[Federal Register Volume 72, Number 215 (Wednesday, November 7, 2007)]
[Proposed Rules]
[Pages 62992-63024]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 07-5486]



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Part III





Department of the Interior





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Fish and Wildlife Service



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50 CFR Part 17



 Endangered and Threatened Wildlife and Plants; Revised Proposed 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; Proposed Rule

  Federal Register / Vol. 72, No. 215 / Wednesday, November 7, 2007 / 
Proposed Rules  

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AV64


Endangered and Threatened Wildlife and Plants; Revised Proposed 
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

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Revised proposed rule.

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SUMMARY: Under the authority of the Endangered Species Act of 1973, as 
amended (Act), we, the U.S. Fish and Wildlife Service (Service), revise 
our February 2, 2005 (70 FR 5404), proposed rule to remove the Preble's 
meadow jumping mouse (Zapus hudsonius preblei) (Preble's) from the List 
of Endangered and Threatened Wildlife. We now propose to amend the 
listing for the Preble's meadow jumping mouse to specify over what 
portion of its range the subspecies is threatened. The best scientific 
and commercial data available demonstrates that: The Preble's meadow 
jumping mouse 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 current range of the 
subspecies located in Colorado represents a significant portion of the 
current range where the Preble's meadow jumping mouse is likely to 
become endangered within the foreseeable future, and the subspecies in 
that portion of its range should retain its threatened status. We seek 
comments from the public regarding this revised proposal. Comments 
previously submitted need not be resubmitted as they have already been 
incorporated into the public record and will be fully considered in the 
final determination.

DATES: Written Comments: We will consider comments on this revised 
proposed rule that we receive by the close of business on January 22, 
2008. Any comments we receive after the closing date may not be 
considered in our final decision on the proposal.
    Open House and Public Hearing: We will hold an open house and 
public hearing on this revised proposed rule in Colorado on December 
10, 2007 and in Wyoming on December 12, 2007. Each open house will run 
from 4 p.m. to 5 p.m., with brief presentations about this revised 
proposed rule given at 4 p.m., and each public hearing will run from 6 
p.m. to 8 p.m.

ADDRESSES: Written Comments: If you wish to comment on this revised 
proposed rule, you may submit your comments and materials by any one of 
several methods:
    (1) By mail to: Susan Linner, Field Supervisor, Colorado Field 
Office, Ecological Services, P.O. Box 25486, MS-65412, Denver Federal 
Center, Denver, CO 80225.
    (2) By hand-delivery to: Susan Linner, Colorado Field Office at 134 
Union Blvd., Suite 670, Lakewood, CO 80228.
    (3) By fax to: (303) 236-4005.
    (4) By electronic mail (e-mail) to: [email protected]. Please see 
the Public Comments Solicited section below for other information about 
electronic filing.
    (5) By the Federal eRulemaking Portal at: http://www.regulations.gov. Follow the instructions on that Web site for 
submitting comments.
    Open House and Public Hearing: We will hold an open house and 
public hearing at the Colorado Field Office, 134 Union Boulevard, Room 
100A--Eagle Conference Room, Lakewood, CO 80228 and at the First State 
Bank Conference Center, 1405 16th Street, Wheatland, WY 82201.

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) 236-4773; facsimile 
(303) 236-4005. If you use a telecommunications device for the deaf 
(TDD), call the Federal Information Relay Service (FIRS) at (800) 877-
8339.

SUPPLEMENTARY INFORMATION:

Public Comments Solicited

    We intend that any final action resulting from this proposal will 
be as accurate and as effective as possible. Therefore, we solicit 
data, comments, new information, or suggestions from the public, other 
concerned governmental agencies, the scientific community, industry, or 
any other interested party concerning this revised proposed rule. 
Generally, we seek information, data, and comments concerning:
    (1) Survey results for Preble's meadow jumping mouse, as well as 
any studies that may show distribution, status, population size, or 
population trends;
    (2) Pertinent aspects of life history, ecology, and habitat use of 
Preble's meadow jumping mouse, especially those pertaining to its 
relationship to the western jumping mouse (Zapus princeps);
    (3) Current and foreseeable threats faced by the Preble's meadow 
jumping mouse in relation to the five factors (as defined in section 
4(a)(1) of the Act (16 U.S.C. 1531 et seq.));
    (4) Effects of current and foreseeable land management practices on 
Preble's meadow jumping mouse status, including conservation efforts;
    (5) Our analysis and conclusions regarding the conservation status 
of the Preble's meadow jumping mouse throughout all of its range, in 
particular information relative to the long-term security of existing 
populations of the subspecies in Wyoming.
    (6) Our analysis and conclusions regarding ``significant portion of 
its range'' in light of the March 14, 2007, Department of the Interior, 
Solicitor Memorandum opinion available at http://www.doi.gov/solicitor/M37013.pdf;
    (7) The contribution of both the Wyoming and Colorado portions of 
the range to the status of the subspecies;
    (8) The range of the subspecies as defined in this proposal and the 
areas where the protections of the Act should remain in place (see 
``Significant Portion of the Range Where the Subspecies is Threatened'' 
for specific information solicited) and
    (9) The Sustainable Ecosystems Institute (SEI) report ``Evaluation 
of scientific information regarding Preble's meadow jumping mouse'' 
(available at http://www.fws.gov/mountain-prairie/species/mammals/preble/) and other information concerning the taxonomic status of 
Preble's meadow jumping mouse.
    You may submit your comments and materials concerning this revised 
proposed rule by one of several methods (see ADDRESSES). If you use e-
mail to submit your comments, please submit them in ASCII file format 
and avoid the use of special characters and encryption. Please include 
``Attn: Preble's meadow jumping mouse'' in your e-mail subject header, 
preferably with your name and return address in the body of your 
message. If you do not receive a confirmation from the system that we 
have received your e-mail, contact us directly by calling our Colorado 
Field Office at (303) 236-4773. Please note that we must receive 
comments by the date specified in the DATES section in order to 
consider them in our final determination and that we will close out the 
e-mail address [email protected] at the termination of the public 
comment period.
    Before including your address, phone number, e-mail address, or 
other personal identifying information in your comment, you should be 
aware that

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your entire comment--including your personal identifying information--
may be made publicly available at any time. While you can ask us in 
your comment to withhold your personal identifying information from 
public review, we cannot guarantee that we will be able to do so. We 
will always make submissions from organizations and businesses, and 
from individuals identifying themselves as representatives or officials 
of organizations and businesses, available for public inspection in 
their entirety.
    Comments and materials we receive, as well as supporting 
documentation we used in preparing this revised proposed rule, will be 
available for public inspection, by appointment, during normal business 
hours at the U.S. Fish and Wildlife Service Colorado Field Office, 134 
Union Blvd., Suite 670, Lakewood, CO 80228, (telephone (303) 236-4773) 
. We will take into consideration all substantive comments and any 
pertinent information we receive during the comment period on this 
revised proposed rule during the preparation of a final rulemaking. 
Accordingly, the final decision may differ from this proposal.

Open Houses and Public Hearings

    We will hold open houses and public hearings on the dates listed in 
the DATES section, and at the addresses listed in the ADDRESSES 
section, of this document. Anyone wishing to make an oral statement for 
the record at either of the public hearing is encouraged to provide a 
written copy of his or her statement and present it to us at the 
hearing. Persons wishing to make an oral statement at the public 
hearing may sign up only at the open house or at the public hearing; we 
will not reserve speaking time in advance of the open house. In the 
event that there is a large attendance, the time allotted for oral 
statements may be limited. Oral and written statements receive equal 
consideration. There are no limits on the length of written comments 
submitted to us. If you have any questions concerning the open house or 
public hearing, please contact Sharon Rose at (303) 236-4580. Persons 
needing reasonable accommodations in order to attend and participate in 
the open house or public hearing should contact Sharon Rose as soon as 
possible in order to allow sufficient time to process requests. Please 
call no later than 1 week before the hearing date. Information 
regarding this revised proposal is available in alternative formats 
upon request.

Previous Federal Actions

    We listed Preble's meadow jumping mouse as threatened under the Act 
on May 13, 1998 (63 FR 26517). We designated critical habitat for 
Preble's meadow jumping mouse on June 23, 2003 (68 FR 37275). On May 
22, 2001 (66 FR 28125), we adopted a final section 4(d) special rule 
for the Preble's meadow jumping mouse 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 sunset May 22, 2004, but was made 
permanent on May 20, 2004 (69 FR 29101).
    In June 2000, the Service established the Preble's Meadow Jumping 
Mouse 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. This technical working draft was 
revised by the Service in November 2003. The Preliminary Draft Recovery 
Plan suggested long-term protection of: One large population (with June 
abundances of 2,500 or more individuals), two medium populations (with 
June abundances of 500-2,499 individuals), and six small populations 
(with evidence of occupancy; possibly 150 mice) within the North Platte 
River basin two large, three medium, and eighteen small populations 
within the South Platte River basin and one large population, and six 
small populations within the Arkansas River basin (Service 2003b, p. 
19-23). Recovery planning efforts were halted in December 2003 after 
new information became available questioning the taxonomic validity of 
the subspecies. While the availability of this document (hereafter 
referred to as the Preliminary Draft Recovery Plan (Service 2003b)) has 
not yet been announced in the Federal Register, it represents the best 
available information on the recovery needs of the subspecies.
    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 Preble's meadow 
jumping mouse from the Federal List of Endangered and Threatened 
Wildlife (Freudenthal 2003; Sonnenberg 2003). The petitions maintained 
that Preble's meadow jumping mouse should be delisted based on the 
taxonomic revision suggested by Ramey et al. (2003) and new 
distribution, abundance, and trends data which 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 90-day 
finding that the petitions presented substantial information indicating 
that the petitioned action may be warranted (69 FR 16944). On February 
2, 2005, we published a 12-month finding that the petitioned action was 
warranted, and a proposed rule to remove Preble's meadow jumping mouse 
from the Federal List of Endangered and Threatened Wildlife, and opened 
a 90-day public comment period (70 FR 5404). 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 Preble's meadow 
jumping mouse 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 
Preble's meadow jumping mouse was likely not a valid subspecies of 
meadow jumping mouse (Zapus hudsonius). Considering the weight that we 
gave Ramey et al. (2004a) in the proposed delisting, verifying the 
results of this study 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 Preble's meadow jumping mouse and four 
neighboring subspecies of meadow jumping mice (U.S. Geological Survey 
2005, pp. 1-4).
    On January 25, 2006, USGS released its report concluding that 
Preble's meadow jumping mouse 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 because 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 (71 
FR 8556). 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.

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    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. differ 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) (Service 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 60-day 
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 Preble's 
meadow jumping mouse's 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)). If a new proposed regulation is deemed necessary, 
the Service is required to submit a final determination to the Federal 
Register no later than June 30, 2008.

Public Comments on the 2005 Proposed Rule

    From February 2, 2005, through May 3, 2005 (70 FR 5404, February 2, 
2005), and from February 17, 2006, through May 18, 2006 (71 FR 8556, 
February 17, 2006; 71 FR 16090, March 30, 2006), we solicited, from all 
interested parties, comments and information that might contribute to 
the final delisting determination for the Preble's meadow jumping 
mouse. We received a total of 67 written comments, including 28 
comments during the initial comment period and 39 during the reopened 
comment period. These included comments from: The Governor of the State 
of Wyoming; the Attorney General of the State of Wyoming; the Colorado 
Department of Natural Resources; U.S. Forest Service, Rocky Mountain 
Region; 6 comments from local governments; and 57 comments from 
individuals or groups. During the reopened comment period we also 
received a challenge under the Information Quality Act (44 U.S.C. 3516) 
to influential information disseminated by the Service during this 
rulemaking process. This challenge and our response are available at 
http://www.fws.gov/informationquality/. This response has been appealed 
and the appeal is currently under review by the Service. Because we 
received the original challenge during the open public comment period, 
these issues are considered public comments on our proposed rule.
    In accordance with our July 1, 1994, Interagency Cooperative Policy 
for Peer Review in Endangered Species Act Activities (59 FR 34270), we 
solicited five expert peer reviews of our proposed rule (70 FR 5404, 
February 2, 2005). We selected peer reviewers for expertise in 
genetics, systematics (the science of dealing with the diversity of 
organisms), and small mammals. We excluded previous peer reviewers of 
Ramey et al. and King et al. from this solicitation. Three of the 
experts approached provided comments (Hoekstra 2005; Kelt 2005; Spencer 
2005). After reopening the public comment period on February 17, 2006 
(71 FR 8556), we contacted the same five experts and invited them to 
provide additional comments given the availability of new information 
(i.e., King et al. 2006a). Two of these reviewers provided comments 
(Kelt 2006; Spencer 2006a).
    All previously submitted comments have been included in the public 
record and will be considered in the final determination regarding this 
proposal. Comments previously submitted need not be resubmitted. 
Additionally, all of the previously submitted comments and reviews 
relevant to the taxonomy discussion were made available to the SEI 
panel for its consideration. Substantive comments will be addressed in 
a series of issues and responses in our final determination.

General Information

    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).
    Across their range, meadow jumping mice typically occur in moist 
habitats, including low undergrowth consisting of grasses, forbs, or 
both, in open wet meadows and riparian corridors, or where tall shrubs 
and low trees provide adequate cover (Krutzsch 1954, p. 351; Armstrong 
1972, p. 248; Jones et al. 1983, p. 238). Trainor et al. (2007, pp. 
471-472) found that high use areas for Preble's meadow jumping mouse 
tended to be close to creeks and were positively associated with the 
percentage of shrubs, grasses, and woody debris. Hydrologic regimes 
that support Preble's meadow jumping mouse 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 Preble's 
meadow jumping mouse uses uplands at least as far out as 100 m (330 ft) 
beyond the 100-year floodplain (Shenk and Sivert 1999a, p. 11; Ryon 
1999, p. 12; Schorr 2001, p. 14; Shenk 2004; Service 2003b, p. 26). 
While the Preble's meadow jumping mouse dispersal capabilities are 
thought to be limited, in one instance a Preble's meadow jumping mouse 
was documented moving as far as 1.1 kilometers (km) (0.7 mile (mi)) in 
24 hours (Ryon 1999, p. 12). The Preble's meadow jumping mouse 
typically enters hibernation between September and 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 Preble's meadow jumping mouse 
as threatened (63 FR 26517) and the June 23, 2003, final rule 
designating critical habitat (68 FR 37275).

Taxonomy

    The Preble's meadow jumping mouse is a member of the family 
Dipodidae (jumping mice) (Wilson and Reeder 1993, p. 499), which 
contains four extant genera. Two of these, Zapus (jumping mice) and 
Napaeozapus (woodland jumping mice), are found in North America (Hall 
1981, p. 841; Wilson and Ruff 1999, pp. 665-667).
    In his 1899 study of North American jumping mice, Edward A. Preble 
concluded the Zapus genus consisted of 10 species (Preble 1899, pp. 13-
41). According to Preble (1899, pp. 14-21), Z. hudsonius (the meadow 
jumping mouse) included five subspecies. Preble (1899, pp. 20-21) 
classified all specimens of the meadow jumping mouse from North Dakota, 
Montana, South Dakota, Wyoming, Nebraska, Colorado, and Missouri as a 
single subspecies, Z. hudsonius campestris. Cockrum and Baker (1950, 
pp. 1-4) later designated specimens from Nebraska,

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Kansas, and Missouri as a separate subspecies, Z. h. pallidus.
    Krutzsch (1954, pp. 352-355) revised the taxonomy of the Zapus 
genus after studying morphological characteristics of 3,600 specimens. 
This revision reduced the number of species within this genus from 10 
to 3, including Z. hudsonius (the meadow jumping mouse), Z. princeps 
(the western jumping mouse), and Z. trinotatus (the Pacific jumping 
mouse). According to Krutzsch (1954, pp. 385-453), the meadow jumping 
mouse included 11 subspecies.
    Krutzsch (1954, pp. 452-453) described and named the subspecies 
Preble's meadow jumping mouse (Zapus hudsonius preblei) based on 
geographic separation and morphological (physical form and structure of 
an organism) differences. Krutzsch (1954, pp. 452-453) discussed the 
presence of physical habitat barriers and the lack of known 
intergradation (merging gradually through a continuous series of 
intermediate forms or populations) between the Preble's meadow jumping 
mouse, known only from eastern Colorado and southeastern Wyoming, and 
other identified subspecies of meadow jumping mice ranging to the east 
and north. Additionally, Krutzsch (1954, pp. 452-453) evaluated the 
morphometric characteristics of 4 adult and 7 non-adult specimens. 
Acknowledging the small number of samples upon which his conclusion was 
based, Krutzsch (1954, p. 453) nonetheless concluded that the 
differences between Preble's meadow jumping mouse and neighboring 
meadow jumping mice was considerable and enough to warrant a 
subspecific designation.
    In Krutzsch's analysis, the subspecies neighboring Preble's meadow 
jumping mouse included Z. h. campestris in northwestern Wyoming, 
southwestern South Dakota, and southeastern Montana; Z. h. intermedius 
in North Dakota, and northwestern, central, and eastern South Dakota; 
and Z. h. pallidus (Cockrum and Baker 1950) in Nebraska, Kansas, and 
Missouri (Krutzsch 1954, pp. 441-442, 447-452). Among recognized 
subspecies, Krutzsch (1954, p. 452) found that Preble's meadow jumping 
mouse most closely resembled Z. h. campestris from northeastern 
Wyoming, but documented differences in coloration and skull 
characteristics.
    In 1981, Hafner et al. (1981, p. 501) identified Zapus hudsonius 
luteus from Arizona and New Mexico as the 12th subspecies of meadow 
jumping mouse. This population had previously been assumed to be a 
subspecies of western jumping mouse (Krutzsch 1954, pp. 406-407; Hall 
and Kelson 1959, pp. 774-776; Jones 1981, p. iv).
    Krutzsch's description (1954) as modified by Hafner et al. (1981, 
p. 501), with 12 subspecies of meadow jumping mice, was generally 
accepted by most small mammal taxonomists for the past half-century 
(Hall and Kelson 1959, pp. 771-774; Long 1965, pp. 664-665; Armstrong 
1972, pp. 248-249; Whitaker 1972, pp. 1-2; Hall 1981, pp. 841-844; 
Jones et al. 1983, pp. 238-239; Clark and Stromberg 1987, p. 184; 
Wilson and Reeder 1993, p. 499; Hafner et al. 1998, pp. 120-121; Wilson 
and Ruff 1999, pp. 666-667).

Other Taxonomic Information Available Prior to Listing

    As part of a doctoral dissertation, Jones (1981, pp. 4-29, 229-303, 
386-394, 472) analyzed the morphology of 9,900 specimens within the 
Zapus genus from across North America, including 39 Preble's meadow 
jumping mouse specimens. Jones's dissertation (1981, p. 144) concluded 
that the Pacific jumping mouse was not a valid taxon and suggested 
reducing the number of species in the genus to two (the western jumping 
mouse and the meadow jumping mouse). At the subspecific level, Jones 
(1981, pp. V, 303) concluded that no population of meadow jumping mouse 
was sufficiently isolated or distinct to warrant subspecific status. 
Regarding the Preble's meadow jumping mouse, Jones (1981, pp. 288-289) 
wrote that ``No named subspecies is geographically restricted by a 
barrier, with the possible exception of Z. h. preblei [Preble's meadow 
jumping mouse]'' which ``appears to be isolated,'' but that ``no 
characteristics indicate that these populations have evolved into a 
separate taxon.'' Jones did not compare the Preble's meadow jumping 
mouse to Z. h. campestris, a neighboring subspecies, nor did he conduct 
statistical tests of morphology between the Preble's meadow jumping 
mouse and any other subspecies. Jones's (1981) findings were not 
published in a peer-reviewed journal and were not incorporated into the 
formal jumping mouse taxonomy, leaving his conclusions difficult to 
evaluate.
    Prior to listing, the Colorado Division of Wildlife (CDOW) 
contracted for a genetic analysis of the Preble's meadow jumping mouse 
(Riggs et al. 1997). Riggs et al. (1997, p. 1) examined a small number 
of base-pairs (433) in one region of the mitochondrial deoxyribonucleic 
acid (mtDNA) (maternally inherited genetic material) across 5 
subspecies of meadow jumping mouse (92 specimens). This study concluded 
that the Preble's meadow jumping mouse specimens formed a homogenous 
group recognizably distinct from other nearby populations of meadow 
jumping mice (Riggs et al. 1997, p. 12). At the request of the Service, 
Hafner (1997, p. 3) reviewed the Riggs study, inspected Riggs' original 
sequence data, and agreed with its conclusions. The Riggs et al. (1997) 
results were not published in a peer-reviewed journal. Prior to 
listing, this study was the only available information concerning the 
genetic uniqueness of the Preble's meadow jumping mouse.
    Our original listing determined that Krutzsch's (1954) revision of 
the meadow jumping mouse species, including the description of the 
Preble's meadow jumping mouse, was widely supported by the scientific 
community as indicated by the available published literature (63 FR 
26517, May 13, 1998). Our 1998 determination weighed the information in 
unpublished reports, such as Jones (1981), and public comments on the 
rule and found that they did not contain enough scientifically 
compelling information to suggest that revising the existing taxonomy 
was appropriate (63 FR 26517, May 13, 1998). Our 1998 conclusion was 
consistent with Service regulations that require us to rely on standard 
taxonomic distinctions and the biological expertise of the Department 
and the scientific community concerning the relevant taxonomic group 
(50 CFR 424.11).

