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RIN ID: RIN 1018-AV64
FWS ID: [FWS-R9-ES-2007-0003; 92220-1113-0000; C6]
SUBJECT CATEGORY: Endangered and Threatened Wildlife and Plants; Final Rule To Amend the Listing for the Preble's Meadow Jumping Mouse (Zapus hudsonius preblei) To Specify Over What Portion of Its Range the Subspecies Is Threatened
DOCUMENT SUMMARY: We, the U.S. Fish and Wildlife Service (Service/USFWS), under the authority of the Endangered Species Act of 1973, as amended (Act), amend the listing for the Preble's meadow jumping mouse (Zapus hudsonius preblei) (Prebles) to specify over what portion of its range the subspecies is threatened. Based on the best scientific and commercial data available, we have determined that the Prebles is a valid subspecies and should not be delisted based upon taxonomic revision; the subspecies is not threatened throughout all of its range; and the portion of the subspecies' current range located in Colorado represents a significant portion of the current range where the subspecies should retain its threatened status. This determination is based on a thorough review of all available information, which indicates that Prebles' populations in Wyoming are more widespread and threats to the subspecies less severe than those known at the time of listing, but that in Colorado the Prebles is likely to become endangered within the foreseeable future.
SUMMARY: Interior Department, Fish and Wildlife Service,
Meadow jumping mice (Zapus hudsonius) are small rodents with long tails, large hind feet, and long hind legs. Total length of an adult is approximately 187 to 255 millimeters (7 to 10 inches), with the tail comprising 108 to 155 millimeters (4 to 6 inches) of that length (Krutzsch 1954, p. 420; Fitzgerald et al. 1994, p. 291).
Typical habitat for Prebles is comprised of welldeveloped riparian vegetation with adjacent, relatively undisturbed grassland communities and a nearby water source (Bakeman 1997, pp. 2231). Prebles are typically captured in areas with multistoried cover with an understory of grasses or forbs or a mixture thereof (Bakeman 1997, pp. 2231; Bakeman and Deans 1997, pp. 2830; Meaney et al. 1997a, pp. 1516; Meaney et al. 1997b, pp. 4748; Shenk and Eussen 1998, pp. 911; Schorr 2001, pp. 2324). The shrub canopy is often willow (Salix spp.), although other shrub species may occur (Shenk and Eussen 1998, pp. 9 11). Trainor et al. (2007, pp. 471472) found that highuse areas for Prebles tended to be close to creeks and were positively associated with the percentage of shrubs, grasses, and woody debris. Hydrologic regimes that support Prebles' habitat range from large perennial rivers such as the South Platte River to small drainages only 1 to 3 meters (m) (3 to 10 feet (ft)) in width.
Meadow jumping mice are primarily nocturnal or crepuscular (active during twilight), but also may be active during the day. The Prebles uses uplands at least as far out as 100 m (330 ft) beyond the 100year floodplain (Shenk and Sivert 1999a, p. 11; Ryon 1999, p. 12; Schorr 2001, p. 14; Shenk 2004; USFWS 2003b, p. 26). While the Prebles' dispersal capabilities are thought to be limited, in one instance a Prebles was documented moving as far as 1.1 kilometers (km) (0.7 mile (mi)) in 24 hours (Ryon 1999, p. 12). The Prebles typically enters hibernation in September or October and emerges the following May (Whitaker 1963, p. 5; Meaney et al. 2003).
For additional information on the biology of this subspecies, see the May 13, 1998, final rule to list the Prebles as threatened (63 FR 26517) and the June 23, 2003, final rule designating critical habitat (68 FR 37275).
We listed the Prebles as threatened under the Act on May 13, 1998 (63 FR 26517). On May 22, 2001 (66 FR 28125), we adopted a final section 4(d) special rule for the Prebles that provides exemptions from section 9 take prohibitions for certain rodent control activities, ongoing agricultural activities, maintenance and replacement of existing landscaping, and existing uses of water. On October 1, 2002 (67 FR 61531), we amended this rule to provide exemptions for certain noxious weed control and ditch maintenance activities. The special rule, as amended, was scheduled to end May 22, 2004, but was made permanent on May 20, 2004 (69 FR 29101). On June 23, 2003, we designated critical habitat for the Prebles in portions of Colorado and Wyoming (68 FR 37275).
In June 2000, the Service established the Preble's Meadow Jumping Mouse Recovery Team (Recovery Team) composed of scientists and stakeholders. In June 2003, the Recovery Team provided their recommendations to the Service in the form of a draft recovery plan. The Service revised this technical working draft in November 2003. This document (hereafter referred to as the Preliminary Draft Recovery Plan) suggests the longterm protection of populations spread throughout the current range of the subspecies in order to lessen or eliminate threats. In particular, the documents suggest longterm protection of 1 large population (with June abundances of 2,500 or more individuals), 2 medium populations (with June abundances of 5002,499 individuals), and 6 small populations (with evidence of occupancy; possibly 150 mice) within the North Platte River basin; 2 large, 3 medium, and 18 small populations within the South Platte River basin; and 1 large population, and 6 small populations within the Arkansas River basin (USFWS 2003b, pp. 1923). Recovery planning efforts were halted in December 2003 after new information became available questioning the taxonomic validity of the subspecies. While the availability of the Preliminary Draft Recovery Plan (USFWS 2003b) has not yet been announced in the Federal Register, it represents the best scientific information available to us concerning recovery needs of the Prebles.
On December 23, 2003, we received two nearly identical petitions, from the State of Wyoming's Office of the Governor and Coloradans for Water Conservation and Development, seeking to remove the Prebles from the Federal List of Endangered and Threatened Wildlife (Freudenthal 2003; Sonnenberg 2003). The petitions maintained that the Prebles should be delisted based on the taxonomic revision suggested by Ramey et al. (2003) and new distribution, abundance, and trends data that suggested the subspecies was no longer threatened or endangered (Freudenthal 2003, p. 1; Sonnenberg 2003, p. 1).
On March 31, 2004, we published a notice announcing a 90day
finding that the petitions presented substantial information indicating that the
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petitioned action may be warranted (69 FR 16944). On February 2, 2005,
we published a 12month finding that the petitioned action was
warranted and a proposed rule to remove Prebles from the Federal List
of Endangered and Threatened Wildlife (70 FR 5404). This notice also
opened a 90day public comment period. The proposed delisting was based
upon a taxonomic revision suggested by Ramey et al. (2004a (a revision
of Ramey et al. 2003)), which concluded that Prebles should be
synonymized with a neighboring subspecies (Ramey et al. 2004a, pp. 1,
13). Although this report remained unpublished and had received mixed
peer reviews, we concluded that a lack of distinct genetic and
morphologic differences suggested that Prebles was likely not a valid
subspecies of meadow jumping mouse (Zapus hudsonius). Considering the
weight that the findings of Ramey et al. (2004a) had in the proposed
delisting, verifying these results prior to making a final decision on
the proposal was a high priority of the Service (Williams 2004;
Morgenweck 2005). As such, we contracted with the U.S. Geological
Survey (USGS) to conduct additional genetic analysis of Prebles and
four neighboring subspecies of meadow jumping mice (USGS 2005, pp. 1 4).
