[Federal Register Volume 78, Number 23 (Monday, February 4, 2013)]
[Proposed Rules]
[Pages 7863-7890]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-01478]



[[Page 7863]]

Vol. 78

Monday,

No. 23

February 4, 2013

Part II





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; Threatened Status for 
the Distinct Population Segment of the North American Wolverine 
Occurring in the Contiguous United States; Establishment of a 
Nonessential Experimental Population of the North American Wolverine in 
Colorado, Wyoming, and New Mexico; Proposed Rules

Federal Register / Vol. 78 , No. 23 / Monday, February 4, 2013 / 
Proposed Rules

[[Page 7864]]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[FWS-R6-ES-2012-0107: 4500030113]
RIN 1018-AY26


Endangered and Threatened Wildlife and Plants; Threatened Status 
for the Distinct Population Segment of the North American Wolverine 
Occurring in the Contiguous United States

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service, propose to list the 
distinct population segment of the North American wolverine occurring 
in the contiguous United States, as a threatened species under the 
Endangered Species Act. If we finalize this rule as proposed, it would 
extend the Act's protections to this species. The effect of this 
regulation is to add the distinct population segment of the North 
American wolverine occurring in the contiguous United States to the 
List of Endangered and Threatened Wildlife in our regulations. We also 
propose a special rule under section 4(d) of the Act to apply the 
specific prohibitions of the Act necessary to protect the wolverine. We 
find that critical habitat is not determinable at this time. The 
Service seeks data and comments from the public on this proposed 
listing rule, the proposed special rule under section 4(d) of the Act, 
and our finding that the designation of critical habitat for the 
species is not determinable at this time.

DATES: We will accept comments received or postmarked on or before May 
6, 2013. Comments submitted electronically using the Federal 
eRulemaking Portal (see ADDRESSES section, below) must be received by 
11:59 p.m. Eastern Time on the closing date. We must receive requests 
for public hearings, in writing, at the address shown in the ADDRESSES 
section by March 21, 2013.
    Public Informational Sessions and Public Hearing: We will hold 3 
public informational sessions and public hearings on this proposed 
rule. Public informational sessions will occur from 2:00 p.m. to 5:00 
p.m. and public hearings will be held from 7:00 p.m. to 9:00 p.m. at 
each location. Public informational sessions and public hearings will 
occur in Boise, ID, on March 13, 2013, from 7:00 p.m. to 9:00 p.m.; in 
Lakewood, CO, on March 19, 2013, from 7:00 p.m. to 9:00 p.m.; and in 
Helena, MT, on March 27, 2013, from 7:00 p.m. to 9:00 p.m., all times 
local (see ADDRESSES). Registration for those providing testimony in 
the public hearings will begin at 6:00 p.m. at each location.

ADDRESSES: You may submit comments by one of the following methods:
    (1) Electronically: Go to the Federal eRulemaking Portal: http://www.regulations.gov. In the Keyword box, enter Docket No. FWS-R6-ES-
2012-0107, which is the docket number for this rulemaking. Then, in the 
Search panel on the left side of the screen, under the Document Type 
heading, click on the Proposed Rules link to locate this document. You 
may submit a comment by clicking on Comment Now!''
    (2) By hard copy: Submit by U.S. mail or hand-delivery to: Public 
Comments Processing, Attn: FWS-R6-ES-2012-0107; Division of Policy and 
Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax 
Drive, MS 2042-PDM; Arlington, VA 22203.
    (3) At a public hearing: We are holding three public hearings on 
this proposed rule (see ADDRESSES for location information). You may 
provide your comments at any of the three hearings.
    We request that you send comments only by the methods described 
above. We will post all comments on http://www.regulations.gov. This 
generally means that we will post any personal information you provide 
us (see the Public Comments section below for more information).
    Public Informational Sessions and Public Hearings: Public 
informational sessions and public hearings will be held on March 13, 
2013, at the Boise Centre on the Grove, 850 West Front Street, Boise, 
ID 83702. The second is scheduled on March 19, 2013, at the Hampton 
Inn, 137 Union Boulevard, Lakewood, CO 80228. The third is scheduled on 
March 27, 2013, at the Red Lion Colonial Inn, 2301 Colonial Drive, 
Helena, MT 59601. At all three locations the public informational 
session will run from 2:00 p.m. to 5:00 p.m., followed by public 
speaker registration at 6:00 p.m., and then the public hearing for oral 
testimony from 7:00 p.m. to 9:00 p.m. People needing reasonable 
accommodations in order to attend and participate in the public hearing 
should contact Brent Esmoil, Montana Ecological Services Field Office, 
as soon as possible (see FOR FURTHER INFORMATION CONTACT).
    Any additional tools or supporting information that we may develop 
for this rulemaking will be available at http://www.fws.gov/mountain-prairie/species/mammals/wolverine/, at http://www.regulations.gov at 
Docket No. FWS-R6-ES-2012-0107, and at the Montana Field Office (see 
FOR FURTHER INFORMATION CONTACT).

FOR FURTHER INFORMATION CONTACT: Brent Esmoil, Field Supervisor 
(Acting), U.S. Fish and Wildlife Service, Montana Field Office, 585 
Shepard Way, Helena, Montana 59601, by telephone (406) 449-5225. 
Persons who use a telecommunications device for the deaf (TDD) may call 
the Federal Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

    Why we need to publish a rule. Under the Endangered Species Act of 
1973, as amended (16 U.S.C. 1531 et seq.) (Act or ESA), if a species is 
determined to be an endangered or threatened species throughout all or 
a significant portion of its range, we are required to promptly publish 
a proposal in the Federal Register and make a determination on our 
proposal within 1 year. Critical habitat shall be designated, to the 
maximum extent prudent and determinable, for any species determined to 
be an endangered or threatened species under the Act. Listing a species 
as an endangered or threatened species and designations and revisions 
of critical habitat can only be completed by issuing a rule.
    This rule consists of:
     A proposed rule to list the distinct population segment 
(DPS) of the North American wolverine occurring in the contiguous 
United States as a threatened species; and
     A proposed special rule under section 4(d) of the Act that 
outlines the prohibitions necessary and advisable for the conservation 
of the wolverine.
    A proposed rule under section 10(j) of the Act to establish an 
experimental non-essential population of wolverine in Colorado is 
published concurrently in this issue of the Federal Register. Also, a 
draft Recovery Outline for the wolverine DPS is available on our Web 
site at http://www.fws.gov/mountain-prairie/species/mammals/wolverine/ 
or on http://www.regulations.gov.
    The basis for our action. Under the Act, we can determine that a 
species is an endangered or threatened species based on any of five 
factors: (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range; (B) Overutilization for 
commercial, recreational, scientific, or educational purposes; (C) 
Disease or predation; (D) The inadequacy of existing regulatory 
mechanisms; or (E)

[[Page 7865]]

Other natural or manmade factors affecting its continued existence.
    We have determined that habitat loss due to increasing temperatures 
and reduced late spring snowpack due to climate change is likely to 
have a significant negative population-level impact on wolverine 
populations in the contiguous United States. In the future, wolverine 
habitat is likely to be reduced to the point that the wolverine in the 
contiguous United States is in danger of extinction.
    We will seek peer review. We are seeking comments from 
knowledgeable individuals with scientific expertise to review our 
analysis of the best available science and application of that science 
and to provide any additional scientific information to improve this 
proposed rule. Because we will consider all comments and information 
received during the comment period, our final determinations may differ 
from this proposal.

Information Requested

    We intend that any final action resulting from this proposed rule 
will be based on the best scientific and commercial data available and 
be as accurate and as effective as possible. Therefore, we request 
comments or information from the public, other concerned governmental 
agencies, Native American tribes, the scientific community, industry, 
or any other interested parties concerning this proposed rule. We 
particularly seek comments concerning:
    (1) Biological, commercial trade, or other relevant data concerning 
any threats (or lack thereof) to this species and regulations that may 
be addressing those threats.
    (2) Additional information concerning the historical and current 
status, range, distribution, and population size of this species, 
including the locations of any additional populations of this species.
    (3) Any information on the biological or ecological requirements of 
the species, and ongoing conservation measures for the species and its 
habitat.
    (4) Current or planned activities in the areas occupied by the 
species and possible impacts of these activities on this species.
    (5) The reasons why we should or should not designate habitat as 
``critical habitat'' under section 4 of the Act (16 U.S.C. 1531 et 
seq.) including whether and how the wolverine may benefit from such a 
designation; whether there are threats to the species from human 
activity, the degree to which it can be expected to increase due to a 
critical habitat designation, and whether that increase in threat 
outweighs the benefit of designation such that the designation of 
critical habitat may not be prudent;
    (6) Specific information on the amount and distribution of 
wolverine habitat,
    (7) Information on the projected and reasonably likely impacts of 
climate change on the wolverine and its habitat;
    (8) Suitability of the proposed 4(d) rule for the conservation, 
recovery, and management of the DPS of the North American wolverine 
occurring in the contiguous United States.
    (9) Additional information concerning whether it is appropriate to 
prohibit incidental take of wolverine in the course of legal trapping 
activities directed at other species in the proposed 4(d) rule, 
including any information about State management plans related to 
trapping regulations and any measures within those plans that may avoid 
or minimize the risk of wolverine mortality from incidental trapping 
for other species.
    (10) Additional provisions the Service may wish to consider to 
conserve, recover, and manage the DPS of the North American wolverine 
occurring in the contiguous United States.
    We will consider all comments and information received during the 
comment period on this proposed listing rule and special rule under 
section 4(d) of the Act during our preparation of a final 
determination. Accordingly, the final decision may differ from this 
proposal.
    Please note that submissions merely stating support for or 
opposition to the action under consideration without providing 
supporting information, although noted, will not be considered in 
making a determination, as section 4(b)(1)(A) of the Act directs that 
determinations as to whether any species is an endangered or threatened 
species must be made ``solely on the basis of the best scientific and 
commercial data available.''
    You may submit your comments and materials concerning this proposed 
rule by one of the methods listed in the ADDRESSES section. We request 
that you send comments only by the methods described in the ADDRESSES 
section.
    If you submit information via http://www.regulations.gov, your 
entire submission--including any personal identifying information--will 
be posted on the Web site. If your submission is made via a hardcopy 
that includes personal identifying information, you may request at the 
top of your document that we withhold this information from public 
review. However, we cannot guarantee that we will be able to do so. We 
will post all hardcopy submissions on http://www.regulations.gov. 
Please include sufficient information with your comments to allow us to 
verify any scientific or commercial information you include.
    Comments and materials we receive, as well as supporting 
documentation we used in preparing this proposed rule, will be 
available for public inspection on http://www.regulations.gov, or by 
appointment, during normal business hours, at the U.S. Fish and 
Wildlife Service, Montana Field Office (see FOR FURTHER INFORMATION 
CONTACT).

Previous Federal Actions

    On April 19, 1995, we published a finding (60 FR 19567) that a 
previous petition, dated August 3, 1994, submitted by the Predator 
Project (now named the Predator Conservation Alliance) and Biodiversity 
Legal Foundation to list the wolverine in the contiguous United States 
as an endangered or threatened species, did not provide substantial 
information indicating that listing the wolverine in the contiguous 
United States may be warranted.
    On July 14, 2000, we received a petition dated July 11, 2000, 
submitted by the Biodiversity Legal Foundation, Predator Conservation 
Alliance, Defenders of Wildlife, Northwest Ecosystem Alliance, Friends 
of the Clearwater, and Superior Wilderness Action Network, to list the 
wolverine within the contiguous United States as an endangered or 
threatened species and designate critical habitat for the species.
    On October 21, 2003, we published a 90-day finding that the 
petition failed to present substantial scientific and commercial 
information indicating that listing may be warranted (68 FR 60112).
    On September 29, 2006, as a result of a complaint filed June 8, 
2005 by Defenders of Wildlife and others alleging we used the wrong 
standards to assess the July 11, 2000, wolverine petition, the U.S. 
District Court, Montana District, ruled that our 90-day petition 
finding (68 FR 60112) was in error and ordered us to submit to the 
Federal Register a 12-month finding for the wolverine by September 29, 
2007. On April 6, 2007, the deadline for this 12-month finding was 
extended to February 28, 2008.
    On March 11, 2008, we published a 12-month finding of ``not 
warranted'' for the wolverine in the contiguous United States (73 FR 
12929). In that finding we determined that the wolverine in the 
contiguous United States did not constitute a distinct population 
segment or a significant portion of the range of a listable entity of 
the wolverine in

[[Page 7866]]

North America and so was not a listable entity under the Act.
    On July 8, 2008 we received a Notice of Intent to Sue from 
Earthjustice alleging violations of the Act in our March 11, 2008, 12-
month finding. On September 30, 2008, Earthjustice filed a complaint in 
the U.S. District Court, District of Montana, seeking to set aside and 
remand the 12-month finding back to the Service for reconsideration.
    On March 6, 2009, the Service agreed to settle the case with 
Earthjustice by voluntarily remanding the 12-month finding and issuing 
a new 12-month finding by December 1, 2010. Following the settlement 
agreement, the court dismissed the case on June 15, 2009, and ordered 
the Service to comply with the settlement agreement.
    On April 15, 2010, the Service published a Notice of Initiation of 
a 12-month finding for wolverines in the contiguous United States (75 
FR 19591). That finding was published on December 14, 2010, and 
determined that the wolverine in the contiguous United States 
constituted a Distinct Population Segment and that the DPS warranted 
listing under the Act, but that listing was precluded by higher 
priority listing actions (75 FR 78030).
    On September 9, 2011, we reached an agreement with plaintiffs in 
Endangered Species Act Section 4 Deadline Litig., Misc. Action No. 10-
377 (EGS), MDL Docket No. 2165 (D. DC) (known as the ``MDL case'') on a 
schedule to publish proposed rules or to withdraw warranted findings 
for the species on our list of candidate species. This agreement 
stipulated that we would submit for publication in the Federal Register 
a proposed listing rule for the wolverine, or withdraw the warranted 
12-month finding, no later than the end of the 2013 Fiscal Year.
    On April 13, 2012, several parties filed an action challenging the 
Service's December 14, 2010 warranted but precluded finding for 
wolverine. Cottonwood Envtl. Law Ctr., et al. v. Salazar, et al., 9:12-
cv-00057-DLC (D. Mont.) On September 20, 2012, the court granted the 
Service's motion to stay that litigation based on the Service's 
representation to the Court that it expected to submit this rule or 
withdraw the warranted finding to the Federal Register by January 18, 
2013.

Threatened Status for the Contiguous United States Wolverine DPS

Background

    It is our intent to discuss below only those topics directly 
relevant to the listing of the contiguous United States DPS of the 
North American wolverine as a threatened species in this section of the 
proposed rule.

Species Information

Taxonomy and Life History
    The wolverine has a Holarctic (habitats found in the northern 
continents) distribution including northern portions of Europe, Asia, 
and North America. The currently accepted taxonomy classifies 
wolverines worldwide as a single species, Gulo gulo, with two 
subspecies. Old World wolverines are found in the Nordic countries of 
Europe, Russia, and Siberia and are part of the subspecies Gulo gulo 
gulo. New World wolverines occur in North America. The wolverines in 
the contiguous United States are a part of the New World subspecies, G. 
g. luscus: the North American wolverine (Kurten and Rausch 1959 p. 19; 
Pasitschniak-Arts and Lariviere 1995, p. 1). The species is known by 
several common names, including mountain devil, glutton, caracajou, 
quickhatch, gulon, skunk bear, as well as wolverine.
    The wolverine is the largest terrestrial member of the family 
Mustelidae. Adult males weigh 12 to 18 kilograms (kg) (26 to 40 pounds 
(lb)), and adult females weigh 8 to 12 kg (17 to 26 lb) (Banci 1994, p. 
99). The wolverine resembles a small bear with a bushy tail. It has a 
broad, rounded head; short, rounded ears; and small eyes. Each foot has 
five toes with curved, semi-retractile claws used for digging and 
climbing (Banci 1994, p. 99).
    A large number of female wolverines (40 percent) are capable of 
giving birth at 2 years old, become pregnant most years, and produce 
average litter sizes of 1 to 2 kits. In one study of known-aged 
females, none reproduced at age 2; 3 of 10 first reproduced at age 3; 
and 2 did not reproduce until age 4. The average age at first 
reproduction was 3.4 years (Persson et al. 2006, pp. 76-77). Another 
study indicated that the average age at first reproduction is likely 
more than 3 years (Inman et al. 2007c, p. 70). Pregnant females 
commonly resorb or spontaneously abort litters prior to giving birth 
(Magoun 1985, pp. 30-31; Copeland 1996, p. 43; Persson et al. 2006, p. 
77; Inman et al. 2007c, p. 70). This may in turn preserve resources to 
increase reproductive success in subsequent years (Persson 2005, p. 
1456). By age 3, nearly all female wolverines become pregnant every 
year, but energetic constraints due to low food availability result in 
loss of pregnancy in about half of them each year. It is likely that, 
in many places in the range of wolverines, it takes 2 years of foraging 
for a female to store enough energy to successfully reproduce (Persson 
2005, p. 1456). It is likely that, despite the high rate of initiation 
of pregnancy, due to the spontaneous abortion of litters resulting from 
resource limitation, actual rates of successful reproduction in 
wolverines are among the lowest known for mammals (Persson 2005, p. 
1456).
    Supplemental feeding of females increases reproductive potential 
(Persson 2005, p. 1456). Food-supplemented females were also more 
successful at raising kits to the time of weaning, suggesting that 
wolverine reproduction and ultimately population growth rates and 
viability are food-limited. Female wolverines appear to use a complex 
strategy of food accumulation and caching to attain enough resources to 
successfully raise a litter (Inman et al. 2012b, pp. 640-641).
    Breeding generally occurs from late spring to early fall (Magoun 
and Valkenburg 1983, p. 175; Mead et al. 1991, pp. 808-811). Females 
undergo delayed implantation until the following winter or spring, when 
active gestation lasts from 30 to 40 days (Rausch and Pearson 1972, pp. 
254-257). Litters are born from mid-February through March, containing 
one to five kits, with an average in North America of between one and 
two kits (Magoun 1985, pp. 28-31; Copeland 1996, p. 36; Krebs and Lewis 
1999, p. 698; Copeland and Yates 2006, pp. 32-36; Inman et al. 2007c, 
p. 68).
    Female wolverines use natal (birthing) dens that are excavated in 
snow. Persistent, stable snow greater than 1.5 meters (m) (5 feet (ft)) 
deep appears to be a requirement for natal denning, because it provides 
security for offspring and buffers cold winter temperatures (Pulliainen 
1968, p. 342; Copeland 1996, pp. 92-97; Magoun and Copeland 1998, pp. 
1317-1318; Banci 1994, pp. 109-110; Inman et al. 2007c, pp. 71-72; 
Copeland et al. 2010, pp. 240-242). Female wolverines go to great 
lengths to find secure den sites, suggesting that predation is a 
concern (Banci 1994, p. 107). Natal dens consist of tunnels that 
contain well-used runways and bed sites and may naturally incorporate 
shrubs, rocks, and downed logs as part of their structure (Magoun and 
Copeland 1998, pp. 1315-1316; Inman et al. 2007c, pp. 71-72). In Idaho, 
natal den sites occur above 2,500 m (8,200 ft) on rocky sites, such as 
north-facing boulder talus or subalpine cirques (steep-walled 
semicircular basin carved by a glacier) in forest openings (Magoun and 
Copeland 1994, pp. 1315-1316). In Montana, natal dens occur above 2,400 
m (7,874 ft) and are located on north aspects in avalanche debris,