Taxonomic Information Solicited After Listing

    In July 2003, we entered into a cooperative agreement with the 
Denver Museum of Natural Science (DMNS) to determine if the Preble's 
meadow jumping mouse was a unique subspecies relative to other nearby 
subspecies of meadow jumping mice (Service 2003a, pp. 1-2). This task 
was a priority of the Recovery Team (Service 2003a, pp. 1-2; Service 
2003b, pp. iv, 38, 43, 76). In December 2003, we received a draft 
report from the DMNS examining the uniqueness of the Preble's meadow 
jumping mouse relative to other nearby subspecies of meadow jumping 
mice (Ramey et al. 2003). In August 2005, an expanded version of this 
original report was published in the journal ``Animal Conservation'' 
(Ramey et al. 2005). This publication included an examination of 
morphometric differences, mtDNA, and microsatellite DNA (a short, 
noncoding DNA sequence, usually 2 to 5 base-pairs, that is repeated 
many times within the genome of an organism). Ramey et al. (2005, pp. 
339-341) also examined the literature for evidence of

[[Page 62996]]

ecological exchangeability among subspecies (a test of whether 
individuals can be moved between populations and can occupy the same 
ecological niche).
    Ramey et al.'s morphometric analysis tested 9 skull measurements of 
40 Preble's meadow jumping mice, 40 Z. h. campestris, and 37 Z. h. 
intermedius specimens (Ramey et al. 2005, p. 331). Their results did 
not support Krutzsch's (1954, p. 452) original description of the 
Preble's meadow jumping mouse as ``averaging smaller in most cranial 
measurements'' (Ramey et al. 2005, p. 334). Ramey et al. (2005, p. 334) 
found that only one cranial measurement was significantly smaller, 
while two cranial measurements were significantly larger.
    Ramey et al. examined a small number of base-pairs (346) in 1 
region of the mtDNA across 5 subspecies of meadow jumping mice (205 
specimens) (Ramey et al. 2005, pp. 331-332, 335). Ramey et al. (2005, 
p. 335, 338) found low levels of difference between the Preble's meadow 
jumping mouse and neighboring subspecies. Their data demonstrated that 
all of the mtDNA haplotypes (alternate forms of a particular DNA 
sequence or gene) found in the Preble's meadow jumping mouse were also 
found in Z. h. campestris. The mtDNA data demonstrated evidence of 
recent gene flow between the Preble's meadow jumping mouse and 
neighboring subspecies (Ramey et al. 2005, p. 338).
    Ramey et al. (2005, pp. 333-334, 338) analyzed a small number (5) 
of microsatellite loci (the specific position of a gene or other 
chromosomal marker) across 5 subspecies of meadow jumping mice (195 
specimens). Ramey et al. (2005, p. 340) concluded that these results 
were consistent with morphometric and mtDNA results.
    Based on morphometrics, mtDNA, and microsatellites data, and a lack 
of recognized adaptive differences, Ramey et al. (2005, p. 340) 
suggested synonymizing the Preble's meadow jumping mouse and Z. h. 
intermedius with Z. h. campestris.
    Prior to publication of Ramey et al. (2005) in ``Animal 
Conservation,'' the CDOW and the Service solicited 16 peer reviews of 
the 2004 draft report provided to the Service (Ramey et al. 2004a). 
Fourteen of these reviewers provided comments (Armstrong 2004; Ashley 
2004; Bradley 2004; Conner 2004; Crandall 2004; Douglas 2004; Hafner 
2004; Meaney 2004; Mitton 2004; Oyler-McCance 2004; Riddle 2004; Sites 
2004; Waits 2004; White 2004). In 2005, the Service approached the same 
16 experts to review Ramey et al. 2004b (an expansion of Ramey et al. 
2004a). Eleven of these reviewers provided comments (Ashley 2005; Baker 
and Larsen 2005; Bradley 2005; Crandall 2005; Douglas 2005; Hafner 
2005; Maldonado 2005; Mitton 2005; Oyler-McCance 2005; Waits 2005; 
White 2005). In August 2006, ``Animal Conservation'' published two 
critiques of Ramey et al. (2005) (Martin 2006; Vignieri et al. 2006) 
and two responses (Crandall 2006b; Ramey et al. 2006a).
    While many of the reviewers supported the findings of Ramey et al. 
(Baker and Larsen 2005; Bradley 2004, 2005; Crandall 2004, 2005; Hafner 
2004; Maldonado 2005; Meaney 2004; Mitton 2004, 2005; Riddle 2004; 
Sites 2004; Waits 2004, 2005), the reviews raised a number of important 
issues. Some of the most significant issues identified included: (1) 
Reliance upon museum specimens which can be prone to contamination 
(Douglas 2004, 2005; Maldonado 2005); (2) the reliability of, and 
failure to validate, specimens' museum tag locality (and thus 
subspecies) identification (Ashley 2005; Douglas 2004, 2005; Hafner 
2004; Oyler McCance 2004, 2005); (3) reliance upon a small portion of 
mtDNA (Ashley 2004, 2005; Baker and Larsen 2005; Crandall 2004, 2005; 
Douglas 2004, 2005; Hafner 2005; Maldonado 2005; Oyler-McCance 2004, 
2005; Riddle 2004; Sites 2004; Waits 2004, 2005); (4) the small number 
of microsatellite DNA loci examined (Vignieri et al. 2006, p. 241); (5) 
the criteria used and factors considered to test taxonomic validity as 
well as alternative interpretations of the data (Ashley 2004; Conner 
2004; Douglas 2004, 2005; Hafner 2005; Oyler-McCance 2004, 2005; 
Vignieri et al. 2006, pp. 241-242; White 2004); (6) whether the authors 
used an appropriate outgroup (a closely related group that is used as a 
rooting point of a phylogenetic tree) (Douglas 2004); (7) the sampling 
regime and its impact on the analysis (Maldonado 2005; Oyler-McCance 
2004); (8) failure to test all of the morphological characters examined 
by Krutzsch (1954) (Vignieri et al. 2006, p. 238); (9) an inadequate 
evaluation of ecological exchangeability and habitat differences among 
subspecies (Ashley 2004; Conner 2004; Douglas 2004; Meaney 2004; Mitton 
2004; Oyler-McCance 2004, 2005; Sites 2004; Vignieri et al. 2006, p. 
238; Waits 2004, 2005); and (10) failure to consider the Preble's 
meadow jumping mouse's geographic isolation (Vignieri et al. 2006, pp. 
237-238). Collectively, these critiques indicated that delisting based 
on the conclusions of Ramey et al. alone might be premature.
    Because the proposed rule to delist the Preble's meadow jumping 
mouse relied solely upon an unpublished report (Ramey et al. 2004a) 
that had received mixed peer reviews (see above), verifying these 
results was a high priority of the Service (Morgenweck 2005; Williams 
2004). Thus, in 2006, the Service contracted with USGS to conduct an 
independent genetic analysis of several meadow jumping mouse subspecies 
(U.S. Geological Survey 2005, pp. 1-4). The USGS study concluded that 
the Preble's meadow jumping mouse should not be synonymized with 
neighboring subspecies (King et al. 2006a, pp. 2, 29). An expanded 
version of this report was published in the journal ``Molecular 
Ecology'' (King et al. 2006b). This publication included an examination 
of microsatellite DNA, 2 regions of mtDNA, and 15 specimens critical to 
the conclusions of Ramey et al. (2005).
    King et al.'s (2006b, p. 4336) microsatellite analysis examined 
approximately 4 times the number of microsatellite loci (21) and 1\1/2\ 
times more specimens (348 specimens) than Ramey et al. (2005) across 
the same 5 subspecies of meadow jumping mice. King et al. (2006b, p. 
4337) concluded that their microsatellite data demonstrated a strong 
pattern of genetic differentiation between the Preble's meadow jumping 
mouse and neighboring subspecies. King et al. (2006b, pp. 4336-4341) 
also reported that multiple statistical tests of the microsatellite 
data verified this differentiation.
    In their evaluation of mtDNA, King et al. (2006b, p. 4341) examined 
approximately 4 times the number of base-pairs across 2 regions (374 
control region and 1,006 cytochrome-B region base-pairs) and 1\1/2\ 
times more specimens (320 specimens for the control region analysis and 
348 for the cytochrome-B analysis) than Ramey et al. (2005) across the 
same 5 subspecies of meadow jumping mice. King et al. (2006b, p. 4341) 
concluded that these data suggested strong, significant genetic 
differentiation among the five subspecies of meadow jumping mice 
surveyed. Additionally, their results indicated that the Preble's 
meadow jumping mouse did not share haplotypes with any neighboring 
subspecies (King et al. 2006b, p. 4341). Such haplotype sharing had led 
Ramey et al. to previously conclude that the Preble's meadow jumping 
mouse was not unique; specifically, Ramey et al. concluded that because 
all of the Preble's meadow jumping mouse haplotypes were found in Z. h. 
campestris, the Preble's meadow jumping mouse was a less genetically 
variable population of Z. h. campestris

[[Page 62997]]

(Ramey et al. 2004a, pp. 1, 9; 2005, p. 335). Because of these 
conflicting results, King et al. (2006b, pp. 4355-4357) reexamined 15 
specimens from the University of Kansas Museum collection relied upon 
by Ramey et al. in determining that neighboring subspecies shared 
haplotypes. Among the specimens reported to contain the Preble's meadow 
jumping mouse's haplotypes by Ramey et al. (2005, pp. 335-336), King et 
al. (2006b, p. 4357) found that the results could not be repeated. If 
these specimens were removed from the analysis, neither study would 
illustrate haplotype sharing between the Preble's meadow jumping mouse 
and neighboring subspecies. King et al. (2006b, p. 4357) concluded that 
``these findings have identified the presence of a systemic error in 
the control region data reported by Ramey et al. (2005)'' and ``calls 
into question all of the results of Ramey et al. (2005) based on the 
mtDNA genome and prevents analysis of the combined data.'' King et al. 
(2006, p. 4357) noted that possible reasons for the difference in 
sequences included contamination, mislabeling of samples, or other 
procedural incongruity.
    Overall, King et al. (2006b, p. 19) concluded that there was 
considerable genetic differentiation among all five subspecies and 
found no evidence to support the proposal to synonymize the Preble's 
meadow jumping mouse, Z. h. campestris, and Z. h. intermedius.
    Prior to its release, King et al. (2006a) underwent an internal 
peer review per USGS policy (U.S. Geological Survey 2003, pp. 3, 6, 12, 
28-33). In an effort to provide consistent, comparable reviews, we 
solicited peer reviews from the same 16 reviewers asked to review Ramey 
et al. (2004a, 2004b). Nine of the experts provided comments (Armstrong 
2006; Ashley 2006; Bradley 2006; Crandall 2006a; Douglas 2006; Hafner 
2006; Maldonado 2006; Oyler-McCance 2006; Riddle 2006). Some of the 
most significant issues raised included the sampling regime and its 
impact on the analysis (Armstrong 2006; Ashley 2006; Crandall 2006a; 
Douglas 2006; Oyler-McCance 2006; Riddle 2006); and the criteria used 
and factors considered to test taxonomic validity and alternative 
interpretations of the data (Bradley 2006; Crandall 2006a).
    Given the discrepancies between the Ramey et al. and King et al. 
reports, we contracted for a scientific review to analyze, assess, and 
weigh the reasons why the data, findings, and conclusions of the two 
studies differed (Service 2006, p. 14). Following an open and 
competitive bid process, we selected SEI as the contractor (Service 
2006).
    SEI assembled a panel of experts with the necessary scientific 
expertise in genetics and systematics (SEI 2006a, p. 7). The panelists 
reviewed, discussed, and evaluated all of the literature relevant to 
this issue, including published literature, unpublished reports, third-
party critiques, and other materials suggested by interested parties 
(SEI 2006a, pp. 48-55). Additionally, the panel examined and reanalyzed 
the raw data (SEI 2006a, pp. 8, 21) used by Ramey et al. and King et 
al., including the mtDNA data, microsatellite DNA data, and original 
sequence chromatograms (automated DNA sequence data output recordings) 
(SEI 2006a, pp. 8, 23). The scientific review panel was open to the 
public and allowed for interactions among panel members, Dr. King, Dr. 
Ramey, other scientists, and the public.
    In July 2006, SEI delivered a report outlining their conclusions to 
the Service (SEI 2006a). Although the panelists were not obligated to 
reach a consensus, they did not disagree on any substantive or 
stylistic issues (SEI 2006a, p. 9). Thus, the report represented the 
consensus of all three panelists, as well as the individual opinions of 
each panelist. The panel organized its evaluation into four sections 
corresponding with the different types of scientific evaluations 
performed, including morphology, ecological exchangeability, mtDNA, and 
microsatellite DNA. The panel's findings with regard to each are 
summarized briefly below. The full report is available for review at 
http://www.fws.gov/mountain-prairie/species/mammals/preble/Prebles_SEI_report.pdf.
    Morphology: Although Ramey et al. (2005) examined two of the seven 
morphological characters identified by Krutzsch (1954, pp. 452-453), 
the panel found that all seven of these characters should have been 
reexamined in order to support the proposed taxonomic revision. The 
panel also concluded that the type specimen (a single specimen 
designated as the type by the original author at the time of 
publication of the original description of a taxon) of each taxon 
should have been included in the analysis. The panel's conclusion was 
that an insufficient test of the morphological definition of the 
Preble's meadow jumping mouse had been conducted to support the 
synonymy of the Preble's meadow jumping mouse with other subspecies 
(SEI 2006a, p. 41).
    Ecological Exchangeability: The panel concluded that no persuasive 
evidence was presented regarding ecological exchangeability, and that 
the ecological exchangeability of the subspecies remains unknown (SEI 
2006a, p. 41).
    MtDNA: The panel noted that data provided by Ramey et al. (2005) 
and King et al. (2006b) differed in geographic sampling strategy, 
amount of sequence data examined, aspects of the analysis, and quality 
(SEI 2006a, p. 41). All of these could help explain why the two studies 
came to differing conclusions. However, the panel noted that the most 
significant difference between the two studies in terms of mtDNA was 
whether the Preble's meadow jumping mouse shared any mtDNA haplotypes 
with other subspecies of meadow jumping mice. Upon review of the raw 
data, the panel found evidence of contamination within some of the key 
sequences reported by Ramey et al. The panel concluded that there was 
no reliable evidence of any haplotype sharing (SEI 2006a, p. 42). The 
panel further determined that if these conflicting mtDNA sequences were 
removed from consideration, the two studies' mtDNA data would largely 
agree (SEI 2006a, p. 32). The panel also suggested that because the 
western jumping mouse and the meadow jumping mouse are distantly 
related, western jumping mouse may perform poorly as an outgroup, 
leading to poor resolution of relationships among meadow jumping mouse 
subspecies. While both Ramey et al. and King et al. used this outgroup, 
unrooted analysis showed clearer structuring between the subspecies 
(SEI 2006a, p. 42).
    Microsatellite DNA: The panel found that the two microsatellite 
datasets contain similar information. The panel pointed out that both 
the Ramey et al. (2005) and King et al. (2006) microsatellite data, as 
well as Crandall and Marshall's (2006) reanalysis of these data, 
strongly support a statistically significant independent cluster that 
corresponds to the Preble's meadow jumping mouse, providing support for 
a distinct subspecies (SEI 2006a, pp. 42-43). The panel indicated that 
while the microsatellite data alone did not make a strong case for 
evolutionary significance, in concert with the mtDNA data (discussed 
above), the two datasets corroborate the distinctness of the Preble's 
meadow jumping mouse (SEI 2006a, pp. 43).
    The panel's overall conclusion was that the available data are 
broadly consistent with the current taxonomic status of the Preble's 
meadow jumping mouse as a valid subspecies and that no evidence was 
presented that critically challenged its status (SEI 2006a, p. 4). In 
August 2006, Ramey et al. (2006c) submitted a statement to the Service 
disputing the findings and conclusions

[[Page 62998]]

of the SEI report. No new data or analyses were presented in this 
statement, and the panel previously considered most of the contentions 
(Ramey et al. 2003, 2004a, 2004b, 2005, 2006a, 2006b; SEI 2006a, 2006b, 
2006c). 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).

Taxonomic Conclusions

    When listed in 1998, the Preble's meadow jumping mouse was widely 
recognized as a valid subspecies by the scientific community (Hall and 
Kelson 1959, pp. 771-774; Long 1965, pp. 664-665; Armstrong 1972, pp. 
248-249; Whitaker 1972, pp. 1-2; Hall 1981, pp. 841-844; Jones et al. 
1983, pp. 238-239; Clark and Stromberg 1987, p. 184; Wilson and Reeder 
1993, p. 499; Hafner et al. 1998, pp. 120-121; Wilson and Ruff 1999, 
pp. 666-667). At the time of listing, Krutzsch (1954) represented the 
best available information on the taxonomy of the Preble's meadow 
jumping mouse (63 FR 26517, May 13, 1998). Our 1998 conclusion was 
consistent with Service regulations that require us to rely on standard 
taxonomic distinctions and the biological expertise of the Department 
and the scientific community concerning the relevant taxonomic group 
(50 CFR 424.11). However, when the best available science indicates 
that the generally accepted taxonomy may be in error, the Service must 
rely on the best available science (Center for Biological Diversity, et 
al., v. Robert Lohn, et al., 296 F. Supp. 2d. 1223 W.D. Wash. 2003). 
Such considerations led to our February 2, 2005, proposal to delist 
Preble's based upon information which questioned the subspecies' 
taxonomic validity (70 FR 5404).
    We now determine the best scientific and commercial data available 
support the conclusion that the Preble's meadow jumping mouse is a 
valid subspecies. Specifically, the Preble's meadow jumping mouse's 
geographic isolation from other subspecies of meadow jumping mice 
(Krutzsch 1954, pp. 452-453; Long 1965, pp. 664-665; SEI 2006a, p. 34) 
has resulted in the accretion of considerable genetic differentiation 
(King et al. 2006b, pp. 4336-4348; SEI 2006a, pp. 41-43). The available 
data suggest that the Preble's meadow jumping mouse meets or exceeds 
numerous, widely accepted subspecies definitions (Mayr and Ashlock 
1991, pp. 43-45; Patten and Unitt 2002, pp. 26-34; SEI 2006a, p. 44). 
In reaching this conclusion, we do not use a presumption that we must 
rely on the established taxonomy in the absence of conclusive data to 
the contrary (see SEI report at p. 39). In Therefore, after a review of 
all available information, we have determined that the taxonomic 
revision for the Preble's meadow jumping mouse suggested in our 
proposed delisting rule (70 FR 5404, February 2, 2005) is no longer 
appropriate.

Historical Range and Recently Documented Distribution

    Generally, the Preble's meadow jumping mouse range includes 
portions of the North Platte, the South Platte, and the Arkansas River 
basins (Long 1965, p. 665; Armstrong 1972, pp. 248-249; Clark and 
Stromberg 1987, p. 184; Fitzgerald et al. 1994, p. 293; Clippinger 
2002, p. 20).
    At the time of listing, we described the historical range in 
Wyoming as including five counties (Albany, Laramie, Platte, Goshen, 
and Converse), but cited only two sites with recent reports of jumping 
mice likely to be the Preble's meadow jumping mouse. We cited a study 
by Compton and Hugie (1993, p. 6) suggesting the subspecies might be 
extirpated in Wyoming and comments by the Wyoming Game and Fish 
Commission that the Preble's meadow jumping mouse had likely been 
extirpated from most or all of its historical range in Wyoming (Wichers 
1997).
    At the time of listing, we assumed that most of the subspecies' 
current range was in Colorado. Within Colorado, the final listing rule 
described a presumed historical range including portions of ten 
counties (Adams, Arapahoe, Boulder, Denver, Douglas, El Paso, Elbert, 
Jefferson, Larimer, and Weld) and cited recent trapping efforts that 
documented the subspecies in seven of these ten counties (Boulder, 
Douglas, El Paso, Elbert, Jefferson, Larimer, and Weld).
    Since we listed the Preble's meadow jumping mouse in 1998, 
knowledge about distribution of the subspecies has grown substantially. 
Numerous trapping surveys conducted during the last 9 years in Wyoming 
and Colorado have documented the subspecies' presence or likely absence 
at locations of suitable habitat. While many recent trapping efforts 
have been at locations with no record of historical surveys, most have 
been within the presumed historical range of the Preble's meadow 
jumping mouse or in adjacent drainages where habitat and elevation 
appeared suitable. Thus, the recent increase in sites of Preble's 
meadow jumping mouse occurrence likely represents an improvement in our 
understanding of the subspecies range as a result of increased trapping 
effort rather than any actual expansion of the range of the Preble's 
meadow jumping mouse.
    In Wyoming, recent captures and confirmed identification have 
expanded our knowledge of the distribution of the Preble's meadow 
jumping mouse from the two sites documented at the time of listing to 
include over two dozen new plains, foothills, and montane sites east of 
the Laramie Mountains in the North Platte River basin, and presence in 
the Upper Laramie River drainage in Albany County (Taylor 1999; Service 
2007). Post-listing activities have identified many additional sites 
occupied by the subspecies. These data also reveal that the Preble's 
meadow jumping mouse occurs in four of the five counties described as 
the likely historical range at the time of listing including Albany, 
Laramie, Platte, and Converse Counties.
    At the time of listing, we discussed how increased trapping efforts 
in Colorado had recently documented distribution in Elbert, Larimer, 
and Weld Counties. We also suggested other sites where trapping should 
occur to determine if the Preble's meadow jumping mouse were present. 
Additional trapping since listing has expanded the documented 
distribution of the Preble's meadow jumping mouse in Colorado to 
include: additional foothill and montane sites along the Front Range in 
Larimer, Boulder, Jefferson, and Douglas Counties; previously untrapped 
rural prairie and foothill streams in southern Douglas County and 
adjacent portions of Elbert County; and additional prairie and foothill 
streams in northwestern El Paso County. Although we have identified 
some additional sites occupied by the Preble's meadow jumping mouse, 
over 80 percent of such trapping efforts throughout Colorado have 
failed to capture Preble's meadow jumping mice (as illustrated in 
Figure 1 below) (Service 2007).
BILLING CODE 4310-55-P

[[Page 62999]]

[GRAPHIC] [TIFF OMITTED] TP07NO07.000

BILLING CODE 4310-55-C
    These negative trap results suggest that the subspecies is rare or 
possibly extirpated from many portions of the subspecies' historical 
range in Colorado.

[[Page 63000]]

Areas where the subspecies is presumed extirpated is discussed in the 
Factor A discussion below.
    The Preble's meadow jumping mouse has now been recently documented 
in portions of Albany, Laramie, Platte, and Converse Counties in 
Wyoming; and in portions of Boulder, Douglas, El Paso, Elbert, 
Jefferson, Larimer, and Weld Counties in Colorado (Figure 1). The North 
Platte River at Douglas, Wyoming, marks the northernmost confirmed 
location for the Preble's meadow jumping mouse. Specimens from Colorado 
Springs, Colorado, mark the southernmost documented location of the 
Preble's meadow jumping mouse.
    The Preble's meadow jumping mouse is generally found at elevations 
between 1,420 m (4,650 ft) and 2,300 m (7,600 ft), although elevations 
vary across the range of the subspecies. At the lower end of this 
elevation gradient, the semi-arid climate of southeastern Wyoming and 
eastern Colorado limits the extent of riparian corridors and restricts 
the range of the Preble's meadow jumping mouse (Beauvais 2001, p. 3). 
The Preble's meadow jumping mouse is likely an Ice Age relic; once the 
glaciers receded from the Front Range of Colorado and the foothills of 
Wyoming and the climate became drier, the Preble's meadow jumping mouse 
was confined to riparian systems where moisture was more plentiful 
(Fitzgerald et al. 1994, p. 1994; Smith et al. 2004, p. 293). The 
eastern boundary for the subspecies is likely defined by the dry 
shortgrass prairie, which may present a barrier to eastward expansion 
(Beauvais 2001, p. 3). In Wyoming, the Preble's meadow jumping mouse 
has not been found east of Cheyenne, Laramie County (Beauvais 2001, p. 
3). Habitat modeling and trapping suggest the subspecies may not occur 
in Wyoming's Goshen, Niobrara, and eastern Laramie Counties (Keinath 
2001, p. 7). In Colorado, the Preble's meadow jumping mouse has not 
been found on the extreme eastern plains (Clippinger 2002, pp. 20-21).
    At the higher elevations, discerning the status of the Preble's 
meadow jumping mouse is complicated by the overlap in the ranges of the 
Preble's meadow jumping mouse and the western jumping mouse (Long 1965, 
pp. 665-666; Clark and Stromberg 1987, pp. 184-187; Schorr 1999, p. 3; 
Bohon et al. 2005; Schorr et al. 2007, p. 5). Field differentiation 
between the Preble's meadow jumping mouse and the western jumping mouse 
is difficult (Conner and Shenk 2003a, p. 1456). Generally, the western 
jumping mouse occurs in the montane and subalpine zones and the 
Preble's meadow jumping mouse occurs lower, in the plains and foothills 
(Smith et al. 2004, p. 10). Using this as a guide, many jumping mice 
were trapped and released without being conclusively identified as 
either a Preble's meadow jumping mouse or a western jumping mouse. 
Because western jumping mice have been verified at elevations well 
below the upper elevation limit of the Preble's meadow jumping mouse 
(Smith et al. 2004, p. 11), this leads to difficulty in making 
assumptions regarding identification based on elevation. Drainages 
where overlapping ranges have been verified include the Glendo 
Reservoir, Lower Laramie, Upper Laramie, and Horse Creek drainages in 
Wyoming (Conner and Shenk 2003b, pp. 31-35; Meaney 2003; King 2006a; 
King 2006b; King et al. 2006b, pp. 4351-4353); and the Cache La Poudre, 
Big Thompson, and Upper South Platte River drainage in Colorado (Bohon 
et al. 2005; King 2005; King 2006a; King et al. 2006b, pp. 4351-4353; 
Schorr et al. 2007).
    Size, external morphology, dentition, skull measurements, and 
genetic analysis can all be used to differentiate meadow jumping mice 
(including the Preble's meadow jumping mouse) from western jumping mice 
(Krutzsch 1954, pp. 351-384; Klingenger 1963, p. 252; Riggs et al. 
1997, pp. 2-8; Conner and Shenk 2003a; Ramey et al.; King et al.). The 
following description of the Preble's meadow jumping mouse's current 
documented distribution and status is based primarily on individuals 
positively identified as Preble's meadow jumping mice, with emphasis on 
locations where individual mice have been identified by genetic 
analysis or discriminant function analysis (DFA) (analysis of cranial 
measurements and an anterior medial toothfold characteristic) (Conner 
and Shenk 2003a). Information regarding individual mice and capture 
locations can be found in Riggs et al. (1997, pp. 8-11, A2-A5), Conner 
and Shenk (2003b, pp. 31-35), and King et al. (2006b, pp. 4351-4353). 
Positive identification of individual mice is most important in areas 
where both the Preble's meadow jumping mouse and the western jumping 
mouse occur. Overlap appears to occur in most of Wyoming's occupied 
drainages. In Colorado, with few exceptions, jumping mice below 2,050 m 
(6,700 ft) have been positively identified as Preble's meadow jumping 
mice. Above 2,050 m (6,700 ft) in Colorado, Preble's meadow jumping 
mice and western jumping mice are known to have an overlapping 
distribution in the Cache La Poudre, Big Thompson, and Upper South 
Platte River drainages.
    Below is a summary of recent (since 1980) trapping data by drainage 
(as defined by 8-digit USGS hydrologic units), within both Wyoming 
(e.g., the North and South Platte River basins) and Colorado (e.g., the 
South Platte River and Arkansas River basins). Although trapping data 
is important because it absolutely confirms the occurrence of jumping 
mice at particular locations, as discussed in detail below, trapping 
data is one of several lines of evidence we use to estimate the actual 
current range of the subspecies. Records have been compiled by the 
Service (2007) in coordination with the Wyoming Natural Diversity 
Database, State of Wyoming, and CDOW. In addition, Figure 1 above 
illustrates all recent Preble's meadow jumping mouse specimens, 
historical (pre-1980) locations no longer believed to be occupied, and 
recent negative trapping efforts. Given wide areas of overlapping range 
in Wyoming, we require all Wyoming specimens to be confirmed as 
Preble's meadow jumping mice in order to be considered below. In 
Colorado, jumping mice are considered Preble's meadow jumping mice when 
identification is confirmed or if they occur in areas where western 
jumping mice are not known.
    North Platte River Basin, Wyoming. In the North Platte River basin, 
occurrence of the Preble's meadow jumping mouse has been confirmed in 
four Wyoming counties (Converse, Platte, Albany, and Laramie) as 
reported by drainage below.
    The Middle North Platte drainage represents the northern extent of 
the reported Preble's meadow jumping mouse range; however, trapping 
surveys have been quite limited and generally at high elevations. 
Although several jumping mice have been trapped in this drainage, these 
specimens have not been confirmed as Preble's meadow jumping mice.
    In the Glendo Reservoir drainage, the Preble's meadow jumping mouse 
is known from several locations, including along the North Platte River 
at Douglas (King 2006b), Cottonwood Creek and its tributaries (Meaney 
2003; King 2006a; King 2006b; King et al. 2006b), and the Horseshoe 
Creek area (Krutzsch 1954, p. 453). While the western jumping mouse has 
also been confirmed from the Glendo Reservoir drainage, the Preble's 
meadow jumping mouse appears more common.
    In the Lower Laramie drainage, the Preble's meadow jumping mouse 
has been confirmed from the Laramie River and its tributaries, 
including the North Laramie River, and Sturgeon, Wyman,