On January 25, 2006, the USGS released its report concluding that the Prebles should not be synonymized with neighboring subspecies of meadow jumping mice (King et al. 2006a, pp. 2, 29). On February 17, 2006, the Service extended the rulemaking process an additional 6 months as allowed under section 4(b)(6)(B)(i) of the Act (71 FR 8556). This USGS study indicated that there was substantial disagreement regarding the sufficiency or accuracy of the available data relevant to the determination contained in our proposed rule. We reopened the comment period for an additional 60 days and announced that we intended to assemble a panel of experts to carefully review and assess the two studies.
On March 30, 2006, we published a notice of availability of the King et al. (2006a) and Ramey et al. (2005) data and extended the comment period on the proposed delisting rule an additional 30 days (71 FR 16090). We then contracted with Sustainable Ecosystems Institute (SEI) to organize a scientific review panel to analyze, assess, and weigh the reasons why the data, findings, and conclusions of King et al. differed from the data, findings, and conclusions of Ramey et al. (as written in this sentence, and hereafter, ``Ramey et al.'' or ``King et al.'' without a modifying date refers to the overall work of these authors instead of a specific publication) (USFWS 2006, p. 14). On July 21, 2006, SEI delivered a final report to the Service (SEI 2006a).
On September 26, 2006, the State of Wyoming submitted a 60day notice of intent to sue over our failure to publish a final determination on our 2005 proposed delisting rule within the timeframes allowed by the Act. On January 24, 2007, the State of Wyoming filed a petition for review with the court. On June 22, 2007, the Service and the State of Wyoming reached a settlement agreement which required that, by October 31, 2007, we submit to the Federal Register for publication either (1) a withdrawal of our 2005 proposed delisting regulation; or (2) a new proposed regulation considering the Prebles' taxonomy and the subspecies' threatened status in light of all current distribution, abundance, and trends data (State of Wyoming v. U.S. Department of the Interior, No. 07CV025J (District of Wyoming 2007)). On November 7, 2007, we published a revised proposed rule to amend the listing of the Prebles to specify over what portion of its range the subspecies is threatened and opened a 75day public comment period (72 FR 62992). Under the settlement agreement with the State of Wyoming, the Service agreed to submit a final determination on the revised proposed rule to the Federal Register no later than June 30, 2008. Public Comments Solicited
Comments on this rulemaking were accepted from February 2 to May 3, 2005 (70 FR 5404, February 2, 2005), from February 17 to April 18, 2006 (71 FR 8556, February 17, 2006; 71 FR 16090, March 30, 2006), and from November 7, 2007 to January 22, 2008 (72 FR 62992, November 7, 2007). Open houses and public hearings were held on December 10, 2007, in Lakewood, Colorado, and on December 12, 2007, in Wheatland Wyoming (72 FR 62992, November 7, 2007). These opportunities to comment were publicized via the Federal Register, press releases, public notices in area newspapers, postings on our Web site, and direct contact with Federal and State agencies, county governments, scientific organizations, and other interested parties. In addition, the media provided substantial coverage of the proposals. Comments could be hand delivered to us, submitted to us via email, mail, the Federal e Rulemaking Portal, fax, or provided during public hearing testimony.
Comments were submitted by a variety of parties including the general public, business interests, environmental organizations, and Federal, State, and local governments. We received 122 written, faxed, or emailed comments during public comment periods (excluding peer reviewers' comments discussed below). An additional eight comments were provided during two public hearings. On March 24, 2006, the Service received a Data Quality Act challenge on behalf of Coloradans for Water Conservation and Development and the Colorado Farm Bureau. While this challenge was handled separately from this rulemaking, all of the relevant issues raised also were considered public comments and considered in this final determination. All of the public comments available prior to the July 2006 SEI panel were made available to the panelists.
In accordance with our Interagency Policy for Peer Review in Act Activities (59 FR 34270, July 1, 1994) and the Office of Management and Budget's (OMB) Final Information Quality Bulletin for Peer Review (70 FR 2664, January 14, 2005), we sought the expert opinions of appropriate and independent specialists regarding this rulemaking. First, we contacted five reviewers with expertise in genetics, systematics, and small mammals to review the taxonomic portions of this document. Four of those solicited provided comments during one or more of the comment periods (Gore 2008; Hoekstra 2005; Kelt 2005, 2006, 2008; Spencer 2005, 2006a, 2008). All of the peer reviews submitted prior to the July 2006 SEI panel meeting were made available to the expert panelists (Hoekstra 2005; Kelt 2005, 2006; Spencer 2005, 2006a). Second, we contacted an additional five reviewers with expertise in smallmammal biology, ripariancommunity ecology and status, population dynamics and extinction risk, and/or development trends and landuse conflicts to review the remainder of the 2007 revised proposal. All five of these reviewers provided comments (Anderson 2008; Beauvais 2008; Buskirk 2008; Nupp 2008; Travis 2008).
Given the information now available, all of the experts who commented on taxonomic portion of the rule were supportive of our discussion, analysis, and/or conclusions. No reviewers expressed significant concerns over our analysis of the Prebles' taxonomy.
Reviews that focused on the remainder of the 2007 revised proposed
rule were generally supportive of Service efforts, but provided criticism
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and suggestions regarding various aspects of the revised proposed rule.
Six reviewers provided comments on whether evidence we presented in the
revised proposed rule sufficiently supported our removal of the Act's
protections for the Wyoming populations. Three reviewers supported our
proposal as being reasonable based on evidence presented. Two reviewers
questioned the proposal based largely on adequacy of existing knowledge
regarding Prebles' populations in Wyoming. One reviewer opposed the
proposal, calling it weakly supported. Two reviewers suggested that the
revised proposed rule should have made better use of geographic
information systems (GIS) to depict and analyze trapping efforts,
documented occurrence, appropriate habitat, and projected threats.
Reviewer opinions also varied on use of the WyomingColorado State line to delineate a significant portion of Prebles' range. While reviewers generally considered a division based on the North Platte River basin and the South Platte River basin more appropriate from an ecological or mouse population perspective, three concluded that the use of the State line was supported by the differing levels of threats described. Two reviewers called for more detailed analysis of threats as related to both sides of the State line. One reviewer discounted significant differences in threats across the State line. Three reviewers mentioned the administrative or practical convenience of using the State line.
