[Federal Register Volume 76, Number 126 (Thursday, June 30, 2011)]
[Proposed Rules]
[Pages 38504-38532]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-16349]

[[Page 38503]]

Vol. 76


No. 126

June 30, 2011

Part III

Department of the Interior


Fish and Wildlife Service


50 CFR Part 17

Endangered and Threatened Wildlife and Plants; 12-Month Finding on a 
Petition To List a Distinct Population Segment of the Fisher in Its 
United States Northern Rocky Mountain Range as Endangered or Threatened 
With Critical Habitat; Proposed Rule

Federal Register / Vol. 76 , No. 126 / Thursday, June 30, 2011 / 
Proposed Rules

[[Page 38504]]



Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R6-ES-2010-0017; MO 92210-0-0008]

Endangered and Threatened Wildlife and Plants; 12-Month Finding 
on a Petition To List a Distinct Population Segment of the Fisher in 
Its United States Northern Rocky Mountain Range as Endangered or 
Threatened With Critical Habitat

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 12-month petition finding.


SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
12-month finding on a petition to list a distinct population segment 
(DPS) of the fisher (Martes pennanti) in its U.S. Northern Rocky 
Mountain range, including portions of Montana, Idaho, and Wyoming, as 
endangered or threatened and designate critical habitat under the 
Endangered Species Act of 1973, as amended (Act). After review of all 
available scientific and commercial information, we find that listing 
the fisher in the U.S. Northern Rocky Mountains as threatened or 
endangered is not warranted at this time.

DATES: The finding announced in this document was made on June 30, 

ADDRESSES: This finding is available on the Internet at http://www.regulations.gov at Docket Number FWS-R6-ES-2010-0017. Supporting 
documentation we used in preparing this finding is available for public 
inspection, by appointment, during normal business hours at the U.S. 
Fish and Wildlife Service, Montana Field Office, 585 Shepard Way, 
Helena, MT 59601; telephone (406) 449-5225. We ask the public to submit 
any new information that becomes available concerning the status of, or 
threats to, the fisher, in addition to new information, materials, 
comments, or questions concerning this finding, to the above address. 
No information will be accepted by facsimile. The petition finding, 
related Federal Register notices, and other pertinent information, may 
be obtained online at http://www.fws.gov/mountain-prairie/species/mammals/fisher/.

FOR FURTHER INFORMATION CONTACT: Mark Wilson, Field Supervisor, Montana 
Ecological Services Field Office (see ADDRESSES); or by telephone at 
(406) 449-5225. If you use a telecommunications device for the deaf 
(TDD), call the Federal Information Relay Service (FIRS) at (800) 877-



    Section 4(b)(3)(B) of the Act (16 U.S.C. 1531 et seq.) requires 
that, for any petition to revise the Federal Lists of Endangered and 
Threatened Wildlife and Plants that contains substantial scientific and 
commercial information that listing may be warranted, we make a finding 
within 12 months of the date of our receipt of the petition. In this 
finding, we will determine that the petitioned action is: (a) Not 
warranted, (b) warranted, or (c) warranted, but the immediate proposal 
of a regulation implementing the petitioned action is precluded by 
other pending proposals to determine whether species are threatened or 
endangered, and expeditious progress is being made to add or remove 
qualified species from the Federal Lists of Endangered and Threatened 
Wildlife and Plants. Section 4(b)(3)(C) of the Act requires that we 
treat a petition for which the requested action is found to be 
warranted but precluded as though resubmitted on the date of such 
finding, requiring a subsequent finding be made within 12 months. We 
must publish these 12-month findings in the Federal Register.

Previous Federal Actions

U.S. Northern Rocky Mountains
    On March 6, 2009, we received a petition dated February 24, 2009, 
from the Defenders of Wildlife, Center for Biological Diversity, 
Friends of the Bitterroot, and Friends of the Clearwater (petitioners) 
requesting that the fisher in the Northern Rocky Mountains of the 
United States (USNRMs) be considered a DPS and listed as endangered or 
threatened, and critical habitat be designated under the Act (Defenders 
of Wildlife et al. 2009, entire). In an April 9, 2009, letter to the 
petitioners, we responded that we had reviewed the information 
presented in the petition and determined that issuing an emergency 
regulation temporarily listing the species under section 4(b)(7) of the 
Act was not warranted (Guertin 2009, entire). We informed the 
petitioners that due to staffing and funding constraints in Fiscal Year 
2009, we would not be able to further address the petition at that 
time, but would complete the action when resources allowed. We 
published a 90-day finding on April 16, 2010, stating that the petition 
presented substantial information that listing a DPS of fisher in the 
USNRMs may be warranted, and initiated a status review of the species 
(75 FR 19925). The notice of a 90-day finding and commencement of a 12-
month status review for the USNRMs DPS was published in the annual 
Candidate Notice of Review on November 10, 2010 (75 FR 69222).
    Fishers in the USNRMs were previously petitioned for listing with a 
U.S. Pacific States' population in 1994 (see below).
U.S. Pacific States
    On June 5, 1990, we received a petition dated May 29, 1990, from 
Mr. Eric Beckwitt, Forest Issues Task Force, Sierra Biodiversity 
Project, and others requesting that the Pacific fisher (Martes pennanti 
pacifica) be listed as an endangered species in California, Oregon, and 
Washington under the Act. On January 11, 1991, we published a 90-day 
finding (56 FR 1159) indicating that the fisher in the Pacific States 
is a distinct population that is geographically isolated from 
populations in the Rocky Mountains and British Columbia and represents 
a listable entity under the Act. The finding also indicated that the 
petition had not presented substantial information indicating that a 
listing may be warranted because of a lack of information on fisher 
habitat needs, population size and trends, and demographic parameters 
(56 FR 1159).
    On December 29, 1994, we received a petition dated December 22, 
1994, from the Biodiversity Legal Foundation requesting that two fisher 
populations in the western United States, including the States of 
Washington, Oregon, California, Idaho, Montana, and Wyoming, be listed 
as threatened under the Act. Based on our review, we found that the 
petition did not present substantial information indicating that 
listing the two western United States fisher populations as a DPS was 
warranted (61 FR 8016, March 1, 1996). The best available scientific 
evidence at that time indicated that the range of the fisher was 
contiguous across Canada with some areas having abundant populations, 
and through southward peninsular extensions, was contiguous with the 
U.S. Rocky Mountain and Pacific populations (61 FR 8016). No evidence 
was presented in the petition to support physical, physiological, 
ecological, or behavioral separations (61 FR 8016).
    On December 5, 2000, we received a petition dated November 28, 
2000, from 12 organizations, with the lead organizations identified as 
the Center for Biological Diversity and the Sierra Nevada Forest 
Protection Campaign, requesting that the West Coast DPS of