[[Page 63001]]

Rabbit, and Luman Creeks; as well as several locations along Chugwater 
Creek and its tributaries (King 2006b; King et al. 2006b). Both 
Preble's meadow jumping mice and western jumping mice occur in the 
Sybille Creek, Friend Creek and the Friend Park areas (Conner and Shenk 
2003b; King 2006a; King 2006b; King et al. 2006b). The Lower Laramie 
drainage appears to support coexisting Preble's meadow jumping mice and 
western jumping mice in multiple locations.
    In the Horse Creek drainage, the Preble's meadow jumping mouse has 
been widely documented west of Interstate Highway 25 (I-25) and at one 
site east of I-25. The majority of these recent captures have been made 
in Bear Creek and its tributaries, and in headwaters of Horse Creek and 
its tributaries. Both Preble's meadow jumping mice and western jumping 
mice inhabit multiple sites on both creeks (Conner and Shenk 2003b; 
Meaney 2003; King 2006b; King et al. 2006b).
    In the Upper Laramie drainage, the Preble's meadow jumping mouse 
has been confirmed at Hutton Lake National Wildlife Refuge (NWR) and 
from a site north of Laramie (Meaney 2003). Other specimens at these 
same sites have been confirmed as western jumping mice (Meaney 2003; 
King 2006a). Therefore, it appears both Preble's meadow jumping mice 
and western jumping mice are present in this drainage. Based on 
positive identification of the Preble's meadow jumping mouse from the 
sites mentioned above, Smith et al. (2004, p. 12) suggested the range 
of the Preble's meadow jumping mouse may extend into the Upper Laramie 
River, Little Laramie River, Rock Creek, and possibly the Medicine Bow 
River.
    South Platte River Basin, Wyoming. Within the Wyoming portion of 
the South Platte River basin, trapping efforts have confirmed Preble's 
meadow jumping mouse occurrence, albeit possibly in low numbers, within 
two drainages in Laramie and Albany Counties.
    In the Upper Lodgepole drainage, jumping mice have been found from 
several locations at and upstream of Highway 211. While at least one 
Preble's meadow jumping mouse has been confirmed (Riggs et al. 1997), 
most of the captured mice have been identified as western jumping mice 
(Meaney 2003; King 2006a). Therefore, while this drainage supports the 
Preble's meadow jumping mouse, its distribution may be limited.
    Although historically reported from the Crow Creek drainage at 
Cheyenne, Preble's meadow jumping mouse occurrence in this drainage 
remains uncertain. Specimens from Warren Air Force Base were assumed to 
be Preble's meadow jumping mice based on the elevation of 1,900 m 
(6,150 ft), but subsequent analyses identified only western jumping 
mice (Riggs et al. 1997; Conner and Shenk 2003b; King 2006a). The only 
trapping evidence confirming Preble's meadow jumping mouse occurrence 
in this drainage comes from a specimen from the South Crow Creek 
Reservoir area originally identified as a western jumping mouse by the 
DMNS and then re-identified as a Preble's meadow jumping mouse based on 
a DFA analysis considering dental characteristics (Meaney 2003). 
Additional specimens have only verified western jumping mice from 
Middle Crow Creek, the South Fork of Middle Crow Creek, and South Crow 
Creek Reservoir (Meaney 2003; King 2006a). No jumping mice have been 
reported trapped downstream of Cheyenne.
    The Lone Tree Creek drainage was previously assumed to be inhabited 
by the Preble's meadow jumping mouse based on the field identification 
of low elevation captures of jumping mice (1,900 m (6,200 ft)). 
However, DFA analysis of existing museum specimens (Conner and Shenk 
2003b) and genetic analysis of specimens obtained from trapping efforts 
(Riggs et al. 1997; King 2006a), have only confirmed presence of 
western jumping mice in this drainage.
    South Platte River Basin, Colorado. Recent presence of the Preble's 
meadow jumping mouse in Colorado has been documented within the South 
Platte River basin in seven counties: Larimer, Weld, Boulder, 
Jefferson, Douglas, Elbert, and El Paso. From the Wyoming State line 
south through the Denver area, little recent documentation of the 
Preble's meadow jumping mouse exists from sites east of the foothills 
where most of the subspecies' historical recordings occurred. This area 
largely corresponds to the Front Range urban corridor, an area 
experiencing continued human population growth and development 
(Clippenger 2002, pp. 22-26; Colorado Demography Office 2007). At 
higher elevation plains and foothills sites south of the Denver area, 
the Preble's meadow jumping mouse has been documented at a number of 
locations where riparian habitats are still largely intact. With rare 
exception, all jumping mouse records verified below 2,050 m (6,700 ft) 
in the South Platte River drainage of Colorado have been Preble's 
meadow jumping mice.
    In the Cache La Poudre River drainage, jumping mice have been 
documented on sites upstream of Fort Collins, Larimer County, at 
elevations consistent with known Preble's meadow jumping mouse 
distribution. These sites include the main stem Cache La Poudre River 
and its tributaries, including Young Gulch and Stove Prairie Creek, and 
the North Fork Cache La Poudre River and its tributaries, including 
Stonewall, Rabbit, and Lone Pine Creeks. Shenk and Eussen (1999, pp. 
11-12) cautioned that both Preble's meadow jumping mice and western 
jumping mice were likely present in some of these areas. Subsequent 
genetic analysis confirmed both Preble's and the western jumping mouse 
in Cherokee Park at 2,260 m. (7,480 ft) (King 2005, 2006b), but only 
Preble's meadow jumping mice have been confirmed from lower elevations, 
including Rabbit and Lone Pine Creeks, the Livermore Mountain area, and 
the North Fork of the Cache La Poudre River (Riggs et al. 1997; King et 
al. 2006b). Despite a number of trapping efforts, no jumping mice have 
been recently documented within the Fort Collins, Larimer County, area 
or downstream on the Cache La Poudre River to its confluence with the 
South Platte River at Greeley, Weld County (Service 2007).
    Within the Big Thompson drainage, the Preble's meadow jumping mouse 
has been documented in foothills sites along Buckhorn Creek and certain 
of its tributaries, and on Dry Creek, in Larimer County. Genetic 
analysis of mice from three tributaries of Buckhorn Creek up to 2,240 m 
(7,360 ft) support identifications as Preble's meadow jumping mice; 
however, both Preble's meadow jumping mice and western jumping mice 
were confirmed from the Lakey Canyon site at 2,170 m (7,120 ft) and a 
mouse from the North Fork of the Big Thompson River at 2,170 m (7,120 
ft) was identified as a western jumping mouse (King 2006a). Despite a 
number of trapping efforts, the Preble's meadow jumping mouse has not 
been documented on the Big Thompson and Little Thompson Rivers through 
the Front Range urban corridor, but has been found on both rivers east 
of I-25, in Weld County.
    In the Saint Vrain drainage, the Preble's meadow jumping mouse has 
been documented along the Saint Vrain River, its tributaries and water 
conveyance ditches upstream of the town of Hygiene, on two tributaries 
of Boulder Creek west of the City of Boulder, and along South Boulder 
Creek, all in Boulder County; and on upper reaches of Coal and Rock 
Creeks, Jefferson County. On Rocky Flats NWR, Jefferson County, the 
Preble's meadow jumping mouse has been documented on Rock Creek as well 
on nearby Walnut

[[Page 63002]]

and Woman Creeks (within the Middle South Platte-Cherry Creek 
drainage). Several of these locations include mice confirmed as 
Preble's meadow jumping mice by genetic analysis or DFA (Riggs et al. 
1997; Conner and Shenk 2003b). The Preble's meadow jumping mouse 
occurrence has not been confirmed by trapping efforts along eastern 
parts of the drainage, the Saint Vrain River from Hygiene, Boulder 
County, downstream to its confluence with the South Platte River, along 
Boulder Creek from the City of Boulder east to its confluence with the 
Saint Vrain River, or downstream of Rocky Flats NWR on Walnut, Woman, 
or Dry Creeks.
    In the Clear Creek drainage, the Preble's meadow jumping mouse has 
been verified in the foothills on Ralston Creek (Riggs et al. 1997), 
and unidentified jumping mice have been captured on two tributaries of 
Clear Creek at elevations of potential Preble's meadow jumping mouse 
occurrence (below 2,300 m (7,600 ft)). No jumping mice have been 
captured on either creek downstream through the urban corridor to the 
South Platte River.
    In the Upper South Platte drainage, the Preble's meadow jumping 
mouse has been documented immediately upstream of Chatfield Reservoir 
on the South Platte River, and also well upstream on the South Platte 
River and its tributaries in Jefferson and Douglas Counties to near the 
Teller County-Douglas County line. The U.S. Forest Service provided a 
summary of Preble's meadow jumping mouse trapping efforts at 15 sites 
in the Upper South Platte drainage in the Pike National Forest. Based 
on examination of voucher specimens, Preble's meadow jumping mice were 
confirmed at six sites up to 2,300 m (7,600 ft) and western jumping 
mice were confirmed from six sites, the lowest of which, at 2,030 m 
(6,660 ft), was lower than five Preble's meadow jumping mouse sites 
(Bohon et al. 2005). Schorr et al. (2007) also summarized co-occurrence 
of Preble's and the western jumping mouse in the same area. Also in the 
Upper South Platte drainage, the Preble's meadow jumping mouse has been 
widely documented upstream of Chatfield Reservoir on Plum Creek, 
including occurrences on East Plum Creek, West Plum Creek, and various 
tributaries, all in Douglas County (Riggs et al. 1997; Conner and Shenk 
2003b; King et al. 2006b). Western jumping mice have also been 
identified in this drainage at 1,800 m (5,900 ft) and 1,950 m (6,400 
ft) (Conner and Shenk 2003b). Pague and Schuerman (1998, p. 5) assessed 
Preble's meadow jumping mouse habitat throughout the Plum Creek 
watershed, randomly trapped suitable habitat, and estimated 64 km (40 
mi) of streams occupied by the Preble's meadow jumping mouse. On the 
downstream portion of this drainage, below Chatfield Reservoir, there 
is no recent documentation of Preble's meadow jumping mouse's presence 
on the South Platte River through Denver.
    In the Middle South Platte, Cherry Creek drainage, Preble's meadow 
jumping mice have been found on Cherry Creek and its tributaries from 
approximately the Arapahoe County-Douglas County line, upstream to the 
headwaters of East and West Cherry Creeks near the Palmer Divide in El 
Paso County. Also within Middle South Platte-Cherry Creek drainage, 
limited trapping efforts have documented the Preble's meadow jumping 
mouse on Running Creek and a tributary, Hay Creek, in Elbert County. 
Based on limited genetic analysis and DFA, western jumping mice have 
not been confirmed from this drainage. The Preble's meadow jumping 
mouse occurrence has not been confirmed by trapping downstream along 
Cherry Creek through Arapahoe County and Denver to the South Platte 
River. Because of numerous negative trapping efforts and lack of 
contiguous suitable habitat, we no longer consider the greater Denver 
area (including most of Denver County and portions of Adams, Arapahoe, 
Boulder, Broomfield, Douglas, and Jefferson Counties) to be occupied. 
On the South Platte River downstream from the Denver area, a single 
Preble's meadow jumping mouse was recently captured from near the South 
Platte River in Milliken, Weld County, not far from the confluence of 
the Big Thompson River and South Platte River (Savage and Savage 2001).
    Farther east, there are two records of a Preble's meadow jumping 
mice on Kiowa Creek, Elbert County. Additional trapping in Elbert 
County would be useful to document whether the Preble's meadow jumping 
mouse is present along significant reaches of the Middle South Platte-
Cherry Creek and Kiowa Creek drainages, and on the Bijou Creek 
drainage, Elbert County, which has not been trapped.
    Arkansas River Basin, Colorado. In the Arkansas River basin, 
confirmed current occurrence of the Preble's meadow jumping mouse is 
limited largely to the Fountain Creek drainage and specifically to 
Monument Creek and its tributaries north of Colorado Springs. Genetic 
analysis and DFA have thus far confirmed no western jumping mice from 
within the Preble's meadow jumping mouse's range in this drainage 
(Conner and Shenk 2003b; King et al. 2006b). The Preble's meadow 
jumping mouse has been well studied at the U.S. Air Force Academy 
(Academy) on Monument Creek and its tributaries, and has been 
documented farther upstream on Monument Creek and on tributaries to the 
east and north toward the Palmer Divide. Numerous records of Preble's 
meadow jumping mouse captures on streams in northwestern El Paso County 
are the result of extensive trapping that has taken place in 
conjunction with proposed development projects. Downstream of the 
Academy, numerous trapping surveys indicate that the Preble's meadow 
jumping mouse has little likelihood of occurrence along Monument Creek 
through the downtown portions of Colorado Springs. Similarly, extensive 
trapping surveys suggest that the Preble's meadow jumping mouse may be 
extirpated from Cottonwood Creek and its tributaries.
    In the Chico Creek drainage, jumping mice (assumed to be Preble's 
meadow jumping mice as explained above) have been documented on the 
upper reaches of Black Squirrel Creek and on a tributary, both in El 
Paso County. Limited trapping efforts in potential Preble's meadow 
jumping mouse habitat farther to the east in the Chico Creek drainage 
and in the Big Sandy Creek drainage have not confirmed Preble's meadow 
jumping mouse occurrence. Downstream, to the east and south, these 
drainages appear to have little habitat suitable for the Preble's 
meadow jumping mouse.
    Within the Arkansas River basin south of the documented Preble's 
meadow jumping mouse locations, trapping efforts targeting the Preble's 
meadow jumping mouse conducted in southern El Paso County, Pueblo 
County, and Fremont County, including surveys funded and carried out by 
the Department of the Army at Fort Carson, have not resulted in capture 
of jumping mice (Bunn et al. 1995; Werner 2003).
    In conclusion, the Preble's meadow jumping mouse appears to be 
widespread in the North Platte River basin were trapping efforts 
confirm the subspecies' distribution across at least four drainages. 
The Preble's meadow jumping mouse appears scarce within the Wyoming 
portion of the South Platte River basin, where trapping efforts to date 
provide few confirmed occurrences of the subspecies and suggest that 
the western jumping mouse is much more widespread. Trapping efforts 
within the Colorado portion of the South Platte River Basin indicate 
the Preble's meadow jumping mouse has little likelihood of occurrence 
in portions of some drainages that coincide with the

[[Page 63003]]

Front Range development corridor (areas around I-25 from Fort Collins 
south through the Denver metropolitan area), is more widespread in 
foothills and some montane areas within these same drainages, and 
generally present in rural portions of drainages south of Denver. In 
the Arkansas River basin in Colorado, Preble's meadow jumping mouse 
distribution appears very limited, with trapping efforts confirming 
occurrence largely in upper Monument Creek and some headwater 
tributaries.
    Data limitations, such as limited trapping data, do not allow us to 
equate documented distribution with range. For example, the subspecies 
has been documented in several places along Hay Creek in Elbert County, 
and it is reasonably likely to occur further downstream in Arapahoe 
County, but no trapping has occurred to confirm or deny this assertion 
(See figure 1). Similarly, on Trout Creek a Preble's meadow jumping 
mouse was found in Douglas County near the Teller County line and it is 
reasonable to assume the subspecies may also occur in Teller County. 
Given the data limitations, ``range'' (relative to the March 14, 2007, 
Department of the Interior, Solicitor Memorandum opinion) is defined in 
the Conclusion of the 5-Factor Analysis section of this rule below.

Abundance

    Intensive trapping studies designed to estimate populations of the 
Preble's meadow jumping mouse have occurred on only a few sites. 
Because not all appropriate habitat has been surveyed for Preble's 
meadow jumping mouse occurrence and because population estimates are 
available for only a few selected sites, no regional, Statewide, or 
rangewide population estimates for the Preble's meadow jumping mouse 
have been developed. Population density and trends are not well known 
in Wyoming (Wyoming Game and Fish Department 2005, p. 36). There are a 
few population estimates but little trend information for Preble's 
meadow jumping mouse populations in Colorado. In addition, because 
jumping mouse populations in a given area vary significantly from year 
to year (Quimby 1951, pp. 91-93; Whitaker 1972, p. 4), short-term 
studies may not accurately characterize abundance. In an ongoing 
trapping study, population highs of 24 Preble's meadow jumping mice per 
site were estimated for two control sites in 1998 and 1999; subsequent 
trapping in 2002, during regional drought conditions, estimated no 
Preble's meadow jumping mice present at either site (Bakeman 2006, p. 
11). Meaney et al. (2003, p. 620) estimated Preble's meadow jumping 
mouse populations on study sites over 4 years, noted absence of the 
Preble's meadow jumping mouse at certain sites during some seasons, and 
suggested that 10 or more years of study might be necessary to assess 
the full extent of population variation.
    White and Shenk (2000, p. 9) summarized abundance estimates from 
nine sites in Colorado for field work conducted during 1998 and 1999 
(Meaney et al. 2000; Kaiser-Hill 2000; Ensight Technical Services 1999, 
2000, 2001; Shenk and Sivert 1999b; Schorr 2001). Since Preble's meadow 
jumping mice are found in linear riparian communities, abundances were 
estimated in number of individuals per km (or mi) of stream corridor. 
Estimates of linear abundance ranged widely, from 4 to 67 mice/km (6 to 
107 mice/mi) with a mean of 33 +/-5 mice/km (53 +/-8 mice/mi) (White 
and Shenk 2000, p. 9). The subsequent addition of new sites and 2 more 
years of data (2000-2001) provided a range of 2 to 67 mice/km (3 to 107 
mice/mi) and a mean of 27 +/-4 mice/km (44 +/-6 mice/mi) (Shenk 2004).
    The above estimates, coupled with sufficient knowledge of occupied 
stream miles, can provide a rough indicator of Preble's meadow jumping 
mouse numbers within a stream reach or drainage. For example, the 
Preble's meadow jumping mouse Recovery Team used the above estimate 
(Shenk 2004) to approximate stream miles required to support varying 
sized populations of the Preble's meadow jumping mouse (Service 2003b, 
p. 25). Hayward (2002) cautioned that reliance on an average number of 
mice per length of stream to predict population sizes would result in 
the overestimation of actual population size for about half of all 
sites. Of additional concern in any assessment of Preble's meadow 
jumping mouse population size is the potential for including western 
jumping mice in the estimate (Bohon et al. 2005; Schorr et al. 2007, p. 
4). This is of particular importance in areas where both Preble's 
meadow jumping mice and western jumping mice are known to occur, 
including higher elevation Colorado sites and at most sites in Wyoming.
    Another potential source of error is that the Preble's meadow 
jumping mouse population estimates above do not include estimates for 
riparian corridors along mountain streams or any sites in Wyoming. In 
Pike National Forest, Colorado, site inspection of many streams 
previously mapped as Preble's meadow jumping mouse habitat revealed 
poorly developed or intermittent riparian vegetation surrounded by 
sparse uplands dominated by pine forest (Bohon et al. 2005). Poor 
trapping success even in suitable habitat suggested low population 
densities in Pike National Forest compared to those at lower elevations 
(Bohon et al. 2005; Hansen 2006, p. 168). In studies targeting the 
Preble's meadow jumping mouse at 11 higher elevations (1,890 to 2,420 m 
(6,200 to 7,940 ft)) riparian sites in Douglas, Jefferson, and Teller 
Counties, Schorr et al. (2007, p. 4) reported a 0.6 percent capture 
rate of jumping mice over 19,500 trap nights. Since coexistence of both 
the Preble's meadow jumping mouse and the western jumping mouse was 
confirmed in these studies, the capture rate of the Preble's meadow 
jumping mouse was probably much lower. In comparable trapping effort in 
high quality habitat at lower elevations, Schorr (2001, p.18) reported 
a 3.5 percent capture rate of Preble's meadow jumping mice over 14,700 
trap nights at the Academy, and Meaney et al. (2003, p. 616) reported a 
3.4 percent capture rate of Preble's meadow jumping mice over 21,174 
trap nights along South Boulder Creek, Boulder County. We believe that 
more research is needed before conclusions can be drawn regarding 
Preble's meadow jumping mouse abundance and security along montane 
streams and headwaters.