We reviewed all comments from peer reviewers and the public for substantive issues and new information regarding this rulemaking. Substantive comments received during the comment periods have been addressed below or incorporated directly into this final rule. Comments of a similar nature have been grouped together under subject headings in a series of issues and responses.
Issue: Several technical and editorial comments were provided by respondents. In addition, peer reviewers and other commenters provided or suggested additional literature to consider in our final rule.
Response: We corrected inaccuracies in the revised proposed rule wherever appropriate. We also edited portions of the text to make it clearer. We reviewed and incorporated relevant additional literature and information when appropriate. The list of literature cited in this rule will be posted online (http://www.fws.gov/mountainprairie/ species/mammals/preble/).
Defining a ``Listable Entity'' under section 4 of the Act.
Issue: We received numerous comments on taxonomic data quality and quantity. Many questioned the amount of data necessary to make such taxonomic determinations. Some commenters questioned the basis for the initial listing of the subspecies. Other commenters discussed whether the available data relied upon in our 2005 proposed rule was sufficient or insufficient. Some commenters suggested we should employ the precautionary principle when making a call on delisting. Other commenters questioned our apparent reliance upon the peer reviewer ``majority vote'' as a justification for our 2005 proposed delisting. Still other commenters noted or questioned evidence of political interference in this rulemaking process.
Response: The Act requires that we base our determinations upon the best scientific and commercial information available. As a result, we evaluate all of the available information, its adequacy and reliability, and determine what the weight of evidence suggests. This final rule meets this standard. These issues and the available data are discussed below in the sections titled: Taxonomy; Other Taxonomic Information Available Prior to Listing; Taxonomic Information Solicited After Listing; and Taxonomic Conclusions.
Issue: Many questioned the standards used to test what is a valid subspecies. Some commenters suggested philosophical differences played a role in shaping the hypothesis of each researcher and what each researcher considered a valid subspecies. Other commenters suggested that the Service is inconsistent in applying subspecies standards in its section 4 determinations. Some commenters noted that there are no quantitative standards in use by the scientific community or the Service with which to objectively describe subspecies. Some commenters suggested that acceptance by the scientific community is often nothing more than opinion.
Response: As defined by the Act, a species includes any subspecies of fish or wildlife or plant, and any distinct population segment (DPS) of any species of vertebrate fish or wildlife which interbreeds when mature. The Act does not further define subspecies. Service regulations (50 CFR 424.11) state that ``In determining whether a particular taxon or population is a species for the purposes of the Act, the Secretary shall rely on standard taxonomic distinctions and the biological expertise of the Department and the scientific community concerning the relevant taxonomic group.'' This regulatory standard is consistent with the Act's requirement that we make such determinations solely on the basis of the best scientific and commercial data available. The Service consistently applies this standard.
In this case, we determine that the best scientific and commercial data available support the conclusion that the Prebles is a valid subspecies. While philosophical differences among researchers may play a role in what a particular researcher considers a biologically meaningful difference, we conclude that the weight of evidence supports the Prebles as a valid subspecies.
Specifically, the Prebles' geographic isolation from other
subspecies of meadow jumping mice (Krutzsch 1954, pp. 452453; Long
1965, pp. 664665; Beauvais 2001, p. 6; Beauvais 2004; SEI 2006a, p. 34) has resulted in the accretion of considerable genetic
differentiation (King et al. 2006b, pp. 43364348; SEI 2006a, pp. 41
43). The available data suggest that the Prebles meets or exceeds
numerous, widely accepted subspecies definitions (Mayr and Ashlock
1991, pp. 4345; Patten and Unitt 2002, pp. 2634; SEI 2006a, p. 44).
In terms of quantitative standards, the 75 percent rule (Amadon 1949; Patten and Unitt 2002) is one of the only widely employed quantitative subspecies definitions (Haig et al. 2006, pp. 15841594). This definition suggests a subspecies is valid if 75 percent or more of a population is separable from all (or > 99 percent of) members of the overlapping population. As noted by SEI (2006a, p. 44), the Prebles exceeds this quantitative standard.
Issue: We received numerous comments regarding the status of the Prebles relative to the requirements of the Interagency Policy Regarding the Recognition of Distinct Vertebrate Population Segments Under the ESA (DPS policy) (61 FR 4722, February 7, 1996) including the suggestion that the Prebles should or could be split into multiple DPSs based on significant genetic differences observed between populations north and south of Denver (Ramey et al. 2005, pp. 334341; King et al. 2006a, pp. 2829).
Response: The available data supports the taxonomic status of the
Prebles as a valid subspecies making most comments about potential
application of the DPS policy moot. We do not believe splitting the
subspecies into multiple DPSs would be prudent or beneficial [[Page 39793]]
from a conservation perspective. In this case, we do not foresee any
significant benefit to recovering multiple DPSs instead of a single listed entity.
Issue: Some commenters suggested that the Service's revised proposed rule (72 FR 62992, November 7, 2007) displayed bias in our presentation of the available information. Specifically, some commenters suggested we highlighted flaws in reports questioning the taxonomic validity of the Prebles, while not offering similar critiques of information supporting the subspecies' taxonomic validity.
Response: To the maximum extent possible, we attempted to objectively portray the available information regardless of the position it articulated. All information was held to a similar level of critical review. However, we have reviewed the final rule relative to the specific objections and made minor revisions where appropriate.
Ramey et al. and King et al.
Issue: Some commenters suggested the Ramey et al. (2003, 2004a, 2004b, 2005) studies exhibited bias. Some commenters questioned whether the studies could be relied upon because the studies were largely funded by the State of Wyoming, one of the petitioners. Other commenters noted that the conclusions strayed beyond genetics and taxonomy into policy considerations.
Response: Ramey et al. (2004a, 2004b, 2005) were subjected to extensive peer and public review, were reviewed and approved by a peer reviewed journal, and were reviewed by the SEI expert panel. All of this information has been taken into consideration in this final determination.
Issue: Some commenters suggested the King et al. (2006a, 2006b) studies exhibited bias. It was suggested that Dr. King has a history of designating unwarranted or questionable subspecies. Some commenters questioned Dr. King's qualifications. Other commenters suggested that USGS was inherently biased because the Service and USGS are sister agencies under the Department of the Interior.
Response: King et al. (2006a, 2006b) were the subject of extensive peer review and public review, were reviewed and approved by a peer reviewed journal, and were reviewed by the SEI expert panel. All of this information has been taken into consideration in this final determination.
We believe the USGS research team was well qualified to conduct the analysis. For example, their previous work concerning Atlantic salmon (Salmo salar) was upheld by a National Research Council (2002b, p. 4) review. This validation provided us with confidence that these researchers' expertise could meet our scientific needs. We do not believe that USGS' research conclusions were biased by the fact that it is a sister agency to the Service.