[[Page 7867]]

typically in alpine habitats near timberline (Inman et al. 2007c, pp. 
71-72). Offspring are born from mid-February through March and the dens 
are typically used through late April or early May (Myrberget 1968, p. 
115; Magoun and Copeland 1998, pp. 1314-1317; Inman et al. 2007b, pp. 
55-59). Occupation of natal dens is variable, ranging from 
approximately 9 to 65 days (Magoun and Copeland 1998, pp. 1316-1317).
    Females may move kits to multiple secondary (maternal) dens as they 
grow during the month of May (Pulliainen 1968, p. 343; Myrberget 1968, 
p. 115), although use of maternal dens may be minimal (Inman et al. 
2007c, p. 69). Timing of den abandonment is related to accumulation of 
water in dens (due to snow melt), the maturation of offspring, 
disturbance, and geographic location (Myrberget 1968, p. 115; Magoun 
1985, p. 73). After using natal and maternal dens, wolverines may also 
use rendezvous sites through early July. These sites are characterized 
by natural (unexcavated) cavities formed by large boulders, downed logs 
(avalanche debris), and snow (Inman et al. 2007c, pp. 55-56). Male 
wolverines likely mate with several females, and although they are not 
known to directly contribute to rearing young, they do tolerate 
subadult wolverines in their territories (usually their own offspring) 
until they reach maturity (Copeland 1996, p. 72).
Habitat, Space, and Food
    In North America, wolverines occur within a wide variety of alpine, 
boreal, and arctic habitats, including boreal forests, tundra, and 
western mountains throughout Alaska and Canada. The southern portion of 
the species' range extends into the contiguous United States, including 
high-elevation alpine portions of Washington, Idaho, Montana, Wyoming, 
California, and Colorado (Wilson 1982, p. 644; Hash 1987, p. 576; Banci 
1994, p. 102, Pasitschniak-Arts and Lariviere 1995, p. 499; Aubry et 
al. 2007, p. 2152; Moriarty et al. 2009, entire; Inman et al. 2009, pp. 
22-25). Wolverines do not appear to specialize on specific vegetation 
or geological habitat aspects, but instead select areas that are cold 
and receive enough winter precipitation to reliably maintain deep 
persistent snow late into the warm season (Copeland et al. 2010, 
entire). The requirement of cold, snowy conditions means that, in the 
southern portion of the species' range where ambient temperatures are 
warmest, wolverine distribution is restricted to high elevations, while 
at more northerly latitudes, wolverines are present at lower elevations 
and even at sea level in the far north (Copeland et al. 2010, Figure 
1).
    In the contiguous United States, wolverines likely exist as a 
metapopulation (Aubry et al. 2007, p. 2147, Figures 1, 3). A population 
is a group of interbreeding individuals of the same species. A 
metapopulation is a population composed of a network of semi-isolated 
subpopulations, each occupying a suitable patch of habitat in a 
landscape of otherwise unsuitable habitat (Pulliam and Dunning 1997, 
pp. 212-214). Metapopulations require some level of regular or 
intermittent migration and gene flow among subpopulations, in which 
individual subpopulations support one-another by providing genetic and 
demographic enrichment through mutual exchange of individuals (Meffe 
and Carroll 1997, p. 678). Individual subpopulations may go extinct or 
lose genetic viability, but are then ``rescued'' by immigration from 
other subpopulations, thus ensuring the persistence of the 
metapopulation as a whole. If metapopulation dynamics break down, 
either due to changes within subpopulations or loss of connectivity, 
then the entire metapopulation may be jeopardized due to subpopulations 
becoming unable to persist in the face of inbreeding or demographic and 
environmental stochasticity (Pulliam and Dunning 1997, pp. 221-222). 
The wolverine metapopulation in the DPS consists of a network of small 
subpopulations on mountain tops, some consisting of less than ten 
individuals. Persistence of subpopulations under these conditions 
requires movement between subpopulations across both suitable and 
unsuitable wolverine habitat. Wolverines prefer to move across suitable 
habitat (as defined by persistent spring snow cover) rather than to 
cross unsuitable habitats during dispersal movements (Schwartz et al. 
2009, p. 3230). Therefore, we would expect that changes resulting in 
reduction of suitable habitat conditions would result in reduced 
movement rates between habitat patches if distances between them became 
greater. This could affect the metapopulation as a whole if movement 
rates became too low to ensure subpopulation demographic or genetic 
health.
    Wolverines are opportunistic feeders and consume a variety of foods 
depending on availability. They primarily scavenge carrion, but also 
prey on small animals and birds, and eat fruits, berries, and insects 
(Hornocker and Hash 1981, p. 1290; Hash 1987, p. 579; Banci 1994, pp. 
111-113). Wolverines have an excellent sense of smell that enables them 
to find food beneath deep snow (Hornocker and Hash 1981, p. 1297).
    Wolverines require a lot of space; the availability and 
distribution of food is likely the primary factor in determining female 
wolverine movements and home range size (Hornocker and Hash 1981, p. 
1298; Banci 1994, pp. 117-118). Male wolverine home range size and 
location is likely tied to the presence of active female home ranges 
and breeding opportunities (Copeland 1996, p. 74). Female wolverines 
forage close to den sites in early summer, progressively ranging 
further from dens as kits become more independent (May et al. 2010, p. 
941). Wolverines travel long distances over rough terrain and deep 
snow, and adult males generally cover greater distances than females 
(Hornocker and Hash 1981, p. 1298; Banci 1994, pp. 117-118; Moriarty et 
al. 2009, entire; Inman et al. 2009, pp. 22-28; Brian 2010, p. 3; 
Copeland and Yates 2006, Figure 9). Home ranges of wolverines are 
large, and vary greatly in size depending on availability and 
distribution of food and gender and age of the animal. Home ranges of 
adult wolverines also vary in size depending on geographic location. 
Home ranges in Alaska were approximately 100 square kilometers (km\2\) 
to over 900 km\2\ (38.5 square miles (mi\2\) to 348 mi\2\) (Banci 1994, 
p. 117). Average home ranges of resident adult females in central Idaho 
were 384 km\2\ (148 mi\2\), and average home ranges of resident adult 
males were 1,522 km\2\ (588 mi\2\) (Copeland 1996, p. 50). Wolverines 
in Glacier National Park had average adult male home ranges of 496 
km\2\ (193 mi\2\) and adult female home ranges of 141 km\2\ (55 mi\2\) 
(Copeland and Yates 2006, p. 25). Wolverines in the Greater Yellowstone 
Ecosystem had average adult male home ranges of 797 km\2\ (311 mi\2\), 
and average adult female home ranges of 329 km\2\ (128 mi\2\) (Inman et 
al. 2007a, p. 4). These home range sizes are large relative to the body 
size of wolverines, and may indicate that wolverines occupy a 
relatively unproductive niche in which they must forage over large 
areas to consume the amount of calories needed to meet their life-
history requirements (Inman et al. 2007a, p. 11).
    Across their worldwide distribution, wolverines are dependent on 
persistent spring snow cover for successful reproduction (Pulliainen 
1968, pp. 338-341; Myrberget 1968, p. 115; Copeland 1996, pp. 93-94; 
Magoun and Copeland 1998, pp. 1315-1319; Aubry et al. 2007, p. 2153; 
Inman et al. 2012a, p.785; Copeland et al. 2010, entire). No records 
exist of wolverines denning anywhere but in snow, despite the wide

[[Page 7868]]

availability of snow-free denning opportunities within the species' 
geographic range. The snow tunnels and complex structure associated 
with dens are likely required to protect young from interspecific and 
intraspecific predation (Persson et al. 2003, pp. 25-26; Magoun and 
Copeland 1998, p. 1318). A layer of deep snow may also add crucial 
insulation from cold temperatures and wind prevalent in wolverine 
habitat (Pulliainen 1968, p. 342; Bj[auml]rvall et al. 1978, p. 24-25; 
Copeland 1996, p. 100; Magoun and Copeland 1998, p. 1318).
    Female wolverines have been observed to abandon reproductive dens 
when temperatures warm and snow conditions become wet (Magoun and 
Copeland 1998, p. 1316); this response indicates that the condition of 
the snow is also important to successful reproduction, and that the 
onset of spring snowmelt forces female wolverines to move kits into 
alternate denning sites with better snow conditions, if they are 
available. These movements may be energetically costly and subject 
females and kits to predation risk. The deep, persistent spring snow 
layer in the Copeland et al. (2010) model captures all known wolverine 
den sites in the DPS; however, on average, most denning occurs at 
higher elevations within the area defined by the model. Female 
wolverines establish reproductive dens at elevations higher than 
average elevations used by nonreproductive wolverines (Copeland 1996, 
p. 94; Magoun and Copeland 1998, pp. 1315-1316; Inman et al. 2007c, p. 
71), suggesting that females find the conditions necessary for 
successful denning in the upper portion of their home range where snow 
is most persistent and occurs in the heaviest accumulations.
    Wolverine year-round habitat use also takes place almost entirely 
within the area defined by deep persistent spring snow (Copeland et al. 
2010, pp. 242-243). Within the DPS, this area is generally centered on 
the alpine tree line (the maximum elevation beyond which tree growth is 
precluded and only low-growing vegetation is found). In the contiguous 
United States, wolverine year-round habitat is found at high elevations 
centered near the tree line in conifer forests (below tree line) and 
rocky alpine habitat (above tree-line) and in cirque basins and 
avalanche chutes that have food sources such as marmots, voles, and 
carrion (Hornocker and Hash 1981, p. 1296; Copeland 1996, p. 124; 
Magoun and Copeland 1998, p. 1318; Copeland et al. 2007, p. 2211; Inman 
et al. 2007a, p. 11). In the southern portion of wolverine range in 
North America which includes the DPS, wolverines are constrained by 
their need for cold conditions and persistent spring snow to using only 
the coldest available landscapes (Copeland et al. 2010, Figure 6).
    Mean seasonal elevations used by wolverines in the northern Rocky 
Mountains and North Cascades vary between 1,400 and 2,600 m (4,592 and 
8,528 ft) depending on location, but are always relatively high on 
mountain slopes (Hornocker and Hash 1981, p. 1291; Copeland et al. 
2007, p. 2207, Aubry et al. 2007, p. 2153; Inman et al. 2012, p. 782). 
Elevation ranges used by historical wolverine populations in the Sierra 
Nevada and southern Rocky Mountains are unknown, but presumably 
wolverines used higher elevations, on average, than more northerly 
populations to compensate for the higher temperatures found at lower 
latitudes. In the contiguous United States, valley bottom habitat 
appears to be used only for dispersal movements and not for foraging or 
reproduction (Inman et al. 2009, pp. 22-28). Wolverine reproductive 
dens have been located in alpine, subalpine, taiga, or tundra habitat 
(Myrberget 1968, p. 115; Pulliainen 1968, pp. 338-341; Bj[auml]rvall 
1982, p. 318; Lee and Niptanatiak 1996, p. 349; Landa et al. 1998, pp. 
451-452; Magoun and Copeland 1998, pp. 1317-1318). Wolverines rarely, 
or never, den in lower elevation forested habitats, although they may 
occupy these habitats occasionally (Magoun and Copeland 1998, p. 1317).
Wolverine Densities
    Wolverines naturally occur in low densities with a reported range 
from one animal per 65 km\2\ (25 mi\2\), to one animal per 337 km\2\ 
(130 mi\2\) (Hornocker and Hash 1981, pp. 1292-1295; Hash 1987, p. 578; 
Copeland 1996, pp. 31-32; Copeland and Yates 2006, p. 27; Inman et al. 
2007a, p. 10; Squires et al. 2007, p. 2218). No systematic population 
census exists over the entire current range of wolverines in the 
contiguous United States, so the current population level and trends 
are not known with certainty. However, based on our current knowledge 
of occupied wolverine habitat and wolverine densities in this habitat, 
it is reasonable to estimate that the wolverine population in the 
contiguous United States numbers approximately 250 to 300 individuals 
(Inman 2010b, pers. comm.). The bulk of the current population occurs 
in the northern Rocky Mountains, with a few individuals in the North 
Cascades and one known individual each in the Sierra Nevada and 
southern Rocky Mountains. Within the area known to currently have 
wolverine populations, relatively few wolverines can coexist due to 
their naturally low population densities, even if all areas were 
occupied at or near carrying capacity. Given the natural limitations on 
wolverine population density, it is likely that historical wolverine 
population numbers were also low (Inman et al. 2007a, Table 6). Because 
of these natural limitations, it is possible that densities and 
population levels in the northern Rocky Mountains and North Cascades 
where populations currently exist may not be substantially lower than 
population densities were in these areas prior to European settlement. 
However, historically, the contiguous United States population would 
likely have been larger than it is today due to the larger area 
occupied by populations when the southern Rocky Mountains, Bighorn 
Mountains, Sierra Nevada, and possibly also the Oregon Cascades and 
mountains of Utah, were occupied at full capacity.
Wolverine Status in Canada and Alaska
    The bulk of the range of North American wolverines is found in 
Canada and Alaska, where wolverines inhabit alpine tundra, boreal 
forest, and arctic habitats (Slough 2007, p. 78). Wolverines in Canada 
have been divided into two populations for management by the Canadian 
Government: An eastern population in Labrador and Quebec, and a western 
population that extends from Ontario to the Pacific coast, and north to 
the Arctic Ocean. The eastern population is currently listed as 
endangered under the Species At Risk Act in Canada, and the western 
population is designated as a species of special concern (COSEWIC 2003, 
p. 8).
    The current status of wolverines in eastern Canada is uncertain. 
Wolverines have not been confirmed to occur in Quebec since 1978 
(Fortin et al. 2005, p. 4). Historical evidence of wolverine presence 
in eastern Canada is also suspect because no evidence exists to show 
that wolverine pelts attributed to Quebec or Labrador actually came 
from that region; animals were possibly trapped elsewhere and the pelts 
shipped through the eastern provinces (COSEWIC 2003, p. 20). Wolverines 
in eastern Canada may currently exist in an extremely low-density 
population, or may be extirpated. Wolverines in eastern Canada, both 
historically and currently, could represent migrants from western 
populations that never became resident animals (COSEWIC 2003, pp. 20-
21). The Federal Government of Canada has completed a recovery plan

[[Page 7869]]

for the eastern population with the goal of establishing a self-
sustaining population through reintroduction and protection (Fortin et 
al. 2005, p. 16).
    Wolverines in western Canada and Alaska inhabit a variety of 
habitats from sea level to high elevations (Slough 2007, pp. 77-78). 
They occur in Alaska, Ontario, Manitoba, Saskatchewan, Alberta, British 
Columbia, Yukon, Northwest Territories, and Nunavut (Slough 2007, pp. 
77-78). Since European colonization, a generally recognized range 
contraction has taken place in boreal Ontario and the aspen parklands 
of Manitoba, Saskatchewan, and Alberta (COSEWIC 2003, pp. 20-21; Slough 
2007, p. 77). This range contraction occurred concurrently with a 
reduction in wolverine records for the Great Lakes region in the 
contiguous United States (Aubry et al. 2007, pp. 2155-2156). Causes of 
these changes are uncertain, but may be related to increased harvest, 
habitat modification, or climate change (COSEWIC 2003, pp. 20-21; Aubry 
et al. 2007, pp. 2155-2156; Slough 2007, pp. 77-78). Analysis supports 
climate change as a factor contributing to population declines in 
southern Ontario, because snow conditions necessary to support 
wolverines do not currently exist in the Great Lakes region of the 
contiguous United States, and are marginal in southern Ontario (Aubry 
et al. 2007, p. 2154). It is not known if these snow conditions existed 
historically in the Great Lakes of the contiguous United States; 
however, the small number of wolverine records from this area suggests 
that they did not. It is possible that suitable snow conditions did 
reach further south in eastern Canada in 1850 than they do today, 
making wolverine dispersal attempts from Canada to the Great Lakes 
region of the contiguous United States more likely than they are now. 
Wolverines occurred historically on Vancouver Island and have been 
given status as a separate subspecies by some (Hall 1981, p. 109). The 
Vancouver Island population is now regarded as possibly extirpated; no 
sightings have occurred since 1992 (COSEWIC 2003, p. 18).
    Wolverines in western Canada and Alaska appear to persist 
everywhere that habitat and climate conditions are suitable (COSEWIC 
2003, pp. 13-21; Aubry et al. 2007, pp. 2152-2155; Slough 2007, p. 79; 
Copeland et al. 2010, Figure 2). Throughout this area, wolverines are 
managed by regulated harvest at the Provincial and State level. 
Population estimates for Canada and Alaska are rough because no 
wolverine surveys have taken place at the State or Provincial scale. 
However, the population in western Canada is estimated to include 
approximately 15,089 to 18,967 individuals (COSEWIC 2003, p. 22). The 
number of wolverines in Alaska is unknown, but they appear to exist at 
naturally low densities in suitable habitats throughout the state 
(Alaska Department of Fish and Game 2004, pp. 1-359). We have no 
information to indicate that wolverine populations have been reduced in 
numbers or geographic range in Alaska.
The Complexity of Geographic Range Delineation
    Information on the nature of historical and current locations of 
wolverine is lacking for several reasons. Wolverines tend to live in 
remote and inhospitable places away from human settlements, where they 
are seldom encountered, documented, or studied. Wolverines naturally 
occur at low population densities and are rarely and unpredictably 
encountered where they do occur. Wolverines often move long distances 
in short periods of time; for example, when dispersing from natal 
ranges, wolverines may transit through habitats that are unsuitable for 
long-term survival (Aubry et al. 2007, p. 2147; Moriarty et al. 2009, 
entire; Inman et al. 2009, pp. 22-28; Brian 2010, p. 3). Such movements 
make it difficult to distinguish with certainty between occurrence 
records that represent established populations in suitable habitats and 
records that represent short-term occupancy or exploratory movements 
without the potential for establishment of home ranges, reproduction, 
or populations. These natural attributes of wolverines make it 
difficult to precisely determine their present range, or trends in 
range expansion or contraction, that may have occurred in the past. 
Therefore, we are cautious and use multiple lines of evidence when 
trying to determine where past wolverine populations occurred.
    Throughout the remainder of this proposed rule, we focus on the use 
of verifiable and documented wolverine occurrence records to define 
historical and present range as we have determined that these records 
constitute the best scientific information available on the past and 
present distribution of wolverines (see Aubry et al. 2007, p. 2148; 
McKelvey et al. 2008, entire). Verifiable records are records supported 
by physical evidence such as museum specimens, harvested pelts, DNA 
samples, and diagnostic photographs. Documented records are those based 
on accounts of wolverines being killed or captured. Use of only 
verifiable and documented records avoids mistakes of misidentification 
often made in eyewitness accounts of visual encounters of unrestrained 
animals in the wild. Visual-encounter records often represent the 
majority of occurrence records for elusive forest carnivores, and they 
are subject to inherently high rates of misidentification of the 
species involved, including wolverines (McKelvey et al. 2008, pp. 551-
552). These misidentifications can result in wildly inaccurate 
conclusions about species occurrence (McKelvey et al. 2008, pp. 550-
553).
    Aubry et al. (2007, entire) used only verifiable and documented 
records to investigate wolverine distribution through time. This paper 
is the only available comprehensive treatment of these distribution 
patterns that attempts to distinguish between records that represent 
resident animals versus animals that have dispersed outside of suitable 
habitat. For these reasons, we find that Aubry et al. (2007, entire) 
represents the best available summary of wolverine occurrence records 
in the contiguous United States at this time. Since the publication of 
Aubry et al. (2007, entire), verified records of wolverines have also 
been documented in Colorado and California, which we will describe in 
greater detail below.
    Aubry et al. (2007, entire) used verifiable and documented records 
from museum collections, literature sources, and State and Federal 
institutions to trace changes in geographic distribution of wolverines 
in the historical record. They then used an overlay of suitable 
wolverine habitats to determine which records represent wolverines in 
habitats that may support residency, and, by extension, populations, 
and which records likely represent wolverines outside the range of 
suitable habitats, so called ``extralimital'' records. Aubry et al.'s 
(2007, entire) focus on verifiable and documented records corrected 
past overly broad approaches to wolverine range mapping (Nowak 1973, p. 
22; Hall 1981, p. 1009; Wilson 1982, p. 644; Hash 1987, p. 576), which 
used a more inclusive but potentially misleading approach when dealing 
with occurrence records. Many of the extralimital records used in these 
publications represented individuals that dispersed from natal ranges 
but ended up in habitats that could not support wolverines. Use of 
these data to determine the historical geographic range of wolverines 
results in gross overestimation of the area that can actually be used 
successfully by wolverines for the establishment of populations. 
Subsequent to publication of Aubry et al. (2007, entire), two 
publications (Copeland et al. 2010,

[[Page 7870]]

entire; Brock et al. 2007, entire) further refined our understanding of 
wolverine habitat needs and corroborated the approach of Aubry et al. 
(2007, entire). Thus, despite the paucity of verifiable records, we now 
have strong information on the areas that are currently suitable to be 
occupied by wolverine based on habitat and climate conditions.
    We agree with Aubry et al. (2007, p. 2149) that the most 
appropriate method to determine the current and historical range of 
wolverines is to use a combination of occurrence records and habitat 
suitability, along with other information, such as documented 
successful reproduction events, indicating where reproductive and 
potentially self-sustaining populations may occur. We also generally 
agree with their conclusions about the historical and current range of 
the species. We find that the species' range is the area that may 
support viable populations, and does not include extralimital 
occurrences outside of habitat that is likely to support wolverine 
life-history needs. Areas that can support wolverine populations may be 
referred to as potential ``source'' populations because they provide 
surplus individuals through reproduction beyond what is needed for 
replacement. Areas that have some of the habitat attributes of 
wolverine habitat but do not have enough habitat to support viable 
populations may be referred to as population ``sinks'' because 
wolverines may disperse to these areas and remain for some time, but 
will either die there without reproducing, leave the area in search of 
better habitat conditions, or may actually reproduce, but at a rate 
lower than that needed for replacement of individuals lost to mortality 
or emigration, leading to eventual population extinction.
    For a widely dispersing species like the wolverine, we expect many 
locality records to represent dispersal attempts into sink habitats or 
nonhabitat. The value to the population (and thus the DPS) of 
dispersers in these areas is unclear; it is likely that most dispersers 
into sink habitats or nonhabitat will be lost to the population unless 
they are able to move back into source habitats. Therefore, it is our 
conclusion that population sink areas and areas of non-wolverine 
habitat, here defined as places where wolverines may be found but where 
habitat is not suitable for long-term occupancy and reproduction, do 
not represent part of the species historical range and have little 
conservation value for the DPS, other than possibly serving as 
temporary stop-overs for attempted dispersers as they search for 
suitable habitats. Compared with broader approaches to defining 
historical geographic range, this focused approach (1) results in 
reducing the bias of extralimital dispersers and (2) concentrates 
conservation attention on areas capable of maintaining populations.
    Aubry et al. (2007, pp. 2147-2148) divided records into 
``historical'' (recorded prior to 1961), ``recent'' (recorded between 
1961 and 1994), and ``current'' (recorded after 1994). Historical 
records occurred before systematic surveys. Historical records 
encompass the time during which wolverine numbers and distribution were 
hypothesized to be at their highest (prior to European settlement) and 
also at their lowest (early 20th century) (Wright and Thompson 1935; 
Grinnell et al. 1937; Allen 1942; Newby and Wright 1955, all as cited 
in Aubry et al. 2007, p. 2148). The recent time interval covers a 
hypothesized population expansion and rebound from the early 20th 
century low. Current records offer the most recent evidence available 
for wolverine occurrences and potential populations. All occurrence 
records must be individually analyzed in light of their context in 
terms of habitat conditions conducive to wolverine population 
establishment and whether or not they occur clustered with other 
records, which might indicate that populations have historically 
occurred in the area. The authors of Aubry et al. (2007) did such an 
analysis as they compiled their records.