Trends

    Without comprehensive population estimates for the subspecies, the 
only basis for trend assessment is presence or absence surveys in 
historical habitat (Smith et al. 2004, p. 29). This presence/absence 
information paints a very different picture for Wyoming compared to 
Colorado.
    In Wyoming, we now have much more information regarding Preble's 
meadow jumping mouse distribution than we had at time of listing, when 
we described only two occupied sites. Much of what we noted in the 
listing to be historical range of the Preble's meadow jumping mouse in 
Wyoming has now been definitively found to support Preble's. But, while 
many jumping mice have been confirmed as Preble's meadow jumping mice 
in the North Platte River basin, the subspecies appears uncommon in the 
South Platte River basin, with only western jumping mice previously 
confirmed at several locations believed to be within Preble's meadow 
jumping mouse range.
    In Colorado, historical trapping records establish that the 
Preble's meadow jumping mouse was present in a range that included 
major plains streams from the base of the Colorado Front Range east to 
at least Greeley, Weld County (Armstrong 1972, p. 249;

[[Page 63004]]

Fitzgerald et al. 1994, p. 293, Clippenger 2002, p. 18). Recent 
trapping efforts have documented that the Preble's meadow jumping mouse 
is rare or, perhaps, absent from these same areas today (Ryon 1996, p. 
2; Clippinger 2002, p. 22; Service, 2007). This pattern is especially 
apparent along prairie riparian corridors directly or indirectly 
impacted by human development. This issue is discussed further in 
Factor A below.

Summary of Factors Affecting the Subspecies

    Section 4 of the Act and its implementing regulations (50 CFR part 
424) set forth the procedures for listing, reclassifying, or removing 
species from listed status. ``Species'' is defined by the Act as 
including any species or subspecies of fish or wildlife or plants, and 
any distinct vertebrate population segment of fish or wildlife that 
interbreeds when mature (16 U.S.C. 1532(16)). Once the ``species'' is 
determined we then evaluate whether that species may be endangered or 
threatened because of one or more of the five factors described in 
section 4(a)(1) of the Act. We must consider these same five factors in 
delisting determinations. Under 50 CFR 424.11(d), we may remove the 
protections of the Act if the best available scientific and commercial 
data substantiate that the species is neither endangered nor threatened 
for the following reasons: (1) the species is extinct; (2) the species 
has recovered and is no longer endangered or threatened; or (3) the 
original scientific data used at the time the species was classified 
were in error. Data error only applies when subsequent investigations 
show that the best scientific or commercial data available when the 
species was listed, or the interpretation of such data, were in error.
    We may delist a species for any of the above reasons only if such 
data substantiate that the species is neither endangered nor 
threatened. Determining whether a species meets these definitions 
requires consideration of the same five categories of threats specified 
in section 4(a)(1) of the Act. For species that are already listed as 
endangered or threatened, this analysis of threats is an evaluation of 
both the threats currently facing the species and the threats that are 
reasonably likely to affect the species in the foreseeable future 
following the delisting or downlisting and the removal or reduction of 
the Act's protections.
    Under section 3 of the Act, a species is ``endangered'' if it is in 
danger of extinction throughout all or a ``significant portion of its 
range'' and is ``threatened'' if it is likely to become endangered 
within the foreseeable future throughout all or a ``significant portion 
of its range.'' The word ``range'' in the phrase ``significant portion 
of its range'' refers to the range in which the species currently 
exists. Range is discussed further in the Conclusion of the 5-Factor 
Analysis section of this proposal below.
    For the purposes of this analysis, we will evaluate whether the 
currently listed subspecies is threatened or endangered. This 
determination is a multiple-step analysis. If we determine that the 
subspecies is endangered throughout all of its range, we list it as 
endangered throughout its range and no further analysis is necessary. 
If not, we then evaluate if the subspecies meets the definition of 
threatened throughout all of its range. If the subspecies is threatened 
in all of its range, we list as threatened and consider if any 
significant portions of the range warrants consideration as endangered. 
If we determine that the subspecies is not threatened or endangered in 
all of its range, we consider whether any significant portions of the 
subspecies' range warrant consideration as threatened or endangered. We 
would then only list that significant portion of its range as 
threatened or endangered and not list the remaining portion of its 
range.
    Foreseeable future is determined by the Service on a case-by-case 
basis, taking into account a variety of species-specific factors such 
as lifespan, genetics, breeding behavior, demography, threat-projection 
timeframes, and environmental variability. For the purposes of this 
proposal, we define 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. As described in more detail below, human-
population-growth projections extend out to 2035 in Colorado and 2036 
in Wyoming. Similarly, water requirements are estimated through 2030 in 
Colorado and 2035 in Wyoming. A Center for the West model predicting 
future land-use patterns projects development changes within the range 
of Preble's through 2040. Such projections frame our analysis as they 
help us understand what factors can reasonably be anticipated to 
meaningfully affect the subspecies' future conservation status. In our 
view, the foreseeable future for this subspecies, based on the 
currently available data, does not extend beyond 2040. While it is 
likely some of the above estimates could be extrapolated out into the 
more distant future, development projections beyond this point are of 
increasingly lower value as uncertainty escalates.
    The following analysis examines all five factors currently 
affecting, or that are likely to affect, the Preble's meadow jumping 
mouse within the foreseeable future.

A. The Present or Threatened Destruction, Modification, or Curtailment 
of Its Habitat or Range

    Introduction. Decline in the extent and quality of Preble's meadow 
jumping mouse habitat has been considered the primary factor 
threatening the subspecies (Bakeman 1997, p. 78; Hafner et al. 1998, p. 
122; Pague and Grunau 2000). In our 1998 final rule to list Preble's 
meadow jumping mouse as threatened (63 FR 26517, May 13, 1998), we 
stated that Colorado east of the Front Range and adjacent areas of 
southeastern Wyoming had changed, over time, from predominantly prairie 
habitat intermixed with perennial and intermittent streams and 
associated riparian habitats to an agricultural and increasingly urban 
setting.
    In our listing decision, we stated that Preble's meadow jumping 
mouse populations had experienced a decline and faced continued threats 
linked to widespread loss and fragmentation of the subspecies' required 
riparian habitat from human land uses including: urban, suburban, and 
recreational development; highway and bridge construction; water 
development; instream changes associated with increased runoff and 
flood control efforts; aggregate (sand and gravel) mining; and 
overgrazing (63 FR 26517, May 13, 1998). These human land-use 
activities affect the Preble's meadow jumping mouse by directly 
destroying its protective cover, nests, food resources, and hibernation 
sites; disrupting behavior; or acting as a barrier to movement. We 
noted that such impacts reduced, altered, fragmented, and isolated 
habitat to the point where Preble's meadow jumping mouse populations 
may no longer persist. We also noted that patterns of capture suggested 
that Preble's meadow jumping mouse populations fluctuate greatly over 
time at occupied sites, raising questions regarding security of the 
many currently documented populations which are isolated and affected 
by human development.
    Historical records in Colorado (pre-1980) illustrate areas of 
Preble's meadow jumping mouse occupancy along the Front Range within 
both foothill and prairie riparian corridors

[[Page 63005]]

(Armstrong 1972, p. 249; Fitzgerald et al. 1994, p. 293). Between 1980 
and 2005, the human population of Colorado counties within the Preble's 
meadow jumping mouse range increased by nearly 60 percent, from 1.7 
million to 2.7 million (Colorado Demography Office, 2007). As explained 
further below, the apparent absence of the Preble's meadow jumping 
mouse in areas of substantial development, where trapping had 
previously confirmed subspecies presence, supports the conclusion that 
human land uses adversely affect Preble's meadow jumping mouse 
populations.
    Ryon (1996) evaluated the condition of eight historical Preble's 
meadow jumping mouse capture sites in six Colorado counties based on 
vegetation structure, dominant plant species, and trapping results. 
Ryon reported no Preble's meadow jumping mouse captures at any of the 
seven sites trapped (one site no longer contained suitable habitat) 
(1996, p. 25). In addition, he reported that the historical sites 
contained fewer native species in plant communities and were lacking 
the multi-strata vegetation structure he observed at sites where 
trapping had recently confirmed Preble's meadow jumping mouse presence 
(Ryon 1996, p. 30). Investigations into land-use changes at the 
historical sites suggested that most had been directly altered in terms 
of habitat or had been influenced by habitat fragmentation (Ryon, 1996, 
p. 30). Clippinger (2002, pp. 14-29) mapped and compared past (through 
1972) and current (post-1972) distribution records of the Preble's 
meadow jumping mouse in central Colorado and southeastern Wyoming based 
on museum specimens, published accounts, and unpublished reports. 
Clippinger reported that his distribution maps illustrated a loss of 
Preble's populations in expanding urban and suburban areas, especially 
around Cheyenne, Denver, and Colorado Springs, and in general along the 
eastern extent of historical range (Clippinger 2002, p. 22). Note that 
Clippinger's reference to historical range is based on the few existing 
records (through 1972) documenting Preble's meadow jumping mouse 
occurrence. These records are focused around what is now the I-25 urban 
corridor and based upon our current knowledge of the subspecies do not 
truly represent the extent of the range of the subspecies. The apparent 
loss of historically occupied sites (those sites where the subspecies 
was documented to occur prior to 1980) also provides some insight into 
this relationship. Based on Service records, consisting of intensive 
trapping efforts and assessments of habitat quality, only 1 of 17 of 
these documented historical sites of Preble's meadow jumping mouse 
occurrence in Colorado (Bear Creek, Boulder County) is thought to 
currently support the Preble's meadow jumping mouse.
    Recent trapping records maintained by the Service indicate that 
Preble's meadow jumping mouse populations have little likelihood of 
occurrence along large portions of major river and stream reaches 
within the subspecies' historical described range in Colorado 
including:
     The Cache La Poudre River within Fort Collins and 
downstream to its confluence with the South Platte River at Greeley, 60 
km (37 mi);
     The Big Thompson River and Little Thompson River through 
the Front Range urban corridor, approximately 50 km (32 mi);
     The Saint Vrain River from Hygiene to its confluence with 
the South Platte River, 35 km (22 mi);
     Boulder Creek from Boulder east to its confluence with the 
Saint Vrain River, approximately 35 km (22 mi);
     Walnut, Woman, and Dry Creeks downstream from Rocky Flats 
National Wildlife Refuge (NWR) to the confluence of Dry Creek and 
beyond to the South Platte River, 40 km (25 mi);
     Ralston Creek and Clear Creek through the urban corridor 
to the South Platte River, approximately 40 km (25 mi);
     The South Platte River downstream of Chatfield Reservoir 
through Denver to Brighton, 60 km (38 mi);
     The South Platte River downstream from Brighton to 
Greeley, approximately 55 km (34 mi) (one recent Preble's capture);
     Cherry Creek from the Arapahoe County-Douglas County line 
downstream through Denver to the South Platte River, 30 km (19 mi);
     Monument Creek downstream from its confluence with 
Cottonwood Creek through Colorado Springs, approximately 15 km (9 mi).
    In total, Preble's meadow jumping mouse populations appear to have 
little likelihood of occurrence along 420 km (260 mi) in and downstream 
of areas with concentrated human development. However, despite apparent 
local extirpations, many of these streams continue to support Preble's 
meadow jumping mouse populations in their upstream reaches or 
tributaries.
    Historical losses relative to ongoing threats are relevant in 
predicting whether the subspecies is likely to become endangered in all 
or a significant portion of its current range within the foreseeable 
future. It appears unlikely that the Preble's meadow jumping mouse can 
be returned to the historical localities within the Front Range urban 
corridor; however, we find that the subspecies' apparent local 
extirpation from areas of human development provides useful perspective 
about the potential impacts of future development within the remaining 
range of the Preble's meadow jumping mouse. If the protections of the 
Act are removed, we expect these threat factors, discussed in more 
detail below, would continue to affect the subspecies in large portions 
of its current range into the foreseeable future.
    For the purposes of this revised proposed rule, we reviewed and 
considered the best available information regarding threats within the 
range of the Preble's meadow jumping mouse, including Ryon (1996), 
Shenk (1998), Bakeman (1997), Pague and Granau (2000), Clippinger 
(2002), and Service (2003b). We summarize these accounts below.
    Following listing, The Nature Conservancy, under a contract with 
the Colorado Division of Natural Resources, formed a Preble's Meadow 
Jumping Mouse Science Team (Pague 1998). With guidance from the Science 
Team and following numerous meetings with scientists and stakeholders, 
Pague and Grunau (2000) developed a conservation planning handbook that 
addressed each of seven Colorado counties containing Preble's meadow 
jumping mouse populations. The document provided ``issues and 
stresses'' for all presumed threat factors operating in known or 
suspected Preble's meadow jumping mouse habitat, and assigned a 
qualitative risk assessment level to each of the identified issues. The 
work of Pague and Granau (2000) continues to provide important, 
science-based insight into threats to, and potential conservation 
strategies for, the Preble's meadow jumping mouse in Colorado on a 
county-by-county basis. Habitat-related ``issues'' identified as high 
or very high priority in one or more counties included habitat 
conversion through housing, commercial, and industrial construction; 
travel corridor (i.e., roadway) construction; travel corridor 
maintenance; fragmentation of habitat and corridors; hydrological flow 
impairment; habitat conversion to a reservoir; bank stabilization; high 
impact livestock management; rock and sand extraction; invasive weeds; 
and catastrophic fire (Pague and Granau 2000, pp. 1-15, 2-12, 3-13, 4-
14, 5-14, 6-15, 7-14). Pague (2007) provided observations updating the 
2000 report. No comparable document exists for the

[[Page 63006]]

four Wyoming counties where the subspecies occurs.
    Colorado's Comprehensive Wildlife Conservation Strategy lists the 
meadow jumping mouse (including both the Preble's meadow jumping mouse 
and Zapus hudsonius luteus which occurs in extreme south-central 
Colorado) as a ``Species of Greatest Conservation Need,'' citing 
threats to habitat and range including habitat conversion (due to 
housing, urban, and exurban development) and habitat degradation (due 
to altered native vegetation and altered hydrological regime) (CDOW 
2006, p. 102).
    The Wyoming Comprehensive Wildlife Plan (WCWP) also lists meadow 
jumping mouse (including both the Preble's meadow jumping mouse and 
Zapus hudsonius campestris which occurs in northeastern Wyoming) as a 
``Species of Greatest Conservation Need.'' This plan identifies 
ecoregions in the State and provides a summary of ``mean habitat 
quality'' scores for each ecological system (or habitat) within the 
ecoregion (WGFD 2005, pp. 19-25). Within the three Wyoming ecoregions 
that include Preble's meadow jumping mouse range (Central Shortgrass 
Prairie, Northern Great Plains Steppe, and Southern Rocky Mountains), 
the two ecological systems most likely to support the Preble's meadow 
jumping mouse (Rocky Mountain Lower Montane Foothill Riparian and 
Shrubland, Western Great Plains Riparian/Western Great Plains 
Floodplain) ranked in the lowest 20 percent in mean habitat quality 
relative to the State's other ecosystems (WGFD 2005, pp. 19-25). Among 
threats to habitat in these ecoregions are invasive plants, residential 
development radiating from the Cheyenne area, and recreation in the 
Southern Rocky Mountain region (WGFD 2005, pp. 53, 55, 56).
    The direct impacts of development on the Preble's meadow jumping 
mouse and its habitat have likely slowed since our 1998 listing because 
of protection afforded to the Preble's meadow jumping mouse and its 
critical habitat rangewide under the Act. One indication of continuing 
impacts to the Preble's meadow jumping mouse and its habitat is the 
number of formal consultations performed to date under section 7 of the 
Act and the number of section 10 permits issued to date in conjunction 
with approved Habitat Conservation Plans (HCPs). Section 7 of the Act 
requires Federal agencies to consult with the Service to ensure that 
their actions do not jeopardize the continued existence of the 
subspecies or cause destruction or an adverse modification of critical 
habitat. Thus far, the section 7 process has been successful in 
avoiding adverse effects, from Federal actions, that would be likely to 
jeopardize the continued existence of the species or result in the 
destruction or adverse modification of critical habitat.
    Section 10(a)(1)(B) of the Act authorizes the Service to issue 
permits for non-Federal actions that result in the incidental taking of 
listed wildlife. Incidental take permit applications must be supported 
by an HCP that identifies conservation measures that the permittee 
agrees to implement for the species to avoid, minimize, and mitigate 
the impacts of the requested incidental take.
    As of August 2007, we have conducted 124 formal section 7 
consultations (109 in Colorado, 15 in Wyoming) and issued 19 HCP 
related incidental take permits (all in Colorado) for projects 
affecting the Preble's meadow jumping mouse. We have authorized take 
for actions that did not result in jeopardy but nevertheless resulted 
in permanent impacts to over 320 hectares (ha) (800 acres (ac)) of 
Preble's meadow jumping mouse habitat, and temporary impacts to more 
than twice that amount of land. These projects have incorporated 
conservation measures or mitigation to avoid or minimize adverse 
impacts to the Preble's meadow jumping mouse.
    However, even with the protections afforded to the species under 
section 7, habitat overall has continued to decline in quality and 
quantity, especially in Colorado. In the absence of listing, projects 
in Preble's meadow jumping mouse habitat would otherwise go forward 
with little Federal oversight. Other Federal, as well as State and 
local regulatory mechanisms, that may provide protection for the 
Preble's meadow jumping mouse and its habitat are evaluated under 
Factor D below.
    Residential and Commercial Development. Clippinger (2002) assessed 
the impacts of residential development on the Preble's meadow jumping 
mouse. He analyzed Colorado land-cover data compared to positive and 
negative trapping results for the Preble's meadow jumping mouse in a 
geographic information system analysis and concluded that the 
likelihood of successful trapping of Preble's meadow jumping mice was 
reduced by either low-or high-density residential developments when the 
developments were within 210 m (690 ft) of the trapping sites 
(Clippinger 2002, pp. iv, 94). Clippinger (2002, p. iv) noted that the 
Preble's meadow jumping mouse can be a useful indicator of 
environmental integrity in riparian areas and associated upland areas 
in the Colorado Piedmont. These data demonstrate that nearby 
development increases the risk of extirpation of Preble's meadow 
jumping mice from occupied sites.
    Theobold et al. (1997) emphasized both housing density and spatial 
patterns in evaluating effects of residential development on wildlife 
habitat. They concluded that while clustered development can decrease 
habitat disturbance (Theobold et al. 1997, p. 34), much of the Rocky 
Mountain West is experiencing what has been termed ``rural sprawl'' 
where rural areas are growing at a faster rate than urban areas 
(Theobold et al. 2001, p. 4). In Colorado, residential demand and State 
law encourage developers to design subdivisions with lots of at least 
14 ha (35 ac) each with one house, to avoid detailed county subdivision 
regulations (Riebsame et al., p. 420). The Larimer County Master Plan 
(Larimer County Planning Division 1997) cites a trend toward 
residential properties with relatively large lots, which leads to 
scattered development and more agricultural land taken out of 
production. Where public and private lands are intermingled, private 
land ownership typically follows valley bottoms (Theobald et al. 2001, 
p. 5), thus rural development is likely to disproportionately affect 
valley-bottom riparian areas (Riebsame et al., p. 402), the favored 
habitat of the Preble's meadow jumping mouse. Beyond direct impact to 
habitat, when ranches are subdivided, subsequent residential 
construction and associated disturbance can result in the disruption of 
wildlife movement along stream corridors (Riebsame et al., p. 402). 
Rural development disproportionately occurs around edges of undisturbed 
public lands and affects the conservation value of the undisturbed 
public lands (Hansen et al. 2005, p. 1900).
    Human development often causes subtle effects on riparian habitat 
as well. Indirect effects of human settlement have resulted in declines 
in native trees and shrubs, greater canopy closure, and a more open 
understory with reduced ground cover within riparian habitat (Miller et 
al. 2003, p. 1055). An open understory does not favor the Preble's 
meadow jumping mouse, which prefers dense ground cover of grasses and 
shrubs and is less likely to use open areas where predation risks are 
assumed to be higher (Trainor et al. 2007, pp. 472-476; Clippinger 
2002, pp. 69, 72).
    Fragmentation is another indirect impact of development in 
proximity to Preble's meadow jumping mouse

[[Page 63007]]

habitat. The Preble's meadow jumping mouse is closely associated with 
narrow riparian systems that represent a small percentage of the 
landscape within the subspecies' range. Fragmentation of these linear 
habitats limits the extent and size of Preble's meadow jumping mouse 
populations. As populations become fragmented and isolated, it becomes 
more difficult for them to persist (Caughley and Gunn 1996, pp. 165-
189). Major risks associated with small populations include--
demographic stochasticity (an increased risk of decline in small 
populations due to variability in population growth rates arising from 
random differences among individuals in survival and reproduction 
within a season); environmental stochasticity (an increased risk of 
decline in small populations due to variation in birth and death rates 
from one season to the next in response to weather, disease, 
competition, predation, or other factors external to the population); 
and loss of genetic variation (a reduction in the amount of diversity 
retained within populations and an increased chance that deleterious 
recessive alleles may be expressed; the loss of diversity can limit a 
population's ability to respond adaptively to future environmental 
changes) (Caughley and Gunn 1996, pp. 165-189). These issues are 
discussed in greater detail in Factor E below. The Recovery Team 
determined that small, fragmented units of habitat will not be as 
successful in supporting the Preble's meadow jumping mouse in the long 
term as larger areas of habitat (Service 2003b, p. 21). On a landscape 
scale, maintenance of dispersal corridors linking patches of Preble's 
meadow jumping mouse habitat may be critical to the subspecies' 
conservation (Shenk 1998, p. 21).
    One indicator of the level of development pressure since listing is 
the number of development-related section 7 consultations and HCPs 
completed by the Service. Of the 109 formal consultations and 19 HCPs 
completed in Colorado, 17 section 7 consultations and 10 HCPs were 
specifically for residential and commercial developments with direct 
adverse effects to the Preble's meadow jumping mouse or its habitat. 
Approved projects allowed for adverse impacts (permanent or temporary) 
in excess of 180 ha (450 ac) of Preble's habitat. While conservation 
measures or mitigation in various forms have been incorporated into all 
permitted projects, implementation of these habitat restoration and 
enhancement measures has been limited by factors such as droughts or 
floods. Recent development pressure has been most concentrated south of 
Denver, Colorado, in Douglas and El Paso Counties; eight section 7 
consultations and three HCPs have occurred in the Middle South Platte-
Cherry Creek drainage, all south of Denver, and six section 7 
consultations and four HCPs have occurred in the Fountain Creek 
drainage. We have also worked with other Federal agencies and a 
substantial number of landowners and developers to avoid adverse 
impacts to Preble's meadow jumping mouse habitat, thus avoiding formal 
consultation. Additional planned residential and commercial development 
projects that would adversely affect Preble's meadow jumping mouse 
habitat in Colorado are continually being reviewed by the Service. 
Since listing, protections afforded under the Act have slowed, but not 
eliminated, the loss of Preble's meadow jumping mouse habitat due to 
residential and commercial development in Colorado. We believe that in 
the absence of the protections under the Act, Preble's meadow jumping 
mouse habitat in Colorado and the populations it supports would be lost 
at a greatly increased rate.
    Continued rapid development is expected along Colorado's Front 
Range as the human population continues to grow. The State of Colorado 
expects the population of counties supporting the Preble's meadow 
jumping mouse to increase by an additional 1.5 million people by 2035, 
including: 99,000 in Boulder County; 272,000 in Douglas County; 42,000 
in Elbert County; 369,000 in El Paso County; 143,000 in Jefferson 
County; 201,000 in Larimer County; and 323,000 in Weld County (Colorado 
Demography Office 2007). These expected increases support Pague and 
Grunau's (2000) conclusion that habitat conversion is a very high 
priority issue to the Preble's meadow jumping mouse in Larimer, Weld, 
and El Paso Counties, and a high priority issue for the remaining 
counties supporting the Preble's meadow jumping mouse in Colorado.
    In contrast to the situation in Colorado, no formal section 7 
consultations or HCPs have been sought for residential or commercial 
development in Wyoming. This reduced level of consultations reflects 
the general lack of development pressure within Preble's meadow jumping 
mouse habitat. This lack of development pressure is predicted to 
continue into the foreseeable future as described below.
    Wyoming estimates that the population of the counties supporting 
the Preble's meadow jumping mouse will increase by about 11,000 people 
from 2005 to 2020, including: an increase of 800 in Albany County; an 
increase of 1,500 in Converse County; an increase of 9,100 in Laramie 
County; and a decrease of 400 in Platte County (Wyoming Department of 
Administration and Information 2007). Commercially available estimates 
suggest counties supporting the Preble's meadow jumping mouse will 
increase by about 18,400 people from 2006 through 2036, including: a 
decline of 3,700 in Albany County; an increase of 3,500 in Converse 
County; an increase of 18,300 in Laramie County; and an increase of 300 
in Platte County (Economy.com 2007 as provided by Lui 2007).
    While population growth rates provide valuable insight into 
development pressures, they may not provide a complete picture. For 
example, human population increases in Cheyenne, Fort Collins, Greeley, 
Longmont, the immediate Denver metropolitan area, and much of Colorado 
Springs are likely to have little direct impact on the Preble's meadow 
jumping mouse because the subspecies appears to have little likelihood 
of occurrence within and downstream from these cities. Conversely, 
substantial human population increases in the Laramie Foothills of 
Larimer County, Colorado, or southern portions of Douglas County, 
Colorado, are likely to have a high impact to the Preble's meadow 
jumping mouse. In Wyoming, given the small projected increases in the 
human population, we expect rural development will continue to have 
only small, localized impacts.
    Modeling exercises can also provide some insights into future land-
use development patterns. While these models have weaknesses, such as 
an inability to accurately predict economic upturns or downturns, 
uncertainty regarding investments in infrastructure that might drive 
development (such as roads, airports, or water projects), and an 
inability to predict open-space acquisitions, we nevertheless believe 
such models are useful in adding to our understanding of likely 
patterns. For example in 2005, Center for the West produced a series of 
maps predicting growth through 2040 for the west including the Colorado 
Front Range and Wyoming (Travis et al. 2005, pp. 2-7). The projections 
for the Colorado Front Range (available at: http://www.centerwest.org/futures/frtrng/2040.html) illustrate significant increases in urban/
suburban, low-density suburban, and exurban land uses across virtually 
all private lands

