section 7(a)(2) of the Act based on the statutory difference between a jeopardy analysis and an adverse modification analysis. In this analysis, we consider the recovery standards and the benefits associated with designation. Further, we determined that the exclusion of these areas will not result in extinction of Peninsular bighorn sheep. This determination to exclude areas where the benefits of exclusion outweigh the benefits of inclusion and where we determined that the exclusion will not result in the extinction of the DPS, is consistent with the statutory obligations of the Act. Therefore, we believe these exclusions are in full compliance with the Act.
Comment 55:
One commenter stated that the exclusion of areas covered under the Coachella Valley MSHCP has some merit, but notes that the conservation areas in that plan are based on the 2001 critical habitat designation for bighorn sheep, which the commenter asserts incorporated the 0.5-mi. (0.8-km) buffer zone from areas of 20 percent slope as described in the 2000 Recovery Plan. The commenter asserted that this presents a potential inconsistency of conservation boundaries and recommends that the Service take steps to assure that the inappropriate buffer zone is removed from the Coachella Valley MSHCP.
Our Response:
It is inappropriate to compare the boundaries of HCP conservation areas to the boundaries of a critical habitat designation. These two areas serve two different functions with regard to the conservation of species and should not be synonymized. Furthermore, critical habitat designations do not signal that habitat outside of the designation is unimportant or may not contribute to recovery. This includes habitat outside of the critical habitat designation but inside Coachella Valley MSHCP modeled Peninsular bighorn sheep habitat.
Comment 56:
One commenter supported the exclusion of lands covered by HCPs under section 4(b)(2) of the Act and suggested that the Service exclude from critical habitat lands covered under the East County MHCP.
Our Response:
At this time, the HCP for east San Diego County (East County MHCP) is being developed, and a draft plan is not available for public review. We understand the commenters' concern that a designation of critical habitat in areas that may be addressed in the future by the East County MHCP may have a negative effect on entities pursuing the HCP and deter its completion. This concern is consistent with our discussion of conservation partnerships in the “Exclusions Under Section 4(b)(2) of the Act” section of this final rule. However, we also recognize that there is a regulatory and recovery benefit to designating critical habitat in areas that are not protected through existing management or conservation plans. Exclusions under section 4(b)(2) of the Act must be considered on a case-by-case basis. Because a draft of the East County MHCP has not been released for public comment or formally evaluated by the Service, it is not clear that this framework plan will adequately address the conservation needs of Peninsular bighorn sheep. Additionally, it is unclear to us at this time which areas will actively develop subarea plans under the East County MHCP. Therefore, we cannot determine that the regulatory and recovery benefits of a critical habitat designation in these areas would be minimized by the measures provided under this future plan, and as such, we did not exclude these lands from critical habitat (portions of Units 2B and 3 in San Diego County). However, if this designation is revised in the future, we will re-evaluate these areas for potential exclusion at that time. We are committed to continue working with all East County MHCP partners to minimize any additional regulatory burden attributable to this critical habitat designation.
Comment 57:
One commenter supported the exclusion of lands within the boundaries of the Coachella Valley MSHCP. The commenter suggested that all lands, including lands owned by such entities as the California Department of Fish and Game and the BLM, should be excluded from critical habitat. The commenter further stated that the Service agreed, in signing the Implementing Agreement, that all lands within the boundary of the Coachella Valley MSHCP would be excluded from critical habitat designation. The commenter indicated that failure to exclude these lands will violate the Service's agreement with the cities and signatories to the Implementing Agreement. Another commenter stated that Federal lands within the Coachella Valley MSHCP area owned by the BLM and Forest Service should be excluded from critical habitat designation, and failure to do so could result in unnecessary duplication of regulatory requirements. The commenter further stated that the BLM and Forest Service are participating in the Coachella Valley MSHCP as partners and that each of these agencies will participate in cooperative management and coordination of habitat conservation for covered species.