Wolverine Distribution

    We assessed the historical, recent, and current distribution data 
for each of the regions below to determine the likelihood of the 
presence of historical populations (rather than extralimital 
dispersers). Of 729 mappable records (those records with precise 
location information) compiled by Aubry et al. (2007, p. 2150), 188 
were from the historical time interval (see Table 1). The discussion 
below draws heavily from both Aubry et al. (2007, entire) and Copeland 
et al. (2010, entire).

                                        Table 1--Wolverine Records From Three Time Periods From Aubry et al. 2007
            [Numbers represent total documented and verifiable records with the subset of those records that were verifiable in parentheses]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                     Historical (<1964)            Recent (1961-1994)              Current (>1994)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Northeast.....................................................                        13 (1)                             0                             0
Upper Midwest.................................................                         4 (2)                             0                             0
Great Lakes...................................................                        36 (4)                             1                             0
Central Great Plains..........................................                      * 71 (2)                             1                             0
Rocky Mountains...............................................                      147 (45)                     332 (283)                     215 (210)
Pacific Coast.................................................                       89 (14)                       23 (15)                             7
                                                               -----------------------------------------------------------------------------------------
    Totals....................................................                      362 (68)                     357 (298)                     222 (210)
--------------------------------------------------------------------------------------------------------------------------------------------------------
* 35 records from a single source (the journals of Alexander Henry).

    Northeast and Upper Midwest--The low number of records and 
scattered nature of their distribution combined with a lack of suitable 
habitat indicate that wolverines were likely only occasional transients 
to the area and not present as a reproducing population after 1800.
    Great Lakes--The lack of large numbers of verifiable records in 
this area of relatively high human population density and the lack of 
suitable habitat suggests that wolverines did not exist in this area as 
a viable population after 1900. Widely scattered records generally 
before 1900, along with occasional subsequent records suggest that if a 
reproducing population existed in the Great Lakes, it predated 1900, 
and that any post-1900 records represent dispersal from a receding 
Canadian population. Wolverine distribution in Ontario, Canada, appears 
to have receded north from the Great Lakes region since the 1800s, and 
currently wolverines occupy only the northern portion of the province, 
a distance of over 644 km (400 mi) from the United States border 
(COSEWIC 2003, p. 9). The distribution pattern of

[[Page 7871]]

record illustrated in Aubry et al. (2007, p. 2152) is consistent with 
what would be expected if those records were of dispersing individuals 
from a Canadian population that receded progressively further north 
into Canada after 1800, possibly due to natural climate changes 
(COSEWIC 2003, p. 28).
    Central Great Plains--The lack of precise locality records and 
suitable habitat from the Great Plains States leads us to conclude that 
reproducing populations of wolverines did not historically inhabit this 
area. Of thirty-six records from North Dakota, 35 are from the journals 
of a single fur trader (see Table 1), and it is not clear that the 
records represent actual collection localities or are localities where 
trades or shipments occurred (Aubry 2007, pers. comm.). Given the 
habitat relationships of wolverines (e.g., Copeland et al. 2010, Figure 
1), it is unlikely that these records represent established wolverines 
or that this area served as wolverine habitat.
    Rocky Mountains--Five Rocky Mountains States (Idaho, Montana, 
Wyoming, Colorado, and Utah) contained numerous wolverine records. 
Records with precise locality information appear to coalesce around 
several areas that may have been population centers, such as central 
Colorado, the greater Yellowstone region, and northern Idaho-
northwestern Montana. The large number of verifiable and documented 
records for this region, along with the suggestion of population 
centers or strongholds, suggests that wolverines existed in reproducing 
populations throughout much of the Rocky Mountains during the 
historical time interval. The lack of records for Colorado and Utah 
after 1921 suggests that the southern Rocky Mountains population of 
wolverines was extirpated in the early 1900s, concurrent with 
widespread systematic predator control by government agencies and 
livestock interests. The northern Rocky Mountains population (north of 
Wyoming) was reduced to historical lows or possibly even extirpated 
during the early 1900s, and then increased dramatically in the second 
half of the 1900s (see Table 1) as predator control efforts subsided 
and trapping regulations became more restrictive (Aubry et al. 2007, p. 
2151). This increase likely indicates a population rebound from 
historical lows in this period.
    Wolverine records from 1995 to 2005 indicate that wolverine 
populations currently exist in the northern Rocky Mountains (see Table 
1). Legal trapping in Montana in the recent past removed an average of 
10.5 individuals from this population each year (Montana Department of 
Fish, Wildlife, and Parks 2007, p. 2), but harvest mortality has been 
reduced due to regulatory changes in 2008 (Montana Department of Fish, 
Wildlife and Parks 2008, p. 8). Populations in British Columbia and 
Alberta, Canada, are extant (COSEWIC 2003, pp. 18-19), and may have 
been a source of surplus wolverines to the contiguous United States 
population during population lows. Recently, a male wolverine moved on 
its own from the southern Greater Yellowstone Area of Wyoming into the 
southern Rocky Mountains of Colorado, where it still persisted as of 
November 2012 (Inman et al. 2009, pp. 22-26; Odell 2012, pers. comm.). 
This attempted dispersal event is the first verified wolverine 
occurrence in Colorado since 1919 and may represent a continuation of 
the wolverine expansion in the Rocky Mountains detailed above. It is 
possible that other wolverines have traveled to the southern Rocky 
Mountains and have remained undetected. There is no evidence that 
Colorado currently hosts a wolverine population or that female 
wolverines have made, or are likely to make, similar movements. Female 
dispersal movements tend to be much shorter than males, usually 
occupying home ranges adjacent to their natal range, and dispersal is 
documented only for lesser distances than males routinely travel 
(Hornocker and Hash 1981, p. 1290; Copeland 1996, p. 91; Kyle and 
Strobeck 2001, p. 338; Tomasik and Cook 2005, p. 390; Cegelski et al. 
2006, p. 206, Inman et al. 2011, p. 7). The largest documented female 
movement occurred in 2010 in the North Cascades of Washington (Aubry et 
al. 2011, pp. 21-22). In that instance, a radio-collared female 
wolverine moved an air-line distance of approximately 233 km (145 mi) 
over a 44-day period. During this movement, her course generally stayed 
within suitable wolverine habitat (as defined by Copeland et al. (2010, 
p. 242)) and was never more than about 19 km (12 mi) from suitable 
wolverine habitat.
    Pacific Coast--Historical records show that wolverines occurred in 
two population centers in the North Cascades Range and the Sierra 
Nevada. However, records do not show occurrences between these centers 
from southern Oregon to northern California, indicating that the 
historical distribution of wolverines in this area is best represented 
by two disjunct populations rather than a continuous peninsular 
extension from Canada. This conclusion is supported by genetic data 
indicating that the Sierra Nevada and Cascades wolverines were 
separated for at least 2,000 years prior to extirpation of the Sierra 
Nevada population (Schwartz et al. 2007, p. 2174).
    Only one Sierra Nevada record exists after 1930, indicating that 
this population was likely extirpated in the first half of the 1900s, 
concurrent with widespread systematic predator control programs. In 
2008, a male wolverine was discovered in the Sierra Nevada Range of 
California, the first verified record from California since 1922 
(Moriarty et al. 2009, entire). Genetic testing revealed that this 
wolverine was not a descendant of the endemic Sierra Nevada wolverine 
population, but was likely derived from wolverines in the Rocky 
Mountains (Moriarty et al. 2009, p. 159). This attempted dispersal 
event may represent a continuation of the wolverine expansion in the 
contiguous United States as detailed above. Other wolverines may have 
travelled to the Sierra Nevada and remain undetected. There is no 
evidence that California currently hosts a wolverine population or that 
female wolverines have made, or are likely to make, similar dispersal 
movements.
    Wolverines were likely extirpated from the North Cascades in the 
early 20th century and then recently recolonized from Canada. 
Currently, a small population persists in this area (Aubrey et al. 
2011, entire). In 2012, reproduction was documented for the first time 
in the North Cascades (Aubry et al. 2012, p. 2). Wolverines have also 
been documented in the southern portion of the North Cascades, near 
Mount Adams, since 2009 (Akins 2010, p. 4). The North Cascades 
population may be connected with, and is possibly dependent on, the 
larger Canadian population for future expansion and long-term 
persistence.

Summary of Wolverine Distribution

    Historical wolverine records were found across the northern tier of 
the contiguous United States, with convincing evidence of wolverine 
populations in the northern and southern Rocky Mountains, Sierra Nevada 
Mountains, and North Cascades Mountains (Aubry et al. 2007, p. 2152).
    Currently, wolverines appear to be distributed as functioning 
populations in two regions in the contiguous United States: the North 
Cascades in Washington, and the northern Rocky Mountains in Idaho, 
Montana, and Wyoming (this area also includes the Wallowa Range in 
Oregon). Wolverines were likely extirpated, or nearly so, from the 
entire contiguous United States in the first half of the 20th century

[[Page 7872]]

(Aubry et al. 2007, Table 1). Although the reasons for this extirpation 
are not known with certainty, unregulated trapping and widespread 
indiscriminant predator control likely contributed to population 
declines. The available evidence suggests that, in the second half of 
the 20th century and continuing into the present time, wolverine 
populations have expanded in the North Cascades and the northern Rocky 
Mountains from sources in Canada, but that populations have not been 
reestablished in the Sierra Nevada Range or the southern Rocky 
Mountains, despite the known movement of single individual males to 
each of these areas. We conclude that the current range of the species 
in the contiguous United States includes the North Cascades Mountains, 
the northern Rocky Mountains, the southern Rocky Mountains, and the 
Sierra Nevada Mountains, but that reestablishment of populations in the 
southern Rocky Mountains and Sierra Nevada Mountains has not yet 
occurred.
    We also conclude that wolverines either did not exist as 
established populations, or were extirpated prior to settlement and the 
compilation of historical records, in the Great Lakes region, possibly 
due to climate changes that occurred through the 1800s and 1900s. The 
Great Lakes region lacks suitable wolverine habitat, and suitable 
habitat does not appear to exist in adjacent Canada (Copeland et al. 
2010, Figure 1). The widely scattered records from this region are 
consistent with dispersing individuals from a Canadian population that 
receded north early in the 1800s. We cannot rule out the possibility 
that wolverines existed as established populations prior to the onset 
of trapping in this area, but we have no evidence of this.
    No evidence in the historical records indicates that wolverines 
were ever present as established populations in the Great Plains, 
Midwest, or Northeast.

Habitat Relationships and Wolverine Distribution

    Deep, persistent, and reliable spring snow cover (April 15 to May 
14) is the best overall predictor of wolverine occurrence in the 
contiguous United States (Aubry et al. 2007, pp. 2152-2156; Copeland et 
al. 2010, entire). Deep, persistent snow correlates well with wolverine 
year-round habitat use across wolverine distribution in North America 
and Eurasia at both regional and local scales (Copeland et al. 2010, 
entire; Inman et al. 2012a, p. 785). It is uncertain why spring snow 
cover so accurately predicts wolverine habitat use; however, it is 
likely related to wolverines' need for deep snow during the denning 
period. In addition, wolverines appear to take advantage of a cold, 
low-productivity niche by using food caching in cold habitats to 
survive food-scarce winters that other carnivores cannot (Inman et al. 
2012b, pp. 640-642). Wolverines' physiological requirement for year-
round cold temperatures may also play a role in habitat use (Copeland 
et al. 2010, pp. 242-243). Snow cover during the denning period is 
essential for successful wolverine reproduction range-wide (Hatler 
1989, p. iv; Magoun and Copeland 1998, p. 1317; Inman et al. 2007c, pp. 
71-72; Persson 2007; Copeland et al. 2010, p. 244). Wolverine dens tend 
to be in areas of high structural diversity such as logs and boulders 
with deep snow (Magoun and Copeland 1998, p. 1317; Inman et al. 2007c, 
pp. 71-72; Persson 2007, entire). Reproductive females dig deep snow 
tunnels to reach the protective structure provided by logs and 
boulders. This behavior presumably protects the vulnerable kits from 
predation by large carnivores, including other wolverines (Pulliainen 
1968, p. 342; Zyryanov 1989, pp. 3-12), but may also have physiological 
benefits for kits by buffering them from extreme cold, wind, and 
desiccation (Pullianen 1968, p. 342, Bj[auml]rvall et al. 1978, p. 23). 
Wolverines live in low-temperature conditions and appear to select 
habitats in part to avoid high summer temperatures (Copeland et al. 
2010, p. 242). Wolverine distribution is likely affected by climatic 
conditions at two different scales. Wolverines require deep persistent 
snow for denning, and this likely determines where wolverine 
populations can be found at the grossest range-wide scale (Copeland et 
al. 2010, p. 244). At smaller scales, wolverines likely select habitats 
to avoid high summer temperatures. These cool habitats also tend to 
retain snow late into spring, leading to wolverines' year-round 
association with areas of persistent spring snow (Copeland et al. 2010, 
p. 244).
    All of the areas in the contiguous United States for which good 
evidence of persistent wolverine populations (either present or 
historical) exists (i.e., North Cascades, Sierra Nevada, northern and 
southern Rocky Mountains) contain large and well-distributed areas of 
deep snow cover that persists through the wolverine denning period 
(Inman et al. 2011, Fig. 3; Aubry et al. 2007, p. 2154; Copeland et al. 
2010, Figure 1). The Great Plains, Great Lakes, Midwest, and Northeast 
lack the spring snow conditions and low summer temperatures thought to 
be required by wolverines for successful reproduction and year-round 
occupancy (Aubry et al. 2007, p. 2154; Copeland et al. 2010, Figure 1). 
The lack of persistent spring snow conditions in the Great Plains, 
Great Lakes, Midwest, and Northeast supports the exclusion of these 
areas from the current range of wolverines. Whether wolverines once 
existed as established populations in any of these regions is 
uncertain, but the current climate appears to preclude their presence 
as reproducing populations, and the sparse historical record of 
wolverine presence in this area makes historical occupation of these 
areas by wolverine populations doubtful. It is our conclusion that the 
ecosystem that supports wolverines does not exist in these areas 
currently, and may not have existed at the time of European settlement 
of these areas.
    Large areas of habitat with characteristics suitable for wolverines 
still occur in the southern Rocky Mountains and Sierra Nevada, despite 
the extirpation of wolverines from those areas (Aubry et al. 2007, p. 
2154, Inman et al. 2011, Fig. 4; Copeland et al. 2010, Figure 1). 
Wolverine extirpations in these areas were coincident with unregulated 
trapping and systematic predator eradication efforts in the early 
1900s, which have been discontinued for many years. Each of these areas 
has received at least one and possibly more migrants from adjacent 
populations in the northern Rocky Mountains; however, there is no 
evidence that females have migrated to these areas or that populations 
of wolverines currently exist there (Aubry et al. 2007, Table 1; 
Moriarty et al. 2009, entire; Inman et al. 2009, entire).
    We conclude that areas of wolverine historical occurrence can be 
placed in one of three categories: (1) Areas where wolverines are 
extant as reproducing and potentially self-sustaining populations 
(North Cascades, northern Rocky Mountains); (2) areas where wolverines 
historically existed as reproducing and potentially self-sustaining 
populations prior to human-induced extirpation, and where 
reestablishment of those populations is possible given current habitat 
conditions and management (the Sierra Nevada Mountains in California 
and southern Rocky Mountains in Colorado, New Mexico, Wyoming, Uinta 
Mountains and surrounding ranges in Utah, Bighorn Mountains in Wyoming, 
and possibly the Oregon Cascades Mountains); and (3) areas where 
historical presence of wolverines in reproducing and potentially self-
sustaining populations is doubtful, and

[[Page 7873]]

where the current habitat conditions preclude the establishment of 
populations (Great Plains, Midwest, Great Lakes, and Northeast). We, 
therefore, consider the current range of wolverines to include suitable 
habitat in the North Cascades of Washington, the northern Rocky 
Mountains of Idaho, Wyoming, Montana, and eastern Oregon, the southern 
Rocky Mountains of Colorado and Wyoming, and the Sierra Nevada of 
California. We here include the Sierra Nevada and southern Rocky 
Mountains in the current range of wolverines despite the probability 
that functional populations do not exist in these areas. They are 
included due to the known existence of one individual in each area and 
the possibility that more, as yet undetected, individuals inhabit these 
areas.

Distinct Population Segment

    Pursuant to the Act, we must consider for listing any species, 
subspecies, or, for vertebrates, any Distinct Population Segment (DPS) 
of these taxa, if there is sufficient information to indicate that such 
action may be warranted. To interpret and implement the DPS provision 
of the Act and Congressional guidance, the Service and the National 
Marine Fisheries Service published, on February 7, 1996, an interagency 
Policy Regarding the Recognition of Distinct Vertebrate Population 
Segments under the Act (61 FR 4722). This policy addresses the 
recognition of DPSs for potential listing actions. The policy allows 
for more refined application of the Act that better reflects the 
biological needs of the taxon being considered, and avoids the 
inclusion of entities that do not require its protective measures.
    Under our DPS policy, three elements are considered in a decision 
regarding the status of a possible DPS as endangered or threatened 
under the Act. These are applied similarly for additions to the list of 
endangered and threatened species, reclassification, and removal from 
the list. They are: (1) Discreteness of the population segment in 
relation to the remainder of the taxon; (2) the biological or 
ecological significance of the population segment to the taxon to which 
it belongs; and (3) the population segment's conservation status in 
relation to the Act's standards for listing (i.e., whether the 
population segment is, when treated as if it were a species or 
subspecies, an endangered or threatened species). Discreteness refers 
to the degree of isolation of a population from other members of the 
species, and we evaluate this factor based on specific criteria. If a 
population segment is considered discrete, we must consider whether the 
discrete segment is ``significant'' to the taxon to which it belongs by 
using the best available scientific and commercial information. If we 
determine that a population segment is both discrete and significant, 
we then evaluate it for endangered or threatened species status based 
on the Act's standards. The DPS evaluation in this proposed rule 
concerns the segment of the wolverine species occurring within the 
contiguous 48 States, including the northern and southern Rocky 
Mountains, Sierra Nevada Range, and North Cascades Range.