Issue: Some commenters questioned the critiques raised by peer reviewers and the scientific community. Rebuttals were offered for each criticism of Ramey et al. (2005) listed in the proposed rule. It was suggested that we failed to explain that many of these issues were relevant to the draft they evaluated (Ramey et al. 2004a, 2004b), but resolved in the publication (Ramey et al. 2005). Finally, it was suggested that many of these same issues plague the King et al. (2006b) report.
Response: We have revised this section (see the Taxonomic Information Solicited After Listing section below) so as to clearly explain that many of the issues raised by peer reviewers of Ramey et al. (2004a, 2004b) were rectified in the 2005 publication (Ramey et al. 2005). Each of these critiques was carefully considered. All of the issues remaining in this section of this final rule continue to remain relevant and may have contributed, at least in part, to the conclusions of Ramey et al. (2005).
For example, while the comment defended the use of museum specimens, we remain concerned that Ramey et al.'s (2004a, 2004b, 2005) reliance upon museum specimens may have contributed to contamination of numerous key samples. As noted by Douglas (2004), the quality of DNA extracted from museum specimens is often inferior, fragmented, and low quantity. As a result, amplification can be difficult and cross contamination with other highquality DNA can occur. Ramey et al. (2004a, p. 6) confirmed ``some DNA extracts, most notably those of older museum specimens (prior to 1980), did not amplify well or at all.'' King et al. (2006b, pp. 43554357) demonstrated that numerous key DNA sequences were not repeatable. Most importantly, SEI (2006a, pp. 2130) confirmed evidence of contamination of key Ramey et al. samples after reviewing the original supporting data. While other explanations are possible (King et al. 2006, p. 4345; Ramey et al. 2007, p. 3519), we have concluded that the Ramey et al. (2005) data demonstrates sufficient evidence of contamination to warrant inclusion on this list of concerns.
Similarly, results can be meaningfully altered if a museum specimen's tag (marking locality and subspecies) is incorrect. This appears to be the case with museum specimens KU115895, KU115896, and KU115897 (Anderson & Jones 1971 as cited in King et al. 2006b, p. 4357). That said, museum specimens remain a valuable resource in providing specimens from a large geographic area and often allow a study to be executed in relatively short time. As recommended by the literature, proper precautions are required (Cooper and Poinar 2000).
Most of the other critiques of Ramey et al. centered on study design and the thoroughness of the evaluation. We continue to list these issues because each of these factors may have influenced the study's results and conclusions. We also have tried to clarify when a similar issue may have influenced the results and conclusions of King et al. The relative importance of many of these issues is discussed in the SEI report (SEI 2006, pp. 2043).
Issue: Numerous commenters suggested that the sampling regime was a critical difference between the two studies (Ramey et al. 2004a, 2004b, 2005; King et al. 2006a, 2006b). Several commenters suggested that Crandall and Marshall (2006) represented the best scientific and commercial information available in that their report combined the Ramey et al. (2005) and King et al. (2006a) data into a single, comprehensive analysis.
Response: We think that an ideal sampling strategy, with unlimited resources, would sample many individuals from many populations across the range of all 12 recognized meadow jumping mouse subspecies. Instead, Ramey et al. sampled a few individuals from many sites, while King et al. sampled many individuals from a few sites. Each approach has its strengths and weaknesses.
The Ramey et al. approach likely captures variation across the
range of the subspecies (Ramey et al. 2005, p. 332), but may
underestimate the level of withinpopulation variation, inflate within
subspecies variance, and potentially lower the betweensubspecies
differentiation (King et al. 2006b, p. 4346). The King et al.
populationoriented approach likely denotes the diversity within a
population (King et al. 2006b, p. 4346), but may not capture variance
along past or present contact zones between the subspecies (SEI 2006a,
pp. 3143) and may predispose the results to an exaggeration of genetic
distances among subspecies (Ramey et al. 2007, p. 3519). We considered
each of these potential sources of bias in our evaluation of the
available data. Overall, we concluded that sampling played only a minor role
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in shaping differences between the two studies. Instead, we believe
apparent contamination among a number of key samples was likely the
primary reason the Ramey et al. (2005) and King et al. (2006b) mtDNA
data differed. While Crandall and Marshall (2006) employed a hybrid
approach reevaluating both the Ramey et al. and King et al. mtDNA
sequences, this unpublished study has a number of important weaknesses
(see Spencer 2006b) including the inclusion of these same questionable
samples. As Crandall and Marshall (2006, p. 5) put it, ``much is
dependent on these few samples.'' We have concluded that inclusion of
these apparently contaminated samples makes the mtDNA results and
conclusions of Ramey et al. (2005) and Crandall and Marshall (2006) unreliable.
Issue: Several commenters suggested that even if the apparently contaminated samples are removed from the analysis, the data still supports the conclusions of Ramey et al. (2005).
Response: No data or analysis were presented to support the assertion that Ramey et al.'s key conclusions would not differ if the suspect samples were removed. Ramey et al. (2007, p. 3520) state that ``With the samples in question excluded, analysis of molecular variance results just exceed our threshold, but the Prebles is still not even close to being reciprocally monophyletic.'' This suggests the mtDNA results would satisfy Ramey et al.'s (2005, p. 332) a priori mtDNA hypothesis for a valid subspecies where there was greater molecular variance among than within subspecies. Overall, we feel the available data is compelling in its support of the validity of this taxon.
Issue: A few commenters suggested that Ramey et al. set up subspecies standards in advance of data collection, while King et al. relied upon posthoc interpretations of the data.
Response: Our evaluation of Ramey et al. (2003, p. 4; 2004a, p. 4; 2005, pp. 331334), USGS (2005, p. 3) and King et al. (2006a, p. 5; 2006b, p. 4332) revealed that both research teams developed their hypotheses in advance of data collection which they consistently applied throughout the process.
Issue: A few commenters questioned whether hybridization between the Prebles and the western jumping mouse could have impacted each study's results.
Response: Genetic distance between the Prebles and the western jumping mouse is significant (King et al. 2006b, p. 4341), and the available genetic studies experienced no difficulty differentiating between the two species (Riggs et al. 1997, pp. 611; Ramey et al. 2005, p. 332; King et al. 2006b, p. 4341). Wunder and Harrington (1996, section 6.0) also ruled out hybridization based on a small sampling of random amplification of polymorphic DNA (RAPD) (an amplification of random segments of DNA with single primer of arbitrary nucleotide sequence). Based upon the best scientific and commercial information available, we do not believe hybridization is occurring between these two distinct species.