[[Page 63008]]

within the Colorado portion of the Preble's meadow jumping mouse range. 
Only small isolated patches of Preble's meadow jumping mouse habitat in 
public ownership, including headwater areas in Federal ownership, would 
avoid the direct impacts of residential and associated commercial 
development. Although similar maps for Wyoming are less refined 
(available at: http://www.centerwest.org/futures/west/2040.html), they 
suggest only limited increases in development, primarily around 
Cheyenne.
    Based upon known impacts to the Preble's meadow jumping mouse 
associated with development and best available projections for future 
development (as described above and in Factor D below), we conclude 
that residential and commercial development constitutes a substantial 
threat to the Preble's meadow jumping mouse in Colorado, now and into 
the foreseeable future. In Wyoming, residential and commercial 
development is likely to be limited with only small, localized impacts 
to the Preble's meadow jumping mouse expected. While some development 
is projected in the vicinity of Cheyenne, trapping efforts to date have 
not confirmed presence of Preble's meadow jumping mice in this area.
    Transportation, Recreation, and Other Rights of Way Through 
Habitat. At the time of listing, the Service concluded that roads, 
trails, or other linear development through the Preble's meadow jumping 
mouse's riparian habitat could act as partial or complete barriers to 
dispersal (63 FR 26517, May 13, 1998). These forms of development have 
continued to affect and fragment Preble's meadow jumping mouse habitat. 
Since listing, the Service has conducted 38 formal consultations under 
section 7 of the Act for road or bridge projects (32 in Colorado and 6 
in Wyoming) resulting in permitted impacts to approximately 50 ha (125 
ac) of Preble's meadow jumping mouse habitat. In addition, a formal 
2005 programmatic section 7 consultation with the Federal Highway 
Administration for the Wyoming Statewide Transportation Improvement 
Program could result in 19 future highway projects with impacts to 42 
ha (104 ac) of Preble's meadow jumping mouse habitat (Service 2005). 
Under the Douglas County (Colorado) Regional HCP for the Preble's 
meadow jumping mouse, completed in May 2006, 67 approved road and 
bridge construction projects by Douglas County, and the cities of 
Parker and Castle Rock, may affect up to 122 ha (302 ac) of Preble's 
meadow jumping mouse habitat over a 10-year period (Service 2006).
    One of the largest road projects is a proposed improvement to I-25 
in El Paso County, Colorado. The proposed construction would affect 10 
of the 11 to 14 eastern tributaries of Monument Creek thought to 
support Preble's (Bakeman and Meaney 2001, p. 21). Impacts to Preble's 
would include habitat fragmentation and modification, change in 
population size, and behavioral impacts (Bakeman and Meaney 2001, pp. 
18-20). While measures to avoid, minimize, and mitigate impacts were 
identified, the project would have significant cumulative effects on 
Preble's meadow jumping mice in the Monument Creek drainage, especially 
east of I-25 (Bakeman and Meaney 2001, pp. i, ii, 22-27).
    With an increased human population, a high level of road 
construction and maintenance projects will occur; in the absence of the 
Act's protective measures, impacts to Preble's and its habitat would 
likely be substantial. While the Act rarely stops such projects, it 
does promote measures to avoid, minimize, or compensate for impacts and 
helps control the level of negative impacts to the Preble's meadow 
jumping mouse and its habitat. Pague and Grunau (2000) considered 
``travel corridor construction'' to be a high priority issue to 
Preble's meadow jumping mouse populations in Weld, Douglas, Elbert, and 
El Paso Counties in Colorado.
    Human-caused impacts associated with recreation include backcountry 
roads, trails, and campgrounds, which are often located along streams 
and near water (Wyoming Game and Fish Department 2005, p. 56). 
Recreational trail systems are frequently located within riparian 
corridors (Meaney et al. 2002, p. 116). The development of trail 
systems can affect the Preble's meadow jumping mouse by modifying its 
habitat, nesting sites, and food resources in both riparian and upland 
areas. Use of these trails by humans or pets can alter wildlife 
activity and feeding patterns (Theobold et al. 1997, p. 26). Meaney et 
al. (2002, pp. 131-132) suggest fewer Preble's meadow jumping mice were 
found on sites with trails than on sites without trails. While temporal 
and spatial variation in Preble's meadow jumping mouse numbers resulted 
in low precision of population estimates and weak statistical support 
for a negative trail effect, the authors considered the magnitude of 
the potential effect sufficient to encourage careful management and 
additional research (Meaney et al. 2002, pp. 115, 131-132). Since the 
listing of the Preble's meadow jumping mouse in 1998, a dozen 
recreational trail projects with proposed impacts to Preble's meadow 
jumping mouse habitat in Larimer, Boulder, Douglas, and El Paso 
Counties, Colorado, have been addressed through section 7 consultations 
or HCPs. An additional 24 trail projects have been permitted under the 
Douglas County Regional HCP. As human populations continue to increase 
(as discussed above), we anticipate increased demand for recreational 
development in public open space and on conservation properties. 
Without protections afforded by the Act, Preble's meadow jumping mouse 
populations on properties free from residential and commercial 
development threats will still be subject to widespread threats from 
future recreational development and increased human use.
    Many utility lines (sewer, water, gas, communication, and electric 
lines, and municipal water ditches) cross Preble's meadow jumping mouse 
habitat. Current and future utility rights-of-way through these 
habitats will cause habitat destruction and fragmentation from periodic 
maintenance and new construction. Since the listing of the Preble's 
meadow jumping mouse, 18 utilities projects adversely affecting the 
Preble's meadow jumping mouse and its habitat have been evaluated 
through section 7 consultations (3 in Wyoming, 15 in Colorado). In 
addition, an approved HCP with Denver Water permits impacts to 34 ha 
(84 ac) of Preble's meadow jumping mouse habitat at multiple sites in 
Colorado. While often more costly than trenching, avoidance measures 
such as directional drilling under riparian crossings can reduce or 
avoid impacts to the Preble's meadow jumping mouse. If the Preble's 
meadow jumping mouse were to be delisted, we do not anticipate that 
project operators would voluntarily directionally drill to avoid 
Preble's meadow jumping mouse habitat.
    Overall, we believe threats related to transportation, recreation, 
and other rights of way through habitat are directly related to human 
population pressures. Thus, we expect these issues will have 
substantial impacts to Preble's meadow jumping mouse populations in 
Colorado, but only minimal impacts to Preble's meadow jumping mouse 
populations in Wyoming.
    Hydrologic Changes. Establishment and maintenance of riparian plant 
communities are dependent on the interactions between surface-water 
dynamics, groundwater, and river-channel processes (Gregory et al. 
1991, pp. 542-545). Changes in hydrology can

[[Page 63009]]

alter the channel structure, riparian vegetation, and valley-floor 
landforms (Gregory et al. 1991, pp. 541-542; Busch and Scott 1995, p. 
287). Thus, changes in the timing and abundance of water can be 
detrimental to the persistence of the Preble's meadow jumping mouse in 
these riparian habitats due to resultant changes in vegetation (Bakeman 
1997, p. 79). Changes in hydrology may occur in many ways, but two of 
the more prevalent are the excessively high and excessively low runoff 
cycles in watersheds with increased areas of paved or hardened 
surfaces, and disruption of natural flow regimes downstream of dams, 
diversions, and alluvial wells (Booth and Jackson 1997, pp. 3-5; Katz 
et al. 2005, pp. 1019-1020).
    Urbanization can dramatically increase frequency and magnitude of 
flooding while decreasing base flows (the portion of stream flow that 
is not surface runoff and results from seepage of water from the ground 
into a channel slowly over time; base flow is the primary source of 
running water in a stream during dry weather) (Booth and Jackson 1997; 
pp. 8-10; National Research Council 2002, pp. 182-186). Infiltration of 
precipitation is greatly reduced by increases in impervious surfaces. 
The magnitude of peak flows increases in urban areas as water runs off 
as direct overland flow. Increased peak flows can exceed the capacity 
of natural channels to transport flows, trigger increased erosion, and 
degrade habitat (Booth and Jackson 1997, pp. 3-5). Changes in hydrology 
associated with urbanization can result in channel downcutting, 
lowering of the water table in the riparian zone, and creation of a 
``hydrologic drought,'' which in turn alters vegetation, soil, and 
microbial processes (Groffman et al. 2003, p. 317). Meanwhile, reduced 
infiltration results in reduced groundwater recharge, reduced 
groundwater contributions to stream flow, and, ultimately, reduced base 
flows during dry seasons (National Research Council 2002, p. 182; 
Groffman et al. 2003, p. 317). Established methods of mitigating 
downstream impacts of urban development, such as detention basins, have 
only limited effectiveness; downstream impacts are probably inevitable 
without limiting the extent of watershed development (Booth and Jackson 
1997, p. 17).
    In response to altered hydrology, stormwater-management, flood-
control, and erosion-control efforts occur along many streams within 
the former and current range of the Preble's meadow jumping mouse. The 
methods used include channelization; construction of detention basins, 
outfall structures, drop structures, riprap banks, impervious cement 
channels; and other structural stabilization. Structural stabilization 
methods designed to manage runoff and control erosion can increase the 
rate of stream flow, shorten channel length, narrow riparian areas, 
destroy riparian vegetation, and prevent or prolong the time required 
for vegetation reestablishment (Booth and Jackson 1997, p. 4). These 
impacts may affect plant composition, soil structure, and physiography 
of riparian systems to the point where habitat supporting the Preble's 
meadow jumping mouse is so altered that populations can no longer 
persist. Pague and Grunau (2000) considered ``bank stabilization'' to 
be a high-priority issue for the Preble's meadow jumping mouse in Weld 
and El Paso Counties. Since the listing of the Preble's meadow jumping 
mouse, 22 stormwater management, stream stabilization, or outfall 
structure projects with impact to Preble's meadow jumping mouse habitat 
have been addressed through formal section 7 consultations in Colorado; 
none have occurred in Wyoming.
    The Preble's meadow jumping mouse's apparent absence downstream 
from most areas of extensive urbanization (including Cheyenne, Wyoming, 
and Fort Collins, Longmont, Boulder, Golden, Denver, Parker, and 
Colorado Springs, Colorado) may be attributable to such changes in 
hydrology. Corn et al. (1995, p. 14) and Schorr (2001, p. 30) expressed 
concern over the integrity of protected riparian habitats on Monument 
Creek and its tributaries through the U.S. Air Force Academy (Academy) 
because of development activities upstream. In 2007, all eastern 
tributaries of Monument Creek on the Academy experienced adverse 
impacts to occupied Preble's meadow jumping mouse habitat due to 
erosive head cutting, channel degradation, and impacts to vegetation 
that were attributable to regional stormwater management, and 
commercial and residential development (Mihlbachler 2007).
    Efforts to restore degraded riparian habitats have occurred in 
Colorado, in part to benefit the Preble's meadow jumping mouse. Efforts 
to restore Preble's meadow jumping mouse habitat through a 0.86 km 
(0.54 mi) urban stream reach of East Plum Creek, Douglas County appear 
to have increased vegetation cover and Preble's meadow jumping mouse 
numbers (Bakeman 2006, pp. 4, 8). Similarly, recent projects on Cherry 
Creek, Douglas County, have attempted to restore groundwater levels and 
downcut channels in or near Preble's meadow jumping mouse habitat by 
employing rock or sheet pile drop structures.
    If we were to delist the Preble's meadow jumping mouse, we believe 
that runoff-related impacts to riparian habitats within and downstream 
of development may increase in areas of high development, such as along 
Colorado's Front Range urban corridor, and that restoration of impacted 
riparian systems would be less likely to occur.
    At the time of listing, we stated that the Preble's meadow jumping 
mouse depended on vegetative habitat that was in turn dependent on 
physical factors including surface flows and groundwater. Water 
development and management in its various forms alters vegetation 
composition and structure, riparian hydrology, and flood-plain 
geomorphology directly, as well as through alterations to habitat 
located downstream; these alterations often, but not always, have 
adverse impacts to the Preble's meadow jumping mouse (63 FR 26517 May 
13, 1998). The creation of irrigation reservoirs at the expense of 
native wetlands is a factor that negatively affected Preble's meadow 
jumping mouse populations over the previous century (Fitzgerald et al. 
1994, p. 293). Reservoirs with barren shorelines can create barriers to 
Preble's meadow jumping mouse movement and fragment populations along 
stream corridors. Current and future reservoir construction is 
necessary to respond to municipal water needs. By 2030, municipal and 
industrial demand for water in Colorado will increase 60 percent, by 
578 million cubic meters (m\3\) (469,000 acre-feet (af)) yearly in the 
South Platte River drainage and by 41 percent, 133 million m\3\ 
(108,000 af) yearly in the Arkansas River drainage (Colorado Water 
Conservation Board 2004). Even under the most optimistic scenarios, the 
Colorado Water Conservation Board (2004, p. 13-17) estimated a 
shortfall relative to municipal and industrial demands of 111 million 
m\3\ (90,000 af) of water in the South Platte drainage and 22 million 
(m\3\) (18,000 af) in the Arkansas drainage by 2030. Pague and Grunau 
(2000) considered hydrological impacts (water quality, flow regime, and 
groundwater) to be a high-priority issue to the Preble's meadow jumping 
mouse in all Colorado counties supporting populations.
    Three water projects currently being considered may significantly 
affect Preble's meadow jumping mouse habitat including: The proposed 
expansions of existing Halligan and Seaman reservoirs in the Cache La 
Poudre drainage,

[[Page 63010]]

Larimer County, Colorado, and storage reallocation at Chatfield 
Reservoir, in the Upper South Platte drainage, Jefferson and Douglas 
Counties, Colorado. Options being considered at Halligan Reservoir 
could inundate up to 4.0 km (2.5 mi) of Preble's meadow jumping mouse 
habitat and affect Preble's critical habitat at the site of the 
proposed dam. At Seaman Reservoir, the currently favored option would 
inundate about 4.0 km (2.5 mi) of Preble's meadow jumping mouse 
critical habitat, while another option being considered would inundate 
about 11 km (7 mi). Options being investigated at Chatfield Reservoir 
have generated a preliminary estimate that up to 130 ha (330 ac) of 
existing Preble's meadow jumping mouse habitat, including almost 28 ha 
(70 ac) of critical habitat, would be inundated.
    In Wyoming, estimates of projected water use in the Platte River 
Basin through 2035, range from a 38 million m\3\ (31,000 af) decrease 
(2 percent) to a 90 million m\3\ (73,000 af) increase (6 percent) 
(Wyoming Water Development Commission 2006, p. 10). No significant 
reservoir projects are currently planned within Preble's habitat in 
Wyoming. While the Platte River Plan identifies ``upper Laramie River 
storage'' as a future storage opportunity (Wyoming Water Development 
Commission 2006, p. 31), potential impacts to Preble's meadow jumping 
mouse are uncertain based on limited knowledge of the subspecies' 
occurrence in the drainage and uncertainty regarding the location of 
any future water projects.
    Beyond direct effects to the Preble's meadow jumping mouse and its 
habitat through construction or inundation, changes in flows related to 
water diversion, storage, and use also affect riparian habitats 
downstream in a variety of ways. As flows are captured or diverted, or 
as groundwater supplies are depleted through wells, natural flow 
patterns are changed, and more xeric plant communities replace the 
riparian vegetation. Sediment transport is disrupted by on-stream 
reservoirs. Loss of sediment encourages channel downcutting, which in 
turn affect groundwater levels (Katz et al. 2005, p. 1020). The 
resulting conversion of habitats from moist or mesic, shrub-dominated 
systems to drier grass-or forb-dominated systems make the area less 
suitable for the Preble's meadow jumping mouse.
    Given the projected future demands for water, we believe that major 
water development projects affecting the Preble's meadow jumping mouse 
in Colorado would likely occur regardless of whether the subspecies 
remains listed. Measures to minimize and compensate for impacts 
specific to the Preble's meadow jumping mouse and its habitat are less 
likely to be incorporated into project plans if the subspecies were to 
be delisted. Fewer and smaller projects are likely to occur in Wyoming.
    Aggregate Mining. At the time of listing, we cited alluvial 
aggregate mining as a threat to the Preble's meadow jumping mouse. 
Aggregate mining is focused on floodplains, where these mineral 
resources most commonly occur, and specifically on the same gravel 
deposits that may provide important hibernation sites (63 FR 26517, May 
13, 1998). Alluvial aggregate mining continues to be a threat to the 
Preble's meadow jumping mouse in Colorado. Alluvial aggregate 
extraction may produce long-term changes to Preble's meadow jumping 
mouse habitat by removing (often permanently) shrub and herbaceous 
vegetation, and by altering hydrology. Often, mined pits are 
constructed with impervious liners and converted to water reservoirs 
after aggregate is removed. This conversion precludes restoration of 
riparian shoreline vegetation and alters adjacent groundwater flow.
    Since listing, we have conducted formal consultation under section 
7 of the Act regarding impacts to the Preble's meadow jumping mouse at 
two aggregate mines in Colorado and we have worked to avoid impacts at 
others. At Rocky Flats National Wildlife Refuge (NWR), private 
aggregate mining activities could affect Preble's meadow jumping mouse 
habitat directly or through alteration of hydrology along Rock Creek. 
While aggregate mining continues to affect floodplains in the Colorado 
Front Range, many project sites are along downstream reaches of larger 
streams and rivers where Preble's meadow jumping mouse populations 
appear absent. Pague and Grunau (2000) considered ``rock and sand 
extraction'' to be a high-priority issue in Weld, Jefferson, and 
Douglas Counties. In Wyoming, aggregate mining has not been an issue in 
Preble's meadow jumping mouse habitat and we have no information on any 
proposed mines in this portion of its range.
    Overall, we believe threats related to aggregate mining are likely 
to be more intense in areas in close proximity to residential and 
commercial development. Thus, we expect this issue will have an impact 
on Preble's meadow jumping mouse populations in Colorado. In Wyoming, 
we expect aggregate mining will have little, if any, effect on Preble's 
meadow jumping mouse populations as future development is projected to 
be far less.
    Agriculture. At the time of listing we cited conclusions by Compton 
and Hugie (1993a; 1993b) that human activities, including conversion of 
grasslands to farms and livestock grazing, had adversely impacted 
Preble's meadow jumping mouse. They concluded that development of 
irrigated farmland had a negative impact on Preble's meadow jumping 
mouse habitat, and that any habitat creation it produced was minimal 
(Compton and Hugie 1993a; Compton and Hugie 1993b). In general, 
negative trapping results suggest that the Preble's meadow jumping 
mouse does not occur in areas cultivated for row crops. Historically, 
the rapid rate of native habitat conversion to row crops likely had a 
significant adverse impact on the Preble's meadow jumping mouse. 
Because 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), such conversions are unlikely to 
present a similar threat in the future in any portion of the subspecies 
range.
    The Preble's meadow jumping mouse uses native grass and alfalfa 
hayfields when they are in or adjacent to suitable riparian habitat. 
This juxtaposition is often the case, since hay production requires 
large amounts of water. Mowing of hay may directly kill or injure 
Preble's meadow jumping mice, reduce food supply (since many plants 
will not mature to produce seed), and remove cover. Late season mowing 
may be especially problematic, because Preble's meadow jumping mice are 
approaching hibernation and their nutritional needs are high 
(Clippinger 2002, p. 72). Additionally, hay production may preclude 
growth of willows and other shrubs that are important as hibernation 
habitat for the Preble's meadow jumping mouse. Hayfields often are 
irrigated through ditch systems. The Preble's meadow jumping mouse uses 
overgrown water conveyance ditches and pond edges, and may use 
agricultural ditches as dispersal routes (Meaney et al. 2003, pp. 612-
613). Ditch maintenance activities may kill individual Preble's meadow 
jumping mice and periodically alter their habitat. Existing special 
regulations at 50 CFR 17.40(1) exempt certain ditch maintenance 
operations from take prohibitions of the Act in recognition that 
habitat the ditches provide is dependent on the ditches retaining their 
function. Preble's meadow jumping mouse populations have persisted in 
areas hayed for many years (Taylor 1999). Haying operations that allow 
dense riparian vegetation to