[[Page 38505]]

the fisher, including portions of California, Oregon, and Washington, 
be listed as endangered and critical habitat be designated under the 
Act. A court order was issued on April 4, 2003, by the U.S. District 
Court, Northern District of California, that required the Service to 
submit for publication in the Federal Register a 90-day finding on the 
2000 petition (Center for Biological Diversity, et al. v. Norton et 
al., No. C 01--2950 SC). On July 10, 2003, we published a 90-day 
petition finding that the petition provided substantial information 
that listing may be warranted and initiated a 12-month status review 
(68 FR 41169).
    On April 8, 2004, we published a warranted 12-month finding for 
listing of the fisher's West Coast DPS (69 FR 18770). A listing action 
was precluded by higher priorities and the West Coast DPS was added to 
our candidate species list. On April 8, 2010, the Center for Biological 
Diversity, Sierra Forest Legacy, Environmental Protection Information 
Center, and Klamath-Siskiyou Wildlands Center filed a complaint in the 
United States District Court for the Northern District of California 
seeking an order for the Service to withdraw the 2004 warranted-but-
precluded finding and proceed with a proposed rule to list the species 
under the Act (Center for Biological Diversity, et al. v. Salazar, et 
al., No. CV 10--1501). A resolution of the complaint is pending.
    The West Coast fisher was included in the Service's candidate 
notices of review in 2005, 2006, 2007, 2008, 2009, and 2010 (70 FR 
24870, May 11, 2005; 71 FR 53756, September 12, 2006; 72 FR 69034, 
December 6, 2007; 73 FR 75176, December 10, 2008; 74 FR 57804, November 
9, 2009; 75 FR 69222, November 10, 2010).

Species Information

    This ``Species Information'' section concentrates on general 
biology and fisher studies conducted in the USNRMs area. Additional 
information regarding fisher biology in the western portion of its 
range can be found in the Service's 12-month finding on a petition to 
list the West Coast DPS of the fisher (69 FR 18770).
    The fisher is a forest-dwelling, medium-sized mammal, light brown 
to dark blackish-brown in color, with the face, neck, and shoulders 
sometimes being slightly gray (Powell 1981, p. 1). The chest and 
underside often have irregular white patches. The fisher has a long 
body with short legs and a long bushy tail. Males range in length from 
90 to 120 centimeters (cm) (35 to 47 inches (in.)), and females range 
from 75 to 95 cm (29 to 37 in.) in length. At 3.5 to 5.5 kilograms (kg) 
(7.7 to 12.1 pounds (lbs)), male fishers weigh about twice as much as 
females (2.0 to 2.5 kg (4.4 to 5.5 lbs)) (Powell et al. 2003, p. 638). 
Heavier males have been reported across the range, including 
individuals within the USNRMs (Sauder 2010 unpublished data; Schwartz 
2010 unpublished data); an exceptional specimen from Maine weighed 9 kg 
(20.1 lbs) (Blanchard 1964, pp. 487-488). Fishers may show variation in 
typical body weight regionally, corresponding with latitudinal 
gradients. For example, fishers in the more southern latitudes of the 
U.S. Pacific States may weigh less than fishers in the eastern United 
States and Canada (Seglund 1995, p. 21; Dark 1997, p. 61; Aubry and 
Lewis 2003, p. 87; Lofroth et al. 2010, p. 10).
    The ``Fisher of Pennant,'' or Mustela pennantii, was formally 
described by Erxleben in 1777, based on accounts of the same specimen 
from either the eastern United States or eastern Canada, by Buffon in 
1765 and the naturalist Thomas Pennant in 1771 (Rhoads 1898 as cited in 
Goldman 1935, p. 177; Powell 1981, p. 1). Taxonomic stability was not 
attained until 80 years after Buffon's original description, when 
taxonomists transferred the fisher to the genus Martes and changed the 
spelling of the species to pennanti (Hagmeier 1959, p. 185; Powell 
1981, p. 1; Powell 1993, pp. 11-12).
    The fisher is classified in the order Carnivora, family Mustelidae, 
a family that also includes weasels, mink, martens, and otters 
(Anderson 1994, p. 14). It is the largest member of the genus Martes, 
classified as subgenus Pekania, and occurs only in North America 
(Anderson 1994, pp. 22-23). Its geographic range overlaps extensively 
with that of the American marten (Martes americana--subgenus Martes), 
the only other Martes species in North America (Gibilisco 1994, p. 59). 
Characteristic of the subgenus Pekania is large body size compared with 
other Martes and the presence of an external median rootlet on the 
upper carnassial (fourth) premolar (Anderson 1994, p. 21).
    Goldman (1935, p. 177) recognized three subspecies of fisher based 
on differences in skull dimensions, although he stated they were 
difficult to distinguish: (1) Martes pennanti pennanti in the east and 
central regions; (2) M. p. columbiana in the central and northwestern 
regions that include the USNRMs; and (3) M. p. pacifica in the western 
coast States of the United States. A subsequent analysis questioned 
whether there is a sufficient basis to support recognition of different 
subspecies based on numerous factors, including the small number of 
samples available for examination (Hagmeier 1959, p. 193). Regional 
variation in characteristics used by Goldman to discriminate subspecies 
appears to be clinal (varying along a geographic gradient), and the use 
of clinal variations is ``exceedingly difficult to categorize 
subspecies'' (Hagmeier 1959, pp. 192-193). Although subspecies taxonomy 
as described by Goldman (1935, p. 177) is often used in literature to 
describe or reference fisher populations in different regions of its 
range, and recent consideration of genetic variation indicates patterns 
of population subdivision similar to the earlier described subspecies 
(Kyle et al. 2001, p. 2345; Drew et al. 2003, p. 59), it is not clear 
whether Goldman's designations of subspecies are taxonomically valid. 
Therefore, for the purposes of this finding, we are evaluating the 
fisher in the USNRMs as a DPS of a full species (i.e., M. pennanti).
    Fishers are opportunistic predators, primarily of snowshoe hares 
(Lepus americanus), squirrels (Tamiasciurus, Sciurus, Glaucomys, and 
Tamias spp.), mice (Microtus, Clethrionomys, and Peromyscus spp.), and 
birds (numerous spp.) (reviewed in Powell 1993, pp. 18, 102). Carrion 
and plant material (e.g., berries) also are consumed (Powell 1993, p. 
18). The fisher is one of the few predators that successfully kills 
porcupines (Erethizon dorsatum), and porcupine remains have been found 
more often in the gastrointestinal tract and scat of fisher than in any 
other predator (Powell 1993, p. 135). There is only one study reporting 
the food habits of an established fisher population in the USNRMs, and 
that study confirms that snowshoe hares, voles (Microtus and 
Clethrionomys spp.), and red squirrels (Tamiasciurus hudsonicus) are 
similarly important prey in north-central Idaho as they are in other 
parts of the range (Jones 1991, p. 87). Fishers from Minnesota 
relocated to the Cabinet Mountains of Montana subsisted primarily on 
snowshoe hare and deer (Odocoileus spp.) carrion (Roy 1991, p. 29). As 
dietary generalists, fishers across their range tend to forage in areas 
where prey is both abundant and vulnerable to capture (Powell 1993, p. 
100). Fishers in north-central Idaho exhibit seasonal shifts in habitat 
use to forests with younger successional structure plausibly linked to 
a concurrent