Issue: Several commenters suggested King et al. examined too much data. Specifically, it was suggested that the statistically significant differences observed by King et al. were the result of the large number of microsatellite loci (the specific position of a gene or other chromosomal marker) examined and not reflective of any meaningful biological difference.
Response: We find no support for the position that significant differences detected by King et al. were an artifact of an excessively large sample size. The Ramey et al. and King et al. microsatellite results do not appear dependent upon the number of loci examined (5 and 21 loci, respectively) as both data sets support a statistically significant independent cluster that corresponds to the Prebles (Crandall and Marshall 2006, pp. 2627; SEI 2006a, p. 43). This, in combination with other available data, supports continued recognition of the subspecies as a valid taxon.
Issue: Numerous commenters suggested we should not rely upon unpublished literature that has not been subjected to a scientific journal's peer review process. They felt that using Ramey et al. or King et al. violated the Data Quality Act (44 U.S.C. 3516 et seq.) and Service policy. Several commenters thought we should reopen the comment period once these documents were accepted for publication or published.
Response: The Act requires that our actions be based upon the best scientific and commercial information available. Occasionally, relevant scientific and commercial information is not, or has not yet been, published. In these cases, peer review may assist us in our evaluation of the available science. At this point, most of the key literature relevant to the subspecies' taxonomy has been subjected to extensive peer review, reviewed and published by peerreviewed journals, and reviewed by the SEI expert panel. Additionally, the public has had an opportunity to review and comment on all of the relevant literature (70 FR 5404, February 2, 2005; 71 FR 8556, February 17, 2006; 71 FR 16090, March 30, 2006; 72 FR 62992, November 7, 2007). Finally, we have conducted numerous peer reviews of our regulatory proposals (70 FR 5404, February 2, 2005; 71 FR 8556, February 17, 2006; 71 FR 16090, March 30, 2006; 72 FR 62992, November 7, 2007) in compliance with the Interagency Cooperative Policy for Peer Review in Act Activities (59 FR 34270, July 1, 1994) and the Office of Management and Budget's ``Final Information Quality Bulletin for Peer Review'' (Office of Management and Budget 2004). We have evaluated all of the available information, its adequacy and reliability, and determined what the weight of evidence suggests. Given the above, we feel we have exceeded all Federal requirements for information quality and peer review.
Issue: Several commenters questioned the independence, impartiality, political motivation, and appropriate expertise of select local peer reviewers. Some commenters questioned the independence and impartiality of the Colorado Division of Wildlife (CDOW) in soliciting these peer reviews.
Response: The CDOW solicited and received nine peer reviews of Ramey et al. (2004a) from regional scientists with a variety of expertise relevant to the questions at hand. These reviews were transmitted to us on April 24, 2004. We believe that the CDOW acted independently and impartially in selecting qualified reviewers of the subject study. During the summer of 2004, we solicited reviews from seven additional scientists selected for expertise in genetics and systematics. Reviewers were targeted from a wide variety of areas to geographically balance the CDOW review. Collectively, this diverse group of experts provided a balanced and objective review. To maintain consistency, we later contacted the same 16 experts to peer review Ramey et al. (2004b) and King et al. (2006a). It should be noted that some reviewers declined to participate in subsequent rounds of review (Ramey et al. 2004b; King et al. 2006a) because of these accusations of bias.
Issue: Some commenters questioned why the Service asked non geneticists to review King et al. (2006a).
Response: As noted above, we solicited peer reviews of King et al.
(2006a) from the same 16 reviewers asked to review Ramey et al. (2004a,
2004b). While we recognized this group included some nongeneticists,
we felt consistency among reviewers was critical. We note that most of the non
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geneticists voluntarily declined to participate in the review of King
et al. (2006a). The one exception, Armstrong (2006), is a respected
academic with considerable expertise on the Prebles. His review was useful.
Issue: Several commenters questioned the Service's decision to organize a scientific panel to review the available information on the species' taxonomic and conservation status.
Response: Recognizing the controversial nature of this determination, the Service decided not to organize and convene an expert panel ourselves. Instead, we contracted with an independent organization to assemble and manage the scientific review panel.
Issue: Numerous parties had issue with the SEI expert panel. Some commenters opined that the SEI panel was tainted because the composition of the panel and the time allotted to participants was altered to favor a particular outcome. Some commenters questioned the objectivity and qualifications of SEI and the panelists.
Response: We stand by the process used in the SEI review panel. Following an open and competitive bid process, SEI was selected as the contractor in June 2006. Once selected, SEI ran all aspects of this process within the bounds of the contract. The selection and retention of panelists as well as the agenda was entirely within SEI's purview. SEI also determined that the public could attend. In addition, Drs. Ramey, Crandall, and King addressed the panel in person. Other scientists participated over the phone. Questions from the audience were also presented for the panel's consideration. The panel also had access to published literature, unpublished reports, thirdparty critiques, public comments, and other materials suggested by interested parties (SEI 2006a, pp. 4855). Overall, we think that the process was fair, open, and unbiased.
Furthermore, we believe SEI and the panelists were well qualified to conduct the contracted review. SEI regularly conducts such scientific reviews including panels on northern spotted owl, pallid sturgeon, and Everglades restoration (see: http://www.sei.org/). The panelists' qualifications are well established. As illustrated in appendix 1 of the SEI (2006a, pp. 5682) report, each panelist has an extensive background in the genetic and systematic issues relevant to the Prebles' review.
Issue: Some commenters suggested that the SEI report went beyond the original scope of their contract. Specifically, commenters suggested the SEI report should have abstained from offering reviewers' taxonomic conclusions.
Response: We contracted with SEI to analyze, assess, and weigh the reasons why the data, findings, and conclusions of the two studies differed (USFWS 2006, p. 14). Incorporation of the panelists' taxonomic conclusions was a natural outgrowth of the contract's stated purpose. The final report fully satisfied SEI's contractual obligations. Availability of Taxonomic Information
Issue: Several commenters raised a concern that we relied on a paper (King et al. in review) for this rulemaking that we did not possess and thus was not available for public review during the comment period. Since this report was not available, some commenters requested an extension of the comment period.
Response: The revised proposed rule referenced a document by USGS cited as ``King et al. (in review).'' This article was not the primary jumping mouse study by King et al. The primary study and its supporting data were released to the public in early 2006 (King et al. 2006a; 71 FR 8556, February 17, 2006; 71 FR 16090, March 30, 2006) and published in Molecular Ecology in late 2006 (King et al. 2006b).
Instead, King et al. (in review) was a comment article that Molecular Ecology intended to publish in the News and Views section of the journal, in response to Ramey et al. (2007) (another comment article). These comment articles were cited once in the revised proposed rule in a sentence that read: ``Other evaluations of the available literature and data include Ramey et al. (in press), King et al. (in review), Crandall and Marshall (2006), Spencer (2006b), and Cronin (2007).'' This sentence cited King et al. (in review), among other documents, to inform the public we were aware of its existence. However, our determination that the Prebles is a valid subspecies did not use or rely on this document.