Our Response:
Contrary to the commenter's assertion, Section 14.9 of the Implementing Agreement does not absolutely preclude critical habitat designation, and we disagree with the assertion that the failure to exclude all lands within the Coachella Valley MSHCP boundary will violate the Service's agreement with the signatories to the Implementing Agreement.
Consistent with the Implementing Agreement, we excluded lands under the jurisdiction of the permittees addressed by the Coachella Valley MSHCP in Unit 1 and Unit 2A from this final revised critical habitat designation because the benefits of exclusion outweigh the minimal benefits of inclusion. See our responses to Comments 53 and 55 above, and “Application of Section 4(b)(2)—Other Relevant Impacts—Conservation Partnerships” section below for more information regarding why we excluded 38,759 ac (15,685 ha) in Unit 1 and Unit 2A.
Finally, regarding the commenter's concern that Federal lands (owned by the BLM and the Forest Service) within the Coachella Valley MSHCP area should also be excluded from critical habitat designation, we acknowledge that these Federal landowners are Cooperating Agencies of the Coachella Valley MSHCP, and as such, are providing Complementary Conservation according to section 7.3 of the Implementing Agreement. We appreciate and commend the efforts of the BLM and the Forest Service to work with the Coachella Valley MSHCP permittees and to conserve federally listed species on their lands.
The Secretary has the discretion to exclude an area from critical habitat under section 4(b)(2) of the Act after taking into consideration the economic impact, the impact on national security, and any other relevant impact if he determines that the benefits of such exclusion outweigh the benefits of
designating such area as critical habitat, unless he determines that the exclusion would result in the extinction of the species concerned. Based on the record before us, we have elected not to exclude the BLM and Forest Service lands and are designating these lands as critical habitat for the Peninsular bighorn sheep.
Consistent with the “No Surprises” assurances provided to the Coachella Valley MSHCP permittees under section 10 of the Act, we do not expect that additional regulatory actions or measures will be required by the BLM or Forest Service due to designation of these lands as critical habitat.
Comments on Lands Designated as Critical Habitat
Comment 58:
One commenter believes that if both the area north of Chino Canyon and near Interstate 8 are to be included in the final designation, then the observations used in support of these “expansions” should be presented in a table and copies of the original field notes used in support of this observation should be available for public inspection. Two commenters stated that if critical habitat is to be “expanded,” the raw data used to make such decisions should be made publicly available and open to inspection and independent validation.
Our Response:
All occurrence data and other information used in the delineation of critical habitat for Peninsular bighorn sheep were available to the public during the comment periods and are on file at the Carlsbad Fish and Wildlife Office and available for public inspection (see
FOR FURTHER INFORMATION CONTACT
section of this rule).
Comment 59:
Several commenters believe that the proposed critical habitat designation fails to protect habitat essential for Peninsular bighorn sheep recovery. One commenter stated the proposed rule excludes significant areas of habitat essential for the DPS and fails to support the goals called for in the Recovery Plan to promote population growth and protect, acquire, enhance, and restore habitat. Several commenters believe the proposal is contrary to the Recovery Plan as well as inconsistent with promoting the survival and recovery of the DPS. One commenter asserted that if Peninsular bighorn sheep were recovered within the newly proposed critical habitat, it would still be threatened or endangered in a significant portion of its range. The same commenter indicated that for critical habitat to facilitate recovery as it was designed to do, the designation should maintain all current critical habitat and be expanded to include reaches in all other areas identified as having recovery value as identified in the Recovery Plan. The commenter further stated that by proposing to exclude currently designated critical habitat, they believe the Service is failing in its obligation to provide for the recovery of Peninsular bighorn sheep because the value of the critical habitat to the recovery of the DPS will be diminished by these omissions. Finally, another commenter believes the Service should designate as critical habitat sufficient areas to allow for full recovery of Peninsular bighorn sheep.