Distinct Population Segment Analysis for Wolverine in the Contiguous 
United States

Analysis of Discreteness

    Under our DPS Policy, a population segment of a vertebrate species 
may be considered discrete if it satisfies either one of the following 
conditions: (1) It is markedly separated from other populations of the 
same taxon as a consequence of physical, physiological, ecological, or 
behavioral factors (quantitative measures of genetic or morphological 
discontinuity may provide evidence of this separation); or (2) it is 
delimited by international governmental boundaries within which 
differences in control of exploitation, management of habitat, 
conservation status, or regulatory mechanisms exist that are 
significant in light of section 4(a)(1)(D) of the Act (inadequacy of 
existing regulatory mechanisms). The wolverine within the contiguous 
United States meets the second DPS discreteness condition because of 
differences in conservation status as delimited by the Canadian-United 
States international governmental boundary.
    In our 12-month finding for the North American wolverine DPS (75 FR 
78030) we conducted a complete analysis of the discreteness of the 
wolverine DPS that we incorporate here by reference. In that analysis 
we concluded that the international boundary between Canada and the 
United States currently leads to division of the control of 
exploitation and conservation status of the wolverine. This division is 
significant because it allows for potential extirpation of the species 
within the contiguous United States through loss of small populations 
and lack of demographic and genetic connectivity of the two 
populations. This difference in conservation status is likely to become 
more significant in light of threats discussed in the five factors 
analyzed below. Therefore, we find that the difference in the 
conservation statuses in Canada and the United States result in 
vulnerability to the significant threat (discussed below) in the U.S. 
wolverine population but not for the Canadian population. Existing 
regulatory mechanisms are inadequate to ensure the continued existence 
of wolverines in the contiguous United States in the face of these 
threats. Therefore, it is our determination that the difference in 
conservation status between the two populations is significant in light 
of section 4(a)(1)(D) of the Act, because existing regulatory 
mechanisms appear sufficient to maintain the robust conservation status 
of the Canadian population, while existing regulatory mechanisms in the 
contiguous United States are insufficient to protect the wolverine from 
threats due to its depleted conservation status. As a result, the 
contiguous United States population of the wolverine meets the 
discreteness criterion in our DPS Policy (61 FR 4725). Consequently, we 
use the international border between the United States and Canada to 
define the northern boundary of the contiguous United States wolverine 
DPS.

Analysis for Significance

    If we determine a population segment is discrete, its biological 
and ecological significance will then be considered in light of 
Congressional guidance that the authority to list DPSs be used 
sparingly while encouraging the conservation of genetic diversity. In 
carrying out this examination, we consider available scientific 
evidence of the population's importance to the taxon to which it 
belongs (i.e., the North American wolverine (Gulo gulo luscus)). Our 
DPS policy states that this consideration may include, but is not 
limited to: (1) Persistence of the discrete population segment in an 
ecological setting unusual or unique for the taxon; (2) evidence that 
loss of the discrete population segment would result in a significant 
gap in the range of the taxon; (3) evidence that the discrete 
population segment represents the only surviving natural occurrence of 
a taxon that may be more abundant elsewhere as an introduced population 
outside its historical range; or (4) evidence that the discrete 
population segment differs markedly from other populations of the 
species in its genetic characteristics.
    In our 12-month finding (75 FR 78030), we conducted an exhaustive 
analysis of the significance of the contiguous United States population 
of the North American wolverine that we incorporate here by reference. 
In that analysis we concluded that the wolverine population in the 
contiguous United States is significant because its

[[Page 7874]]

loss would result in a significant gap in the range of the taxon.

Summary of the Distinct Population Segment Analysis

    We conclude that the wolverine population in the contiguous United 
States is both discrete and significant under our DPS policy. The 
conservation status of wolverines in the contiguous United States is 
less secure than wolverines in adjacent Canada due to fragmented 
habitat, small population size, reduced genetic diversity, and their 
vulnerability to threats analyzed in this finding. Loss of the 
contiguous United States wolverines would result in a significant gap 
in the range of the taxon. Therefore, we determine that the population 
of wolverines in the contiguous 48 States, as currently described, 
meets both the discreteness and significance criteria of our DPS 
policy, and is a listable entity under the Act as a DPS.

Summary of Factors Affecting the Species

    Section 4 of the Act (16 U.S.C. 1533), and its implementing 
regulations at 50 CFR part 424, set forth the procedures for adding 
species to the Federal Lists of Endangered and Threatened Wildlife and 
Plants. Under section 4(a)(1) of the Act, we may list a species based 
on any of the following five factors: (A) The present or threatened 
destruction, modification, or curtailment of its habitat or range; (B) 
overutilization for commercial, recreational, scientific, or 
educational purposes; (C) disease or predation; (D) the inadequacy of 
existing regulatory mechanisms; and (E) other natural or manmade 
factors affecting its continued existence. Listing actions may be 
warranted based on any of the above threat factors, singly or in 
combination. Each of these factors is discussed below.

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

    Under Factor A we will discuss a variety of impacts to wolverine 
habitat including: (1) Climate change, (2) human use and disturbance, 
(3) dispersed recreational activities, (4) infrastructure development, 
(5) transportation corridors, and (6) land management. Many of these 
impact categories overlap or act in concert with each other to affect 
wolverine habitat. Climate change is discussed under Factor A because 
although climate change may affect wolverines directly by creating 
physiological stress, the primary impact of climate change on 
wolverines is expected to be through changes to the availability and 
distribution of wolverine habitat.
    Two efforts to map wolverine habitat in the contiguous United 
States have been completed (Inman et al. 2012, entire; Copeland et al. 
2010, entire). Both of these habitat models rely on snow as a primary 
input. The Copeland et al. (2010) model defines wolverine habitat as 
simply the area continuously covered by snow from mid-winter until mid-
May. The Inman et al. (2012) model is based on snowpack and also 
incorporates other habitat variables, such as terrain ruggedness and 
some aspects of human development. The two models result in estimates 
of wolverine habitat that are very similar across most of the range of 
wolverines in the contiguous United States. Areas of significant 
departure between the models are the California Sierras and Oregon 
Cascades where the Copeland et al. (2010) model predicts significantly 
greater habitat area than does the Inman et al. (2012) model. Given the 
general agreement between the two models, we combined the areas 
depicted by them into a composite wolverine habitat model that includes 
all areas described by one or both of these models. This composite 
model serves as the basis for our estimates of wolverine habitat below. 
Within the four States that currently harbor wolverines (Montana, 
Idaho, Oregon (Wallowas) and Wyoming), an estimated 124,014 km\2\ 
(47,882 mi\2\) of wolverine habitat exists. Habitat in the North 
Cascades and Eastern Washington (Kettle Range and associated habitat) 
add approximately 20,356 km\2\ (7859 mi\2\). Ninety-four percent 
(135,396 km\2\; 52,277 mi\2\) of total wolverine habitat is in Federal 
ownership with most of that managed by the U.S. Forest Service (Forest 
Service).

Reduction in Habitat Due to Climate Change

    Our analyses under the Act include consideration of ongoing and 
projected changes in climate. The terms ``climate'' and ``climate 
change'' are defined by the Intergovernmental Panel on Climate Change 
(IPCC). ``Climate'' refers to the mean and variability of different 
types of weather conditions over time, with 30 years being a typical 
period for such measurements, although shorter or longer periods also 
may be used (IPCC 2007, p. 78). The term ``climate change'' thus refers 
to a change in the mean or variability of one or more measures of 
climate (e.g., temperature or precipitation) that persists for an 
extended period, typically decades or longer, whether the change is due 
to natural variability, human activity, or both (IPCC 2007, p. 78). 
Various types of changes in climate can have direct or indirect effects 
on species. These effects may be positive, neutral, or negative and 
they may change over time, depending on the species and other relevant 
considerations, such as the effects of interactions of climate with 
other variables (e.g., habitat fragmentation) (IPCC 2007, pp. 8-14, 18-
19).
    We recognize that there are scientific uncertainties on many 
aspects of climate change, including the role of natural variability in 
climate. In our analysis, we rely both on synthesis documents (e.g., 
IPCC 2007; Karl et al. 2009) that present the consensus view of a very 
large number of experts on climate change from around the world, and on 
five analyses that relate the effects of climate changes directly to 
wolverines (Gonzalez et al. 2008, entire; Brodie and Post 2009, entire; 
Peacock 2011, entire; McKelvey et al. 2011, entire, Johnston et al. 
2012, entire). To date, McKelvey et al. (2011) is the most 
sophisticated analysis regarding climate change effects to wolverines. 
This report is based on data from global climate models including both 
temperature and precipitation, downscaled to reflect the regional 
climate patterns and topography found within the range of wolverines in 
the contiguous United States. For this reason we find that McKelvey et 
al. (2011, entire) represents the best scientific information available 
regarding the impacts of climate change to wolverine habitat.
    Snowpack changes as well as concomitant changes to wolverine 
habitat suitability result from both changes in temperature (negative 
relationship) and changes in snowfall (positive relationship). Because 
many climate models predict higher precipitation levels associated with 
climate warming, the interaction between these two variables can be 
quite complex. Consequently, predictions about snow coverage that rely 
only on temperature projections are less reliable than those that rely 
on both temperature and precipitation. McKelvey et al. (2011, entire) 
report projections for wolverine habitat and dispersal routes through 
the time interval from 2070 to 2099.
Climate Effects to Wolverines
    Due to dependence of wolverines on deep snow that persists into 
late spring both for successful reproduction and for year-round 
habitat, and their restricted distribution to areas that maintain 
significant snow late into the spring season, we conclude that deep 
snow maintained through the denning period is required for wolverines 
to

[[Page 7875]]

successfully live and reproduce. Reduction of this habitat feature 
would proportionally reduce wolverine habitat, or to an even greater 
extent if habitat reduction involved increasing fragmentation.
    Based on the information described above, we analyzed the effects 
of climate change on wolverines through three primary mechanisms: (1) 
Reduced snowpack and earlier spring runoff, which would reduce suitable 
habitat for wolverine denning; (2) increase in summer temperatures 
beyond the physiological tolerance of wolverines; and (3) ecosystem 
changes due to increased temperatures, which would move lower elevation 
ecosystems to higher elevations, thereby eliminating high-elevation 
ecosystems on which wolverines depend and increasing competitive 
interactions with species that currently inhabit lower elevations. 
These mechanisms would tend to push the narrow elevation band that 
wolverines use into higher elevation. Due to the conical structure of 
mountains, this upward shift would result in reduced overall suitable 
habitat for wolverines.
Reduced Snow Pack and Earlier Spring Runoff
    Warmer winter temperatures are reducing snow pack in western North 
American mountains through a higher proportion of precipitation falling 
as rain and higher rates of snowmelt during winter (Hamlet and 
Lettenmaier 1999, p. 1609; Brown 2000, p. 2347; Mote 2003, p. 3-1; 
Christensen et al. 2004, p. 347; Knowles et al. 2006, pp. 4548-4549). 
This trend is expected to continue with future warming (Hamlet and 
Lettenmaier 1999, p. 1611; Christensen et al. 2004, p. 347; Mote et al. 
2005, p. 48). Shifts in the initiation of spring runoff toward earlier 
dates are also well documented (Hamlet and Lettenmaier 1999, p. 1609; 
Brown 2000, p. 2347; Cayan et al. 2001, pp. 409-410; Christensen et al. 
2004, p. 347; Mote et al. 2005, p. 41; Knowles et al. 2006, p. 4554). 
Earlier spring runoff leads to lack of snow or degraded snow conditions 
during April and May, the critical time period for wolverine 
reproductive denning. In addition, a feedback effect hastens the loss 
of snow cover due to the reflective nature of snow and the relative 
heat-absorbing properties of non-snow-covered ground. This effect leads 
to the highest magnitude of warming occurring at the interface of snow-
covered and exposed areas, increasing the rate at which melting occurs 
in spring (Groisman et al. 1994a, pp. 1637-1648; Groisman et al. 1994b, 
pp. 198-200). Due to the importance of deep snow cover in spring for 
wolverine reproduction, currently suitable habitat that loses this 
feature would be rendered unsuitable for wolverines.
Ecosystem Changes Associated with Climate Change
    Changes in temperature and rainfall patterns are expected to shift 
the distribution of ecosystems northward (IPCC 2007c, p. 230) and up 
mountain slopes (McDonald and Brown 1992, pp. 411-412; Danby and Hik 
2007, pp. 358-359; IPCC 2007c, p. 232). As climate changes over a 
landscape, the ecosystems that support wolverines are likely to move 
according to the change of temperature, but with a time lag depending 
on the ability of individual plant species to migrate (McDonald and 
Brown 1992, pp. 413-414; Hall and Fagre 2003, p. 138; Peterson 2003, p. 
652). Wolverines are not dependent on any particular ecosystem in the 
sense that they do not appear to depend on a certain vegetative 
component or other biological ecosystem attribute; however, it is 
likely that wolverines would respond to similar climatic cues as other 
members of the alpine ecosystem such that changes in tree-line location 
up or down slope would predict a similar change in wolverine 
distribution. Because of their reliance on mountainous habitat, 
wolverines in the contiguous United States will most likely adjust to 
climate changes by using higher elevations on mountain slopes, not by 
shifting their latitudinal distribution. Along a latitudinal gradient 
through the historical distribution of wolverines, records tend to be 
found at higher elevations in southern latitudes (Aubry et al. 2007, p. 
2153), suggesting that wolverines compensate for increased temperature 
at low latitudes by selecting higher elevations. Therefore, the 
regional availability of suitable habitat is not likely to 
significantly change (i.e., at least some wolverine habitat will 
continue to be available in all regions where wolverines currently 
occur), but within these landscapes, smaller areas will remain suitable 
for wolverines. Mountain ranges with maximum elevations within the 
elevation band that wolverines currently use, such as much of the 
wolverine habitat in central Idaho, may become entirely unsuitable for 
wolverines with the projected level of warming reported in McKelvey et 
al. (2011, Figure 3; see below for discussion).
Timing of Climate Effects
    Unlike snow conditions, which respond directly to temperature 
change without a time lag, ecosystem responses to temperature change do 
lag, with the magnitude of the lag depending on constituent species' 
individual migratory abilities. Wolverines are described as a ``tree-
line'' species because they are most often found in an elevation band 
that is approximately centered on the alpine tree-line at any given 
locality within their range (Inman et al. 2012a, p. 785). Alpine tree 
lines are maintained by a complex set of climactic and biotic factors, 
of which temperature is significantly important (Cogbill and White 
1991, p. 169; H[auml]ttenschwiler and K[ouml]rner 1995, p. 367; 
Jobb[aacute]gy and Jackson 2000, p. 259; Pellat et al. 2000, pp. 80-
81). However, the conditions that favor tree establishment and lead to 
elevation advance in the tree line may exist only sporadically, 
increasing time lags associated with tree line response to warming 
beyond the species-specific generation time of the trees involved 
(Hessl and Baker 1997, p. 181; Klasner and Fagre 2002, p. 54). Within 
wolverine habitats, tree lines have advanced up mountain slopes since 
1850, due to climate warming, and this trend is expected to continue 
into the future (Hessl and Baker 1997, p. 176; Hall and Fagre 2003, p. 
138). We expect that species reliant on resources associated with this 
biome, such as wolverines, will need to shift accordingly, not 
necessarily due to their dependence on the specific vegetation 
conditions, but due to wolverines likely being keyed into similar 
climatic variables. Since wolverine association with tree-line location 
is likely coincident with their dependence on climatic conditions, and 
the fact that wolverines can move about in response to climate changes, 
it is not likely that wolverines would respond to climate changes with 
a similar time lag. More likely, wolverines would respond to climate 
changes in real time, shifting habitat use more rapidly than tree-line 
shifts would occur. Given the irregular nature of tree-line response to 
warming, tree-line migration is likely to lag behind the climate 
warming that causes it.
Magnitude of Climate Effects on Wolverine
    Several studies relating the effects of climate changes on 
wolverines in the past, present, and future are now available (Brock 
and Inman Personal Communication 2007, entire; Gonzales et al. 2008, 
pp. 1-5; Brodie and Post 2010, entire; McKelvey et al. 2011, entire; 
Peacock 2011, entire; Johnston et al. 2012, entire). The Gonzalez et 
al. report and the report by Brock and Inman (Personal Communication 
2007) were both preliminary attempts to

[[Page 7876]]

analyze climate change impacts to wolverines, but are not currently 
considered the best available science because they did not consider the 
effects of both changes in temperature and precipitation that may 
affect the distribution of persistent spring snow cover (McKelvey 2011, 
entire). The analysis by Peacock (2011) is a sophisticated look at 
climate change impacts to wolverines, but suffers from the large-scale 
data presentation used. This large scale makes relating specific 
impacts to wolverines difficult, because the montane habitat inhabited 
by wolverines is climatologically complex on a small scale, and without 
significant downscaling of climate results, it is not possible to 
determine how much habitat may be left after climate change impacts 
have occurred. Both Brock and Inman (Personal Communication 2007) and 
Gonzalez et al. (2008) have been superseded by a more sophisticated 
analysis provided by McKelvey et al. (2011, entire). The course-grain 
scale of the analysis in Peacock (2011, entire) limits its use to that 
of supporting the conclusion that wolverine habitat is likely to 
decline. Likewise, the limited area analyzed by Johnston et al. (2012) 
also limits its use for this wide-ranging species. The McKelvey et al. 
(2011, entire) analysis includes climate projections at a local scale 
for wolverine habitats and analyzes the effects of both temperature 
changes and changes to precipitation patterns. Lack of accounting for 
changes in precipitation was a weakness of their own work cited by the 
authors of both Brock and Inman (Personal Communication 2007) and 
Gonzalez et al. (2008).
    Brodie and Post (2010, entire) correlate the decline in wolverine 
populations in Canada over the past century with declining snowpack due 
to climate change over the same period. However, correlation does not 
infer causation; other factors could have caused the decline. The 
Brodie and Post (2010, entire) analysis used harvest data to infer 
population trends in addition to its reliance on correlation to infer 
causation (McKelvey et al. 2010a, entire); in this case, historic 
climate changes are inferred to have caused the declines in harvest 
returns, which are thought by the authors to reflect actual population 
declines. Due to the above-stated concerns, we view the analysis of 
Brodie and Post (2010, entire) with caution, although we do agree that 
the posited mechanism, of loss of snowpack affecting wolverine 
populations and distribution, likely has merit.
    McKelvey et al. (2011, entire) used downscaled global climate 
models to project the impacts of changes in temperature and 
precipitation to wolverine habitat as modeled by Copeland et al. (2010, 
entire). The authors also present an alternative method for evaluating 
climate impacts on wolverine habitat, by merely projecting onset of 
spring snowmelt to occur 2 weeks earlier than it currently does. Based 
on this information, wolverine habitat in the contiguous United States, 
which supports approximately 250 to 300 wolverines, is shrinking and is 
likely to continue to shrink with increased climate warming (McKelvey 
et al. 2011, Figure 4). Habitat losses are likely to occur throughout 
the range of the DPS and are projected to be most severe in central 
Idaho. However, large areas of snow cover are likely to remain in the 
North Cascades, Greater Yellowstone Area (GYA), and the Glacier Park-
Bob Marshall Wilderness of Montana (McKelvey et al. 2011 Figures 4, 
13). The southern Rocky Mountains of Colorado retained significant 
high-elevation snow in some models but not others, and so may be 
another area that could support wolverine populations in the face of 
climate changes (McKelvey et al. 2011, p. 2889).
    Overall, wolverine habitat in the contiguous United States is 
expected to get smaller and more highly fragmented as individual 
habitat islands become smaller and the intervening areas between 
wolverine habitats become larger (McKelvey et al. 2011, Figures 4, 13). 
McKelvey et al. (2011) predict that 31 percent of current wolverine 
habitat in the contiguous United States will be lost due to climate 
warming by the time interval centered on 2045 (2030-2059) (McKelvey et 
al. 2011, pp. 2887-2888). That loss expands to 63 percent of wolverine 
habitat by the time interval centered on 2085 (2070 to 2099). Estimates 
for the northern Rocky Mountain States (Montana, Idaho, and Wyoming) 
are similar, with an estimated 32 percent and 63 percent of persistent 
spring snow lost for the 2045 and 2085 intervals respectively. Central 
Idaho is predicted to be especially sensitive to climate change effects 
losing 43 percent and 78 percent of wolverine habitat for the 2045 and 
2085 intervals respectively. Conversely, the mountains of Colorado 
appear to be slightly less sensitive to climate changes in their 
analysis losing 31 percent and 57 percent of habitat over the same 
intervals. Given the spatial needs of wolverines and the limited 
availability of suitable wolverine habitat in the contiguous United 
States, this projected gross loss of habitat area is likely to result 
in a loss of wolverine numbers that is greater than the overall loss of 
habitat area.
    We expect wolverine populations to be negatively affected by 
changes in the spatial distribution of habitat patches as remaining 
habitat islands become progressively more isolated from each other due 
to climate changes (McKelvey et al. 2011, Figure 8). Currently, 
wolverine habitat in the contiguous United States can be described as a 
series of habitat islands. Some of these groups of islands are large 
and clumped closely together, such as in the North Cascades, Glacier 
Park-Bob Marshall Wilderness complex in Montana, and the GYA. Other 
islands are smaller and more isolated, such as the island mountain 
ranges of central and southwestern Montana. Inbreeding and consequent 
loss of genetic diversity have occurred in the past within these 
smaller islands of habitat (Cegelski et al. 2006, p. 208), and genetic 
exchange between subpopulations is difficult to achieve (Schwartz et 
al. 2009, Figure 4). Climate change projections indicate that, as 
warming continues, large contiguous blocks of habitat will decrease in 
size and become isolated to the extent that their ability to support 
robust populations becomes questionable (McKelvey et al. 2010b, Figure 
8). Under the moderate climate change scenarios analyzed by McKelvey et 
al. (2011, entire), the current wolverine stronghold in central Idaho 
begins to look similar to the current situation in the more isolated 
mountain ranges of southwestern Montana (McKelvey et al. 2011, Figure 
4) where wolverines persist, but subpopulations are small. These 
subpopulations are essentially family groups, which require 
connectivity with other groups for genetic and possibly demographic 
enrichment. This habitat alteration would result in a high likelihood 
of reduced genetic diversity due to inbreeding within a few generations 
(Cegelski et al. 2006, p. 209). Further isolation of wolverines on 
small habitat islands with reduced connectivity to other subpopulations 
would also increase the likelihood of subpopulations loss due to 
demographic stochasticity, impairing the functionality of the wolverine 
metapopulation in the contiguous United States.
    We find that McKelvey et al. (2011, entire) represents the best 
available science for projecting the future impacts of climate change 
on wolverine habitat for four primary reasons. First, their habitat 
projections are based on global climate models that are thought to be 
the most reliable predictors of future climate available (IPCC 2007a, 
p. 12).