[[Page 63011]]

remain in place are likely compatible with persistence of Preble's 
meadow jumping mouse populations.
    Impacts to riparian habitat from livestock are well documented in 
the scientific literature (Kauffman and Krueger 1984, pp. 431-435; 
Armour et al. 1991, pp. 7-11; Fleischner 1994, pp. 629-638; Belsky et 
al. 1999, pp. 419-431; Freilich et al. 2003, pp. 759-765). Livestock 
have damaged 80 percent of stream and riparian ecosystems in the 
western United States (Belsky et al. 1999, p 419.). Adverse impacts of 
grazing include changes to stream channels (downcutting, trampling of 
banks, increased erosion), to flows (increased flow and velocity, 
decreased late-season flow), to the water table (lowering of the water 
table), and to vegetation (loss to grazing, trampling, and through 
altered hydrology) (Kauffman and Krueger 1984, pp. 432-435).
    Impacts from cattle grazing to other jumping mice subspecies have 
been documented by Frey (2005), Giuliano and Homyack (2004), and Medin 
and Clary (1989). Ryon (1996, p. 3) cited livestock grazing as a 
contributor to the lack of structural habitat diversity he observed on 
historical Preble's meadow jumping mouse sites in Colorado. On a 
working ranch in Douglas County, Colorado, Preble's meadow jumping mice 
were detected within cattle exclosures, but not on grazed areas. 
Previous trapping had documented Preble's meadow jumping mice upstream 
and downstream, but not on the ranch (Ensight Technical Services 2004, 
p. 9). On private lands in Douglas County, Colorado, Pague and 
Schuerman (1998, pp. 4-5) observed a swift rate of residential land 
development and significant fragmentation of habitat, but noted that in 
some cases accompanying secession of grazing had allowed recovery of 
degraded riparian habitats.
    In Colorado, City of Boulder lands endured intensive grazing, 
farming, or haying regimes until they became part of the Boulder Open 
Space system. Grazing and haying, used as land management tools, 
continue on Boulder Open Space sites currently supporting the Preble's 
meadow jumping mouse. In their study of small mammals on Boulder Open 
Space, Meaney et al. (2002, p. 133) found no adverse effects of managed 
grazing on abundance of individual small mammal species or on species 
diversity.
    Cattle can undoubtedly greatly affect herbaceous vegetation, 
especially in times of drought; grazing practices that assure 
maintenance of riparian shrub cover may be a key consideration in 
maintaining Preble's meadow jumping mouse populations (Ensight 
Technical Services 2004, p. 9). The recent drought, in combination with 
grazing, may have had an increased effect on Preble's meadow jumping 
mouse habitat.
    Overgrazing threats are not limited to large livestock producing 
operations. On subdivided ranch properties, often termed 
``ranchettes,'' horses and other livestock can heavily affect the small 
tracts within which they are fenced (Pague and Grunau 2000, pp. 1-14). 
Pague and Grunau (2000) considered ``high impact livestock grazing'' to 
be a high-priority issue for the Preble's meadow jumping mouse in 
Larimer, Weld, Elbert, and El Paso Counties in Colorado, largely due to 
the projected increase in such ranchettes.
    In Wyoming, where large-scale commercial ranching is more prevalent 
in the Preble's meadow jumping mouse's range than in Colorado, 
overgrazing is thought to occur sporadically across the landscape, most 
obviously where cattle congregate in riparian areas in winter and 
spring. Grazing has occurred within Preble's meadow jumping mouse 
habitat for many decades, and populations of Preble's meadow jumping 
mice have been documented on sites with a long history of grazing. For 
example, jumping mice were trapped at 18 of 21 sites on True Ranches 
properties (mice from 14 of these sites have since been confirmed as 
Preble's meadow jumping mice (King et al. 2006b, p. 4351)), primarily 
within sub-irrigated hay meadows that have been subjected to livestock 
grazing and hay production for approximately 100 years (Taylor 1999, p. 
5).
    At the time of listing, we addressed overgrazing by livestock, 
stating that it may have caused significant impacts to Preble's meadow 
jumping mouse habitat, but that timing and intensity of grazing were 
probably important to some degree in maintaining habitat and that 
maintenance of woody vegetative cover could be key (63 FR 26517, May 
13, 1998). Overgrazing was thought to have eliminated the Preble's 
meadow jumping mouse from much of its former Wyoming range (Clark and 
Stromberg 1987, p. 185; Compton and Hugie 1993b, p. 4). Trapping 
efforts since listing have greatly expanded our understanding of the 
subspecies' range in Wyoming, suggesting that our assertions that 
grazing eliminated Preble's from these areas were incorrect.
    As suggested by Bakeman (1997, p. 79) and Pague and Grunau (2000, 
p. 1-17), and as supported by the examples above, grazing is compatible 
with Preble's meadow jumping mouse when timing and intensity are 
appropriately managed. We now believe that agricultural operations that 
have maintained habitat supportive of Preble's meadow jumping mouse 
populations are consistent with conservation and recovery of the 
subspecies. In recognition of this, we adopted in 2001 special 
regulations at 50 CFR 17.40(1) which exempted existing agricultural 
activities, including grazing, plowing, seeding, cultivating, minor 
drainage, burning, mowing, and harvesting, from the prohibitions of the 
Act. The exemption does not apply to new agricultural activities or to 
those that expand the footprint or intensity of the activity. We 
established the exemption to provide a positive incentive for 
agricultural interests to participate in voluntary conservation 
activities and to support surveys and studies designed to determine 
status, distribution, and ecology of Preble's meadow jumping mouse, 
which in turn could lead to more effective recovery efforts.
    The number of cattle in counties currently known to support the 
Preble's meadow jumping mouse in Wyoming totaled 270,000 head in 2006 
(National Agriculture Statistics Service 2007). Cattle numbers appear 
stable in Albany, Converse, and Laramie Counties, but higher than the 
average for the last 20 years in Platte County. Cattle numbers in 
Colorado counties supporting the Preble's meadow jumping mouse totaled 
666,000 head in 2006, but they total only 116,000 head if Weld County, 
where few Preble's meadow jumping mice are thought to persist, is 
excluded (National Agriculture Statistics Service 2007). Excluding 
Weld, all of these Colorado counties have shown a marked downward trend 
in cattle numbers over the past 20 years, reflecting human development 
on former agricultural lands (National Agriculture Statistics Service 
2007).
    Overall, we expect traditional grazing operations to continue in 
Wyoming. Such operations have generally proven compatible with Preble's 
meadow jumping mice as timing and intensity have been managed 
appropriately. This management has taken place without ESA oversight as 
allowed in the special regulations at 50 CFR 17.40(1). We have no 
reason to believe the management of these facilities will change 
significantly in the future.
    In Colorado, many large ranch properties are being subdivided into 
``ranchettes.'' These small tracts can be heavily affected by 
concentrated grazing pressures. We believe that this represents a 
widespread threat to significant areas of Colorado, where an increase 
in rural development is forecast

[[Page 63012]]

in the foreseeable future. Based on growth projections, subdivision of 
ranches is expected to be minimal in portions of Wyoming where the 
Preble's meadow jumping mouse exists.
    Summary. Within Colorado, human land uses within the Preble's 
meadow jumping mouse's range have destroyed, degraded, and fragmented 
habitat and continue to do so. While protections of the Act have 
avoided, minimized, and helped to compensate for direct human land-use 
impacts to occupied Preble's meadow jumping mouse habitat, secondary 
impacts to riparian habitats have likely diminished the areas that are 
capable of sustaining Preble's populations. Given the projected future 
growth rates in Colorado, and absent protections associated with 
Federal activities and listing under the Act, we believe that threats 
posed by human development activities discussed above would rise 
dramatically following delisting. Most of the new Preble's meadow 
jumping mouse sites documented since listing in Colorado are subject to 
the same level of threats discussed above for the Colorado portion of 
the range in general and do not change our conclusion as to the current 
and future conservation status of the subspecies in this portion of its 
range. Regulatory mechanisms that could help reduce such negative 
impacts, while currently limited, are discussed under Factor D below.
    In Wyoming, the Preble's meadow jumping mouse appears to be much 
more widely distributed than previously assumed, while current and 
future threats to habitat and range appear limited. Such impacts to the 
Wyoming portion of the subspecies' range are likely to be minor with 
only small and localized effects. Therefore, we believe that present or 
threatened destruction, modification, or curtailment of the Preble's 
meadow jumping mouse habitat and range in Wyoming do not suggest that 
this subspecies is likely to become endangered within the foreseeable 
future throughout all of its range.

B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    The Preble's meadow jumping mouse is not collected for commercial 
or recreational reasons. Some collection of specimens occurs for 
scientific and educational purposes, but currently only through permits 
issued by the Service, CDOW, or WGFD. Although unintentional 
mortalities have resulted from capture and handling of Preble's meadow 
jumping mice by permitted researchers, we believe that the level of 
take associated with this activity does not rise to the level that 
would affect populations of the subspecies, nor is it likely to do so 
if we remove the protections of the Act.

C. Disease or Predation

    At the time of listing, we had no evidence of disease causing 
significant impacts to the Preble's meadow jumping mouse (63 FR 26517, 
May 13, 1998). No further evidence exists that any parasite or disease 
has caused a significant impact to populations. While plague 
relationships for most North American rodents are poorly understood, 
plague may interact synergistically with other natural and human-
induced disturbances, increasing risk of local extirpation and 
rangewide extinction (Biggins and Kosoy 2001, p. 913). Plague has not 
been documented in the Preble's meadow jumping mouse. However, Pague 
and Grunau (2000, pp. 1-19) considered disease to be a potentially 
high-priority issue for the Preble's meadow jumping mouse. They cited 
unknown resistance of the Preble's meadow jumping mouse to plague and 
other diseases, and noted that small populations could be especially 
vulnerable to effects of an epizootic. Should disease materialize into 
a substantive issue, we believe populations in Colorado would be at 
higher risk because development pressures in this portion of the range 
are more likely to result in small, fragmented, and unsustainable 
populations.
    At the time of listing, we addressed potential predators of the 
Preble's meadow jumping mouse whose densities could increase in the 
suburban or rural environment, including striped skunk (Mephitis 
mephitis), raccoon (Procyon lotor), and the domestic cat (Felis catus) 
(63 FR 26517, May 13, 1998). Increased impacts of native and exotic 
predators that accompany rural development can affect species viability 
(Hansen et al. 2005, p. 1899). We noted opinions that free-ranging 
domestic cats and feral cats locally presented a problem to Preble's 
meadow jumping mouse populations. Where predator populations are 
increased through human land uses, they may contribute to the loss or 
decrease of Preble's meadow jumping mouse. Generally, we have found 
proponents of new residential developments near Preble's meadow jumping 
mouse habitat to be receptive to prohibitions on free-ranging cats and 
dogs (Canis domesticus) when negotiating minimization measures through 
section 7 of the Act. However, enforcement is often through covenants 
administered by homeowners' associations with uncertain success. If the 
Preble's meadow jumping mouse were to be delisted and Federal 
protection under the Act discontinued, similar covenants on new 
development in and near Preble's meadow jumping mouse habitat would be 
less likely, and existing covenants may not be as strictly enforced. 
Beyond previously known or anticipated predators of jumping mice, 
introduction of non-native bullfrogs (Rana catesbiana) in Colorado has 
resulted in predation on Preble's meadow jumping mice (Trainor 2004, p. 
58). However, we have no information to suggest that predation from 
bullfrogs has affected Preble's meadow jumping mouse populations.
    While many uncertainties remain regarding disease and predation, we 
believe the best available scientific and commercial data suggest that 
disease is most likely to only be a factor in small and fragmented 
populations, and that increases in predation will likely only 
contribute to the reduction, fragmentation, and loss of Preble's meadow 
jumping mouse populations when such populations are exposed to 
increased human presence. As noted above, increased human presence is 
expected to be a significant issue in Colorado and of minimal concern 
in Wyoming. Thus, we expect these issues have the potential to 
meaningfully affect Preble's meadow jumping mouse populations in 
developing areas of Colorado, but comparable impacts in Wyoming are not 
expected.

D. The Inadequacy of Existing Regulatory Mechanisms

    This factor considers the regulatory mechanisms that would remain 
in place in the absence of the Act's protective measures. Current and 
likely future protections are considered. If the protections of the Act 
are removed, the Service has no assurances previous conservation 
commitments made under sections 7 or 10 of the Act would remain in 
place.
    At the time of listing, we cited the lack or ineffectiveness of 
laws and regulations protecting the Preble's meadow jumping mouse and 
its habitat (63 FR 26517, May 13, 1998). Protective measures discussed 
below include Federal, State, and local protections.
    Federal Protections. Existing Federal laws, such as the Clean Water 
Act (33 U.S.C. 1251 et seq.), Federal Power Act (16 U.S.C. 791a et 
seq.), Fish and Wildlife Coordination Act (16 U.S.C. 661 et seq.), 
National Forest Management Act (16 U.S.C. 1600 et seq.), Federal Land 
Policy and Management Act (43 U.S.C. 1701 et seq.), Food Security Act 
(16 U.S.C. 3801 et seq.), and National Environmental

[[Page 63013]]

Policy Act (42 U.S.C. 4321 et seq.), provide limited protection for 
non-listed species.
    Section 404 of the Clean Water Act generally requires avoidance, 
minimization (when practicable), and mitigation of adverse impacts to 
jurisdictional wetlands and waters of the United States associated with 
filling. Human impacts to jurisdictional wetlands may be permitted when 
alternatives that would avoid wetlands are found not to be practicable. 
Section 404 of the Clean Water Act does not apply to non-jurisdictional 
waters or wetlands that include some streams corridors known to support 
the Preble's meadow jumping mouse (most notably Running Creek and its 
tributaries in Elbert County, Colorado, but potentially on other 
streams with intermittent flows or where there is no regular connection 
to waters of the United States). In these cases, activities effecting 
these waters or wetlands would not require Federal permits under 
Section 404 of the Clean Water Act. In addition, Section 404 of the 
Clean Water Act provides no comparable safeguards for nearby uplands 
used by the Preble's meadow jumping mouse. Thus, the Clean Water Act 
provides only limited protection of habitats utilized by the Preble's 
meadow jumping mouse and is not capable of substantially reducing 
threats to individual Preble's populations or to the subspecies as a 
whole.
    On lands administered by the U.S. Forest Service and U.S. Bureau of 
Land Management, the current status of the Preble's meadow jumping 
mouse as threatened invokes management priorities in accordance with 
the Act. If delisted, these protections would no longer apply. However, 
Federal land-management agencies, through their regulations, policies, 
and management plans, work to ensure long-term protection of all listed 
species. Of the three National Forests supporting Preble's meadow 
jumping mouse populations, the Medicine Bow--Routt National Forest has 
a forest management plan that includes standards and guidelines 
specific to conservation of the Preble's meadow jumping mouse. The 
Arapahoe-Roosevelt National Forest and the Pike-San Isabel National 
Forest have forest plans that predate the listing of the Preble's 
meadow jumping mouse (Warren 2007). If delisted, the Preble's meadow 
jumping mouse would likely be considered a subspecies warranting 
conservation concern by Federal land-holding agencies and, as such, 
retain some continued degree of conservation priority.
    On military installations, the Sikes Act Improvement Act of 1997 
(16 U.S.C. 670a et seq.) requires each facility that includes land and 
water suitable for the conservation and management of natural resources 
to complete an Integrated Natural Resources Management Plan (INRMP). 
This plan must integrate implementation of the military mission of the 
installation with stewardship of the natural resources found there. In 
both Colorado and Wyoming, this process has provided the opportunity to 
consider the potential impacts of military actions on the Preble's 
meadow jumping mouse.
    Warren Air Force Base in Laramie County, Wyoming, has an INRMP and 
a conservation and management plan. However, the base may only support 
the western jumping mouse. The Air Force Academy in El Paso County, 
Colorado, has an INRMP in place, a conservation and management plan, 
and a programmatic consultation under section 7 of the Act, which 
provides guidance for Air Force management decisions for certain 
activities that may affect the subspecies. Research on the Preble's 
meadow jumping mouse is ongoing at the Academy; the conservation and 
management plan is designed to be updated as new information is 
collected. Both plans are designed to be in place for 5 years. The 
emphasis given to conservation of the Preble's meadow jumping mouse in 
these plans may decline in the future if the subspecies were to be 
delisted.
    The presence of Preble's meadow jumping mouse has been documented 
at two of the Service's NWRs. We manage the Rocky Flats NWR, near 
Boulder, Colorado, in a manner consistent with conservation of the 
Preble's meadow jumping mouse. This management is unlikely to change if 
the Preble's meadow jumping mouse were to be delisted.
    More recently, a single Preble's meadow jumping mouse as well as 
western jumping mice have been confirmed from Hutton Lake NWR near 
Laramie, Wyoming. Because this subspecies was only recently documented 
on Huttom Lake NWR, the subspecies needs are not explicitly addressed 
in management documents (Timberman 2007). While it is unknown if 
ongoing management (primarily waterfowl oriented) is consistent with 
the subspecies' needs, the refuge has expressed a willingness to 
provide for the needs of the subspecies in the future (Timberman 2007).
    Service-approved HCPs and their incidental take permits contain 
management measures and protections for identified areas that protect, 
restore, and enhance the value of these lands as habitat for the 
Preble's meadow jumping mouse. These measures, which include explicit 
standards to avoid, minimize, and mitigate any impacts to the covered 
(sub)species and its habitat, are designed to ensure that the 
biological value of covered habitat for the Preble's meadow jumping 
mouse is maintained, expanded, or improved. Large regional HCPs expand 
upon the basic requirements set forth in section 10(a)(1)(B) of the Act 
and reflect a voluntary, cooperative approach to large-scale habitat 
and (sub)species conservation planning. The primary goal of such HCPs 
is to provide for the protection and management of habitat essential 
for the conservation of the (sub)species while directing development to 
other areas. In any HCP, permittees may terminate their participation 
in the agreement and abandon the take authorization set forth in the 
permit.
    To date, we have approved 19 single species HCPs for the Preble's 
meadow jumping mouse, all in Colorado. Eighteen of the associated 
permits allow approximately 280 ha (700 ac) of permanent or temporary 
impact to Preble's meadow jumping mouse habitat, and preserve or 
enhance habitat to offset impacts. The largest of these, the approved 
HCP for Douglas County and the Towns of Castle Rock and Parker, allows 
impacts of up to 170 ha (430 ac), in exchange for the acquisition of 9 
km (15 mi) of stream and 455 ha (1,132 ac) of habitat, was acquired and 
preserved for the long-term benefit of the Preble's meadow jumping 
mouse.
    The remaining HCP, issued in January 2006, is the Livermore Area 
HCP in Larimer County. The planning area for this HCP includes a large 
portion of Larimer County, approximately 1,940 square km (750 square 
mi), including a Preble's meadow jumping mouse ``conservation zone'' 
estimated at approximately 324 km (201 mi) of stream and 8,570 ha 
(21,320 ac). The HCP cites protection of 114 km (71 mi) of stream, 
mostly on CDOW lands; however, it is not clear what proportion of these 
areas support Preble's. Local landowners and public agencies holding 
land within the boundaries of this HCP may opt for coverage under the 
HCP and receive take permits for activities consistent with the HCP. 
The Livermore Area HCP is designed to support current land uses, 
including ranching and farming. However, inclusion of landowners is 
optional, and they may choose to pursue land uses inconsistent with 
those specified in the HCP. Thus far, we have issued no individual 
permits under this HCP.
    Of the two regional HCPs in the process of being developed, the El 
Paso

[[Page 63014]]

County effort is proceeding slowly and the Boulder County effort 
appears to be on hold. It is unlikely that these conservation plans 
will be completed or implemented if the Preble's meadow jumping mouse 
does not remain listed under the Act.
    State Protections. Under the nongame provisions of the CDOW 
Regulations (Chapter 10, Article IV) the Preble's meadow jumping mouse 
currently may only be taken legally by permitted personnel for 
educational, scientific, or rehabilitation purposes. However, if 
delisted, Colorado could rescind its current State designation of 
threatened. In Wyoming, continued classification of the meadow jumping 
mouse as a ``nongame species'' under Section 11 of Chapter 52 (Nongame 
Wildlife) of the Wyoming Game and Fish Commission regulations would 
protect the Preble's meadow jumping mouse from takings and sales by 
allowing the issuance of permits only for the purpose of scientific 
collection. As mentioned previously in our discussion under Factor B, 
overutilization for commercial, recreational, scientific, or 
educational purposes is not now, nor is it likely to become a 
significant threat to the subspecies, even if the protections afforded 
the subspecies under Colorado and Wyoming laws are removed.
    Numerous State lands (CDOW lands, State Park lands, State Land 
Board lands) and mitigation properties (such as those of the Colorado 
Department of Transportation) would continue to provide a measure of 
protection for the Preble's meadow jumping mouse should it be delisted. 
While some conservation properties may have management specifically 
designed to preserve and enhance Preble's meadow jumping mouse habitat, 
others concentrate more on open-space preservation and general 
wildlife-habitat conservation.
    State programs have been available to help preserve the Preble's 
meadow jumping mouse through the acquisition, preservation, and 
management of its habitat. These include the Great Outdoors Colorado 
Trust Fund and the Species Conservation Trust Fund. In comments to the 
Service, then Colorado Department of Natural Resources Commissioner, 
Russell George, stated that State and local initiatives could provide 
for conservation of the Preble's meadow jumping mouse, independent of 
Federal oversight. He listed nearly 40 conservation projects in 5 Front 
Range Colorado counties where the Preble's meadow jumping mouse ``may 
be present'' (George 2004). The conservation value of many of these 
projects is uncertain since most were developed without specific regard 
to the Preble's meadow jumping mouse's distribution and its 
conservation.
    Local Protections. At the time of listing, we pointed out that 
while a myriad of regional or local regulations, incentive programs, 
and open-space programs existed, especially in Colorado, few 
specifically protected the Preble's meadow jumping mouse or its habitat 
from inadvertent or intentional adverse impacts (63 FR 26517, May 13, 
1998). Many local regulations create a process of site-plan review that 
``considers'' or ``encourages'' conservation of wildlife, wetlands, and 
other natural habitats. Effectiveness of local regulations in 
maintaining naturally functioning riparian corridors varies greatly 
depending on how these apparently flexible regulations are implemented. 
Following listing under the Act, development and other projects in and 
near Preble's meadow jumping mouse habitat have received increased 
scrutiny from local jurisdictions, often in coordination with Service 
authorities. Open-space acquisitions and easements have also taken the 
presence of the Preble's meadow jumping mouse into account. It is not 
clear what level of interest in Preble's meadow jumping mouse 
conservation would continue following delisting. Local governments 
would likely relax review procedures for projects in known or suspected 
Preble's meadow jumping mouse habitat. Beyond the direct impact to 
Preble's meadow jumping mouse habitat, secondary impacts of development 
(including increased recreational use, altered flow regimes and 
groundwater levels, and increase in domestic predators) are unlikely to 
be adequately addressed. While certain local regulations are designed 
to conserve wetlands or floodplains on private lands, it is unlikely 
they would effectively control land uses (grazing, mowing, cutting, and 
burning) that may affect the hydrology, vegetation, and hibernacula 
sites on which Preble's depends. The adequacy of such protective 
measures is more important within Colorado than Wyoming given the 
intense development pressures in the Colorado counties where the 
Preble's meadow jumping mouse occurs.
    Douglas County, Colorado, owns 14 properties that encompass 24 km 
(15 mi) of stream and associated riparian habitats potentially 
beneficial to the Preble's meadow jumping mouse (Matthews 2004). Of 
Douglas County streams on non-Federal property within the Riparian 
Conservation Zone, 105 km (65 mi), or 23 percent, are under some form 
of permanent protection (Matthews 2004). However, occurrence of the 
Preble's meadow jumping mouse on many of these properties has not been 
extensively documented. For example, while there are 23.4 km (14.5 mi) 
of mapped riparian corridors on the large Greenland Ranch conservation 
property, the presence of the Preble's meadow jumping mouse has been 
documented at only two sites. Future conservation efforts to augment 
protected areas and to link protection over large expanses of connected 
streams in Douglas County could contribute greatly to maintaining 
secure Preble's meadow jumping mouse populations in the Upper South 
Platte and Middle South Platte--Cherry Creek drainages. Should the 
Preble's meadow jumping mouse be delisted, management priorities on 
protected lands and direction of future conservation efforts would 
likely change. In order to ensure long-term management for the Preble's 
meadow jumping mouse, the Preliminary Draft Recovery Plan suggests the 
Service and our partners develop and implement long-term management 
plans and cooperative agreements prior to delisting (Service 2003b, pp. 
iv, 33, 39, 47-47, 51-52).
    Larimer County has acquired or secured easements to considerable 
lands, including some properties under the Laramie Foothills Project, 
in partnership with The Nature Conservancy, the City of Fort Collins, 
and the Legacy Land Trust. While conservation efforts have increased, 
especially in the Livermore Valley, residential development remains the 
largest threat to Preble's in the county (Pague 2007). The extent to 
which Preble's meadow jumping mouse populations are supported by these 
properties, the fate of remaining private lands in the North Fork Cache 
La Poudre River and its tributaries, and the ability to link 
conservation lands and traditional agricultural lands supporting the 
Preble's meadow jumping mouse along stream reaches are key to 
protecting the potentially large Preble's meadow jumping mouse 
population thought to exist in this area.
    The City of Boulder, Boulder County, and Jefferson County have 
extensive lands protected under their open-space programs. While the 
extent of known Preble's meadow jumping mouse occurrences in these 
counties is limited compared to that documented in Larimer and Douglas 
Counties, known populations exist on open space protected from 
residential and commercial development.
    Summary. In the absence of the Act's protective measures, Federal 
conservation efforts for the Preble's meadow jumping mouse would be

[[Page 63015]]

largely limited to Federal properties, where the subspecies may be 
maintained as a priority subspecies and conserved through existing or 
future management plans.
    While state regulations in both Colorado and Wyoming would regulate 
killing of Preble's meadow jumping mice, as noted in Factor B above, we 
do not view this as a significant concern driving the subspecies long-
term conservation status. If delisted, State and local regulations 
would do little to conserve the Preble's meadow jumping mouse or its 
habitat on private lands. Public land holdings, conservation easements, 
and other conservation efforts, past and future, could support the 
Preble's meadow jumping mouse on specific sites.
    In Colorado, the extent and pattern of conservation efforts in 
relation to Preble's meadow jumping mouse distribution, and the 
appropriate management of Preble's meadow jumping mouse habitat, would 
largely dictate the long-term viability of Preble's meadow jumping 
mouse populations. At this time, no large populations and few medium 
populations, as described in the Preliminary Draft Recovery Plan, are 
known to exist in Colorado on contiguous stream reaches that are secure 
from development. Management plans that specifically address threats to 
the Preble's meadow jumping mouse are few, and management priorities 
would likely change if we were to delist the subspecies. Much of the 
intervening private lands would likely be subject to development within 
the foreseeable future (this issue is described in more detail in 
Factor A above). If we were to delist the subspecies, given current and 
projected levels of protections, we believe that most Preble's meadow 
jumping mouse populations in Colorado would not be secure into the 
foreseeable future.
    In Wyoming, the best available scientific and commercial 
information suggests that at least one large population and two medium 
populations occur in the State as recommended in the Preliminary Draft 
Recovery Plan (Service 2003b, pp. 19, 22). While regulatory measures in 
Wyoming do not guarantee protection of these populations, such 
assurances are not needed because threats to the Preble's meadow 
jumping mouse and the subspecies' habitat are limited for the 
foreseeable future.