[[Page 38506]]

seasonal shift in habitat use by their prey species (Jones and Garton 
1994, p. 383).
    Fishers are estimated to live up to 10 years (Arthur et al. 1992, 
p. 404; Powell et al. 2003, p. 644). Both sexes reach maturity their 
first year but may not be effective breeders until 2 years of age 
(Powell et al. 2003, p. 638). Fishers are solitary except during the 
breeding season, which is generally from late February to the middle of 
May (Wright and Coulter 1967, p. 77; Frost et al. 1997, p. 607). The 
breeding period in north-western Montana and north-central Idaho is 
approximately late February through April based on observations of 
significant changes of fisher movement patterns and examination of the 
reproductive tracts of harvested specimens (Weckwerth and Wright 1968, 
p. 980; Jones 1991, pp. 78-79; Roy 1991, pp. 38-39). Uterine 
implantation of embryos occurs 10 months after copulation; active 
gestation is estimated to be between 30 and 60 days; and birth occurs 
nearly 1 year after copulation (Wright and Coulter 1967, pp. 74, 76; 
Frost et al. 1997, p. 609; Powell et al. 2003, p. 639).
    Litter sizes for fishers range from one to six, with a mean of two 
to three kits (Powell et al. 2003, pp. 639-640). Potential litter sizes 
in the USNRMs are between two to three per female, based on the 
frequency of embryos recovered from harvested females (Weckwerth and 
Wright 1968, p. 980; Jones 1991, p. 84). Newborn kits are entirely 
dependent and may nurse for 10 weeks or more after birth (Powell 1993, 
p. 67). Kits develop their own home ranges by 1 year of age (Powell et 
al. 2003, p. 640). Populations of fisher fluctuate in size, and 
reproductive rates may vary widely from year to year in response to the 
availability of prey (Powell and Zielinski 1994, p. 43).
    An animal's home range is the area traversed by the individual in 
its normal activities of food gathering, mating, and caring for young 
(Burt 1943, p. 351). Only general comparisons of fishers' home range 
sizes can be made, because studies across the range have been conducted 
by different methods. Generally, fishers have large home ranges, male 
home ranges are larger than females, and fisher home ranges in British 
Columbia and the USNRMs are larger than those in other areas in the 
range of the taxon (reviewed in Powell and Zielinski 1994, p. 58; 
reviewed in Lofroth et al. 2010, pp. 67-70). Fisher home ranges vary in 
size across North America and range from 16 to 122 square kilometers 
(km\2\) (4.7 to 36 square miles (mi\2\)) for males, and from 4 to 53 
km\2\ (1.2 to 15.5 mi\2\) for females (reviewed by Powell and Zielinski 
1994, p. 58; Lewis and Stinson 1998, pp. 7-8; Zielinski et al. 2004, p. 
652). In north-central Idaho, the movements of a small number of radio-
collared fishers indicated that males range from approximately 30 to 
120 km\2\ (8.7 to 35 mi\2\) year round, and females range from 6 to 75 
km\2\ (1.7 to 22 mi\2\), with a slight reduction in summer (Jones 1991, 
pp. 82-83). Fishers in Idaho have home ranges larger than any other 
home ranges reported within the range of the taxon (Idaho Office of 
Species Conservation (IOSC) 2010, p. 4).
    The abundance or availability of vulnerable prey may play a role in 
home range selection (Powell 1993, p. 173; Powell and Zielinski 1994, 
p. 57). Fishers exhibit territoriality, with little overlap between 
members of the same sex; in contrast, overlap between opposite sexes is 
extensive, and size and overlap are possibly related to the density of 
prey (Powell and Zielinski 1994, p. 59). Male fishers may extend or 
temporarily abandon their territories to take long excursions during 
the breeding season from the end of February to April presumably to 
increase their opportunities to mate (Arthur 1989a, p. 677; Jones 1991, 
pp. 77-78). However, males who maintained their home ranges during the 
breeding season were more likely to successfully mate than were 
nonresident males encroaching on an established range (Aubry et al. 
2004, p. 215).
    It is not known how fishers maintain territories; it is possible 
that scent marking plays an important role (Leonard 1986, p. 36; Powell 
1993, p. 170). Direct aggression between individuals in the wild has 
not been observed, although signs of fishers fighting and the capture 
of male fishers with scarred pelts have been reported (Douglas and 
Strickland 1987, p. 516). Combative behavior has been observed between 
older littermates and between adult females in captivity (Powell and 
Zielinski 1994, p. 59).
    There is little information available regarding the long-distance 
movements of fishers, although long-distance movements have been 
documented for dispersing juveniles and recently relocated individuals 
before they establish a home range. Fishers relocated to novel areas in 
Montana's Cabinet Mountains and British Columbia moved up to 163 km 
(100 mi) from release sites, crossing large rivers and making 700-m 
(2,296-ft) elevation changes (Roy 1991, p. 42; Weir and Harestad 1997, 
pp. 257, 259).
    Juveniles dispersing from natal areas are capable of moving long 
distances and navigating various landscape features such as highways, 
rivers, and rural communities to establish their own home range (York 
1996, p. 47; Weir and Corbould 2008, p. 44). In Maine and British 
Columbia, juveniles dispersed from 0.7 km (0.4 mi) to 107 km (66.4 mi) 
from natal areas (York 1996, p. 55; Weir and Corbould 2008, p. 44). 
Dispersal characteristics may be influenced by factors such as sex, 
availability of unoccupied areas, turnover rates of adults, and habitat 
suitability (Arthur et al. 1993, p. 872; York 1996, pp. 48-49; Aubry et 
al. 2004, pp. 205-207; Weir and Corbould 2008, pp. 47-48). Long-
distance dispersal by vulnerable, less experienced individuals is made 
at a high cost and is not always successful. Fifty-five percent of 
transient fishers in a British Columbia study died before establishing 
home ranges, and only one in six juveniles successfully established a 
home range (Weir and Corbould 2008, p. 44). One dispersing juvenile 
female traveled an unusually long distance of 135 km (84 mi) over 
rivers and through suboptimal habitats before succumbing to starvation 
(Weir and Corbould 2008, p. 44). Individuals traveling longer distances 
are subject to greater mortality risk (Weir and Corbould 2008, p. 44), 
and very few establish the stability of a home range, which improves 
the chance of successful recruitment (Aubry et al. 2004, p. 215).
    The occurrence of fishers at regional scales is consistently 
associated with low- to mid-elevation environments of mesic (moderately 
moist), coniferous and mixed conifer and hardwood forests with abundant 
physical structure near the ground (reviewed by Hagmeier 1956, entire; 
Arthur et al. 1989a, pp. 683-684; Banci 1989, p. v; Aubry and Houston 
1992 p. 75; Jones and Garton 1994, pp. 377-378; Powell 1994, p. 354; 
Powell et al. 2003, p. 641; Weir and Harestad 2003, p. 74). Fishers 
avoid areas with little or no cover (Powell and Zielinski 1994, p. 39; 
Buskirk and Powell 1994, p. 286); an abundance of coarse woody debris, 
boulders, shrub cover, or subterranean lava tubes sometimes provide 
suitable overhead cover in non-forested or otherwise open areas 
(Buskirk and Powell, 1994, p. 293; Powell et al. 2003, p. 641). In the 
understory, the physical complexity of coarse woody debris such as 
downed trees and branches provides a diversity of foraging and resting 
locations (Buskirk and Powell 1994, p. 295).
    Forest succession is a dynamic continuum that begins with an event 
such as wildfire, windthrow (areas of downed trees due to high winds) 