[[Page 7877]]

Second, they conducted downscaling analyses to infer geographic climate 
variation at a scale relevant to wolverine habitat. Third, they used a 
hydrologic model to predict snow coverage during the spring denning 
period (the strongest correlate with wolverine reproductive success). 
Fourth, they used the habitat model developed by Copeland et al. (2010, 
entire), to relate projected climate changes to wolverine habitat. 
Based on our analysis of the methods and analysis used by the authors, 
we conclude it constitutes the best available information on the likely 
impact of climate change on wolverine distribution in the contiguous 
United States. Other analyses of climate change discussed above (Brock 
and Inman Personal Communication 2007, entire; Gonzales et al. 2008, 
entire; Brodie and Post 2010, entire; Peacock 2011, entire) all support 
the conclusion that climate changes caused by warming are likely to 
negatively affect wolverine habitat in the future. Based on the 
analysis presented, we conclude that climate changes are likely to 
result in permanent loss of a significant portion of wolverine habitat 
in the future. Additional impacts of climate change will be increased 
habitat fragmentation as habitat islands become smaller and intervening 
habitat disappears. Eventually, habitat fragmentation will likely lead 
to a breakdown of wolverine metapopulation dynamics, as subpopulations 
are no longer able to rescue each other after local extinctions due to 
a lack of connectivity. It is also likely that loss of genetic 
diversity resulting in lower fitness will occur as population isolation 
increases.
Summary of Impacts of Climate Changes
    Wolverine habitat is projected to decrease in area and become more 
fragmented in the future as a result of climate changes that result in 
increasing temperatures, earlier spring snowmelt, and loss of deep, 
persistent, spring snowpack. These climate change impacts are expected 
to have direct and indirect effects to wolverine populations in the 
contiguous United States including reducing the number of wolverines 
that can be supported by available habitat and reducing the ability of 
wolverines to travel between patches of suitable habitat. This 
reduction in population size and connectivity is likely to affect 
metapopulation dynamics, making it more difficult for subpopulations to 
recolonize areas where wolverines have been extirpated and to bolster 
the genetics or demographics of adjacent subpopulations.

Habitat Impacts Due to Human Use and Disturbance

    Because wolverine habitat is generally inhospitable to human use 
and occupation and most wolverine habitat is also federally managed in 
ways that must consider environmental impacts, wolverines are somewhat 
insulated from impacts of human disturbances from industry, 
agriculture, infrastructure development, or recreation. Human 
disturbance in wolverine habitat in the contiguous United States has 
likely resulted in the loss of some minor amount of wolverine habitat, 
although this loss has not yet been quantified. Sources of human 
disturbance to wolverines has been speculated to include winter and 
summer recreation, housing and industrial development, road corridors, 
and extractive industry, such as logging or mining. In the contiguous 
United States, these human activities and developments sometimes occur 
within or immediately adjacent to wolverine home ranges, such as in 
alpine or boreal forest environments at high elevations on mountain 
slopes. They can also occur in a broader range of habitats that are 
occasionally used by wolverines during dispersal or exploratory 
movements--habitats that are not suitable for the establishment of home 
ranges and reproduction.
    Little is known about the behavioral responses of individual 
wolverines to human presence, or about the species' ability to tolerate 
and adapt to repeated human disturbance. Some speculate that 
disturbance may reduce the wolverine's ability to complete essential 
life-history activities, such as foraging, breeding, maternal care, 
routine travel, and dispersal (Packila et al. 2007, pp. 105-110). 
However, wolverines have been documented to persist and reproduce in 
areas with high levels of human use and disturbance including developed 
alpine ski areas and areas with motorized use of snowmobiles 
(Heinenmeyer 2012, entire). This suggests that wolverines can survive 
and reproduce in areas that experience human use and disturbance. How 
or whether effects of disturbance extend from individuals to 
characteristics of subpopulations and populations, such as vital rates 
(e.g., reproduction, survival, emigration, and immigration) and gene 
flow, and ultimately to wolverine population or metapopulation 
persistence, remains unknown at this time.
    Wolverine habitat is characterized primarily by spring snowpack, 
but also by the absence of human presence and development (Hornocker 
and Hash 1981 p. 1299; Banci 1994, p. 114; Landa et al. 1998, p. 448; 
Rowland et al. 2003 p. 101; Copeland 1996, pp. 124-127; Krebs et al. 
2007, pp. 2187-2190). This negative association with human presence is 
sometimes interpreted as active avoidance of human disturbance, but it 
may simply reflect the wolverine's preference for cold, snowy, and 
high-elevation habitat that humans avoid. In the contiguous United 
States, wolverine habitat is typically associated with high-elevation 
(e.g., 2,100 m to 2,600 m (6,888 ft to 8,528 ft)) subalpine forests 
that comprise the Hudsonian Life Zone (weather similar to that found in 
northern Canada), environments not typically used by people for 
housing, industry, agriculture, or transportation. However, a variety 
of activities associated with extractive industry, such as logging and 
mining, as well as recreational activities in both summer and winter 
are located in a small amount of occupied wolverine habitat.
    For the purposes of this rulemaking, we analyze human disturbance 
in four categories: (1) Dispersed recreational activities with primary 
impacts to wolverines through direct disturbance (e.g., snowmobiling 
and heli-skiing); (2) disturbance associated with permanent 
infrastructure such as residential and commercial developments, mines, 
and campgrounds; (3) disturbance and mortality associated with 
transportation corridors; and (4) disturbance associated with land 
management activities such as forestry, or fire/fuels reduction 
activities. Overlap between these categories is extensive, and it is 
often difficult to distinguish effects of infrastructure from the 
dispersed activities associated with that infrastructure. However, we 
conclude that these categories account for most of the human activities 
that occur in occupied wolverine habitat.
Dispersed Recreational Activities
    Dispersed recreational activities occurring in wolverine habitat 
include snowmobiling, heli-skiing, hiking, biking, off- and on-road 
motorized use, hunting, fishing, and other uses.
    One study documented (in two reports) the extent that winter 
recreational activity spatially and temporally overlapped modeled 
wolverine denning habitat in the contiguous United States (Heinemeyer 
and Copeland 1999, pp. 1-17; Heinemeyer et al. 2001, pp. 1-35). This 
study took place in the Greater Yellowstone Area (GYA) in an area of 
high dispersed recreational use. The overlap of modeled wolverine 
denning habitat and dispersed recreational activities was extensive. 
Strong temporal overlap existed between snowmobile activity (February-
April)

[[Page 7878]]

and the wolverine denning period (February-May). During 2000, six of 
nine survey units, ranging from 3,500 to 13,600 (ha) (8,645 to 33,592 
(ac)) in size, showed evidence of recent snowmobile use. Among the six 
survey units with snowmobile activity, the highest use covered 20 
percent of the modeled denning habitat, and use ranged from 3 to 7 
percent over the other survey units. Snowmobile activity was typically 
intensive where detected.
    Three of nine survey units in this study showed evidence of skier 
activity (Heinemeyer and Copeland 1999, p. 10; Heinemeyer et al. 2001, 
p. 16). Among the three units with activity, skier use covered 3 to 19 
percent of the survey unit. Skiers also intensively used the sites they 
visited. Combined skier and snowmobile use covered as much as 27 
percent of potential denning habitat in one unit where no evidence of 
wolverine presence was detected. We conclude from this study that in 
some areas, high recreational use may coincide substantially with 
wolverine habitat. The authors of the study cited above chose the study 
area based on its unusually high level of motorized recreational use. 
Although we do not have information on the overlap of wolverine and 
winter recreation in the remaining part of the contiguous United States 
range, it is unlikely that any of the large areas of wolverine habitat 
such as the southern Rocky Mountains, Northern Rocky Mountains, GYA, or 
North Cascades get the high levels of recreational use seen in the 
portion of the GYA examined in this study across the entire landscape. 
Rather, each of these areas has small (relative to wolverine home range 
size) areas of intensive recreational use (ski resorts, motorized play 
areas) surrounded by a landscape that is used for more dispersed 
recreation such as backcountry skiing or snowmobile trail use.
    Although we can demonstrate that recreational use of wolverine 
habitat is heavy in some areas, we do not have any information to 
suggest that these activities have negative effects on wolverines. No 
rigorous assessments of anthropogenic disturbance on wolverine den 
fidelity, food provisioning, or offspring survival have been conducted. 
Disturbance from foot and snowmobile traffic associated with historical 
wolverine control activities (Pulliainen 1968, p. 343), and field 
research activities, have been purported to cause maternal females to 
abandon natal dens and relocate kits to maternal dens (Myrberget 1968, 
p. 115; Magoun and Copeland 1998, p. 1316; Inman et al. 2007c, p. 71). 
However, this behavior appears to be rare, even under intense 
disturbance associated with capture of family groups at the den site 
(Persson et al. 2006, p. 76), and other causes of den abandonment may 
have acted in these cases. Preliminary results from an ongoing study on 
the potential impacts of winter recreation on wolverines in central 
Idaho indicate that wolverines are present and reproducing in this area 
in spite of heavy recreational use, including a developed ski area, 
dispersed winter and summer recreation, and dispersed snowmobile use 
(Heinemeyer et al. 2012, entire). The security of the den and the 
surrounding foraging areas (i.e., protection from predation by 
carnivores) is an important aspect of den site selection. Abandonment 
of natal and maternal dens may be a preemptive strategy that females 
use in the absence of predators (i.e. females may abandon dens without 
external stimuli), as this may confer an advantage to females if 
prolonged use of the same den makes that den more evident to predators. 
Evidence for effects to wolverines from den abandonment due to human 
disturbance is lacking. The best scientific information available does 
not substantiate dispersed recreational activities as a threat to 
wolverine.
    Most roads in wolverine habitat are low-traffic volume dirt or 
gravel roads used for local access. Larger, high-volume roads are dealt 
with below in the section ``transportation corridors. At both a site-
specific and landscape scale, wolverine natal dens were located 
particularly distant from public (greater than 7.5 km (4.6 mi)) and 
private (greater than 3 km (1.9 mi)) roads (May 2007, p. 14-31). 
Placement of dens away from public roads (and away from associated 
human-caused mortality) was also a positive influence on successful 
reproduction. It is not known if the detected correlation is due to the 
influence of the roads but we find it unlikely that wolverines avoid 
the type of low-use forest roads that generally occur in wolverine 
habitat. Other types of high-use roads are rare in wolverine habitat 
and are not likely to affect a significant amount of wolverine habitat 
(see transportation corridors section below).
Infrastructure Development
    Infrastructure includes all residential, industrial, and 
governmental developments such as buildings, houses, oil and gas wells, 
and ski areas. Infrastructure development on private lands in the Rocky 
Mountain West has been rapidly increasing in recent years and is 
expected to continue as people move to this area for its natural 
amenities (Hansen et al. 2002, p. 151). Infrastructure development may 
affect wildlife directly by eliminating habitats, or indirectly, by 
displacing animals from suitable habitats near developments.
    Wolverine home ranges generally do not occur near human 
settlements, and this separation is largely due to differential habitat 
selection by wolverines and humans (May et al. 2006, pp. 289-292; 
Copeland et al. 2007, p. 2211). In one study, wolverines did not 
strongly avoid developed habitat within their home ranges (May et al 
2006, p. 289). Wolverines may respond positively to human activity and 
developments that are a source of food. They scavenge food at dumps in 
and adjacent to urban areas, at trapper cabins, and at mines (LeResche 
and Hinman 1973 as cited in Banci 1994 p. 115; Banci 1994, p. 99). 
Based on the best available science, we conclude that wolverines do not 
avoid human development of the types that occur within suitable 
wolverine habitat.
    There is no evidence that wolverine dispersal is affected by 
infrastructure development. Linkage zones are places where animals can 
find food, shelter, and security while moving across the landscape 
between suitable habitats. Wolverines prefer to travel in habitat that 
is most similar to habitat they use for home-range establishment, i.e., 
alpine habitats that maintain snow cover well into the spring (Schwartz 
et al. 2009, p. 3227). Wolverines may move large distances in an 
attempt to establish new home ranges, but the probability of making 
such movements decreases with increased distance between suitable 
habitat patches, and the degree to which the characteristics of the 
habitat to be traversed diverge from preferred habitat in terms of 
climatic conditions (Copeland et al. 2010, entire; Schwartz et al. 
2009, p. 3230).
    The level of development in these linkage areas that wolverines can 
tolerate is unknown, but it appears that the current landscape does 
allow wolverine dispersal (Schwartz et al. 2009, Figures 4, 5; Moriarty 
et al. 2009, entire; Inman et al. 2009, pp. 22-28). For example, 
wolverine populations in the northern Rocky Mountains appear to be 
connected to each other at the present time through dispersal routes 
that correspond to habitat suitability (Schwartz et al. 2009, Figures 
4, 5). However, gene flow between wolverine subpopulations in the 
contiguous United States may not be high enough to prevent genetic 
drift (Cegelski et al. 2006, p. 208). To ensure long-term genetic 
viability, each subpopulation

[[Page 7879]]

within the contiguous United States would need an estimated 400 
breeding pairs, or 1 to 2 effective migrants per generation (Cegelski 
et al. 2006, p. 209). Our current understanding of wolverine ecology 
suggests that no subpopulation historically or presently at carrying 
capacity would approach 400 breeding pairs within the contiguous United 
States (Brock et al. 2007, p. 26); nor is the habitat capable of 
supporting anywhere near this number. It is highly unlikely that 400 
breeding pairs exist in the entire contiguous United States. Because no 
wolverine subpopulations are likely to be large enough to maintain 
genetic diversity over time on their own, long-term viability of 
wolverines in the contiguous United States requires exchange of 
individuals between subpopulations.
    Wolverines are capable of long-distance movements through variable 
and anthropogenically altered terrain, crossing numerous transportation 
corridors (Moriarty et al. 2009, entire; Inman et al. 2009, pp. 22-28). 
Wolverines are able to successfully disperse between habitats, despite 
the level of development that is currently taking place in the current 
range of the DPS (Copeland 1996, p. 80; Copeland and Yates 2006, pp. 
17-36; Inman et al. 2007a, pp. 9-10; Pakila et al. 2007, pp. 105-109; 
Schwartz et al. 2009, Figures 4, 5). Dispersal between populations is 
needed to avoid further reduction in genetic diversity; however, there 
is no evidence that human development and associated activities are 
preventing wolverine movements between suitable habitat patches. 
Rather, wolverine movement rates are limited by suitable habitat and 
proximity of suitable habitat patches, not the characteristics of the 
intervening unsuitable habitat (Schwartz et al. p. 3230).
Transportation Corridors
    Transportation corridors are places where transportation 
infrastructure and other forms of related infrastructure are 
concentrated together. Examples include interstate highways and high-
volume secondary highways. These types of highway corridors often 
include railroads, retail, industrial, and residential development and 
also electrical and other types of energy transmission infrastructure. 
Transportation corridors may affect wolverines if located in wolverine 
habitat or between habitat patches. If located in wolverine habitat, 
transportation corridors result in direct loss of habitat. Direct 
mortality due to collisions with vehicles is also possible (Packila et 
al. 2007, Table 1).
    The Trans Canada Highway at Kicking Horse Pass in southern British 
Columbia, an important travel corridor over the Continental Divide, has 
a negative effect on wolverine movement (Austin 1998, p. 30). 
Wolverines partially avoided areas within 100 m (328 ft) of the 
highway, and preferred to use distant sites (greater than 1,100 m 
(3,608 ft)). Wolverines that approached the highway to cross repeatedly 
retreated, and successful crossing occurred in only half of the 
attempts (Austin 1998, p. 30). Highway-related mortality was not 
documented in the study. Where wolverines did successfully cross, they 
used the narrowest portions of the highway right-of-way. A railway with 
minimal human activity, adjacent to the highway, had little effect on 
wolverine movements. Wolverines did not avoid, and even preferred, 
compacted, lightly used ski trails in the area. The extent to which 
avoidance of the highway may have affected wolverine vital rates or 
life history was not measured.
    In the tri-State area of Idaho, Montana, and Wyoming, most 
crossings of Federal or State highways were done by subadult wolverines 
making exploratory or dispersal movements (ranges of resident adults 
typically did not contain major roads) (Packila et al. 2007, p. 105). 
Roads in the study area, typically two-lane highways or roads with less 
improvement, were not absolute barriers to wolverine movement. The 
individual wolverine that moved to Colorado from Wyoming in 2008 
successfully crossed Interstate 80 in southern Wyoming (Inman et al. 
2008, Figure 6). Wolverines in Norway successfully cross deep valleys 
that contain light human developments such as railway lines, 
settlements, and roads (Landa et al. 1998, p. 454). Wolverines in 
central Idaho avoided portions of a study area that contained roads, 
although this was possibly an artifact of unequal distribution of roads 
that occurred at low elevations and peripheral to the study site 
(Copeland et al. 2007, p. 2211). Wolverines frequently used un-
maintained roads for traveling during the winter, and did not avoid 
trails used infrequently by people or active campgrounds during the 
summer (Copeland et al. 2007, p. 2211).
    At both a site-specific and landscape scale, wolverine natal dens 
were located particularly distant from public (greater than 7.5 km (4.6 
mi)) and private (greater than 3 km (1.9 mi)) roads (May 2007, p. 14-
31). Placement of dens away from public roads (and away from associated 
human-caused mortality) was a positive influence on successful 
reproduction (May 2007, p. 14-31). Predictive, broad-scale habitat 
models, developed using historical records of wolverine occurrence, 
indicated that roads were negatively associated with wolverine 
occurrence (Rowland et al. 2003, p. 101). Although wolverines appear to 
avoid transportation corridors in their daily movements, studies of the 
few areas where transportation corridors are located in wolverine 
habitat leads us to conclude that the effects are most likely local in 
scale. There are no studies that address potential effects of 
transportation corridors in linkage areas (i.e. outside of wolverine 
habitat). In the few documented long-distance movements by wolverines, 
the animals successfully crossed transportation corridors (Inman et al. 
2009, Fig. 6). The available evidence indicates that dispersing 
wolverines can successfully cross transportation corridors.
Land Management
    Few effects to wolverines from land management actions such as 
grazing, timber harvest, and prescribed fire have been documented. 
Wolverines in British Columbia used recently logged areas in the summer 
and moose winter ranges for foraging (Krebs et al. 2007, pp. 2189-
2190). Males did not appear to be influenced strongly by the presence 
of roadless areas (Krebs et al. 2007, pp. 2189-2190). In Idaho, 
wolverines used recently burned areas despite the loss of canopy cover 
(Copeland 1996, p. 124).
    Intensive management activities such as timber harvest and 
prescribed fire do occur in wolverine habitat; however, for the most 
part, wolverine habitat tends to be located at high elevations and in 
rugged topography that is unsuitable for intensive timber management. 
Much of wolverine habitat is managed by the U.S. Forest Service or 
other Federal agencies and is protected from some practices or 
activities such as residential development. In addition, much of 
wolverine habitat within the contiguous United States is already in a 
management status such as wilderness or national park (see Factor D for 
more discussion) that provides some protection from management, 
industrial, and recreational activities. Wolverines are not thought to 
be dependent on specific vegetation or habitat features that might be 
manipulated by land management activities, nor is there evidence to 
suggest that land management activities are a threat to the 
conservation of the species.
Summary of Factor A
    The threat of current, and future impacts to wolverine habitat due 
to climate change occurs over the entire range of the contiguous United 
States