E. Other Natural or Manmade Factors Affecting the Subspecies' Continued 
Existence

    At the time of listing, we judged this subspecies susceptible to a 
number of other factors, including impact from naturally occurring 
events such as fire and flooding, invasive weeds and weed control 
programs, pesticides and herbicides, and secondary impacts associated 
with human-caused development (63 FR 26517, May 13, 1998). For most of 
these factors, we have little more information than we had at the time 
of listing. Additional concerns that were not considered at the time of 
listing include the potential for competition between the Preble's 
meadow jumping mouse and the western jumping mouse, and future effects 
of changing climate on the Preble's meadow jumping mouse.
    Flooding and fire are natural components of the Wyoming and 
Colorado foothills and plains, and Preble's meadow jumping mouse 
habitat naturally waxes and wanes with these events. While these 
natural events may affect Preble's meadow jumping mouse populations by 
killing individuals and by destroying riparian and adjacent upland 
habitat on which they depend, the effects to vegetation are often 
temporary. Normal flooding and fire events also may help maintain the 
vegetative communities that provide suitable habitat for the Preble's 
meadow jumping mouse. Increase in impervious surfaces and denuding of 
vegetation caused by human activity can result in increased frequency 
and severity of flood events and prevent the re-establishment of 
favored riparian communities. An extreme flood event may eliminate an 
entire Preble's meadow jumping mouse population in an affected stream 
reach or drainage.
    Periodic fire may be of value in maintaining riparian, 
transitional, and upland vegetation within Preble's meadow jumping 
mouse habitat. In a review of the effects of grassland fires on small 
mammals, Kaufman et al. (1990) found a positive effect of fire on 
meadow jumping mice in one study and no effect on the species in 
another study. Fire may regenerate decadent willow (Salix sp.) stands 
along streams and encourage higher stem densities considered more 
favorable to the Preble's meadow jumping mouse.
    Long periods of fire suppression result in fuel build-up, 
especially in forested areas, and can result in catastrophic fires that 
alter habitat dramatically, change the structure and composition of the 
vegetative communities, and potentially affect large numbers of 
Preble's meadow jumping mice or multiple populations. Following more 
intense fires, precipitation in a burned area may degrade Preble's 
meadow jumping mouse habitat by causing greater levels of flooding, 
erosion, and sedimentation along creeks. As habitat redevelops, it will 
likely be reoccupied by the Preble's meadow jumping mouse, assuming 
that there are occupied, connected stream reaches where sufficient 
Preble's meadow jumping mouse populations have continued to persist.
    An example of catastrophic fire in Preble's meadow jumping mouse 
habitat occurred in 2002. The Hayman and Schoonover fires in Jefferson 
and Douglas Counties, Colorado, encompassed over 3,000 ha (7,500 ac) of 
potential Preble's meadow jumping mouse habitat, or approximately 20 
percent of the potential habitat within the boundaries of Pike National 
Forest (Mike Elson 2003). Approximately 342 ha (844 ac) of proposed 
critical habitat were burned. While riparian habitat that was lightly 
burned was expected to recover relatively quickly, increases in erosion 
and sedimentation downstream have been severe, and may continue to 
affect Preble's meadow jumping mouse habitat for several years. Because 
of severe fire-related impacts, we withdrew from the final critical 
habitat designation for the Preble's meadow jumping mouse (68 FR 37275, 
June 23, 2003) a portion of Gunbarrel Creek that we had proposed as 
critical habitat for the subspecies before the Hayman fire. Even prior 
to the Hayman and Schoonover fires, Pague and Granau (2000) considered 
catastrophic fire to be a high-priority issue for Douglas County.
    We believe fire has the potential to affect the Preble's meadow 
jumping mouse populations both directly and indirectly. The intensity, 
extent, and location of any fire event will likely dictate the severity 
of the impact to the Preble's meadow jumping mouse. Catastrophic fire 
events are, by their nature, rare.
    Invasive, noxious plants can encroach upon a landscape, displace 
native plant species, form monocultures of vegetation, and may 
negatively affect food and cover for the Preble's meadow jumping mouse. 
The control of noxious weeds may entail large-scale removal of 
vegetation and mechanical mowing operations, which also may affect the 
Preble's meadow jumping mouse. The tolerance of the Preble's meadow 
jumping mouse for invasive plant species remains poorly understood. 
Leafy spurge (Euphorbia esula) may form a monoculture, displacing 
native vegetation and thus reducing available

[[Page 63016]]

habitat (Selleck et al. 1962; Pague and Grunau 2000, p. 1-18). 
Nonnative species including tamarisk (Tamarix ramosissima) and Russian 
olive (Elaeagnus angustifolia) may adversely affect the Preble's meadow 
jumping mouse (Garber 1995, p. 16; Pague and Grunau 2000, p. 1-18). 
Existing special regulations at 50 CFR 17.40(1) exempt take incidental 
to noxious weed control. We instituted this exemption to recognize that 
control of noxious weeds is likely to produce long-term benefits to 
native vegetation supportive of the Preble's meadow jumping mouse.
    It remains unknown to what extent point and non-point source 
pollution (sewage outfalls, spills, urban or agricultural runoff) that 
degrades water quality in potential habitat may affect the abundance or 
survival of the Preble's meadow jumping mouse. Likewise, it is unknown 
whether pesticides and herbicides, commonly used for agricultural and 
household purposes within the range of the Preble's meadow jumping 
mouse, pose a threat to Preble's meadow jumping mice directly, or 
through their food supply, including possible bioaccumulation.
    Human-caused development creates a range of additional potential 
impacts (through human presence, noise, increased lighting, introduced 
animals, and the degradation of air and water quality) that could alter 
Preble's meadow jumping mouse behavior, increase the levels of stress, 
and ultimately contribute to loss of vigor or death of individuals, and 
extirpation of populations. Introduced animals associated with human 
development may displace, prey upon, or compete with the Preble's 
meadow jumping mouse. Feral cats and house mice were common in and 
adjacent to historical capture sites where Preble's meadow jumping mice 
were no longer found (Ryon 1996, p. 26). While no cause and effect 
relationship was documented, the Preble's meadow jumping mouse was 13 
times less likely to be present at sites where house mice were found 
(Clippinger 2002, p. 104). We have an incomplete understanding of the 
mechanisms by which the breadth of human-caused development impacts 
Preble's meadow jumping mouse populations. However, the absence of 
Preble's meadow jumping mouse populations in portions of Colorado 
drainages where riparian habitat appears relatively favorable but human 
encroachment is pervasive suggests a potential cause-and-effect 
relationship. A combination of factors in addition to habitat loss may 
contribute to local extirpations.
    Colorado's Comprehensive Wildlife Conservation Strategy lists 
``scarcity'' as a threat to meadow jumping mice that may lead to 
inbreeding depression (CDOW 2006, p. 102). Small populations can be 
threatened by stochastic, or random, changes in a wild population's 
demography or genetics (Brussard and Gilpin 1989, pp. 37-48; Caughley 
and Gunn 1996, pp. 165-189). A stochastic demographic change in small 
populations, such as a skewed age or sex ratio (for example, a loss of 
adult females), can negatively affect reproduction and increase the 
chance of extirpation. Isolation of populations may disrupt gene flow 
and create unpredictable genetic effects that could impact Preble's 
meadow jumping mouse persistence in a given area. While the 
susceptibility of the Preble's meadow jumping mouse to such events has 
not been researched, the documented tendency for Preble's meadow 
jumping mouse populations to vary widely over time heightens concern 
for small and isolated populations. The lowest population numbers of 
Preble's meadow jumping mice more accurately reflect potential 
vulnerability than typical or average population numbers present. 
Although many trapping efforts have targeted Preble's meadow jumping 
mice in small, isolated reaches of habitat, few have documented 
presence. As noted above, we believe populations in Colorado would be 
at higher risk because development pressures in this portion of the 
range are more likely to result in small, fragmented and unsustainable 
populations.
    The relative ranges, abundance, and relationship between the 
Preble's meadow jumping mouse and the western jumping mouse are not yet 
clearly understood, especially in Wyoming. Recent confirmation of 
extensive range overlap in Wyoming and the apparent predominance of the 
western jumping mouse in some southern Wyoming drainages with few or no 
Preble's meadow jumping mice, provide reason for concern. It is unknown 
whether western jumping mice are actively competing with Preble's 
meadow jumping mice, affecting Preble's meadow jumping mouse population 
size and possibly limiting distribution, or if this distribution 
patterns is unrelated to their interaction. Additional study of this 
issue would be desirable. Although questions remain, we do not have 
sufficient information to indicate this is a threat to the Preble's 
meadow jumping mouse in any portion of its range.
    Impacts to the Preble's meadow jumping mouse under predicted future 
climate change are unclear. A trend of warming in the mountains of 
western North America is expected to decrease snowpack, hasten spring 
runoff, and reduce summer flows (Intergovernmental Panel on Climate 
Change 2007, p. 10). Increased summer heat may increase the frequency 
and intensity of wildfires (Intergovernmental Panel on Climate Change 
2007, p. 14). Stream-flow reductions or seasonal changes in flow due to 
climate change will probably cause a greater disruption in watersheds 
with a high level of human development than in those with a lower level 
of development (Hurd et al. 1999, p. 1402). The three major river 
basins that support the Preble's meadow jumping mouse have heightened 
vulnerability to the effects of climate change due to the degree of 
human development, natural variability in stream-flow, ratio of 
precipitation lost to evapotranspiration, and groundwater depletion 
(Hurd et al. 1999, p. 1404). Conflicts between human needs for water 
and maintenance of existing wetland and riparian habitats will be 
heightened. Therefore, while it appears reasonable to assume that 
Preble's meadow jumping mouse may be affected, we lack sufficient 
certainty to know how climate change will affect the subspecies.
    Overall, the impacts associated with other natural or manmade 
factors affecting the Preble's meadow jumping mouse and the subspecies' 
habitat remain largely unassessed, and therefore, largely unknown. 
Although questions remain regarding these factors, we do not have 
sufficient information to indicate that these factors are a threat to 
Preble's meadow jumping mouse long-term conservation status. To the 
extent that meaningful impacts are possible, small and fragmented 
populations are likely to be more vulnerable.

Conclusion of the 5-Factor Analysis

    Is the Subspecies Threatened or Endangered throughout ``All'' of 
its Range--As required by the Act, we considered the five potential 
threat factors to assess whether the Preble's meadow jumping mouse is 
threatened or endangered throughout all or a significant portion of its 
range. When considering the listing status of the subspecies, the first 
step in the analysis is to determine whether the subspecies is in 
danger of extinction throughout all of its range. If this is the case, 
then we list the subspecies in its entirety. For instance, if the 
threats to a subspecies are directly acting on only a portion of its 
range, but they are at such a large scale that they place the entire

[[Page 63017]]

subspecies in danger of extinction, we would list the entire 
subspecies.
    Destruction and modification of habitat and the resulting 
curtailment of range is the most significant factor affecting the 
future conservation status of the subspecies. Within Wyoming, new 
distributional data and a better understanding of threats has altered 
our perception of the subspecies' status in this portion of its range. 
At the time of listing, data confirming the presence of the Preble's 
meadow jumping mouse was available for only a few sites in Wyoming. 
Since listing, additional distributional data has verified that the 
subspecies is widespread in the North Platte River basin with 
distribution across at least four drainages. Trapping efforts to date 
suggest that the subspecies may remain limited in number and 
distribution within the Wyoming portion of the South Platte River 
basin. An improved understanding of the subspecies' distribution 
suggests that historical agricultural activities, such as grazing and 
haying, have had a minimal impact on the subspecies to date. In short, 
continuation of these long-standing activities appears supportive of 
existing Preble's meadow jumping mouse populations. We have no 
indication these agricultural practices are likely to change in the 
foreseeable future in ways that would affect the subspecies' long-term 
conservation status. A low projected human population growth rate is 
predicted for the four Wyoming counties occupied by the Preble's meadow 
jumping mouse, suggesting that few development-related threats are 
likely in this portion of the subspecies' range into foreseeable 
future.
    Within Colorado, riparian habitat has been severely modified or 
destroyed by human activities. With current and projected human 
population increases and commensurate increases in urban and rural 
development, road construction, and water use, the ongoing loss and 
modification of riparian habitat will continue in much of the Preble's 
meadow jumping mouse Colorado range. Even with protection under the 
Act, development in Colorado has continued to affect Preble's meadow 
jumping mouse habitat, both directly and indirectly. Much of the 
Preble's meadow jumping mouse current range in Colorado is on private 
land. In the absence of the Act's protections, most of this habitat 
would be lost or made unsuitable within the foreseeable future. While 
appreciable lands in Colorado supporting the Preble's meadow jumping 
mouse are controlled by Federal or State agencies, or have been set 
aside as open space by local governments, many of these areas also are 
likely to experience habitat degradation in the absence of the Act's 
protections. Some of these areas will experience negative indirect 
effects from upstream development. Where conservation properties are 
not extensive, the Preble's meadow jumping mouse populations are likely 
to be small, fragmented, and unsustainable. Additional recovery efforts 
are required to provide such extensive contiguous conservation 
properties in Colorado.
    In contrast to Wyoming, our improved understanding of the 
subspecies' range in Colorado has not changed our conclusion as to the 
Preble's meadow jumping mouse's status in this portion of the 
subspecies' range. As noted above, new data have expanded the confirmed 
distribution of the Preble's meadow jumping mouse to include additional 
sites in Boulder, Douglas, El Paso, Jefferson, and Larimer Counties. 
Most of the newly discovered sites are subject to the same level of 
threats discussed above. Thus, unlike Wyoming, recently documented 
sites in Colorado do not meaningfully alter the future conservation 
status of the subspecies in this portion of its range.
    Besides ``present or threatened destruction, modification, or 
curtailment of its habitat or range,'' a variety of other factors were 
considered including: Overutilization, disease, predation, fire, 
flooding, invasive weeds, weed control programs, pesticides, 
herbicides, non-point source pollution, secondary impacts associated 
with human-caused development, scarcity, the potential for competition 
between the Preble's meadow jumping mouse and the western jumping 
mouse, and the future effects of climate change. The threats to the 
Preble's meadow jumping mouse from these factors are generally poorly 
understood and difficult to predict. Although questions remain 
regarding these factors, we do not have sufficient information to 
indicate that these factors are a threat to the subspecies long-term 
conservation status. To the extent that meaningful impacts are 
possible, these factors are likely to be more significant in areas 
where development pressures have or are likely to destroy or modify 
habitat resulting in small and fragmented populations. Thus, we expect 
these issues could be meaningful as cumulative impacts in the Colorado 
portion of subspecies' range where development pressures are high. In 
Wyoming, we expect these factors will continue to have only small, 
localized impacts on the subspecies.
    Based on a better understanding of distribution and threats, we 
find that the available data do not support the conclusion that the 
Preble's meadow jumping mouse is likely to become endangered in the 
foreseeable future throughout ``all'' of its range. We determine this 
because distributional data has verified that the subspecies is more 
widespread in the North Platte River basin of Wyoming than previously 
known, and we are not aware of any threats that are likely to have 
significant affects on the long-term conservation status of populations 
of Preble's meadow jumping mouse in Wyoming. We expect impacts to the 
Wyoming portion of the subspecies' range to be minor with only small 
and localized effects. We believe a lack of present or threatened 
impacts to the Preble's meadow jumping mouse in Wyoming suggests that 
this subspecies is neither in danger of extinction, nor likely to 
become endangered within the foreseeable future in this portion of its 
range. Threats in the Colorado portions of the subspecies' range, while 
severe, do not place the entire subspecies in danger of extinction 
within the foreseeable future. Thus, the Preble's meadow jumping mouse 
does not merit continued listing as threatened throughout ``all'' of 
its range.
    Is the Subspecies Threatened or Endangered in a Significant Portion 
of its Range--Having determined that the Preble's meadow jumping mouse 
does not meet the definition of threatened or endangered in all of its 
range, we must next consider whether there are any significant portions 
of the subspecies' range that are in danger of extinction or are likely 
to become endangered in the foreseeable future. On March 16, 2007, a 
formal opinion was issued by the Solicitor of the Department of the 
Interior, ``The Meaning of `In Danger of Extinction Throughout All or a 
Significant Portion of Its Range'' (U.S. Department of the Interior 
2007). We have summarized our interpretation of that opinion and the 
underlying statutory language below. A portion of a subspecies' range 
is significant if it is part of the current range of the subspecies and 
is important to the conservation of the subspecies because it 
contributes meaningfully to the representation, resiliency, or 
redundancy of the subspecies. The contribution must be at a level such 
that its loss would result in a decrease in the ability to conserve the 
subspecies.
    The first step in determining whether a subspecies is threatened or 
endangered in a significant portion of its range is to identify any 
portions of the range of the subspecies that warrant further 
consideration. The range of a subspecies can theoretically be divided

[[Page 63018]]

into portions in an infinite number of ways. However, there is no 
purpose to analyzing portions of the range that are not reasonably 
likely to be both significant and either threatened or endangered. To 
identify those portions that warrant further consideration, we 
determine whether there is substantial information indicating that (1) 
the portions may be significant, and (2) the subspecies may be in 
danger of extinction there or likely to become so within the 
foreseeable future. In practice, a key part of this analysis is whether 
the threats are geographically concentrated in some way. If the threats 
to the subspecies are essentially uniform throughout its range, no 
portion is likely to warrant further consideration. Moreover, if any 
concentration of threats applies only to portions of the range that are 
unimportant to the conservation of the subspecies, such portions will 
not warrant further consideration.
    If we identify any portions that warrant further consideration, we 
then determine whether in fact the subspecies is threatened or 
endangered in any significant portion of its range. Depending on the 
biology of the subspecies, its range, and the threats it faces, it may 
be more efficient for the Service to address the significance question 
first, or the status question first. Thus, if the Service determines 
that a portion of the range is not significant, the Service need not 
determine whether the subspecies is threatened or endangered there; if 
the Service determines that the subspecies is not threatened or 
endangered in a portion of its range, the Service need not determine if 
that portion is significant.
    The terms ``resiliency,'' ``redundancy,'' and ``representation'' 
are intended to be indicators of the conservation value of portions of 
the range. Resiliency of a subspecies allows the subspecies to recover 
from periodic disturbances. A subspecies will likely be more resilient 
if large populations exist in high-quality habitat that is distributed 
throughout the range of the subspecies in such a way as to capture the 
environmental variability found within the range of the subspecies. It 
is likely that the larger size of a population will help contribute to 
the viability of the subspecies overall. Thus, a portion of the range 
of a subspecies may make a meaningful contribution to the resiliency of 
the subspecies if the area is relatively large and contains 
particularly high-quality habitat or if its location or characteristics 
make it less susceptible to certain threats than other portions of the 
range. When evaluating whether or how a portion of the range 
contributes to resiliency of the subspecies, it may help to evaluate 
the historical value of the portion and how frequently the portion is 
used by the subspecies. In addition, the portion may contribute to 
resiliency for other reasons; for instance, it may contain an important 
concentration of certain types of habitat that are necessary for the 
subspecies to carry out its life-history functions, such as breeding, 
feeding, migration, dispersal, or wintering.
    Redundancy of populations may be needed to provide a margin of 
safety for the subspecies to withstand catastrophic events. This 
concept does not mean that any portion that provides redundancy is per 
se a significant portion of the range of a subspecies. The idea is to 
conserve enough areas of the range such that random perturbations in 
the system act on only a few populations. Therefore, we must examine 
each area based on whether that area provides an increment of 
redundancy that is important to the conservation of the subspecies.
    Adequate representation ensures that the subspecies' adaptive 
capabilities are conserved. Specifically, we should evaluate a portion 
to see how it contributes to the genetic diversity of the subspecies. 
The loss of genetically based diversity may substantially reduce the 
ability of the subspecies to respond and adapt to future environmental 
changes. A peripheral population may contribute meaningfully to 
representation if there is evidence that it provides genetic diversity 
due to its location on the margin of the subspecies' habitat 
requirements.
    Based on the discussion above, we readily identified the Colorado 
portion of the current range of the Preble's meadow jumping mouse as 
warranting further consideration to determine if it is a significant 
portion of the range that is threatened or endangered. Even with the 
new information confirming the extent of the range in Wyoming, the 
range in Colorado still constitutes the bulk of the current range, and 
the threats are largely concentrated in that portion.
    We had to consider the question of how to define the portion of the 
current range that we would consider further. We concluded that it was 
appropriate to consider all of the current range in Colorado as a 
single portion of the range for the purpose of this analysis. We 
believe the Wyoming/Colorado State line is an appropriate delineation 
for separating the populations in the two States here because the 
respective threats to the subspecies appear to be significantly 
different in the two states. While we could also consider splitting the 
subspecies into significant portions of the range based on river basins 
(i.e., only removing protections in the drainages of the North Platte 
River basin), we believe this would be more difficult to administer 
with little conservation benefit to the species. We believe removing 
protections in the Wyoming portion of the South Platte River basin 
(comprised of the Upper Lodgepole Creek drainage and portions of the 
Crow Creek and Lone Tree Creek drainages) would be of little biological 
consequence. While limited trapping data and analysis of museum 
specimens provide evidence of Preble's meadow jumping mouse occurrence 
in two of these drainages, trapping data also indicate that the western 
jumping mouse is much more widespread suggesting that in these 
drainages the Preble's meadow jumping mouse may simply be uncommon. 
Thus, given that any additional biological benefit to the subspecies is 
likely to be minimal and our assertion that the respective threats to 
the Preble's meadow jumping mouse appear to be significantly different 
in the two states we are instead proposing State lines as the northern 
boundary for the Colorado significant portions of range. We are 
accepting comments on this approach and may consider using river basins 
in a final rule should the available data demonstrate such an approach 
is more appropriate.
    Within Colorado, threats to the Preble's meadow jumping mouse are 
comparable between the South Platte River basin and Arkansas River 
basin. Similarly, threats to the Preble's meadow jumping mouse are 
comparable north and south of Denver. Because both of these possible 
partitions have a comparable status, further division of the 
subspecies' range between these two portions of its range in Colorado 
is unnecessary.
    Another possibility to consider is whether smaller units might be 
appropriate. For example, one could consider each individual drainage 
or each individual county. Given the best scientific and commercial 
information available, we do not believe such subdivisions would result 
in units that would each meaningfully contribute to the representation, 
resiliency, or redundancy of the subspecies at a level such that its 
loss would result in a decrease in the ability to conserve the 
subspecies. In our view, only when drainages or counties are aggregated 
are they significant per the above definition. The most logical 
aggregation of drainages is basins which are already considered above. 
The most logical aggregation of Counties within Colorado is a north and 
south of Denver split which is also already considered above.