[[Page 38507]]

timber harvest that removes or alters major components of an 
environment. Over time the affected environment experiences a series of 
changes or seral stages in vegetation species and structure. In the 
absence of disturbance and over many decades to hundreds of years 
depending on the forest type, mature or late-seral structure and 
species composition may result. Late-seral forests (also known as old-
growth) are generally characterized by more diversity of structure and 
function than younger developmental stages. Specific characteristics of 
late-seral forests vary by region, forest type, and local conditions. 
Fishers are associated more commonly with mature forest cover and late-
seral forests with greater physical complexity than other habitats 
(reviewed by Powell and Zielinski 1994, p. 52). Other forest 
successional stages may suffice if adequate cover and structure is 
provided. For example, extensive, mid-mature, second growth forests are 
used by fishers in the Northeast and Midwest United States (Coulter 
1966, pp. 59-60; Arthur et al. 1989b, pp. 680-683; Powell 1993, p. 92).
    To what extent late successional forests are required to support 
fisher may be dependent on scale (Powell et al. 2003, p. 641). Home 
ranges may be established based on attributes at a landscape scale, 
foraging at a site scale, and resting and denning use based on the 
element or structural scale (Powell 1993, p. 89; Buskirk and Powell 
1994, p. 284; Weir and Corbould 2008, p. 103). Within areas of low and 
mid-elevation forests, the most consistent predictor of fisher 
occurrence at larger spatial scales is moderate to high levels of 
contiguous canopy cover rather than any particular forest plant 
community (Buck 1982, p. 30; Arthur et al. 1989b, pp. 681-682; Powell 
1993, p. 88; Jones and Garton 1994, p. 41; Weir and Corbould 2010, p. 
408). In north-central Idaho, mature to old-growth mesic forests of 
grand and subalpine fir in close proximity to riparian areas are used 
extensively (Jones 1991, pp. 90, 113; Jones and Garton 1994, p. 381); 
fishers in this study avoided forests with less than 40 percent crown 
cover and drier upland sites composed of Abies grandis (grand fir), 
Abies lasiocarpa (subalpine fir), Pseudotsuga menziesii (Douglas fir), 
and Pinus ponderosa (ponderosa pine) (Jones 1991, p. 90). A preliminary 
analysis of habitat associations in the USNRMs indicates that in 
summer, fishers select areas with larger diameter trees and landscapes 
with a higher proportion of large trees, and avoid dry areas typically 
populated by ponderosa pine (Schwartz 2010, unpublished data). Winter 
detections of fisher are more likely in drainages with a high amount of 
canopy cover, and winter avoidance of dry areas is similar to summer 
(Schwartz 2010, unpublished data). Fishers in Idaho include forested 
environments of differing configurations in their home range including 
roadless areas, industrial forest, and national forests managed for 
multiple uses (Albrecht and Heusser 2009, p. 19; IOSC 2010, p. 4).
    The physical structure of the forest and prey associated with 
forest structures are thought to be critical features that explain 
fisher habitat use, rather than specific forest types (Buskirk and 
Powell 1994, p. 286), and the composition of individual fisher home 
ranges is usually a mosaic of different forested environments and 
successional stages (reviewed by Lofroth et al. 2010, p. 94). Further, 
fishers are opportunistic predators with a relatively general diet, and 
the vulnerability of prey may be more important to the use of an area 
for foraging than the abundance of a particular prey species (Powell 
and Zielinski 1994, p. 54). In north-central Idaho, fishers expand 
their use of young forest stages in winter, likely in response to a 
seasonal shift in habitat use by their prey or an increase in prey 
vulnerability in these areas (Jones and Garton 1994, p. 383). 
Individuals translocated to the Cabinet Mountains of Montana from 
Minnesota and Wisconsin exhibit winter habitat use similar to that 
reported for fishers in north-central Idaho (Roy 1991, p. 60). Fishers 
in north-central Idaho and Montana also select forest riparian areas 
and draws or valley bottoms that have a strong association with spruce, 
which tend to have dense cover, high densities of snowshoe hare, and a 
diversity of other prey types (Powell 1994, p. 354; Jones 1991, pp. 90-
93; Heinemeyer 1993, p. 90).
    Fishers are more selective of habitat for resting than they are 
about foraging or traveling habitat (Arthur et al. 1989b, p. 686; 
Powell and Zielinski 1994, p. 54; Powell 1994, p. 353). Across the 
range, fishers select resting sites with characteristics of late 
successional forests--higher canopy closure, large-diameter trees, 
coarse downed wood, and singular features of large snags, tree 
cavities, or deformed trees (Powell and Zielinski 1994, p. 54; Lofroth 
et al. 2010, pp. 101-103). Rest sites may be selected for their 
insulating or thermoregulatory qualities and their effectiveness at 
providing protection from predators (Weir et al. 2004, pp. 193-194). 
Resting locations for fishers in north-central Idaho are predominately 
in mature forest types (Jones and Garton 1994, p. 383). When fishers 
use younger forest types, they will select large-diameter trees or 
snags, if present, that are remnants of a previously existing older 
forest stage (Jones 1991, p. 92). Because of this selectivity for 
mature forest type or structure, resting and denning sites may be more 
limiting to fisher distribution than foraging habitats, and should 
receive particular consideration in managing habitat for fishers 
(Powell and Zielinski 1994, pp. 56-57).
    Cavities and branches in trees, snags, stumps, rock piles, and 
downed timber are used as resting sites, and cavities in large-diameter 
live or dead trees are selected more often for natal and maternal dens 
(Powell and Zielinski 1994, pp. 47, 56). Fishers do not appear to 
excavate their own natal or maternal dens; therefore, other factors 
(i.e., heartwood decay of trees, excavation by woodpeckers, broken 
branches, frost or fire scars) are important in creating cavities and 
narrow entrance holes (Lofroth et al. 2010, p. 112). The tree species 
may vary from region to region based on local influences. In regions 
where both hardwood and conifers occur, hardwoods are selected more 
often, although they may be a minor component of the area (Lofroth et 
al. 2010, p. 115). Den trees tend to be older and larger in diameter 
than other available trees in the vicinity (reviewed by Lofroth et al. 
2010, pp. 115, 117). Little is known of natal or maternal den use or 
selection in the USNRMs. A habitat study conducted in north-central 
Idaho found no kits or evidence of denning (Jones 1991, p. 83). A 
female introduced into Montana's Cabinet Mountains used a downed hollow 
log for a natal den only months after release, and it is likely that 
this suboptimal site was selected only because of the female's 
unfamiliarity with the area (Roy 1991, p. 56).
    Snow conditions and ambient temperatures may affect fisher activity 
and habitat use. Fishers in eastern parts of the taxon's range may be 
less active during winter and avoid areas where deep, soft snow 
inhibits movement (Leonard 1980, pp. 108-109; Raine 1981, p. 74). 
Historical and current fisher distributions in California and 
Washington are consistent with forested areas that receive low or lower 
relative snowfall (Krohn et al. 1997, p. 226; Aubry and Houston 1992, 
p. 75). Fishers in Ontario, Canada, moved from low-snow areas to high-
snow areas during population increases, indicating a possible density-
dependent migration to less suitable habitats factored by snow 
conditions (Carr et al. 2007, p. 633). These distribution and activity 