The comment was correct that we did not have this document in our files. By citing the document as ``in review,'' we intended to convey that the document had been drafted and submitted for publication, but not yet accepted as it was still undergoing peer review. The USGS typically does not release documents unless they have been accepted for publication or otherwise peer reviewed. As the peer review process for this document remains incomplete, the article is solely in the possession of USGS and the reviewing journal.
Given the context of this citation and its inconsequentiality to
our determination, we do not think that this document was critical to
the public's review or understanding of our proposal. Therefore, we did not grant an extension of the comment period.
Distribution, Status, Population Size, and Population Trends
Issue: Some commenters contended that our 2005, 12month finding and proposed rule should have evaluated the distribution, abundance, trends, and threats information from the delisting petitions.
Response: On February 2, 2005, we issued a 12month finding on a petition to delist the Prebles and proposed to remove the mouse from the Federal list of endangered and threatened species (70 FR 5404, February 2, 2005). The basis for the proposed action was that the Prebles was ``likely not a valid subspecies of meadow jumping mouse.'' It was not necessary or appropriate to consider distribution, abundance, trends, or threats until it was determined that the Prebles qualified as a listable entity under the Act. Once we determined that the Prebles was a valid subspecies, we considered all relevant information on Prebles' distribution, abundance, trends, and threats in our revised proposed rule (72 FR 62992, November 7, 2007) and in this final rule.
Issue: Some commenters suggested that Figure 1 could have been more clear or more informative. Specific suggestions put forth were to: Include more detail; depict all jumping mouse captures noting the species; and provide a better explanation of the data depicted in the key and text. One reviewer commented that the database from which Figure 1 was derived should be available to the public.
Response: Figure 1 was too busy and difficult to read in the Federal Register. As a result, we have split this graphic
representation of occupancy into a Wyoming (Figure 1) and a Colorado
figure (Figure 2). We also revised the corresponding text. This final
rule more clearly depicts known Prebles' distribution and results of
other trapping efforts. The supporting data (Service 2008) is available upon request.
Issue: Reviewers commented that distribution of available habitat and threats to the Prebles could be mapped, quantified, and better visualized through use of GIS. One reviewer suggested that we clearly map all threats or confirm that project constraints make these measures impractical.
Response: The Service has mapped potential Prebles' habitat (67 FR 47154, July 17, 2002; 68 FR 37276, June 23, 2003), as has the Wyoming Natural Diversity Database (WNDD) (Beauvais 2001, 2004), the CDOW, and some Colorado counties. The Center for the West produced a series of GIS maps predicting growth through 2040 for the west including the Colorado Front Range and Wyoming (Travis et al. 2005, pp. 27). These models represent a good approximation of projected development pressures. We also worked with the CDOW to examine protection status of designated critical habitat units and other selected areas supporting the Prebles. These results are summarized in the 5factor analysis below.
Issue: We received numerous comments on data quality and quantity relative to the subspecies' status. Many noted limited available information or data on historical and current range, current abundance, population trends, threats, and ecological relationships. Some commenters suggested this illustrated the weakness of our original listing and, therefore, suggested we should delist rangewide. Other commenters suggested a change in listing status in any portion of the subspecies' range should be precluded until better data is available.
Response: The Act requires our determinations be based upon the best scientific and commercial information available. As a result, we evaluate all of the available information, its adequacy and reliability, and determine what the weight of evidence suggests. This final rule meets this standard.
Issue: One reviewer suggested that we quantify relative abundance of the Prebles and compare abundance estimates to habitat features to better define quality habitat. This reviewer thought we could estimate relative abundance by calculating and comparing Prebles captured per trap night (number of traps employed times number of nights of trapping) for all trapping efforts throughout Prebles' range.
Response: Where we have abundance information, we present it in this final rule. Data available is not adequate to quantify and compare the relative abundance of the Prebles across its range with any reasonable degree of confidence (i.e., much of the trapping was on small sites and over short periods with inconsistent timing and conditions).
Issue: One commenter claimed our analysis is flawed because the Prebles cannot be differentiated from the western jumping mouse.
Response: Genetic markers are effective in differentiating meadow jumping mice and western jumping mice (Riggs et al. 1997, pp. 28; Ramey et al. 2005, pp. 344346; King et al. 2006b, pp. 4341, 4344). Additionally, Discriminant Function Analysis (DFA) (analysis of cranial measurements and an anterior medial toothfold characteristic) appears to be a reliable technique for differentiating the two species (Conner and Shenk 2003a). We acknowledge that, for a number of historical and recent capture sites, mice were tentatively identified in the field based on capture location, size, and external features, but definitive identification to species was never attempted. In many of these cases, genetic samples were not obtained nor were voucher specimens taken; therefore, the specimen's species identity remains inconclusive. As noted below, positive identification to species is only an issue in areas of overlapping range (i.e., highelevation sites in Colorado and most of Wyoming). We have addressed potential shortcomings for species identification in our analysis, and we have reviewed and modified the text for added clarity.
Issue: Several commenters noted that Prebles are now known from more drainages and a greater number of sites than at the time of listing. These commenters suggested this was evidence that Prebles' populations are secure. One commenter requested that we state the specific number of sites where the Prebles is known to occur.
Response: We have acknowledged an increase in our knowledge of distribution of Prebles, especially in the Wyoming portion of its range. We have summarized areas of known or potential occurrence by river basin, drainage (8digit USGS hydrologic units), and river or stream. We also have emphasized instances where confirmed captures have extended our knowledge of Prebles' range and occurrence. We think that the number of individual capture sites is less meaningful. Documentation of multiple capture sites within portions of drainages or along streams where Prebles' populations occur is largely a function of trapping effort. When multiple sites are within close proximity of each other, counting each occurrence instead of a single population exaggerates abundance. Further, as one peer reviewer correctly cautioned, trends cannot be established from the number of documented sites alone, and that an increase in documented sites resulting from increased trapping efforts could mask a decreasing population trend.
Issue: One commenter stated that the Prebles' range has not declined significantly. This commenter suggested the subspecies is now known to be present in virtually all historically documented locations except those in the greater Denver area.
Response: The subspecies' declines within Colorado are fully explained in Factor A below. This analysis includes the apparent extirpation of the subspecies from approximately 420 km (260 mi) in and downstream of areas with concentrated human development. In terms of historically documented locations (i.e., sites from which we have specimens prior to 1980), we are aware of 17 such sites in Colorado. Of these, only one of these sites is currently thought to support the Prebles. The majority of historical records of Prebles in Colorado come from what is now widely known as the Front Range urban corridor, which extends well beyond the Denver area. In Wyoming, with the possible exception of Cheyenne, the Prebles is likely present at the few sites where it was historically documented.