[[Page 63019]]

Therefore, further division of the subspecies' range within Colorado is 
either not appropriate or unnecessary.
    To determine whether the Preble's meadow jumping mouse is 
threatened in any significant portion of its range, we first consider 
how the concepts of resiliency, representation, and redundancy apply to 
the conservation of this particular subspecies. The Preble's Meadow 
Jumping Mouse Preliminary Draft Recovery Plan provides some 
perspective. The Preliminary Draft calls for populations across the 
current range of the subspecies and because the Preble's meadow jumping 
mouse is a riparian-associated subspecies, contends that river 
drainages provide an appropriate geographic scale and unit for 
addressing their conservation. The Preliminary Draft states (Service 
2003b, p. 20), ``Species well-distributed across their historical range 
are less susceptible to extinction and more likely to reach recovery 
than species confined to a small portion of their range. Distributing 
populations throughout different drainages reduces the risk that a 
large portion of the range-wide population will be negatively affected 
by any particular natural or anthropogenic event at any one time. 
Spreading the recovery populations across hydrologic units throughout 
the range of the subspecies also preserves the greatest amount of the 
remaining genetic variation, and may provide some genetic security to 
the range-wide population.''
    In this case, projected losses of habitat in Colorado would 
meaningfully affect the representation, resiliency, or redundancy of 
the subspecies, making this portion of the range a significant portion 
of the range. The Colorado portion of the range includes:
     Two of the 3 river basins within the subspecies' range, 
amounting to approximately 65 percent of the subspecies' habitat by 
river-mile and total acreage (67 FR 47154, July 17, 2002);
     Thirteen (11 for which trapping has confirmed presence) of 
the 19 drainages comprising the range of the Preble's meadow jumping 
mouse (each of which should, according to the Preliminary Draft 
Recovery Plan, contain at least one population in order to achieve 
representation, resiliency, and redundancy) including 3 of the 4 
recommended large populations and 3 of the 5 recommended medium 
populations (Service 2003b, p. 22); and
     Genetic material substantially unique within the range of 
the Preble's meadow jumping mouse (King et al. 2006b, pp. 4336-4347).
    In conclusion, we believe that loss of the Preble's meadow jumping 
mouse within Colorado would result in a decrease in the ability to 
conserve the subspecies. We have determined that, based on its 
importance to the conservation of the subspecies and because it 
contributes meaningfully to Preble's meadow jumping mouse 
representation, resiliency, or redundancy, the Colorado portion of the 
range constitutes a significant portion of the subspecies' range as 
described in the Act.
    If we identify any portions as significant, we then determine 
whether in fact the subspecies is threatened or endangered in this 
significant portion of its range. This determination involves weighing 
the magnitude and immediacy of the threats. In our view, the cumulative 
magnitude of threat within Colorado is very high. Immediacy will vary 
geographically across the range. Some areas will be subject to imminent 
threats that would, in the absence of the Act's protections, extirpate 
populations in the near future. In other areas, direct and indirect 
impacts, in the absence of the Act's protections, will not result in 
extirpation for some time. Thus, based on the best scientific and 
commercial information available, we find that the Preble's meadow 
jumping mouse is likely to become endangered within the foreseeable 
future throughout the Colorado portion of its range.
    In conclusion, the best scientific and commercial data suggest that 
the Preble's meadow jumping mouse is not likely to become endangered in 
the foreseeable future throughout all of its range. We base this 
conclusion primarily on a lack of present or threatened impacts to the 
Preble's meadow jumping mouse or its habitat in Wyoming. Threats in the 
Colorado portions of the subspecies' range, while severe, do not place 
the entire subspecies in danger of extinction within the foreseeable 
future. However, based on the magnitude of development threats and 
other pressures to the populations throughout the Colorado portion of 
the range, and the lack of effective regulatory mechanisms in the 
absence of the Act's protective measures, we conclude that the 
significant portion of the subspecies' range within Colorado continues 
to meet the definition of threatened under the Act, and should remain 
listed. Therefore, we propose to amend the listing for the Preble's 
meadow jumping mouse to specify that the subspecies is threatened in 
the Colorado portion of its range only.
    Significant Portion of the Range Where the Subspecies Is 
Threatened--We propose to amend the list to specify that the Preble's 
meadow jumping mouse is threatened in a significant portion of its 
range. Therefore, we must describe that portion because it is the area 
where the protections of the Act would remain in place. As previously 
stated the range of a species is the general area in which the species 
can be found, including migratory corridors, seasonal habitats, and 
habitats used on a regular, though not necessarily seasonal, basis.
    The scale at which one defines the range of a particular species is 
fact and context dependant. In other words, whether one defines the 
range at a relatively course or fine scale depends on the life history 
of the species at issue, the data available, and the purpose for which 
one is considering range.
    The Preble's meadow jumping mouse is secretive, almost never 
observed without trapping, and relatively rare even where present. 
Confirmed occupancy is based almost entirely on intensive trapping 
efforts, requiring hundreds of traps set over multiple nights. Preble's 
meadow jumping mice are able to move miles along stream corridors over 
their lifetime (Ryon 1999; Shenk and Sivert 1999a), typically utilizing 
riparian (river) corridors. Although the subspecies commonly uses 
riparian vegetation immediately adjacent to a stream, other features 
that provide habitat for the subspecies include seasonal streams 
(Bakeman 1997), low moist areas and dry gulches (Shenk 2004), 
agricultural ditches (Meaney et al. 2003), and wet meadows and seeps 
near streams (Ryon 1996). Given records of confirmed presence and 
patterns of existing riparian habitat, we can draw inferences as to 
what we would consider occupied drainages or portions of these 
drainages.
    To date, aside from some earlier work from Colorado Department of 
Wildlife and the Colorado Natural Heritage Program, the objective of 
most trapping surveys has not been to document the limits of occupied 
habitat in Colorado. While much of the Preble's meadow jumping mouse's 
distribution is on private lands, most trapping surveys on private 
lands have been conducted by consultants based on anticipated 
development of the property by landowners (in compliance with section 7 
of the Act). This has resulted in far more trapping within the 
expanding development corridor than in rural lands where no current 
development is planned. Therefore, we have less assurance of current 
presence or potential absence of the Preble's meadow jumping mouse in 
areas east, south and west of the development corridor.

[[Page 63020]]

    Trapping can only confirm presence, not prove absence. At some 
sites, researchers have seen dramatic changes in estimated populations 
from season to season and year to year. A single trapping effort in any 
presumed occupied site could be unsuccessful if it corresponded to 
times when few or no animals are present. There is speculation that the 
Preble's meadow jumping mouse may move in and out of areas (individuals 
have been shown to move miles along stream corridors over their 
lifetime). In areas within the range of the subspecies, multiple trap 
efforts in a drainage or portions of a drainage are needed to provide 
strong evidence that Preble's meadow jumping mice are likely absent. 
Again, in many areas outside the Front Range development corridor 
trapping has been more limited and in some areas where presence has not 
been confirmed by trapping, we do not believe trapping data is 
determinative of Preble's presence at particular sites, much less whole 
drainages of portions thereof .
    As with other determinations under the Act, we do not define the 
current range on the basis of conclusive evidence; rather, we use the 
best available data. The purpose of defining range (and hence the 
significant portion of the range) is to set the boundaries of the 
protections of the Act. Therefore, defining the boundaries too narrowly 
may lead to the failure to protect some Preble's meadow jumping mice. 
On the other hand, drawing the boundaries relatively expansively will 
not lead to unnecessary expense on the part of the Service or the 
public because, as described in detail below, existing guidance on 
block clearance zones will remain in place. Therefore, in the context 
of describing the current range for the purpose of defining the scope 
of the listing for the Preble's meadow jumping mouse, we have 
determined that it is appropriate to use a relatively coarse scale to 
capture all of the areas where the best available data suggests the 
Preble's meadow jumping mouse is likely to occur.
    The Preliminary Recovery Plan suggests maintaining at least one 
recovery population within each drainage (to provide resiliency, 
representation, and redundancy) within the existing range of the 
subspecies. The Preliminary Recovery Plan, which represents the best 
available science, identifies thirteen drainages that comprise the area 
significant to the conservation of the subspecies including Big Sandy, 
Big Thompson, Bijou, Cache La Poudre, Clear Creek, Crow Creek, Fountain 
Creek Chico, Kiowa, Lone-Tree Owl, Middle South Platte--Cherry Creek, 
Saint Vrain, and Upper South Platte (as illustrated in figure 2). 
Recognizing that complete information is currently lacking that would 
definitively confirm the presence of existing Preble's meadow jumping 
mouse populations and suitable habitat in some drainages, these 
drainages have been included in the Preliminary Recovery Plan as 
representative of the current range of the subspecies on the 
presumption that at least a small population occurs in each. The intent 
of the Preliminary Recovery Plan was to preserve populations throughout 
the existing range to maximize the preservation of the remaining 
genetic diversity that may be present.
    For convenience in distinguishing this boundary on-the-ground we 
employ latitude and longitude coordinates. We believe the latitude and 
longitude boundaries below provide an appropriate delineation for the 
significant portion of the Preble's meadow jumping mouse range in 
Colorado. These boundaries are inclusive of all areas likely to support 
Preble's meadow jumping mouse populations in Colorado. As a result, all 
records confirming Preble's meadow jumping mouse occurrence in Colorado 
are captured within these boundaries. We believe that it is highly 
unlikely that there will be discovery of currently existing Preble's 
meadow jumping mouse populations outside these boundaries in Colorado. 
Therefore, we believe removing protections outside these boundaries 
would be of little biological consequence. Thus, based on best 
available data, we have identified the portion of Colorado west of 103 
degrees 40 minutes West, north of 38 degrees 30 minutes North, and east 
of 105 degrees 50 minutes West as the significant portion of the range 
of the subspecies (illustrated in figure 2).
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[[Page 63021]]

[GRAPHIC] [TIFF OMITTED] TP07NO07.001

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    Eastern boundary (103 degrees, 40 minutes west)--This boundary is 
inclusive of all areas within the current survey guidelines (east to a 
north-south

[[Page 63022]]

line through Fort Morgan, Morgan County) and also includes the eastern 
extent of the Big Sandy drainage (designated in the draft of the 
recovery plan).
    Southern Boundary (38 degrees, 30 minutes north)--This boundary is 
inclusive of all areas within the current survey guidelines (south 
including all of El Paso County) and also includes the majority of the 
Fountain Creek and Chico Creek drainages (designated in the draft of 
the recovery plan). Habitat in the southern portion of El Paso County 
is limited. The small portions of the Fountain and Chico drainages that 
fall outside the boundary are outside the current survey guidelines and 
believed not to support Preble's.
    Western boundary (105 degrees 50 minutes west)--This boundary is 
inclusive of elevations to 7,600 feet (2,316 meters) in the Cache La 
Poudre River, Clear Creek and Upper South Platte drainages and all 
portions of the Big Thompson and St. Vrain drainages.
    Administrative Processes--As part of our management of the 
subspecies on-the-ground within this significant portion of range area, 
the Service will continue to utilize block clearance zones to eliminate 
unnecessary processes (e.g., compliance with section 7 of the Act) 
while protecting the listed species. In designating a block clearance 
zone, the Service eliminates the need for individuals or agencies to 
coordinate with the Service prior to conducting activities at locations 
within the Preble's meadow jumping mouse range. The establishment of 
these block clearance zones is based on the likely absence of the 
subspecies within the area, and little likelihood that any of the area 
would be of importance to the recovery of the subspecies. Block 
clearance zones have been approved for the Denver metropolitan area 
(including most of Denver County and portions of Adams, Arapahoe, 
Boulder, Broomfield, Douglas, and Jefferson Counties) and along 
Monument, Cottonwood, and Sand Creeks in the Colorado Springs area. 
While this substantially reduces the regulatory burden, should an 
individual Preble's meadow jumping mouse be found in a block-cleared 
area, it would be fully protected under the Act. In addition, outside 
of the block clearance zone, but within the SPR, we would continue to 
identify, on a project-by-project basis, whether surveys for the 
Preble's meadow jumping mouse are needed based on whether suitable 
habitat is present within the action area of the project.
    We considered excluding block clearance zones from the listing as 
outside the current range of the subspecies, but we believe that 
approach would be impractical and ill-advised. For example, Preble's 
meadow jumping mouse block clearance zones expand on a near annual 
basis. If a revision to the Code of Federal Regulations was required to 
achieve this revision, the process would require annual proposed and 
final rules. This would be both unwieldy from a workload perspective 
and result in an unnecessary delay in reducing our regulatory oversight 
as this process typically takes a year to complete. Furthermore, the 
listing backlog (i.e., a shortfall of funds that preclude the listing 
of species that are warranted-but-precluded from threatened or 
endangered status and the designation of critical habitat) would 
preclude relisting areas even if future information suggests the area 
was removed prematurely (unless emergency listing was deemed 
appropriate). This double standard as well as the difficult and time-
consuming nature of the process suggests this approach is not 
realistic, not desirable, and inappropriate. As we have in the past, 
the Service will consider modification of the current block-clearance 
zones, or the addition of new zones, when the available data 
demonstrate such an action is appropriate.
    The above discussion relating to specifying a significant portion 
of the range of the Preble's meadow jumping mouse as threatened 
represents our current thinking based on the data we now have 
available. However, this is our first proposal to specify such a 
portion since issuance of the opinion of the Solicitor's Office on this 
topic on March 16, 2007. Thus, we note that we will be considering 
alternative formulations and analyses before issuing a final 
determination, and the final determination may vary in its particulars 
from this proposed rule.
    We particularly invite data, analyses, and other comments regarding 
the following issues:
    (1) What is the current range of the Preble's meadow jumping mouse? 
In the absence of confirmation of presence of Preble's meadow jumping 
mouse by trapping, what information is sufficient for the Service to 
determine that, based on the best data available, an area is part of 
the current range of the subspecies?
    (2) On how fine or coarse a scale should we define the portion of 
the range that we may specify as both significant and threatened? 
Theoretically, the scale could be as coarse as the entire state of 
Colorado, or as fine as the scale used in critical habitat 
designations. For the reasons discussed above, this proposed rule is 
based on an intermediate scale.
    (3) How should the boundaries of the portion of the range at issue 
be defined? By latitude and longitude lines? By drainage boundaries? By 
county lines? By reference to particular streams? By some other means?
    (4) Is it appropriate to use the Colorado/Wyoming border to divide 
the range of the subspecies? If the Preble's meadow jumping mouse in 
particular sites within Colorado (particularly those adjacent to the 
border with Wyoming) are not threatened, should they be included within 
the significant portion of the range specified as threatened? Likewise, 
if the Preble's meadow jumping mouse in particular sites within Wyoming 
(particularly those adjacent to the border with Colorado) are 
threatened, should they be included within the significant portion of 
the range specified as threatened?
    (5) If we use a relatively coarse scale to define the current range 
of the subspecies, how should we address an area within that range if 
we have information suggesting that the subspecies does not currently 
occupy--or has never actually occupied--that particular area within its 
overall range? Should those areas be geographically excluded from the 
significant portion of the range specified as threatened? Or are those 
areas best addressed through administrative implementation, such as the 
block clearance zones described above? What impacts to the subspecies, 
the public, and the Service will result from employing each of the 
possible strategies?
    (6) If we determine to define the portion of the range specified as 
threatened as excluding areas (at the appropriate scale) that the best 
data available suggests are not currently occupied by the Preble's 
meadow jumping mouse, how should we do that? Should such areas (for 
example, parts of the Denver metropolitan area) be mapped, or excluded 
by narrative text? What sort of boundaries would be available for 
defining such areas as not part of the range specified as threatened? 
What purposes would be served by adding to the complexity of the 
listing rule? What purposes would be served by reducing the complexity 
of the listing rule?
    (7) Is it appropriate to aggregate all of the current range of the 
Preble's meadow jumping mouse in Colorado into one portion for the 
purpose of this analysis? If particular sites within Colorado are not 
independently significant portions of the range of the Preble's meadow 
jumping mouse, should they still be considered part of

[[Page 63023]]

the portion of the range that is collectively significant?
    Depending on the comments received during the public comment period 
and our further analysis of these issues, the final determination could 
incorporate any of the possible answers to these questions.

Effects of the Proposed Rule

    If finalized, this action would amend the listing for the Preble's 
meadow jumping mouse by specifying that the subspecies is threatened in 
the Colorado portion of its range. This action also would eliminate 
critical habitat (June 23, 2003, 68 FR 37275) in Wyoming. Additionally, 
the take exemptions of the 4(d) species rule would no longer be 
necessary, and therefore would no longer apply, in Wyoming (May 22, 
2001, 66 FR 28125; October 1, 2002, 67 FR 61531; May 20, 2004, 69 FR 
29101). Thus, the prohibitions and conservation measures provided by 
the Act would no longer apply to this subspecies in Wyoming. Federal 
agencies would no longer be required to consult with us to insure that 
any action they authorize, fund, or carry out in Wyoming would not 
likely jeopardize the continued existence of the subspecies or result 
in destruction or adversely modify critical habitat in Wyoming. 
However, to the extent an activity in Wyoming would adversely affect 
the subspecies or critical habitat within its range listed in Colorado, 
consultation under section 7 would still be required.

Future Conservation Measures

    No specific preservation or management programs exist for the 
Preble's meadow jumping mouse in Wyoming. We believe that sufficient 
habitat will remain in Wyoming over the foreseeable future to allow for 
the continued viability of this subspecies. In the significant portion 
of the range within Colorado, the Preble's meadow jumping mouse would 
continue to be protected under the Act.

Peer Review

    In accordance with our peer review policy published in the Federal 
Register on July 1, 1994 (59 FR 34270) and the Office of Management and 
Budget's (OMB) Final Information Quality Bulletin for Peer Review, we 
seek the expert opinions of appropriate and independent specialists 
regarding this proposal. In this case, we will seek the comments of two 
sets of reviewers. First, we will contact the same five experts invited 
to provide comments on the previous proposed rule (70 FR 5404, February 
2, 2005; 71 FR 8556, February 17, 2006; 71 FR 16090, March 30, 2006). 
The selected reviewers were selected for their expertise in genetics, 
systematics, and small mammals. We will ask these reviewers to review 
this proposal's taxonomic discussion. Second, we will contact an 
additional five experts to review the remainder of this proposal. We 
will select reviewers for expertise in small-mammal biology, riparian-
community ecology and status, population dynamics and extinction risk, 
and/or development trends and land-use conflicts. The purpose of such 
review is to ensure that we base our final decision on scientifically 
sound data, assumptions, and analyses. We will send copies of this 
proposed rule to these peer reviewers immediately following publication 
in the Federal Register. We will invite these peer reviewers to 
comment, during the public comment period, on the specific assumptions 
and conclusions regarding our revised proposal. We will consider all 
comments and information received during the comment period on this 
proposed rule during preparation of a final rulemaking. Accordingly, 
the final decision may differ from this proposed rule.

Clarity of the Rule

    We are required by Executive Orders 12866 and 12988 and by the 
Presidential Memorandum of June 1, 1998, to write all rules in plain 
language. This means that each rule we publish must:
    (a) Be logically organized;
    (b) Use the active voice to address readers directly;
    (c) Use clear language rather than jargon;
    (d) Be divided into short sections and sentences; and
    (e) Use lists and tables wherever possible.
    If you feel that we have not met these requirements, send us 
comments by one of the methods listed in the ADDRESSES section. To 
better help us revise the rule, your comments should be as specific as 
possible. For example, you should tell us the numbers of the sections 
or paragraphs that are unclearly written, which sections or sentences 
are too long, the sections where you feel lists or tables would be 
useful, etc.

Energy Supply, Distribution, or Use

    On May 18, 2001, the President issued an Executive Order (E.O. 
13211; Actions Concerning Regulations That Significantly Affect Energy 
Supply, Distribution, or Use) on regulations that significantly affect 
energy supply, distribution, and use. The E.O. 13211 requires agencies 
to prepare Statements of Energy Effects when undertaking certain 
actions. As this proposed rule is not expected to significantly affect 
energy supplies, distribution, or use, this action is not a significant 
energy action and no Statement of Energy Effects is required.

Paperwork Reduction Act

    This proposed rule does not contain any new collections of 
information that require approval by the Office of Management and 
Budget (OMB) under the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 
et seq.). This proposed rule will not impose recordkeeping or reporting 
requirements on State or local governments, individuals, businesses, or 
organizations. An agency may not conduct or sponsor, and a person is 
not required to respond to, a collection of information unless it 
displays a currently valid OMB control number.

National Environmental Policy Act

    The Service has determined that Environmental Assessments and 
Environmental Impact Statements, as defined under the authority of the 
National Environmental Policy Act of 1969, need not be prepared in 
connection with regulations adopted pursuant to section 4(a) of the 
Act. We published a notice outlining the Service's reasons for this 
determination was published in the Federal Register on October 25, 1983 
(48 FR 49244).

References

    A complete list of all references cited herein is available upon 
request from the Colorado Field Office (see ADDRESSES).

Author

    The primary authors of this document are staff located at the 
Colorado Field Office (see ADDRESSES).

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 
record keeping requirements, Transportation.

Proposed Regulation Promulgation

    Accordingly, we propose to amend part 17, subchapter B of chapter 
I, title 50 of the Code of Federal Regulations as set forth below.

PART 17--[AMENDED]

    1. The authority citation for part 17 continues to read as follows:

    Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C. 
4201-4245; Pub. L. 99-625, 100 Stat. 3500; unless otherwise noted.

    2. Amend Sec.  17.11(h) by revising the entry for ``Mouse, Preble's 
meadow jumping'' under ``MAMMALS'' in the

[[Page 63024]]

List of Endangered and Threatened Wildlife to read as follows:


Sec.  17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
                       Species                                                Vertebrate population
------------------------------------------------------    Historic range      where  endangered or        Status        When      Critical     Special
           Common name              Scientific name                                threatened                          listed     habitat       rules
--------------------------------------------------------------------------------------------------------------------------------------------------------
             Mammals
 
                                                                      * * * * * * *
Mouse, Preble's meadow jumping..  Zapus hudsonius      U.S.A. (CO, WY)....  U.S.A., north-central CO  T.............       636     17.95(a)     17.40(l)
                                   preblei.                                  (that portion of
                                                                             Colorado west of 103
                                                                             degrees 40 minutes
                                                                             West, north of 38
                                                                             degrees 30 minutes
                                                                             North, and east of 105
                                                                             degrees 50 minutes
                                                                             West).
 
                                                                      * * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------

    3. Amend Sec.  17.40(l) as follows:
    a. By revising paragraph (l)(2)(vi)(E) to read as set forth below; 
and
    b. By revising paragraph (l)(4) to read as set forth below.


Sec.  17.40  Special rules--mammals.

* * * * *
    (l) * * *
    (2) * * *
    (vi) * * *
    (E) Any future revisions to the authorities listed in paragraphs 
(l)(2)(vi)(A) through (D) of this section that apply to the herbicides 
proposed for use within the species' range as specified in Sec.  
17.11(h).
* * * * *
    (4) Where does this rule apply? The take exemptions provided by 
this rule are applicable within the range of the Preble's meadow 
jumping mouse as specified in Sec.  17.11(h).
* * * * *


Sec.  17.95  [Amended]

    4. In Sec.  17.95(a), amend the entry for ``Preble's Meadow Jumping 
Mouse (Zapus hudsonius preblei)'' by removing paragraphs (4) through 
(7), and by redesignating paragraphs (8) through (13) as (4) through 
(9), respectively.

    Dated: October 30, 2007.
H. Dale Hall,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 07-5486 Filed 11-1-07; 8:45 am]
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