[[Page 38508]]

suggest that the presence of fisher and their populations may be 
limited by deep snowfall. However, the reaction to snow conditions 
appears to be variable across the range, with fishers in some locations 
not affected by snow conditions or increasing their activity with fresh 
snowfall (Jones 1991, p. 94; Roy 1991, p. 53; Weir and Corbould 2007, 
p. 1512). Thus, fishers' reaction to snow may be dependent on a myriad 
of factors, including, but not limited to, local freeze-thaw cycles, 
the rapidity of crust formation, snow interception by the forest 
canopy, and prey availability (Krohn et al. 1997, p. 226; Mote et al. 
2005, p. 44; Weir and Corbould 2007, p. 1512).
Historical Distribution Across the Range of the Species
    Fishers occur only in North America, appearing in the fossil record 
approximately 30,000 years ago in the eastern United States throughout 
the Appalachian Mountains, south to Georgia, Alabama, and Arkansas, and 
west to Ohio and Missouri (Anderson 1994, p. 18). No fossil evidence of 
a fisher range expansion to the north or west exists until the middle 
Holocene (4,000 to 8,000 years ago) in southern Wisconsin, and only 
within the past 4,000 years is there evidence that fishers inhabited 
northwestern North America (Graham and Graham 1994, pp. 46, 58). 
Although there is limited fossil evidence available from central 
Canada, fishers' expansion westward and northward likely coincided with 
glacier retreat and the subsequent development of the boreal spruce 
forests (Graham and Graham 1994, p. 58). Fossil remains of early fisher 
in the northwest have been found in British Columbia, Washington, and 
Oregon, and no fossil remains have been discovered in the USNRMs region 
(Graham and Graham 1994, pp. 50-55).
    Our present understanding of the historical (before European 
settlement) distribution of fishers is based on the accounts of natural 
historians of the early 20th century and general assumptions of what 
constitutes fisher habitat. The presumed fisher range prior to European 
settlement of North America (c. 1600) was throughout the boreal forests 
across North America in Canada from approximately 60[deg] north 
latitude, extending south into the United States in the Great Lakes 
area and along the Appalachian, Rocky, and Pacific Coast Mountains 
(Figure 1) (Hagmeier 1956, entire; Hall 1981, pp. 985-987; Powell 1981, 
pp. 1-2; Douglas and Strickland 1987, p. 513; Gibilisco 1994, p. 60).
    The distribution of fishers has been described by numerous authors, 
and the distribution boundaries vary depending on the evidence used for 
occurrences. The presumed presence of fishers has been drawn along the 
lines of forest distribution, and the species has been consistently 
described as an associate of boreal forest in Canada, mixed deciduous-
evergreen forests in eastern North America, and coniferous forest 
ecosystems in the west (Lofroth et al. 2010, p. 39). Subsequently, 
range maps of historical distribution typically portray large areas of 
continuous occurrence, although it is likely that the suitability of 
habitat to support fishers within the portrayed range varied over time 
and spatial scales, subject to climatic variation, large-scale 
disturbances, and other ecological factors (Giblisco 1994, p. 70; 
Graham and Graham 1994, pp. 57-58). Fishers do not occur in all 
forested habitats today, and evidence would indicate they did not 
occupy all forest types in the past (Graham and Graham 1994, p. 58). 
Based on the contemporaneous assemblages of fossilized remains, it is 
likely that habitat selection by fishers has historically been 
influenced by the availability of specific types of prey (Graham and 
Graham 1994, p. 58).

[[Page 38509]]



Post-European Settlement Distribution Across the Range of the Species

    In the late 1800s and early 1900s, fishers experienced reductions 
in range, decreases in population numbers, and local extirpations 
attributed to overtrapping, predator control, or habitat destruction in 
the United States, including the USNRMs, and to a lesser extent in 
Canada (Weckwerth and Wright 1968, p. 977; Brander and Books 1973, p. 
53; Douglas and Strickland 1987, p. 512; Powell and Zielinski 1994, p. 
39). Since the 1950s, fishers have

[[Page 38510]]

recovered in some of the central (Minnesota, Wisconsin, Michigan) and 
eastern (Northeastern States and West Virginia) portions of their 
historical range in the United States as a result of trapping closures 
and regulations, habitat regrowth, and reintroductions (Brander and 
Books 1973, pp. 53-54; Powell 1993, p. 80; Gibilisco 1994, p. 61; Lewis 
and Stinson 1998, p. 3; Proulx et al. 2004, pp. 55-57; Kontos and 
Bologna 2008, entire). Fishers have not returned to the areas south of 
the Great Lakes to the southern Appalachian States (Proulx et al. 2004, 
p. 57). The historical, early European settlement, and contemporary 
distribution of fishers in the USNRMs is discussed in detail in the 
following sections.
Current Distribution Outside of the U.S. Northern Rocky Mountains
    Presently, fishers are found in all Canadian provinces and 
territories except Newfoundland and Prince Edward Island (Proulx et al. 
2004, p. 55) (Figure 1). The fisher range in Quebec, Ontario, and 
eastern Manitoba is contiguous with currently occupied areas in New 
England, northern Atlantic States, Minnesota, Wisconsin, and the Upper 
Peninsula of Michigan in the United States (Proulx et al. 2004, pp. 55-
57). In Saskatchewan and Alberta, fishers are found primarily north of 
52 degrees and 54 degrees north latitude, respectively, and form no 
known breeding population with the United States (Proulx et al. 2004, 
p. 58). In Alberta, trapping data indicate that a rare fisher may occur 
to the south of high-density population areas to approximately 32 km 
(20 mi) north of the United States border along the Continental Divide 
near Waterton Lakes National Park, (Corrigan 2010, pers. comm.; Hale 
2010, pers. comm.)--an area contiguous with the USNRMs. However, there 
is no indication that there is a population of fisher in southern 
Alberta or whether the source of the occasional rare fisher detected 
there is the distant fisher population of central Alberta, central 
British Columbia, or the USNRMs. Fishers occupy low- to mid-elevation 
forested areas throughout British Columbia, but are rare or absent from 
the coast and from the southern region for at least 200 km (125 mi) to 
the border with the United States (Weir et al. 2003, p. 25; Weir and 
Lara Almuedo 2010, p. 36).
    After reviewing known distribution records for fishers in 1956, 
Hagmeier (p. 156) noted that there were no known records from 
southeastern British Columbia, which includes the Rocky Mountains in 
the eastern Kootenay Region contiguous with northern Idaho and 
northwest Montana. A reintroduction of fishers to the Kootenay Region 
of southeast British Columbia, an area just north of the USNRMs, was 
attempted in the 1990s (Fontana et al. 1999, entire), but ``the 
observed survival rate of translocated adults and the few cases of 
confirmed reproduction in the area were not likely sufficient for the 
population to expand and become self-sustaining'' (Weir et al. 2003, p. 
25). The South Thompson Similkameen area of south-central British 
Columbia, bordering north-central Washington, produced 88 legally 
harvested fishers between 1928 and 2007, and 13 since 1985 (Lofroth et 
al. 2010, p. 48). Because the northern boundary of the South Thompson 
Similkameen is considered the southern extent of the fisher population 
distribution in the province (Weir and Lara Almuedo 2010, p. 36), the 
significance of the trapping data to fisher distribution is not clear 
without more specific location information. Harvest data could indicate 
that individuals were captured at the periphery of larger, established 
populations, that there is a low-density population in south-central 
British Columbia, or that individuals represent transient or 
extralimital (outside an established population area) records.
    In the western United States outside of the USNRMs, fishers occur 
in a few disjunct and relatively small areas of their former range in 
the Cascade Mountains of southwest Oregon, the Klamath and Coastal 
Ranges of southwest Oregon and northwest California, and the Southern 
Sierra Nevada Mountains in east-central California (Proulx et al. 2004; 
Lofroth et al. 2010, pp. 47-49). A reintroduction program is underway 
on the Olympic Peninsula of Washington State, and the program's 
objective of establishing a self-sustainable population of fisher has 
yet to be achieved (Lewis et al. 2009, p. 3).
Historical Distribution and Early European Settlement Distribution in 
the U.S. Northern Rocky Mountains
    Presumed historical distribution of fishers in the USNRMs is 
depicted as continuous with eastern British Columbia and southwestern 
Alberta in Canada, bounded on the east by the forested areas of the 
front range of the Rocky Mountains at approximately 113 degrees west 
longitude in Montana, the south at approximately 44 degrees north 
latitude, and the west in Idaho at approximately 116.5 degrees west 
longitude, extending to the northwest, north of the Palouse Prairie in 
Idaho to include the forested Pend Oreille River area of northeastern 
Washington (Hagmeier 1956, entire; Hall 1981, pp. 985-987; Gibilisco 
1994, p. 64) (Figure 1). The described historical distribution also 
includes individually isolated areas in the present-day Greater 
Yellowstone Ecosystem (northwest Wyoming, southern Montana and east-
central Idaho), and north-central Utah (Gibilisco 1994, p. 64). The 
representation of historical fisher distribution in the USNRMs by the 
sources above should be viewed cautiously, because it is based on 
limited information and records collected in the late 1800s to mid-
1900s (Hagmeier 1956, pp. 154, 156, 161, 163; Hall 1981, p. 985) after 
European settlement had influence in the area. In addition, as stated 
previously, fishers have been consistently described as associates of 
coniferous forest ecosystems in the west, and the presumed historical 
presence of fishers was drawn along the lines of forest distribution, 
with little physical evidence of whether fishers occupied those 