[[Page 7880]]

population of the wolverine. This threat is likely to have already 
reduced the overall areal extent and distribution of wolverine suitable 
habitat. Determining whether or not wolverine populations have been 
impacted by this threat is complicated by the historical extirpation of 
wolverines in the early 20th century followed by recolonization and 
expansion. It is possible that expansion of wolverine populations 
through the second half of the 20th century has masked climate change 
effects that would have otherwise reduced populations had they existed 
at presettlement levels. Despite the lack of detectable population-
level impacts, it is still likely that habitat is already reduced from 
historic levels due to this threat.
    Suitable wolverine habitat is projected to be reduced by 31 percent 
in the contiguous United States by 2045 and 63 percent by the time 
interval 2070 to 2099 due to climate warming. This reduction will 
likely result in suitable wolverine habitat shifting up mountain 
slopes, and becoming smaller and more isolated due to the conical 
structure of mountains. Because wolverine home ranges tend to be so 
large, some small mountain ranges are likely to lose the ability to 
support wolverine populations. We expect that the secondary effects of 
this habitat loss, such as increased habitat fragmentation and 
isolation, will intensify the overall impacts of habitat loss on 
wolverines.
    Deep snow that persists into the month of May is essential for 
wolverine reproduction. This life-history parameter for the species 
(reproductive rate) is likely to be most sensitive to climate changes. 
Wolverine are vulnerable to habitat modification (specifically, 
reduction in persistent spring snow cover) due to climate warming in 
the contiguous United States. Further, it is likely that year-round 
wolverine habitat, not just denning habitat, will also be significantly 
reduced due to the effects of climate warming. Reductions in habitat 
would result in greater habitat isolation, thereby likely reducing the 
frequency of dispersal between habitat patches and the likelihood of 
recolonization after local extinction events. This reduced dispersal 
ability, if not compensated for by higher population levels or assisted 
dispersal, is likely to result in loss of genetic diversity within 
remaining habitat patches and population loss due to demographic 
stochasticity. The contiguous United States population of wolverines is 
already very small and fragmented and is, therefore, particularly 
vulnerable to these impacts.
    Human activities, including dispersed recreation activities, 
infrastructure, and the presence of transportation corridors occur in 
occupied wolverine habitat. However, the alpine and subalpine habitats 
preferred by wolverine typically receive little human use relative to 
lower elevation habitats. The majority of wolverine habitat (over 90 
percent) occurs within Forest Service and National Park Service lands 
that are subject to activities, but usually not direct habitat loss to 
infrastructure development. The best available science leads us to 
determine that human activities and developments do not pose a current 
threat to wolverines in the contiguous United States.
    Wolverines coexist with some modification of their environment, as 
wilderness characteristics such as complete lack of motorized use or 
any permanent human presence are likely not critical for maintenance of 
populations. It is clear that wolverines coexist with some level of 
human disturbance and habitat modification.
    We know of no examples where human activities such as dispersed 
recreation have occurred at a scale that could render a large enough 
area unsuitable so that a wolverine home range would be likely to be 
rendered unsuitable or unproductive. Given the large size of home 
ranges used by wolverine, most human activities affect such a small 
portion that negative effects to individuals are unlikely. These 
activities do not occur at a scale that is likely to have population-
level effects to wolverine.
    Little scientific or commercial information exists regarding 
effects to wolverines from development or human disturbances associated 
with them. What little information does exist suggests that wolverines 
can adjust to moderate habitat modification, infrastructure 
development, and human disturbance. In addition, large amounts of 
wolverine habitat are protected from human disturbances and 
development, either legally through wilderness and National Park 
designation, or by being located at remote and high-elevation sites. 
Therefore, wolverines are afforded a relatively high degree of 
protection from the effects of human activities by the nature of their 
habitat. Wolverines are known to successfully disperse long distances 
between habitats through human-dominated landscapes and across 
transportation corridors. The current level of residential, industrial, 
and transportation development in the western United States does not 
appear to have precluded the long-distance dispersal movements that 
wolverines require for maintenance of genetic diversity. We do not have 
information to suggest that future levels of residential, industrial, 
and transportation development would be a significant conservation 
concern for the DPS.
    In summary, the best scientific and commercial information 
available indicates that only the projected decrease and fragmentation 
of wolverine habitat or range due to future climate change is a threat 
to the species now and in the future. The available scientific and 
commercial information does not indicate that other potential stressors 
such as land management, recreation, infrastructure development, and 
transportation corridors pose a threat to the DPS.

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

    Over much of recent history, trapping has been a primary cause of 
wolverine mortality (Banci 1994, p. 108; Krebs et al. 2004, p. 497; 
Lofroth and Ott 2007, pp. 2196-2197; Squires et al. 2007, p. 2217). 
Unregulated trapping is believed to have played a role in the 
historical decline of wolverines in North America in the late 1800s and 
early 1900s (Hash 1987, p. 580). Wolverines are especially vulnerable 
to targeted trapping and predator reduction campaigns due to their 
habit of ranging widely in search of carrion, bringing them into 
frequent contact with poison baits and traps (Copeland 1996, p. 78; 
Inman et al. 2007a, pp. 4-10; Packila et al. 2007, p. 105; Squires et 
al. 2007, p. 2219).
    Human-caused mortality of wolverines is likely additive to natural 
mortality due to the low reproductive rate and relatively long life 
expectancy of wolverines (Krebs et al. 2004, p. 499; Lofroth and Ott 
2007, pp. 2197-2198; Squires et al. 2007, pp. 2218-2219). This means 
that trapped subpopulations likely live at densities that are lower 
than carrying capacity, and may need to be reinforced by recruits from 
untrapped subpopulations to maintain population viability and 
persistence.
    A study in British Columbia determined that, under a regulated 
trapping regime, trapping mortality in 15 of 71 wolverine population 
units was unsustainable, and that populations in those unsustainable 
population units were dependent on immigration from neighboring 
populations or untrapped refugia (Lofroth and Ott 2007, pp. 2197-2198). 
Similarly, in southwestern Montana, legal trapping in isolated mountain 
ranges accounted for 64 percent of documented mortality and reduced the 
local wolverine subpopulation (Squires et al. 2007, pp. 2218-2219). The 
observed harvest

[[Page 7881]]

levels, which included two pregnant females in a small mountain range, 
could have significant negative effects on a small subpopulation 
(Squires et al. 2007, p. 2219). Harvest refugia, such as jurisdictions 
with closed seasons, national parks, and large wilderness areas, are 
important to wolverine persistence on the landscape because they can 
serve as sources of surplus individuals to bolster trapped populations 
(Squires et al. 2007, p. 2219; Krebs and Ott 2004, p. 500). Due to 
their large space requirements, wolverine population refuges must be 
large enough to provide protection from harvest mortality; and complete 
protection is only available for wolverines whose entire home range 
occurs within protected areas. Glacier National Park, though an 
important refuge for a relatively robust population of wolverines, was 
still vulnerable to trapping because most resident wolverine home 
ranges extended into large areas outside the park (Squires et al. 2007, 
p. 2219). It is likely that the largerscale refuges provided by the 
states of Idaho and Wyoming (which do not permit wolverine trapping) 
provide wolverine habitat that is fully protected from legal harvest in 
Montana; however, wolverines with home ranges that partially overlap 
Montana and dispersers that move into Montana would be vulnerable to 
harvest. Due to the restrictive, low level of harvest now allowed by 
Montana, the number of affected wolverines would be correspondingly 
small.
    Despite the impacts of trapping on wolverines in the past, trapping 
is no longer a threat within most of the wolverine range in the 
contiguous United States. Montana is the only State where wolverine 
trapping is still legal. Before 2004, average wolverine harvest was 
10.5 wolverines per year. Due to preliminary results of the study 
reported in Squires et al. (2007, pp. 2213-2220), the Montana 
Department of Fish, Wildlife, and Parks adopted new regulations for the 
2004-2005 trapping season that divided the State into three units, with 
the goal of spreading the harvest more equitably throughout the State.
    For the 2008-2009 trapping season, the Montana Department of Fish, 
Wildlife, and Parks adjusted its wolverine trapping regulations again 
to further increase the geographic control on harvest to prevent 
concentrated trapping in any single area, and to completely stop 
trapping in isolated mountain ranges where small populations are most 
vulnerable (Montana Department of Fish Wildlife and Parks 2010, pp. 8-
11). Their new regulations spread harvest across three geographic units 
(the Northern Continental Divide area, the Greater Yellowstone area, 
and the Bitterroot Mountains), and established a statewide limit of 
five wolverines. In the four trapping seasons that have occurred since 
these rules were implemented, wolverine take averaged 3.25 wolverines 
annually (Montana Department of Fish Wildlife and Parks 2010, pp. 8-11; 
Brian Giddings Pers. Comm. August 30, 2012), with reduced harvest being 
due to season closure rather than lack of wolverines. Under the current 
regulations, no more than three female wolverines can be legally 
harvested each year, and harvest in the more vulnerable isolated 
mountain ranges is prohibited. The size of the wolverine population 
subjected to trapping in this area is not known precisely but is likely 
not more than about 300 animals in states of Montana, Idaho, and 
Wyoming combined (Bob Inman pers. comm. 2010b).
    The Montana Department of Fish, Wildlife, and Parks conduct yearly 
furbearer monitoring using track surveys. These surveys involve 
snowmobiling along transect routes under good tracking conditions and 
visually identifying all carnivore tracks encountered. The protocol 
does not use verification methods such as DNA collection or camera 
stations to confirm identifications. Consequently, misidentifications 
are likely to occur. Given the relative rarity of wolverines and the 
relative abundance of other species with which they may be confused, 
such as bobcats (Lynx rufus), Canada lynx (Lynx canadensis), and 
mountain lions (Felis concolor), lack of certainty of identifications 
of tracks makes it highly likely that the rare species is 
overrepresented in unverified tracking records (McKelvey et al. 2008, 
entire). The Montana Department of Fish, Wildlife, and Parks wolverine 
track survey information does not meet our standard for reliability 
described in the geographic distribution section, and we have not 
relied on this information in this finding.
    Montana wolverine populations have rebounded from historic lows in 
the early 1900s while at the same time being subjected to regulated 
trapping (Aubry et al. 2007, p. 2151; Montana Department of Fish, 
Wildlife, and Parks 2007, p. 1). In fact, much of the wolverine 
expansion that we have described above took place under less-
restrictive (i.e., higher harvest levels) harvest regulations than are 
in place today. The extent to which wolverine population growth has 
occurred in Montana as a result of within-Montana population growth, 
versus population growth attributable to surrounding states where 
wolverines are not trapped, i.e., population growth driven by the 
entire metapopulation versus just the portion of the metapopulation 
found in Montana, is unknown.
    Current levels of incidental trapping (i.e., capture in traps set 
for species other than wolverine) have been suggested by the 
petitioners to be a threat to wolverines. In the 2008-2009 trapping 
season, two wolverines were incidentally killed in traps set for other 
species in Beaverhead and Granite Counties, Montana (Montana Fish, 
Wildlife, and Parks 2010, p. 2). These two mortalities occurred within 
the portion of southwestern Montana that is currently closed to legal 
wolverine trapping to ensure that wolverines are not unsustainably 
harvested in this area of small, relatively isolated mountain ranges. 
Four cases of incidental wolverine trapping have occurred in Idaho in 
recent years. One wolverine was trapped by a coyote/bobcat trapper in 
2006 and was collared and released after all of its toes and a portion 
of its left front foot were amputated (Inman et al. 2008, p. 1). That 
animal (a female) survived and successfully reproduced after release. 
The Department of Agriculture Wildlife Services trapped three 
wolverines (one each in 2004, 2005, and 2010) incidental to trapping 
wolves involved in livestock depredations. One of these sustained 
severe injuries and was euthanized. The other two were released without 
visible injury. Another wolverine was trapped in Wyoming in 2006. This 
animal was released unharmed (Inman 2012, pers. comm.). The three 
documented mortalities are possibly locally significant for wolverines 
in these areas because local populations in each of the mountain ranges 
are small and relatively isolated from nearby source populations.
Summary of Factor B
    Legal wolverine harvest occurs in one state, Montana, within the 
range of the DPS. The extent to which this harvest affects populations 
occurring outside of Montana is unknown. However, the State of Montana 
contains most of the habitat and wolverines that exist in the current 
range of the DPS, and regulates trapping to reduce the impact of 
harvest on wolverine populations. Incidental harvest also occurs within 
the range of the DPS; however, the level of mortality from incidental 
trapping appears to be low. Harvest,when combined with the likely 
effects of climate change, may contribute to the likelihood that the 
wolverine will become extirpated in the

[[Page 7882]]

future. This may occur by increasing the speed with which small 
populations of wolverine are lost from isolated habitats, and also by 
increasing mortality levels for dispersing wolverines, with the result 
of reducing dispersal rates. Regular dispersal and exchange of genetic 
material are required to maintain the genetics and demographics of 
wolverine subpopulations in the contiguous United States.
    The current known level of incidental trapping mortality is low. We 
note that it is unknown whether or not increased trapping of wolves 
associated with wolf trapping regulations recently approved by the 
states of Idaho and Montana would be likely to result in increased 
incidental trapping of wolverines. Idaho began its wolf trapping 
program in the winter of 2011-2012, and Montana began theirs in the 
winter of 2012-2013. These wolf trapping activities are relatively new 
in the DPS area, and we do not yet have reliable information on the 
level of incidental take of wolverines that may result from them.
    Based on the best scientific and commercial information available, 
we conclude that trapping, including known rates of incidental trapping 
in Montana and Idaho, result in a small number of wolverine mortalities 
each year and that this level of mortality by itself would not be a 
threat to the wolverine DPS. However, by working in concert with 
habitat loss resulting from climate change, mortality due to harvest 
and incidental trapping may contribute to population declines. 
Therefore, we conclude that trapping, when considered cumulatively with 
habitat loss resulting from climate change, is likely to become a 
threat to the DPS (see discussion under Synergistic Interactions 
Between Threat Factors, below).

Factor C. Disease or Predation

    No information is currently available on the potential effects of 
disease on wild wolverine populations. Wolverines are sometimes killed 
by wolves (Canis lupus), black bears (Ursus americanus), and mountain 
lion (Burkholder 1962, p. 264; Hornocker and Hash 1981, p. 1296; 
Copeland 1996, p. 44-46; Inman et al. 2007d, p. 89). In addition, 
wolverine reproductive dens are likely subject to predation, although 
so few dens have been discovered in North America that determining the 
intensity of this predation is not possible.
Summary of Factor C
    We have no information to suggest that wolverine mortality from 
predation and disease is above natural or sustainable levels. The best 
scientific and commercial information available indicates that disease 
or predation is not a threat to the species now or likely to become so 
in the future.

Factor D. Inadequacy of Existing Regulatory Mechanisms

    Based on our calculations using a composite map showing the 
coverage of both the Copeland et al. (2010, entire) and Inman et al. 
(2012, entire) wolverine habitat models, the majority (94 percent) of 
wolverine habitat currently occupied by wolverine populations in the 
lower contiguous United States is Federally owned and managed, mostly 
by the U.S. Forest Service. An estimated 144,371 km\2\ (49,258 mi\2\) 
of wolverine habitat occurs in the occupied area in Montana, Idaho, 
Oregon (Wallowa Range), and Wyoming. Of that, 135,396 km\2\ (46,332 
mi\2\) is in Federal ownership. Additionally, 47,150 km\2\ (12,973 
mi\2\) (32.7 percent) occurs in designated wilderness, and 23,062 km\2\ 
(1,630 mi\2\) (16.0 percent) occurs in inventoried roadless areas. An 
additional 13,784 km\2\ (3,288 mi\2\) (9.5 percent) are within national 
parks.
    None of the existing Federal or State regulatory mechanisms were 
designed to address the threat of modification of wolverine habitat due 
to the loss of snowpack associated with climate change. Several 
existing regulatory mechanisms protect wolverine from other forms of 
disturbance and from overutilization from harvesting; these are 
described in more detail below.
Federal Laws and Regulations
The Wilderness Act
    The Forest Service and National Park Service both manage lands 
designated as wilderness areas under the Wilderness Act of 1964 (16 
U.S.C. 1131-1136). Within these areas, the Wilderness Act states the 
following: (1) New or temporary roads cannot be built; (2) there can be 
no use of motor vehicles, motorized equipment, or motorboats; (3) there 
can be no landing of aircraft; (4) there can be no other form of 
mechanical transport; and (5) no structure or installation may be 
built. A large amount of suitable wolverine habitat, about 28 percent 
for the states of Montana, Idaho, and Wyoming, occurs within Federal 
wilderness areas in the United States (Inman personal communication 
2007b). As such, a large proportion of existing wolverine habitat is 
protected from direct loss or degradation by the prohibitions of the 
Wilderness Act.
National Environmental Policy Act
    All Federal agencies are required to adhere to the National 
Environmental Policy Act (NEPA) of 1970 (42 U.S.C. 4321 et seq.) for 
projects they fund, authorize, or carry out. The Council on 
Environmental Quality's regulations for implementing NEPA (40 CFR 1500-
1518) state that agencies shall include a discussion on the 
environmental impacts of the various project alternatives (including 
the proposed action), any adverse environmental effects which cannot be 
avoided, and any irreversible or irretrievable commitments of resources 
involved (40 CFR 1502). The NEPA itself is a disclosure law, and does 
not require subsequent minimization or mitigation measures by the 
Federal agency involved. Although Federal agencies may include 
conservation measures for wolverines as a result of the NEPA process, 
any such measures are typically voluntary in nature and are not 
required by the statute. Additionally, activities on non-Federal lands 
are subject to NEPA if there is a Federal action.
    For example, wolverines are designated as a sensitive species by 
the Forest Service, which requires that effects to wolverines be 
considered in documentation completed under NEPA. NEPA does not itself 
regulate activities that might affect wolverines, but it does require 
full evaluation and disclosure of information regarding the effects of 
contemplated Federal actions on sensitive species and their habitats.
National Forest Management Act
    Under the National Forest Management Act of 1976, as amended (16 
U.S.C. 1600-1614), the Forest Service shall strive to provide for a 
diversity of plant and animal communities when managing national forest 
lands. Individual national forests may identify species of concern that 
are significant to each forest's biodiversity. Outside of designated 
wilderness but still on Forest Service-managed lands, wolverines occur 
mainly in alpine areas. Their habitat is generally offered more 
protections from timber harvest than would otherwise be the case in 
lowland areas due to the difficulty of accessing wolverine habitat, 
especially in areas where motorized access is limited or absent, such 
as most National Forest land and all designated wilderness areas.
National Park Service Organic Act
    The NPS Organic Act of 1916 (16 U.S.C. 1 et seq.), as amended, 
states that the NPS ``shall promote and regulate the use of the Federal 
areas known as