Issue: One commenter concluded that the high number of section 7 consultations conducted in Colorado as compared to Wyoming was evidence of ``expansive range and increasing populations'' in Colorado.
Response: A more reasonable explanation for the number of section 7 consultations is that human development is expanding into areas of Prebles' occurrence. In Wyoming, far less development is occurring in areas where the Prebles is present.
Issue: Some commenters questioned how we established that over 80 percent of trapping efforts in Colorado since listing have failed to capture Prebles. They questioned whether western jumping mice were included in the results and questioned the expertise of the trappers conducting the studies. Some commenters requested comparative trapping success rates from Wyoming trapping.
Response: From 1998 to 2007, 27 percent of 1,350 data points associated with trapping efforts targeting Prebles in Colorado have resulted in captures of jumping mice (USFWS 2008). When we controlled for repeated trapping at single sites, such as established research sites, jumping mouse capture rates drop to less than 20 percent. Even this estimate may be high as some of these jumping mice were likely western jumping mice, particularly those from highelevation trapping efforts.
From 1998 to 2007, 74 percent of 219 data points associated with
trapping efforts in Wyoming have resulted in captures of jumping mice (USFWS
[[Page 39797]]
2008). The overlapping range of Prebles and western jumping mouse in
Wyoming must be considered when comparing Preble's capture success
between the two States. Based on individual mice confirmed to species,
it is likely that more of the successful trapping efforts in Wyoming
captured only western jumping mice. Of positive jumping mouse capture
sites, 29 percent of the sites included only Prebles, 55 percent of the
sites included only western jumping mice, 5 percent of the sites had
both species present, and specimens from 11 percent of the successful sites were never positively identified to species.
All jumping mouse trapping efforts since listing have been carried out by researchers holding Service and State permits. While experience of individual biologists may vary, we believe all individuals permitted to trap Prebles are qualified to conduct such surveys.
Issue: One commenter stated that foreseeable future as defined in the revised proposed rule was too short, citing climate change projections to 100 years and Service HCPs issued for 50 years.
Response: The term foreseeable future is not defined by the Act or in the implementing regulations at 50 CFR part 424. MerriamWebster's Law Dictionary (1996) defines ``foreseeable'' as such as that which reasonably can or should be anticipated such that a person of ordinary prudence would expect it to occur or exist under the circumstances (MerriamWebster's Dictionary of Law 1996; Western Watershed Project v. Foss (D. Idaho 2005; CV 04168MHW). Determination of foreseeable future is typically based on the timeframe over which the best available scientific data allows us to reasonably assess the threats and the species' response to those threats, and is supported by speciesspecific factors, including the species' life history characteristics (e.g., generation time) and population dynamics. From a scientific perspective, it would be inappropriate to set foreseeable future timeframes so short that natural variability in the ecosystem of the species, shortterm population dynamics, or the expression of life history traits of the species through generationalscale variation in reproductive success or recruitment cannot be accounted for in the longerterm examination of factors impacting the species. Typically, threats tend to operate through their effects on survival and productivity over multiple generations, with one to two generations being insufficient to separate natural variability from directional effects of threats. Whenever possible, we will determine the ``foreseeable future'' based on a detailed assessment of threats and speciesspecific biological information.
For the Prebles, we defined foreseeable future based upon a threat projection timeframe because future development intensity and patterns are likely to be the single greatest factor contributing to the subspecies' future conservation status. The foreseeable future for the Prebles, based on the currently available data, extends to approximately 2040. While it is likely human population growth and development projections could be extrapolated out into the more distant future, growth and development projections beyond this point are of increasingly lower value as uncertainty escalates. However, we agree that not all threat factors are necessarily foreseeable over the same time horizon and that for some threat factors a longer time horizon may be appropriate. Thus, this rule considers the range of climatic conditions predicted by the Intergovernmental Panel on Climate Change (IPCC) for the 21st century. While climate projections routinely go out past this 2040 time horizon (IPCC 2007, p. 7), climate change forecasts, like human development projections, become less certain as they are extended into the future (Hall 2008; Meyers 2008). The IPCC acknowledged this uncertainty in their most recent report when they stated that projections beyond the next two decades depend on specific emission scenarios (IPCC 2007, p. 7). The duration of section 10 permits, issued in support of approved Habitat Conservation Plans, have no bearing on what is foreseeable for this subspecies.
Issue: Some commenters stated that local extirpations of Prebles in the Front Range urban corridor cannot be used to speculate about future threats in other portions of its range. They suggested that development threats are localized and do not affect most Prebles' populations.
Response: While threats do vary across the range of the subspecies, we believe that the rule adequately captures and presents the severity of the issue across all portions of the subspecies' range. The direct and indirect effects of human development have resulted in substantial habitat alteration across large parts of the Colorado range. While habitat alteration has been most severe in the expanding Front Range urban corridor, projected future human growth will substantially extend this area of impact. Additional threats exist outside of areas of intense human development. For example, linear projects such as roads and pipelines may impact multiple counties and can affect rural habitat as well as that in urbanizing areas, and potential impacts from overgrazing are more likely to affect Prebles' habitat in rural areas than in areas of high residential density.
Issue: Some commenters suggested that population growth forecasts can be unreliable. They pointed to the current housing slump and suggest that population growth within the Prebles' range will be less than predicted. One commenter stated that the Center for the American West models' depiction of development patterns in the future have limited utility since they assume that all private land is technically buildable and available for development.
Response: Any future predictions include a degree of uncertainty. That said, we consider projections and related models to be the best information available on this subject. Economic downturns, that are relatively shortlived, are unlikely to significantly alter longterm forecasts.
The Center for the American West models (Travis et al. 2005, pp. 2 7) predict development patterns on a subregional basis. The fate of individual parcels could be determined by a number of factors not addressed by the models, and the model developers have noted that the projections should not be applied to individual properties. We have cited these models in evaluating threats related to likely patterns of future human growth, not the presumed fate of individual properties. We have expanded our discussion of the models and their use in the text.
Issue: One reviewer noted that while human development in Wyoming is likely to be far less than in Colorado, Wyoming does not ``lack'' development and much of it will be in rural areas. A few commenters addressed current and modeled future human population growth in Wyoming centered near Cheyenne. One reviewer questioned whether the absence of the Prebles in Cheyenne area was the result of development. Another reviewer concluded that projected growth in the Cheyenne area would not result in impacts to the Prebles because it would not overlap areas known to support the subspecies.