    No reliable records are available for Montana, and historical and 
early settlement distribution in the western forested areas of the 
State was assumed based on the reports of the presence of fishers in 
northwest Wyoming and central Idaho (Hagmeier 1956, p. 156). Vinkey 
(2003, pp. 44-69) investigated fisher records in the Rocky Mountains, 
concentrating on Montana, to determine the fisher distribution post-
settlement and prior to their apparent disappearance in the 1920s 
(Newby and McDougal 1964, p. 487; Weckworth and Wright 1968, p. 977). 
The first reference to fisher in Montana was a shipping record of pelts 
from Fort Benton in 1875 (Vinkey 2003, p. 49). Although shipping 
records are not definitive of the product origin, it is likely some of 
the fisher pelts were of Montana origin because of Montana's prominence 
in the fur trade and Fort Benton's location at the upper reaches of the 
Missouri River (Vinkey 2003, p. 49).
    Reports of fishers in Montana's Glacier National Park in the early 
1900s were dismissed as ``unreliable'' and ``unauthentic'' by Newby 
(cited in Hagmeier 1956, p. 156); nevertheless, these records have been 
cited by other authors, in addition to reports from early trappers, to 
support a distribution of fishers in Montana as far south as Wyoming 
(Hoffman et al. 1969, p. 596; Vinkey 2003, p. 50). Hoffman et al. 
(1969, p. 596) interpreted the lack of reliable records as an 
indication of the fisher's extirpation in Montana and adjacent areas 
before any specimens

[[Page 38511]]

could be preserved. Thus, in Montana, the presumed occurrence of 
fishers before translocations occurred in 1959 is based on trapper 
accounts alone (Weckworth and Wright 1968, p. 977; Hoffman et al. 1969, 
p. 596).


    The historical presence of fisher in Idaho was based on an 1890 
specimen from Alturas Lake (originally Sawtooth Lake) in the Sawtooth 
Mountains of Blaine County in central Idaho (Goldman 1935, p. 177; 
Hagmeier 1956, p. 154; Drew et al. 2003, p. 62; Schwartz 2007, p. 922), 
and other 20th century reports of fishers in the ``mountainous parts of 
the state,'' including the Selkirk (north), Bitterroot (northeast), and 
Salmon River (central) ranges (Hagmeier 1956, p. 154). Only two fisher 
specimens document the presence of fishers in the USNRMs prior to their 
presumed extirpation in the 1920s (Williams 1963, p. 9). Both specimens 
originated in Idaho. The above-mentioned 1890 specimen from Alturas 
Lake, Blaine County, in central Idaho is housed in the collection of 
the National Museum of Natural History in Washington, DC, and this 
specimen has been pivotal for supporting historical distribution and 
post-settlement representation, and for suggesting that an indigenous 
population has survived since the 1920s in the USNRMs (Hagmeier 1956, 
p. 154; Hall 1981, p. 985; Drew et al. 2003, pp. 59, 62; Vinkey et al. 
2006, p. 269). An 1896 Harvard Museum specimen collected in Idaho 
County in north-central Idaho west of the Bitterroot Divide, which 
separates Idaho and Montana, further supports the extent of fisher 
distribution in the late 1800s, and supports a close ecological 
connection between north-central Idaho and west-central Montana (Vinkey 
et al. 2006, p. 269; Schwartz 2007, pp. 923-924).

Wyoming and Utah

    The first reported fisher capture in Wyoming is often cited as 
occurring in the 1920s from the Beartooth Plateau east of Yellowstone 
National Park near the Montana State line (Thomas 1954, p. 28; Hagmeier 
1956, p. 163). The pelt of a poached fisher was confiscated in 
Yellowstone National Park in the 1890s, but it is not clear where the 
animal was captured originally (Skinner 1927, p. 194; Buskirk 1999, p. 
169). Fishers have been seldom described in Wyoming (Buskirk 1999, p. 
169), and by the 1950s fishers were considered ``extinct or nearly so'' 
in the Yellowstone area (Thomas 1954, p. 3; Hagmeier 1956, p. 163). As 
early as the 1920s the fisher was considered rare or absent from 
Yellowstone National Park (Skinner 1927, p. 180). The inclusion of Utah 
in the historical range of the fisher was based solely on photographs 
of tracks taken in 1938 (Hagmeier 1956, p. 161).