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national parks, monuments, and reservations to conserve the scenery and 
the national and historic objects and the wildlife therein and to 
provide for the enjoyment of the same in such manner and by such means 
as will leave them unimpaired for the enjoyment of future 
generations.'' Where wolverines occur in National Parks, they and their 
habitats are protected from large-scale loss or degradation due to the 
Park Service's mandate to ``* * * conserve scenery * * * and wildlife * 
* * [by leaving] them unimpaired.'' Wolverine harvest and trapping of 
other furbearers is also prohibited in National Parks.
Clean Air Act of 1970
    On December 15, 2009, the Environmental Protection Agency (EPA) 
published in the Federal Register (74 FR 66496) a rule titled, 
``Endangerment and Cause or Contribute Findings for Greenhouse Gases 
under Section 202(a) of the Clean Air Act.'' In this rule, the EPA 
Administrator found that the current and projected concentrations of 
the six long-lived and directly emitted greenhouse gases (GHGs)--carbon 
dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, 
and sulfur hexafluoride--in the atmosphere threaten the public health 
and welfare of current and future generations; and that the combined 
emissions of these GHGs from new motor vehicles and new motor vehicle 
engines contribute to the GHG pollution that threatens public health 
and welfare (74 FR 66496). In effect, the EPA has concluded that the 
GHGs linked to climate change are pollutants, whose emissions can now 
be subject to the Clean Air Act (42 U.S.C. 7401 et seq.) (see 74 FR 
66496). However, specific regulations to limit GHG emissions were only 
proposed in 2010 and, therefore, cannot be considered an existing 
regulatory mechanism. At present, we have no basis to conclude that 
implementation of the Clean Air Act in the future (40 years, based on 
global climate projections) will substantially reduce the current rate 
of global climate change through regulation of GHG emissions. Thus, we 
conclude the Clean Air Act is not designed to address the primary 
threat to wolverine of the loss of snowpack due to the effects of 
climate change.
State Laws and Regulations
State Comprehensive Wildlife Conservation Strategies and State 
Environmental Policy and Protection Acts
    The wolverine is listed as State Endangered in Washington, 
California, and Colorado. In Idaho and Wyoming it is designated as a 
protected nongame species (Idaho Department of Fish and Game 2010, p. 
4; Wyoming Game and Fish 2005, p. 2). Oregon, while currently not 
considered to have any individuals other than possible unsuccessful 
dispersers, has a closed season on trapping of wolverines. These 
designations largely protect the wolverine from mortality due to 
hunting and trapping. In Montana, the wolverine is classified as a 
regulated furbearer (Montana Fish, Wildlife, and Parks 2010, p. 8). 
Montana is the only State in the contiguous United States where 
wolverine trapping is still legal.
    Wolverines receive some protection under State laws in Washington, 
California, Idaho, Montana, Wyoming, and Colorado. Each State's fish 
and wildlife agency has some version of a State Comprehensive Wildlife 
Conservation Strategy (CWCS) in place. These strategies, while not 
State or Federal legislation, can help prioritize conservation actions 
within each State. Named species and habitats within each CWCS may 
receive focused attention during State Environmental Protection Act 
(SEPA) reviews as a result of being included in a State's CWCS. 
However, only Washington, California, and Montana appear to have SEPA-
type regulations in place. In addition, each State's fish and wildlife 
agency often specifically names or implies protection of wolverines in 
its hunting and trapping regulations. Only the State of Montana 
currently allows wolverine harvest (see discussion under Factor B).
    Before 2004, the Montana Department of Fish, Wildlife, and Parks 
regulated wolverine harvest through the licensing of trappers, a bag 
limit of one wolverine per year per trapper, and no statewide limit. 
Under this management, average wolverine harvest was 10.5 wolverines 
per year. Due to preliminary results of the study reported in Squires 
et al. (2007, pp. 2213-2220), Montana Department of Fish, Wildlife, and 
Parks adopted new regulations for the 2004-2005 trapping season that 
divided the State into three units with the goal of spreading the 
harvest more equitably among available habitat. In 2008, Montana 
Department of Fish, Wildlife, and Parks further refined their 
regulations to prohibit trapping in isolated mountain ranges, and 
reduced the overall statewide harvest to five wolverines with a 
statewide female harvest limit of three. Under factor B, above, we 
concluded that trapping, including known rates of incidental trapping 
in Montana, by itself, is not a threat to the wolverine DPS, but that 
by working in concert with the primary threat of climate change, the 
trapping program may contribute to population declines (see Synergistic 
Interactions Between Threat Factors, below).
Summary of Factor D
    The existing regulatory mechanisms appear to protect wolverine from 
several of the factors described in Factors A and B above. 
Specifically, State regulations for wolverine harvest appear to be 
sufficient to prohibit range-wide overutilization from hunting and 
trapping in the absence of other threats. However, given that climate 
change impacts are expected to reduce wolverine populations and 
fragment habitat, the impact of harvest to wolverine would be expected 
to increase if harvest levels were maintained at current levels. 
Federal ownership of much of occupied wolverine habitat protects the 
species from direct losses of habitat and provides further protection 
from many of the forms of disturbance described above. Wolverines use 
habitats affected by human disturbance, and additional protection is 
afforded wolverines by the large area of their range that occurs in 
designated wilderness and national parks. The current regulatory regime 
does not address the potential impacts of dispersed winter recreation 
outside of protected areas; however, at this time the available 
information does not suggest that dispersed winter recreation is a 
threat to the DPS.
    Our review of the regulatory mechanisms in place at the national 
and State level demonstrates that the short-term, site-specific threats 
to wolverine from direct loss of habitat, disturbance by humans, and 
direct mortality from hunting and trapping are, for the most part, 
adequately addressed through State and Federal regulatory mechanisms. 
However, as described under Factor A, the primary threat with the 
greatest severity and magnitude of impact to the species is loss of 
habitat due to continuing climate warming. The existing regulatory 
mechanisms currently in place at the national level were not designed 
to address the threat to wolverine habitat from climate change.

Factor E. Other Natural or Manmade Factors Affecting Its Continued 
Existence

Small Population Size
    Population ecologists use the concept of a population's 
``effective'' size as a measure of the proportion of the actual 
population that contributes to future generations (for a review of 
effective population size, see Schwartz et al.

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1998, entire). In a population where all of the individuals contribute 
offspring equally, effective population size would equal true 
population size, referred to as the population census size. For 
populations where contribution to the next generations is often 
unequal, effective population size will be smaller than the census 
size. The smaller the effective population size, the more reproduction 
in each generation is dominated by a few individuals in each 
generation. For wolverines it is likely that high-quality home ranges 
are limited, and individuals occupying them are better able to 
reproduce. Therefore, mature males and females that are successful at 
acquiring and defending a territory may dominate reproduction. Another 
contributing factor that reduces effective population size is the 
tendency in wolverines for a few males to monopolize the reproduction 
of several females, reducing reproductive opportunities for other 
males. Although this monopolization is a natural feature of wolverine 
life history strategy, it can lead to lower effective population size 
and reduce population viability by reducing genetic diversity. The 
effective population is not static, members of the effective population 
in 1 year may lose this status in the following year and possibly 
regain it again later depending on their reproductive success. When 
members of the effective population are lost, it is likely that their 
territories are quickly filled by younger individuals who may not have 
been able to secure a productive territory previously.
    Effective population size is important because it determines rates 
of loss of genetic variation and the rate of inbreeding. Populations 
with small effective population sizes show reductions in population 
growth rates and increases in extinction probabilities when genetic 
diversity is low enough to lead to inbreeding depression (Leberg 1990, 
p. 194; Jimenez et al. 1994, pp. 272-273; Newman and Pilson 1997, p. 
360; Saccheri et al. 1998, p. 492; Reed and Bryant 2000, p. 11; 
Schwartz and Mills 2005, p. 419; Hogg et al. 2006, p. 1495, 1498; 
Allendorf and Luikart 2007, pp. 338-342). Franklin (1980, as cited in 
Allendorf and Luikart 2007, p. 359) proposed an empirically based rule 
suggesting that for short-term (a few generations) maintenance of 
genetic diversity, effective population size should not be less than 
50. For long-term (hundreds of generations) maintenance of genetic 
diversity, effective population size should not be less than 500 (for 
appropriate use of this rule and its limitations see Allendorf and 
Luikart 2007, pp. 359-360). Others suggest that even higher numbers are 
required to ensure that populations remain viable, suggesting that 
long-term connectivity to the reservoir of genetic resources in the 
Canadian population of wolverines will be required for the long-term 
genetic health of the DPS (Traill et al. 2010, p. 32). All evidence 
suggests that no habitat area within the contiguous United States is 
large enough to support a wolverine population with an effective 
population size of 500 animals. Given the life history of wolverines 
that includes high inequality of reproductive success and a 
metapopulation of semi-isolated subpopulations, effective population 
sizes would likely never reach even 100 individuals at full habitat 
occupancy as this would suggest a census population of over 1,000. In 
this case, population connectivity exchange with the larger Canadian/
Alaskan population would likely be required for long-term viability.
    Wolverine effective population size in the northern Rocky 
Mountains, which is the largest extant population in the contiguous 
United States, is exceptionally low and is below what is thought 
necessary for short-term maintenance of genetic diversity. Estimates 
for effective population size for wolverines in the northern Rocky 
Mountains averaged 35 (credible limits = 28-52) (Schwartz et al. 2009, 
p. 3226). This study excluded the small population from the Crazy and 
Belt Mountains (hereafter ``CrazyBelts'') as they may be an isolated 
population, which could bias the estimate using the methods of Tallmon 
et al. (2007, entire). Measures of the effective population sizes of 
the other populations in the contiguous United States have not been 
completed, but given their small census sizes, their effective sizes 
are expected to be smaller than for the northern Rocky Mountains 
population. Thus, wolverine effective population sizes are very low. 
For comparison, estimates of wolverine effective population size are 
bracketed by critically endangered species, such as the black-footed 
ferret (Mustela nigripes) (4.10) (Wisely et al. 2007, p. 3) and the 
ocelot (Leopardus pardalis) (2.9 to 13.9) (Janecka et al. 2007, p. 1), 
but are substantially smaller than estimates for the Yellowstone 
grizzly bear (Ursus arctos) (greater than 100), which has reached the 
level of recovery under the Act (Miller and Waits 2003, p. 4338). 
Therefore, we conclude that effective population size estimates for 
wolverines do not suggest that populations are currently critically 
endangered, but they do suggest that populations are low enough that 
they could be vulnerable to loss of genetic diversity, and may require 
intervention in the future to remain viable. To date, no adverse 
effects of the lower genetic diversity of the contiguous United States 
wolverines have been documented.
    Wolverines in the contiguous United States are thought to be 
derived from a recent recolonization event after they were extirpated 
from the area in the early 20th century (Aubry et al. 2007, Table 1). 
Consequently, wolverine populations in the contiguous United States 
have reduced genetic diversity relative to larger Canadian populations 
as a result of founder effects or inbreeding (Schwartz et al. 2009, pp. 
3228-3230). Wolverine effective population size in the northern Rocky 
Mountains was estimated to be 35 (Schwartz et al. 2009, p. 3226) and is 
below what is thought to be adequate for short-term maintenance of 
genetic diversity. Loss of genetic diversity can lead to inbreeding 
depression and is associated with increased risk of extinction 
(Allendorf and Luikart 2007, pp. 338-343). Small effective population 
sizes are caused by small actual population size (census size), or by 
other factors that limit the genetic contribution of portions of the 
population, such as polygamous mating systems. Populations may increase 
their effective size by increasing census size or by the regular 
exchange of genetic material with other populations through 
interpopulation mating.
    The concern with the low effective population size was highlighted 
in a recent analysis that determined that, without immigration from 
other wolverine populations, at least 400 breeding pairs would be 
necessary to sustain the long-term genetic viability of the northern 
Rocky Mountains wolverine population (Cegelski et al. 2006, p. 197). 
However, the entire population is likely only 250 to 300 (Inman 2010b, 
pers. comm.), with a substantial number of these being unsuccessful 
breeders or nonbreeding subadults (i.e., part of the census population, 
but not part of the effective population).
    Genetic studies demonstrate the essential role that genetic 
exchange plays in maintaining genetic diversity in small wolverine 
populations. The concern that low effective population size would 
result in negative effects is already being realized for the contiguous 
United States population of wolverine. Genetic drift has already 
occurred in subpopulations of the contiguous United States: Wolverines 
here contained 3 of 13 haplotypes found

[[Page 7885]]

in Canadian populations (Kyle and Strobeck 2001, p. 343; Cegelski et 
al. 2003, pp. 2914-2915; Cegelski et al. 2006, p. 208; Schwartz et al. 
2007, p. 2176; Schwartz et al. 2009, p. 3229). The haplotypes found in 
these subpopulations were a subset of those in the larger Canadian 
population, indicating that genetic drift had caused a loss of genetic 
diversity. One study found that a single haplotype dominated the 
northern Rocky Mountain wolverine population, with 71 of 73 wolverines 
sampled expressing that haplotype (Schwartz et al. 2007, p. 2176). The 
reduced number of haplotypes indicates not only that genetic drift has 
occurred but also some level of genetic separation; if these 
populations were freely interbreeding, they would share more haplotypes 
(Schwartz et al. 2009, p. 3229). The reduction of haplotypes is likely 
a result of the fragmented nature of wolverine habitat in the United 
States and is consistent with an emerging pattern of reduced genetic 
variation at the southern edge of the range documented in a suite of 
boreal forest carnivores (Schwartz et al. 2007, p. 2177).
    Immigration of wolverines from Canada is not likely to bolster the 
genetic diversity of wolverines in the contiguous United States. There 
is an apparent lack of connectivity between wolverine populations in 
Canada and the United States based on genetic data (Schwartz et al. 
2009, pp. 3228-3230). The apparent loss of connectivity between 
wolverines in the northern Rocky Mountains and Canada prevents the 
influx of genetic material needed to maintain or increase the genetic 
diversity in the contiguous United States. The continued loss of 
genetic diversity may lead to inbreeding depression, potentially 
reducing the species' ability to persist through reduced reproductive 
output or reduced survival. Currently, the cause for this lack of 
connectivity is uncertain. Wolverine habitat appears to be well-
connected across the border region (Copeland et al. 2010, Figure 2) and 
there are few manmade obstructions such as transportation corridors or 
alpine developments. However, this lack of genetically detectable 
connectivity may be related to harvest management in southern Canada.
Summary of Factor E
    Small population size and resulting inbreeding depression are 
potential, though as-yet undocumented, threats to wolverines in the 
contiguous United States. There is good evidence that genetic diversity 
is lower in wolverines in the DPS than it is in the more contiguous 
habitat in Canada and Alaska. The significance of this lower genetic 
diversity to wolverine conservation is unknown. We do not discount the 
possibility that loss of genetic diversity could be negatively 
affecting wolverines now and continue to do so in the future. It is 
important to point out, however, that wolverine populations in the DPS 
area are thought to be the result of colonization events that have 
occurred since the 1930s. Such recent colonizations by relatively few 
individuals and subsequent population growth are likely to have 
resulted in founder effects, which could contribute to low genetic 
diversity. The effect of small population sizes and low genetic 
diversity may become more significant if populations become smaller and 
more isolated, as predicted due to climate changes.
    Based on the best scientific and commercial information available 
we conclude that demographic stochasticity and loss of genetic 
diversity due to small effective population sizes, by itself, is not a 
threat to the wolverine DPS. However, by working in concert with the 
primary threat of habitat loss due to climate change, this may 
contribute to the cumulative effect of population declines. Therefore, 
we conclude that demographic stochasticity and loss of genetic 
diversity due to small effective population sizes is a threat to 
wolverines when considered cumulatively with habitat loss due to 
climate change (see discussion under Synergistic Interactions Between 
Threat Factors).
Synergistic Interactions Between Threat Factors
    We have evaluated individual threats to the distinct population 
segment of the North American Wolverine throughout its range in the 
contiguous United States. The wolverine DPS faces one primary threat 
that is likely to drive its conservation status in the future: habitat 
change and loss due to climate change. This factor alone is enough to 
determine that the species should be proposed for listing under the 
Act. Other factors, though not as severe or geographically 
comprehensive as the potential habitat effects from climate change may, 
when considered in the context of changes likely to occur due to 
climate change, become threats due to the cumulative effects they have 
on wolverine populations. For wolverines, the only such threat factors 
found in our analysis to have a basis of support as threats to 
wolverines were the effects of small subpopulation sizes and 
subpopulation isolation on wolverine genetic and demographic health, 
and the subsequent potential future influence of trapping.
    As discussed in our analysis of the effects on wolverine habitat 
from climate change under Factor A, wolverine habitat in the contiguous 
United States is likely to become smaller overall, and remaining 
habitat is likely to be more fragmented and fragments more isolated 
from one another than they are today (McKelvey et al. 2011, Figure 8). 
Given that wolverine subpopulations in the DPS are already so small, 
and movement between subpopulations so restricted, inbreeding has 
become likely (Kyle and Strobeck 2001, p. 343; Cegelski et al. 2003, 
pp. 2914-2915; Cegelski et al. 2006, p. 208; Schwartz et al. 2007, p. 
2176; Schwartz et al. 2009, p. 3229). The longterm maintenance of 
wolverines in the DPS will require continued connectivity between 
subpopulations within the DPS, and with populations to the north in 
Canada. To the extent that wolverine habitat becomes more fragmented, 
and fragments become more isolated due habitat loss resulting from 
climate change, these factors will become more significant to wolverine 
conservation. The risk factor of small population size, including 
measures of effective population size and their consequent effects on 
maintenance of genetic diversity, is a threat to the North American 
wolverine DPS when considered cumulatively with habitat loss resulting 
from climate change.
    Wolverine populations have been expanding in the DPS area since the 
early 20th century, when they were likely at or near zero (Aubry et al. 
2007, p. 2151). Most of this expansion has occurred under trapping 
regulations that allowed a higher level of trapping than currently 
occurs (see Montana Department of Fish, Wildlife, and Parks 2007, p. 
1). Therefore, it might be argued that wolverine trapping is not 
occurring at levels that would significantly affect conservation of the 
DPS. However, future habitat changes due to climate change are 
predicted to reduce habitat connectivity and extent. As described 
above, these changes are likely to exacerbate the problem of loss of 
genetic diversity and demographic stability caused by low effective 
population size and insufficient movement between populations, leading 
to inbreeding. Given these likely secondary effects of climate change, 
human-caused mortality due to harvest is likely to become more 
significant to the wolvereine population as connectivity needs increase 
and connectivity simultaneously becomes more difficult. As habitats 
become

[[Page 7886]]

smaller and more isolated from one another, more wolverines will be 
needed to attempt to move between subpopulations to maintain population 
viability. Harvest currently removes up to five wolverines from the 
population every year, reducing the number of animals available for 
dispersal. In addition, incidental trapping of wolverines removes still 
more. For these reasons, we find that harvest and incidental trapping, 
when considered cumulatively with habitat loss resulting from climate 
change, are likely to become threats to the DPS due to the likely 
synergistic effects they may have on the population as habitat becomes 
smaller and more fragmented.

Proposed Determination

    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
to the wolverine DPS. We have identified threats to the contiguous 
United States population of the North American wolverine attributable 
to Factors A, B, and E. The primary threat to the DPS is from habitat 
and range loss due to climate warming (Factor A). Wolverines require 
habitats with near-arctic conditions wherever they occur. In the 
contiguous United States, wolverine habitat is restricted to high-
elevation areas in the West. Wolverines are dependent on deep 
persistent snow cover for successful denning, and they concentrate 
their year-round activities in areas that maintain deep snow into 
spring and cool temperatures throughout summer. Wolverines in the 
contiguous United States exist as small and semi-isolated 
subpopulations in a larger metapopulation that requires regular 
dispersal of wolverines between habitat patches to maintain itself. 
These dispersers achieve both genetic enrichment and demographic 
support of recipient populations. Climate changes are predicted to 
reduce wolverine habitat and range by 31 percent over the next 30 years 
and 63 percent over the next 75 years, rendering remaining wolverine 
habitat significantly smaller and more fragmented. We anticipate that, 
by 2045, maintenance of the contiguous United States wolverine 
population in the currently occupied area may require human 
intervention to facilitate genetic exchange and possibly also to 
facilitate metapopulation dynamics by moving individuals between 
habitat patches if they are no longer accessed regularly by dispersers, 
or risk loss of the population.
    Other threats are minor in comparison to the driving primary threat 
of climate change; however, cumulatively, they could become significant 
when working in concert with climate change if they further suppress an 
already stressed population. These secondary threats include harvest 
(including incidental harvest) (Factor B) and demographic stochasticity 
and loss of genetic diversity due to small effective population sizes 
(Factor E). All of these factors affect wolverines across their current 
range in the contiguous United States.
    The Act defines an endangered species as any species that is ``in 
danger of extinction throughout all or a significant portion of its 
range'' and a threatened species as any species ``that is likely to 
become endangered throughout all or a significant portion of its range 
within the foreseeable future.'' We find that the contiguous United 
States wolverine DPS presently meets the definition of a threatened 
species due to the likelihood of habitat loss caused by climate change 
resulting in population decline leading to breakdown of metapopulation 
dynamics. Breakdown in metapopulation dynamics would make the DPS 
vulnerable to further loss of genetic diversity through inbreeding, and 
likely vulnerable to demographic endangerment as small subpopulations 
could no longer rely on demographic rescue from nearby populations. At 
that point wolverine populations would meet the definition of an 
endangered species under the Act. We base this determination on the 
immediacy, severity, and scope of the threats described above. 
Therefore, on the basis of the best available scientific and commercial 
information, we propose listing the contiguous United State DPS of the 
North American wolverine as a threatened species in accordance with 
sections 3(6) and 4(a)(1) of the Act.
    Under the Act and our implementing regulations, a species may 
warrant listing if it meets the definition of an endangered or 
threatened species throughout all or a significant portion of its 
range. The contiguous United States DPS of the North American wolverine 
proposed for listing in this rule is wide-ranging and the threats occur 
throughout its range. Therefore, we assessed the status of the DPS 
throughout its entire range. The threats to the survival of the species 
occur throughout the species' range and are not restricted to any 
particular significant portion of that range. Accordingly, our 
assessment and proposed determination applies to the DPS throughout its 
entire range.