Response: We acknowledge that human development is likely to occur
in portions of Wyoming now supporting the Prebles. However, we believe that expansion of human presence and
[[Page 39798]]
related threats will be localized and relatively minor, and will not
threaten the continued persistence of the Prebles in those areas.
Known occurrence records suggest that the Prebles is not common or widely present in the South Platte River basin in Wyoming. The cause of this rarity is unknown. The continued existence of the Prebles in the Cheyenne area also is unknown. Sites of recent confirmation of the Prebles in the South Platte River basin of Wyoming have been well upstream from Cheyenne. Development could impact Prebles' populations in the Cheyenne area, should they exist. However, the longterm viability of populations in these drainages is more likely to depend on persistence in upstream portions of the drainages rather than the Cheyenne area.
Issue: Some commenters predicted that secondary impacts associated with human development in Colorado would impact Prebles' habitat in southern Wyoming. Particular issues raised included vacation homes, human recreational activities, water resource development and storage, and aggregate mining.
Response: As human populations in Colorado, particularly northern Colorado, continue to grow, secondary impacts may spill over into southeastern Wyoming. Regarding vacation homes, the Center for the West models of human population growth take into account urban, suburban, exurban, and rural development (http://www.centerwest.org/futures/ west/2040.html; http://www.centerwest.org/futures/archive/development/ development_wy.html). These projections suggest exurban development could link Cheyenne and Fort Collins by midcentury, but indicate little development in the documented range of the Prebles in Wyoming. While some development will undoubtedly occur, we do not have data to indicate meaningful impacts are likely anywhere in the Wyoming portion of the subspecies' range, except around Cheyenne where the subspecies has not been recently documented to occur.
While increasing population may result in increased recreation, new water development, or additional aggregate mining, we are not aware of any specific proposals that would increase the effects of these types of activities on Prebles' populations. These issues are evaluated further in our 5Factor analysis below.
Issue: Some commenters stated that grazing is not a significant threat, as evidenced by the special 4(d) rule allowing continued agricultural activities. One commenter stated that chronic violations of grazing regulations on public grazing lands impact Prebles' habitat. One commenter provided a Bureau of Land Management (BLM) (2004) report on public range in Wyoming, to demonstrate that range improvements have occurred over time. The report stated that range conditions have improved over time; efforts are under way to stop invasive weeds; and wildlife populations have increased.
Response: Our special rule provides exemption from take prohibitions under section 9 of the Act for certain land uses including continued agriculture. While overgrazing can and does impact Prebles' habitat, and in some cases can be a threat, the 4(d) rule (66 FR 28125, May 22, 2001; 67 FR 61531, October 1, 2002; 69 FR 29101, May 20, 2004) was instituted to acknowledge that those ongoing agricultural operations maintaining habitat that supports the Prebles are an asset to conservation and recovery. Through this special rule, we anticipated increased opportunity to partner with agricultural interests toward conservation of the Prebles.
While we are aware of instances where operators have violated provisions of their grazing permits, we have concluded that this is not a widespread threat within the Prebles' range. We solicited and received data and information on livestock grazing from the U.S. Forest Service (USFS) regarding three National Forests that support Prebles' populations. Allotment inspection records or monitoring reports were received from the Laramie Ranger District, Medicine Bow National Forest in Wyoming (Florich 2008); the Canyon Lakes Ranger District, Arapahoe National Forest (Hodges 2008); and the South Park Ranger District, Pike National Forest (Branch 2008). While the records include instances of noncompliance and note grazing impacts to habitat, more often they reflect livestock grazing conducted in accordance with grazing plans that are consistent with maintenance of Prebles' habitat. Federal agencies, including the USFS and BLM, work cooperatively with the Service to fulfill their responsibilities under the Act. For example, we recently coordinated with the USFS regarding permittee non compliance issues on the Arapahoe National Forest's Greyrock allotment. In that area, riparian habitat along the North Fork, Cache La Poudre River is recovering following remedial measures to counteract overgrazing.
We reviewed BLM (2004). While not specific to the Prebles' range, we are encouraged by its conclusions that conditions on BLM grazing lands in Wyoming are improving.
Issue: One commenter stated that the Service inappropriately cited the Taylor (1999) trapping study as evidence of Prebles' compatibility with grazing. This comment indicated that: The properties on which the trapping was conducted are not representative of most grazing operations; the report documents grazing impacts on riparian habitat; and Prebles' populations may have decreased since this study because of drought.
Response: The study at issue is by far the most extensive effort conducted on private lands in Wyoming. Jumping mice were captured at 18 of 21 survey sites representing diverse habitat conditions. Genetic testing confirmed Prebles at 11 sites, western jumping mice at 3 sites, both species at 3 sites, and one site was never identified to species (it is also worth noting that although many sites had multiple captures, not all specimens were preserved for species identification). Capture sites included both ideal habitat, such as riparian habitat or subirrigated hayfields, and sites where grazing or other factors had impacted habitat quality. While Prebles' habitat and populations are likely affected by periodic droughts, results of this trapping effort demonstrate a broad, longterm ability of the subspecies to coexist with traditional agricultural operations in Wyoming.
Issue: Some commenters recommended that we explore additional threats to the Prebles in Wyoming from agricultural conversion to biofuels.
Response: As discussed in the revised proposed rule, the conversion of native habitat to row crops has become increasingly rare in both Colorado and Wyoming (U.S. Department of Agriculture 2000, Tables 2, 3, & 9). This trend likely reflects that riparian habitats (and other areas) that could be feasibly converted to crop production have already been converted. Although pressures to increase agricultural production may result from the demand to produce biofuels, we are not aware of information that indicates this would result in meaningful de
FOR FURTHER INFORMATION CONTACT Susan Linner, Field Supervisor, U.S. Fish and Wildlife Service, Colorado Field Office at 134 Union Blvd., Suite 670, Lakewood, CO 80228; telephone (303) 2364773. Individuals who are hearingimpaired or speechimpaired may call the Federal Relay Service at 18008778339 for TTY assistance.
14 CFR Part 39 40 CFR Part 52 14 CFR Part 71 33 CFR Part 165 47 CFR Part 73 26 CFR Part 1 50 CFR Part 679 40 CFR Part 180 50 CFR Part 17 33 CFR Part 117 44 CFR Part 67 50 CFR Part 648 14 CFR Part 97 40 CFR Part 63 6 CFR Part 5 33 CFR Part 100 50 CFR Part 622 50 CFR Part 660 26 CFR Part 301 44 CFR Part 65 39 CFR Part 111 40 CFR Part 271 40 CFR Part 300 47 CFR Part 64 40 CFR Parts 52 and 81 50 CFR Part 665 39 CFR Part 3020 50 CFR Part 229 44 CFR Part 64 49 CFR Part 571