Location of Restocking Efforts in the U.S. Northern Rocky Mountains

    By 1930, fishers were thought to be extirpated from the USNRMs in 
Montana and Idaho as they were in other parts of the United States 
(Williams 1963, p. 9; Newby and McDougal 1964, p. 487; Weckworth and 
Wright 1968, p. 977). Montana Department of Fish and Game (now Montana 
Fish, Wildlife and Parks (MTFWP)) initiated a restocking program for 
fisher in 1959 with 36 individuals from central British Columbia 
transplanted to the Purcell, Swan, and Pintler Ranges in northwestern 
and west-central Montana (Weckworth and Wright 1968, p. 979). Idaho 
Fish and Game (IDFG) followed with a reintroduction program for fishers 
in 1962. Forty-two fishers from central British Columbia were 
transplanted to areas considered to have been formerly occupied before 
presumed extirpation in north-central Idaho, including the Bitterroot 
divide area (Williams 1963, p. 9; reviewed by Vinkey 2003, p. 55). 
Minnesota and Wisconsin were the sources for 110 fishers transplanted 
to the Cabinet Mountains of northwest Montana between 1989 and 1991 
(Roy 1991, p. 18; Heinemeyer 1993, p. ii). After an absence of 
authenticated records for over 20 years in the USNRMs, areas near 
release sites yielded fisher captures in Montana in the years following 
the first reintroduction efforts in 1959 (Newby and McDougal 1964, p. 
487; Weckworth and Wright 1968, p. 979). No post-release studies were 
conducted in Idaho until the mid-1980s, but marten trappers in the 
State reported inadvertent captures of fishers by the late 1970s (Jones 
1991, p. 1).
Contemporary Distribution in the U.S. Northern Rocky Mountains
    The use of unreliable records to support distribution and 
population extent has led to overestimation of other species' ranges 
(Aubry and Lewis 2003, p. 86; McKelvey et al. 2008, p. 550). Mindful of 
that, we have used the most reliable and verified data in this analysis 
of the fisher in the USNRMs. We base the contemporary (1960 to present) 
record of fisher distribution in the USNRMs on verifiable or documented 
records of physical evidence such as legal harvest or incidentally 
captured specimens, animals captured for scientific study, genetic 
analysis of biological samples, and photographs identified by a 
knowledgeable expert. Eyewitness accounts of a fisher itself, or its 
sign, by the general public or untrained observer also may be found in 
agency databases (IOSC 2010, p. 5-6); however, a correct identification 
of fisher or its sign can be difficult by an untrained observer and 
these unverified records or anecdotal reports should be viewed 
cautiously (Aubry and Lewis 2003, p. 81; Vinkey 2003, p. 59; McKelvey 
et al. 2008, p. 551). Other animals that are similar in appearance and 
share similar habitats, such as the American marten, mink (Mustela 
vison), or domestic cat (Felis catus), may be mistaken for fishers 
(Aubry and Lewis 2003, p. 82; Lofroth et al. 2010, p.11; Kays 2011, p. 
1). Animal signs, such as tracks, can be significantly altered by 
environmental conditions, and fisher tracks can be confused with those 
of the more common American marten (Vinkey 2003, p. 59; Giddings 2010, 
pers. comm.).

Montana and Idaho

    A legal trapping season for fisher was reopened in Montana in 1983 
after a series of fisher transplantations and evidence that fishers 
were reproducing in the State (Weckwerth and Wright 1968, entire; MTFWP 
2010, p. 3). The majority of verified fisher records in the State 
through 2009 result from the harvest program (Vinkey 2003, p. 51; MTFWP 
2010, p. 2, Attachment 3). In addition, Montana agency files include 48 
incidental harvest records between 1968 and 1979 (Vinkey 2003, p. 51). 
Prior to 2002, Idaho records included verified fisher presence by 
targeted live-trapped and incidental captures, or otherwise-obtained 
physical specimens, photographs, and individuals observed directly by 
qualified experts (IOSC 2010, p. 7). From 2004 to the present, multiple 
State and Federal agencies in Montana and Idaho have partnered to 
collect biological data and samples by live-trapping and hair-snares 
for genetic testing (Albrecht and Heusser 2010, p. 23; Albrecht 2010, 
unpublished data; IOSC 2010, pp. 4-6; MTFWP 2010, p. 2); many surveys 
are conducted using a standardized protocol specific to fisher 
(Schwartz et al. 2007, entire). Fisher detections (species 
identification) and genetic analyses to identify individual fishers 
have been provided to us as they become available (Albrecht 2010, 
unpublished data); the results of some targeted fisher surveys are 
pending (IOSC 2010, p. 10). Harvest specimens and targeted studies 
provide confident identification of fishers, but may not represent the 
full extent of fisher

[[Page 38512]]

distribution due to biases of trapper effort, site accessibility, 
nonrandom site selection to increase the efficacy of detection, or a 
lack of either survey or trapping exposure (Vinkey 2003, p. 59; 
Schwartz et al. 2007, p. 6; Albrecht and Heusser 2009, p. 19).
    In western Montana from 1968 to the late 1980s, fishers were known 
to occur in the Bitterroot Mountains bordering north-central Idaho, and 
west of the Continental Divide in the Whitefish Range, Flathead, and 
Swan Mountain Ranges (Vinkey 2003, p. 53). Trapping or targeted 
sampling has not been robust in these areas west of the Continental 
Divide since the early 1990s, but there are verified fisher detections 
over the past two decades (Vinkey 2003, p. 53; MTFWP 2010, Attachment 
2) (Figure 2). Fisher presence has been consistent in the Bitterroot 
Mountains to the present, and in the Cabinet Mountains in northwest 
Montana since the late 1980s introduction (Vinkey 2003, p. 53; MTFWP 
2010, Attachment 2).
    Fishers in Idaho are found in the Selkirk Mountains in the north, 
the Clearwater and Salmon River Mountains in central Idaho, and the 
Bitterroot Range, including the Selway-Bitterroot Wilderness, in the 
north-central portion of the State.

[[Page 38513]]



[[Page 38514]]