Available Conservation Measures

    Conservation measures provided to species listed as an endangered 
or threatened species under the Act include recognition, recovery 
actions, requirements for Federal protection, and prohibitions against 
certain practices. Recognition through listing results in public 
awareness and conservation by Federal, State, Tribal, and local 
agencies, private organizations, and individuals. The Act encourages 
cooperation with the States and requires that recovery actions be 
carried out for all listed species. The protection required by Federal 
agencies and the prohibitions against certain activities are discussed, 
in part, below.
    The primary purpose of the Act is the conservation of endangered 
and threatened species and the ecosystems upon which they depend. The 
ultimate goal of such conservation efforts is the recovery of these 
listed species, so that they no longer need the protective measures of 
the Act. Subsection 4(f) of the Act requires the Service to develop and 
implement recovery plans for the conservation of endangered and 
threatened species. The recovery planning process involves the 
identification of actions that are necessary to halt or reverse the 
species' decline by addressing the threats to its survival and 
recovery. The goal of this process is to restore listed species to a 
point where they are secure, self-sustaining, and functioning 
components of their ecosystems.
    Recovery planning includes the development of a recovery outline 
shortly after a species is listed, preparation of a draft and final 
recovery plan, and revisions to the plan as significant new information 
becomes available. The recovery outline guides the immediate 
implementation of urgent recovery actions and describes the process to 
be used to develop a recovery plan. The recovery plan identifies site-
specific management actions that will achieve recovery of the species, 
measurable criteria that determine when a species may be downlisted or 
delisted, and methods for monitoring recovery progress. Recovery plans 
also establish a framework for agencies to coordinate their recovery 
efforts and provide estimates of the cost of implementing recovery 
tasks. Recovery teams (composed of species experts, Federal and State 
agencies, nongovernmental organizations, and stakeholders) are often 
established to develop recovery plans. The recovery outline is 
available on our Web site at http://www.fws.gov/mountain-prairie/species/mammals/wolverine/ and on http://

[[Page 7887]]

www.regulations.gov concurrently with the publication of this proposed 
rule. When completed, the draft recovery plan and the final recovery 
plan will be available on our Web site or from our Montana Ecological 
Services Field Office (see FOR FURTHER INFORMATION CONTACT).
    Implementation of recovery actions generally requires the 
participation of a broad range of partners, including other Federal 
agencies, States, Tribal, nongovernmental organizations, businesses, 
and private landowners. Examples of recovery actions include habitat 
restoration (e.g., restoration of native vegetation), research, captive 
propagation and reintroduction, and outreach and education. The 
recovery of many listed species cannot be accomplished solely on 
Federal lands because their range may occur primarily or solely on non-
Federal lands. To achieve recovery of these species requires 
cooperative conservation efforts on private, State, and Tribal lands.
    If this species is listed, funding for recovery actions will be 
available from a variety of sources, including Federal budgets, State 
programs, and cost share grants for nonfederal landowners, the academic 
community, and nongovernmental organizations. In addition, pursuant to 
section 6 of the Act, the States inhabited by wolverines or uninhabited 
states with suitable habitat would be eligible for Federal funds to 
implement management actions that promote the protection and recovery 
of wolverines. Information on our grant programs that are available to 
aid species recovery can be found at: http://www.fws.gov/grants.
    Although the wolverine DPS is only proposed for listing under the 
Act at this time, please let us know if you are interested in 
participating in recovery efforts for this species. Additionally, we 
invite you to submit any new information on this species whenever it 
becomes available and any information you may have for recovery 
planning purposes (see FOR FURTHER INFORMATION CONTACT).
    Section 7(a) of the Act requires Federal agencies to evaluate their 
actions with respect to any species that is proposed or listed as 
endangered or threatened and with respect to its critical habitat, if 
any is designated. Regulations implementing this interagency 
cooperation provision of the Act are codified at 50 CFR part 402. 
Section 7(a)(4) of the Act requires Federal agencies to confer with the 
Service on any action that is likely to jeopardize the continued 
existence of a species proposed for listing or result in destruction or 
adverse modification of proposed critical habitat. If a species is 
listed subsequently, section 7(a)(2) of the Act requires Federal 
agencies to ensure that activities they authorize, fund, or carry out 
are not likely to jeopardize the continued existence of the species or 
destroy or adversely modify its critical habitat. If a Federal action 
may affect a listed species or its critical habitat, the responsible 
Federal agency must enter into formal consultation with the Service.
    Federal agency actions within the species habitat that may require 
conference or consultation or both as described in the preceding 
paragraph include management and any other landscape altering 
activities on Federal lands in suitable wolverine habitat within the 
range of the species administered by the Department of Defense, U.S. 
Fish and Wildlife Service, Bureau of Land Management, National Park 
Service, and U.S. Forest Service; construction and management of gas 
pipeline and power line rights-of-way in suitable wolverine habitat by 
the Federal Energy Regulatory Commission; construction and maintenance 
of roads or highways by the Federal Highway Administration in suitable 
wolverine habitat; and permitting of infrastructure development in 
suitable wolverine habitat for recreation, oil and gas development, or 
residential development by the U.S. Forest Service, National Park 
Service, Bureau of Land Management, U.S. Fish and Wildlife Service, or 
Department of Defense.
    The Act and its implementing regulations set forth a series of 
general prohibitions and exceptions that apply to all endangered 
wildlife. The prohibitions of section 9(a)(2) of the Act, codified at 
50 CFR 17.21 for endangered wildlife, in part, make it illegal for any 
person subject to the jurisdiction of the United States to take 
(includes harass, harm, pursue, hunt, shoot, wound, kill, trap, 
capture, or collect; or to attempt any of these), import, export, ship 
in interstate commerce in the course of commercial activity, or sell or 
offer for sale in interstate or foreign commerce any listed species. 
Under the Lacey Act (18 U.S.C. 42-43; 16 U.S.C. 3371-3378), it is also 
illegal to possess, sell, deliver, carry, transport, or ship any such 
wildlife that has been taken illegally. Certain exceptions apply to 
agents of the Service and State conservation agencies.
    We may issue permits to carry out otherwise prohibited activities 
involving endangered and threatened wildlife species under certain 
circumstances. Regulations governing permits are codified at 50 CFR 
17.22 for endangered species, and at 17.32 for threatened species. With 
regard to endangered wildlife, a permit must be issued for the 
following purposes: for scientific purposes, to enhance the propagation 
or survival of the species, and for incidental take in connection with 
otherwise lawful activities.
    It is our policy, as published in the Federal Register on July 1, 
1994 (59 FR 34272), to identify to the maximum extent practicable at 
the time a species is listed, those activities that would or would not 
constitute a violation of section 9 of the Act. The intent of this 
policy is to increase public awareness of the effect of a proposed 
listing on proposed and ongoing activities within the range of species 
proposed for listing. The following activities could potentially result 
in a violation of section 9 of the Act; this list is not comprehensive:
    Unauthorized collecting, handling, possessing, selling, delivering, 
carrying, or transporting of the species, including import or export 
across State lines and international boundaries, except for properly 
documented antique specimens of these taxa at least 100 years old, as 
defined by section 10(h)(1) of the Act.
    Questions regarding whether specific activities would constitute a 
violation of section 9 of the Act should be directed to the Montana 
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT). 
Requests for copies of the regulations concerning listed animals and 
general inquiries regarding prohibitions and permits may be addressed 
to the U.S. Fish and Wildlife Service, Endangered Species Permits, 134 
Union Boulevard, Suite 650, Lakewood, CO 80228; Telephone 303-236-4265.
    A determination to list the contiguous United States DPS of the 
North American wolverine as a threatened species under the Act, if we 
ultimately determine that listing is warranted, will not regulate 
greenhouse gas emissions. Rather, it will reflect a determination that 
the DPS meets the definition of a threatened species under the Act, 
thereby establishing certain protections for them under the ESA. While 
we acknowledge that listing will not have a direct impact on the loss 
of deep, persistent, late spring snowpack or the reduction of 
greenhouse gases, we expect that it will indirectly enhance national 
and international cooperation and coordination of conservation efforts, 
enhance research programs, and encourage the development of mitigation 
measures that could help slow habitat loss and population declines. In 
addition, the development of a recovery plan will guide efforts 
intended to ensure the long-term

[[Page 7888]]

survival and eventual recovery of the lower 48 states DPS of the 
wolverine.

Special Rule Under Section 4(d) of the Act

    Whenever a species is listed as a threatened species under the Act, 
the Secretary may specify regulations that he deems necessary and 
advisable to provide for the conservation of that species under the 
authorization of section 4(d) of the Act. These rules, commonly 
referred to as ``special rules,'' are found in part 17 of title 50 of 
the Code of Federal Regulations (CFR) in Sec. Sec.  17.40-17.48. This 
special rule for Sec.  17.40 would prohibit take of any wolverine in 
the contiguous United States when associated with or related to 
trapping, hunting, shooting, collection, capturing, pursuing, wounding, 
killing, and trade. In this context, any activity where wolverines are 
attempted to be, or are intended to be, trapped, hunted, shot, 
captured, or collected, in the contiguous United States, will be 
prohibited. It will also be prohibited to incidentally trap, hunt, 
shoot, capture, pursue, or collect wolverines in the course of 
otherwise legal activities. All otherwise legal activities involving 
wolverines and their habitat that are conducted in accordance with 
applicable State, Federal, tribal, and local laws and regulations are 
not considered to be take under this regulation. This includes 
activities that occur in and may modify wolverine habitat such as those 
described below.
    In this proposed listing rule, we identified several risk factors 
for the wolverine DPS that, in concert with climate change, may result 
in reduced habitat value for the species. These risk factors include 
human activities like dispersed recreation, land management activities 
by Federal agencies and private landowners, and infrastructure 
development. However, the scale at which these activities occur is 
relatively small compared to the average size of wolverine's home 
range, between 300 and 500 km\2\ (186 and 310 mi\2\). For example, ski 
resorts constitute the largest developments in wolverine habitats. In 
Colorado, the state with the most ski resorts in the range of the 
wolverine, ski resort developments cover only 0.6 percent of available 
wolverine habitat (Colorado Division of Wildlife 2010, p. 16). Other 
developments are more localized still, such as mines and small 
infrastructure. It is possible that these forms of habitat alteration 
may affect individual wolverines, by causing the temporary movement of 
a few individuals within or outside of their home ranges during or 
shortly after construction. However, due to the small scale of the 
habitat alteration involved in these sorts of activities, we conclude 
that the overall impact of these activities is not significant to the 
conservation of the species. Dispersed recreation like snowmobiling and 
back country skiing, and warm season activities like backpacking and 
hunting, occur over larger scales; however, there is little evidence to 
suggest that these activities may affect wolverines significantly or 
have a significant effect on conservation of the DPS. Preliminary 
evidence suggests that wolverines can coexist amid high levels of 
dispersed motorized and nonmotorized use (Heinenmeyer et al. 2012, 
entire), possibly shifting activity to avoid the most heavily used 
areas within their home ranges.
    Transportation corridors and urban development in valley bottoms 
between patches of wolverine habitat may inhibit individual wolverines' 
movement between habitat patches; however, wolverines have made several 
long-distance movements in the recent past that indicates they are able 
to navigate current landscapes as they search for new home ranges. As 
described above, we have no evidence to suggest that current levels of 
transportation infrastructure development or residential development 
are a threat to the DPS or will become one in the future.
    Land management activities (principally timber harvest, wildland 
firefighting, prescribed fire, and silviculture) can modify wolverine 
habitat, but this generalist species appears to be little affected by 
changes to the vegetative characteristics of its habitat. In addition, 
most wolverine habitat occurs at high elevations in rugged terrain that 
is not conducive to intensive forms of silviculture and timber harvest. 
Therefore, we anticipate that habitat modifications resulting from 
these types of land management activities would not significantly 
affect the conservation of the DPS, as we described above.
    The proposed special rule under section 4(d) of the Act will 
provide for the possession and take of wolverines that are (1) legally 
held at the time of listing (2) legally imported pursuant to applicable 
Federal and state statutes, or (3) captively bred without a permit. The 
special rule will also allow the continuation of the export of captive-
bred wolverines provided applicable Federal and state laws are 
followed, and provide for the transportation of wolverine skins in 
commerce within the United States. The export skins from wolverines 
documented as captive-bred will be permitted. Legally possessed skins 
may be transported in interstate trade without permits.
    In this proposed rule, we include a prohibition against incidental 
take of wolverine in the course of legal trapping activities directed 
at other species. However, documented take of wolverine from incidental 
trapping has been low. In the 2008-2009 trapping season, two wolverines 
were incidentally killed in traps set for other species in Beaverhead 
and Granite Counties, Montana (Montana Fish, Wildlife, and Parks 2010, 
p. 2). In Idaho, the U.S. Department of Agriculture Wildlife Services 
trapped three wolverines (one each in 2004, 2005, and 2010) incidental 
to trapping wolves involved in livestock depredations. One of these 
sustained severe injuries and was euthanized. We are requesting the 
public, Federal agencies, and the affected State fish and wildlife 
agencies to submit public comments on this issue, including any State 
management plans related to trapping regulations and any measures 
within those plans that may avoid or minimize the risk of wolverine 
mortality from incidental trapping for other species.
Critical Habitat
    Section 3(5)(A) of the Act defines critical habitat as ``(i) the 
specific areas within the geographical area occupied by the species, at 
the time it is listed * * * on which are found those physical or 
biological features (I) Essential to the conservation of the species 
and (II) which may require special management considerations or 
protection; and (ii) specific areas outside the geographical area 
occupied by the species at the time it is listed * * * upon a 
determination by the Secretaries of Commerce and Interior that such 
areas are essential for the conservation of the species.'' Section 3(3) 
of the Act (16 U.S.C. 1532(3)) also defines the terms ``conserve,'' 
``conserving,'' and ``conservation'' to mean ``to use and the use of 
all methods and procedures which are necessary to bring any endangered 
species or threatened species to the point at which the measures 
provided pursuant to this chapter are no longer necessary.''
    Section 4(a)(3) of the Act and implementing regulations (50 CFR 
424.12) require that, to the maximum extent prudent and determinable, 
we designate critical habitat at the time a species is determined to be 
an endangered or threatened species. Critical habitat may only be 
designated within the jurisdiction of the United States, and may not be 
designated for jurisdictions outside of the United States (50 CFR 
424(h)). Our regulations

[[Page 7889]]

(50 CFR 424.12(a)(1)) state that designation of critical habitat is not 
prudent when one or both of the following situations exist: (1) The 
species is threatened by taking or other activity and the 
identification of critical habitat can be expected to increase the 
degree of threat to the species; or (2) such designation of critical 
habitat would not be beneficial to the species. Our regulations (50 CFR 
424.12(a)(2)) further state that critical habitat is not determinable 
when one or both of the following situations exists: (1) Information 
sufficient to perform required analysis of the impacts of the 
designation is lacking; or (2) the biological needs of the species are 
not sufficiently well known to permit identification of an area as 
critical habitat.
    Delineation of critical habitat requires, within the geographical 
area occupied by the DPS of the North American wolverine in the 
contiguous United States, identification of the physical and biological 
features essential to the conservation of the species. In general 
terms, physical and biological features essential to the wolverine may 
include (1) Areas defined by persistent spring snowpack and (2) areas 
with avalanche debris (bottom of avalanche chutes where large trees, 
rocks, and other debris are swept) and talus slopes or boulder fields 
(debris piles of large rocks, trees, and branches) in which females can 
construct dens which provide security from large predators and buffer 
against wind and low temperatures.
    Information regarding the wolverine's life functions and habitats 
associated with these functions has expanded greatly in recent years. 
We need additional time to assess the potential impact of a critical 
habitat designation, including whether there will be any benefit to 
wolverine from such a designation. A careful assessment of the habitats 
that may qualify for designation as critical habitat will require a 
thorough assessment in light of projected climate change and other 
threats. At this time, we also need more time to analyze the 
comprehensive data to identify specific areas appropriate for critical 
habitat designation. Accordingly, we find designation of critical 
habitat to be ``not determinable'' at this time.

Peer Review

    In accordance with our joint policy on peer review published in the 
Federal Register on July 1, 1994 (59 FR 34270), we will seek the expert 
opinions of at least three appropriate and independent specialists 
regarding this proposed rule. The purpose of peer review is to ensure 
that our listing determination and critical habitat designation are 
based on scientifically sound data, assumptions, and analyses. We have 
invited these peer reviewers to comment during this public comment 
period.
    We will consider all comments and information received during this 
comment period on this proposed rule during our preparation of a final 
determination. Accordingly, the final decision may differ from this 
proposal.

Required Determinations

Clarity of the Rule

    Executive Order 12866 requires each agency to write regulations 
that are easy to understand. We invite your comments on how to make 
this rule easier to understand including answers to questions such as 
the following: (1) Are the requirements in the rule clearly stated? (2) 
Does the rule contain technical language or jargon that interferes with 
its clarity? (3) Does the format of the rule (grouping and order of 
sections, use of headings, paragraphing, etc.) aid or reduce its 
clarity? (4) Would the rule be easier to understand if it were divided 
into more (but shorter) sections? (5) Is the description of the rule in 
the SUPPLEMENTARY INFORMATION section of the preamble helpful in 
understanding the rule? What else could we do to make the rule easier 
to understand?
    Send a copy of any comments that concern how we could make this 
rule easier to understand to Office of Regulatory Affairs, Department 
of the Interior, Room 7229, 1849 C Street NW., Washington, DC 20240. 
You also may email the comments to this address: Exsec@ios.goi.gov.

Paperwork Reduction Act of 1995 (44 U.S.C. 3501, et seq.)

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

National Environmental Policy Act (42 U.S.C. 4321 et seq.)

    We have 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 listing a species as an endangered or threatened species under the 
Endangered Species Act. We published a notice outlining our reasons for 
this determination in the Federal Register on October 25, 1983 (48 FR 
49244).

References Cited

    A complete list of all references cited in this proposed rule is 
available on the Internet at http://www.regulations.gov or upon request 
from the Field Supervisor, Montana Ecological Services Field Office 
(see FOR FURTHER INFORMATION CONTACT section).

Authors

    The primary authors of this proposed rule are the staff members of 
the Montana Ecological Services Field Office (see FOR FURTHER 
INFORMATION CONTACT).

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 
recordkeeping requirements, and 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]

0
1. The authority citation for part 17 continues to read as follows:

    Authority: 16 U.S.C. 1361-1407; 1531-1544; and 4201-4245, unless 
otherwise noted.

0
2. In Sec.  17.11(h) add entries for ``Wolverine, North American'' to 
the List of Endangered and Threatened Wildlife in alphabetical order 
under Mammals to read as set forth below:


Sec.  17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

[[Page 7890]]



--------------------------------------------------------------------------------------------------------------------------------------------------------
                        Species                                                    Vertebrate
--------------------------------------------------------                        population where                                  Critical     Special
                                                            Historic range       endangered or         Status      When listed    habitat       rules
           Common name                Scientific name                              threatened
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mammals
 
                                                                      * * * * * * *
Wolverine, North American........  Gulo gulo luscus....  U.S.A. (Alaska and   Where found within   T               ...........           NA     17.40(a)
                                                          northern             contiguous U.S.A.,
                                                          contiguous           except where
                                                          States); Canada.     listed as an
                                                                               experimental
                                                                               population.
Wolverine, North American........  Gulo gulo luscus....  U.S.A. (Alaska and   U.S.A. (specified    XN              ...........           NA     17.84(d)
                                                          northern             portions of CO,
                                                          contiguous           NM, and WY; see
                                                          States); Canada.     17.84(d)).
 
                                                                      * * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------

0
3. Amend Sec.  17.40 by revising paragraph (a) to read as follows:


Sec.  17.40  Special rules--mammals.

    (a) Wolverine, North American (Gulo gulo luscus).
    (1) Which populations of the North American wolverine are covered 
by this special rule? This rule covers the distribution of this species 
in the contiguous United States.
    (2) What activities are prohibited? Any activity where wolverines 
are attempted to be, or are intended to be, trapped, hunted, shot, 
captured, or collected, in the contiguous United States, will be 
prohibited. It will also be prohibited to incidentally trap, hunt, 
shoot, capture, pursue, or collect wolverines in the course of 
otherwise legal activities.
    (3) What activities are allowed? Incidental take of wolverines will 
not be a violation of section 9 of the Act, if it occurs from any other 
otherwise legal activities involving wolverines and their habitat that 
are conducted in accordance with applicable State, Federal, tribal, and 
local laws and regulations. Such activities occurring in wolverine 
habitat include:
    (i) Dispersed recreation such as snowmobiling, skiing, backpacking, 
and hunting for other species;
    (ii) Management activities by Federal agencies and private 
landowners such as timber harvest, wildland firefighting, prescribed 
fire, and silviculture;
    (iii) Transportation corridor and urban development;
    (iv) Mining;
    (v) Transportation and trade of legally possessed wolverine skins 
and skins from captive-bred wolverines within the United States.
* * * * *

    Dated: January 16, 2013.
Rowan W. Gould,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2013-01478 Filed 2-1-13; 8:45 am]
BILLING CODE 4310-55-P