Our Response:
It is important to note that the designation of critical habitat is a different process than the development of a recovery plan. A critical habitat designation is a specific regulatory action that defines specific areas within the geographical area occupied by the species at the time of listing containing physical or biological features essential to the conservation of a species, and areas outside the geographical area occupied by the species at the time of listing that are essential for the conservation of the species. In contrast, a recovery plan is a guidance document developed in cooperation with partners and provides a roadmap with detailed site-specific management actions to help conserve listed species and their ecosystems.
Conservation (i.e., recovery) is defined in section 3 of the Act as the “use of all methods and procedures which are necessary to bring any endangered species or threatened species to the point at which the measures provided pursuant to this Act are no longer necessary.” In accordance with section 4(a)(1) of the Act, we determine if any species is an endangered or threatened species (or revise its listed status) because of any of the five threat factors identified in the Act. Therefore, conservation, or recovery, is achieved when a five-factor analysis indicates that current and future threats are minimized to an extent that the species is no longer in danger of extinction or likely to become endangered in the foreseeable future. Recovery is a dynamic process requiring adaptive management of threats, and there are many paths to accomplishing recovery of a species. We believe that the lands identified in this rule as meeting the definition of critical habitat are adequate to ensure the conservation of Peninsular bighorn sheep throughout their extant range based on the best available scientific information at this time.
Additionally, we recognize that the designation of critical habitat may not include all of the habitat that may be determined to be necessary for the recovery of Peninsular bighorn sheep, and critical habitat designations do not signal that habitat outside of the designation is unimportant or may not contribute to recovery. Areas outside the final critical habitat designations will continue to be subject to conservation actions implemented under section 7(a)(1) of the Act, as well as regulatory protections afforded by the section 7(a)(2) jeopardy standard and the prohibitions of section 9 of the Act if actions occurring in these areas may affect sheep. See the “Criteria Used To Identify Critical Habitat,” “Summary of Changes From the 2001 Critical Habitat Designation To the 2007 Proposed Rule To Revise Critical Habitat,” and “Summary of Changes From the 2007 Proposed Rule To Revise Critical Habitat To This Final Rule To Revise Critical Habitat” sections of this final rule for more information. Please also see additional discussion regarding recovery plans and conservation of Peninsular bighorn sheep in our responses to Comments 1, 5, 6, 7, and 53 above.
Comment 60:
Several commenters stated that the proposed rule calls for eliminating large swaths of essential habitat, including a large area of low-elevation habitat along the eastern slopes of the bighorn's range that is considered by scientists familiar with Peninsular bighorn sheep to be essential habitat for the DPS and requisite for their recovery. Several commenters stated that the proposed critical habitat designation would eliminate alluvial-fan habitat (about 249,000 ac (100,767 ha), as noted by several commenters), much of which is the most important Peninsular bighorn sheep habitat in need of protection due to threats of housing and golf course projects. One commenter believes that not including these areas stands in stark contrast to the discussion in the proposed rule itself which acknowledges that: “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 (October 10, 2007, 72 FR 57746).” The same commenter believes that this retraction of habitat ignores management actions currently in place (e.g., restrictions on trails, prohibitions on dogs) to limit disturbance in habitat so that this DPS could re-colonize historically used areas. Several commenters indicated that it is
important to the sheep's recovery that low-elevation alluvial areas remain critical habitat.
Our Response:
We agree that low-elevation habitat is important for Peninsular bighorn sheep, and where occurrence data indicated sheep use, we revised our proposed revision of critical habitat to include additional areas, including habitat along the eastern edge of the Santa Rosa Mountains (August 26, 2008, 73 FR 50498). We included low-elevation, low-slope, and alluvial-fan habitat in the designation of critical habitat where the available data support a determination that those areas contain the physical and biological features essential to the conservation of the DPS. See our response to Comment 3 and the “Criteria Used To Identify Critical Habitat” and “Summary of Changes From the 2007 Proposed Rule To Revise Critical Habitat To This Final Rule To Revise Critical Habitat” sections of this final rule for further discussion of this topic.
Comment 61:
On
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