Wyoming and Utah

    The contemporary distribution of fisher in Wyoming is unknown. Rare 
reports of fisher tracks and harvested specimens are available up until 
the 1950s (Thomas 1954, p. 31; Hagemeier 1956, p. 163; Buskirk 1999, p. 
169). A photograph of an animal near Yellowstone National Park 
described as a fisher was featured in a popular publication in 1995 
(Gehman, p. 2), but to date there has been no professional or expert 
verification that the photographed animal is indeed a fisher. Carnivore 
detection surveys were conducted in the Gallatin National Forest in the 
northern Greater Yellowstone Ecosystem between 1997 and 2000, using 
camera stations, hair-snares, and snow track transects; the surveyors 
reported fisher tracks in snow in the Gallatin and Madison Ranges of 
southern Montana (Gehman and Robinson 2000, p. 7). These records are 
considered unverified, because the use of sighting and track 
measurements alone are dependent on the observer's level of skill, snow 
and weather conditions, and ``notoriously unreliable'' (Vinkey 2003, p. 
    The Wyoming Fish and Game Department (2010, p. IV-2-26) and 
Gibilisco (1994, pp. 63-64) report only two verified records, both 
prior to 1970, in or near Yellowstone National Park. One specimen was 
described from Ucross, Wyoming, in 1965 (Hall 1981, p. 985) over 217 km 
(135 mi) east of the Beartooth Plateau and Yellowstone National Park, 
but most of that distance is open grassland or sagebrush, which is 
unsuitable for fisher. Proulx et al. (2004, p. 59) could not confirm 
the presence of fisher in Wyoming in their status review of Martes 
distribution. Schwartz et al. (2007, p. 1) acknowledge that Wyoming may 
contain fisher, but there is no evidence to confirm that presence. 
Recently, fishers are described as ``accidental'' or ``rare'' in 
Wyoming with assumed breeding or records of breeding in the northwest 
part of the State (Orabona et al. 2009, p. 152; Wyoming Fish and Game 
Department 2010, p. IV-2-26). However, the statement of fisher breeding 
in Wyoming is unsubstantiated and apparently made in error, (Oakleaf 
2010, pers. comm.). The fisher is considered extirpated in Utah 
(Biotics Database 2005, pp. 1-2).
Summary of Contemporary Distribution of Fisher in the U.S. Northern 
Rocky Mountains
    Based on the available verified specimen data, contemporary fisher 
distribution in western Montana and Idaho (Figure 2) covers an area 
similar to that depicted in the historical distribution synthesized by 
Gibilisco in 1994 (p. 64) (Figure 1). The contemporary distribution of 
fishers includes forested areas of western Montana and north-central to 
northern Idaho, and the boundary is further described in the ``Distinct 
Vertebrate Population Segment'' section of the finding. Based on a lack 
of verified records or documentation, we cannot conclude that the 
fisher is present, or if a breeding population was ever present, in 
Wyoming, including the Greater Yellowstone Ecosystem, which includes 
parts of south-central Montana, northwest Wyoming, and south-east 
Distribution Based on Genetic Characteristics
    Recent genetic analyses revealed the presence of a remnant native 
population of fishers in the USNRMs that escaped the extirpation 
presumed to have occurred early in the 20th century (Vinkey et al. 2006 
p. 269; Schwartz 2007, p. 924). Fishers in the USNRMs today reflect a 
genetic legacy of this remnant native population, with unique genetic 
identity found nowhere else in the range of the fisher and genetic 
contributions from fishers introduced from British Columbia and the 
Midwest United States. We discuss the genetic differences due to this 
the native legacy and its significance to the fisher taxon in the 
``Significance'' section of the DPS analysis later in this document.
    Individuals with native genes are concentrated in the Bitterroot 
Mountains of west-central Montana and north-central Idaho, the St. Joe 
and Clearwater Regions, and the Lochsa River corridor in Idaho (Vinkey 
2003, p. 76; Vinkey et al. 2006, p. 267; Albrecht 2010, unpublished 
data). Individuals in these areas appear to form one population based 
on the frequency of gene types (Schwartz 2007, p. 924). The unique 
genetic type also has been identified in the only two existing USNRMs 
fisher specimens from the 1890s (Schwartz 2007, p. 922). The presence 
of this unique variation would indicate that fishers in the USNRMs were 
isolated from populations outside the region by distance, small 
population number, or both, for some time before the influences that 
led to the presumed extirpation in the early 20th century (Vinkey 2003, 
p. 82). Today, a genetic identity more commonly found in British 
Columbia populations also is present in the Bitterroot Divide area, and 
fishers in this region are likely a mix of native and individuals 
translocated from British Columbia (Vinkey 2003, p. 76; Vinkey et al. 
2006, p. 268; Schwartz 2007, p. 924).
    Fishers in northwestern Montana and extreme northern Idaho 
represent the geographically distant source populations from Minnesota 
and Wisconsin that were introduced into the Cabinet Mountains of 
Montana in the late 1980s (Drew et al. 2003, p. 59; Vinkey et al. 2006, 
pp. 268-269; Albrecht 2010, unpublished data). British Columbia types 
also are found in this region, reflecting offspring of a 1959 
introduction from Canada, a remnant native population, or possibly 
natural immigration from Canada (Vinkey et al. 2006, p. 270; Schwartz 
2007, p. 924).
    An assessment of the degree of hybridization between native and 
introduced individuals is difficult based on the assessment techniques. 
Analysis of genetic identity is conducted on mitochondrial DNA, which 
only reflects the genetic contribution of the mother (Forbes and 
Alledorf 1991, p. 1346; Vinkey 2003, p. 82). Males could make a greater 
contribution to distant populations based on their larger home range 
sizes and expanded wanderings during the breeding period (Arthur 1989a, 
p. 677; Jones 1991, pp. 7-78), but based on mitochondrial DNA analysis 
alone, this contribution would not be detected.
Population Status
    Estimates of fisher abundance and vital rates are difficult to 
obtain and often based on harvest records, trapper questionnaires, and 
tracking information (Douglas and Strickland 1987, p. 522), and recent 
information is limited. Habitat modeling and behavioral or other 
natural history characteristics (e.g., home range sizes) also are used 
to estimate population sizes over a geographic area (Lofroth 2004, pp. 
19-20; Lofroth et al. 2010, p. 50). Fisher densities over areas of 
suitable habitat have been reported, but there are no total or 
comprehensive population sizes for the fisher in the eastern United 
States or Canada. In the western range, fisher populations have been 
estimated using habitat models and home range sizes. Late winter 
populations in British Columbia range from 1,403 to 3,715 individuals 
(Lofroth 2004, p. 20). In the Southern Sierra Nevada Mountains, the 
fisher population is estimated between 160 to 598 individuals depending 
on the methods used, and an estimated 4,616 fishers inhabit the 
Southwest Oregon/Northern California area (reviewed by Lofroth et al. 
2010, p. 50).
    As previously noted, fishers in the USNRMs have increased in number 
and distribution since their perceived

[[Page 38515]]

extirpation in the 1920s. However, little is known of the population 
numbers, trends, or vital rates of fishers in the USNRMs today. 
Preliminary work is ongoing to determine the geographic range of the 
species, identify populations with native and introduced genes, and 
determine the abundance of individuals in populations using DNA 
analyses (Schwartz et al. 2007, pp. 1-2). An evaluation of the 
translocation effort in the Cabinet Mountains of northwest Montana 
between 2001 and 2003 yielded only 4 live-trapped individuals and 28 
track detections over 25 survey weeks, indicating that the population 
there is likely small and limited in distribution (Vinkey 2003, p. 33) 
(Figure 2). Based on genetic similarities, fishers in the Selkirk 
Mountains of northern Idaho, just south of the Canadian border, are 
likely associated with the fishers from Minnesota and Wisconsin 
introduced to Montana's Cabinet Mountains to the east (Cushman et al. 
2008, p. 180). Efforts to detect fisher in the Selkirk Mountains 
between 2003 and 2005 using hair-snares for genetic analysis produced 
26 samples identified as fisher, although the number of unique 
individuals is likely much smaller than the number of samples (Cushman 
et al. 2008, p. 180).
    A review of historical records and carnivore research in Montana 
indicates that the fisher is one of the lowest-density carnivores in 
the State (Vinkey 2003, p. 61). What is known of fisher populations 
today in Montana is primarily derived from harvest data and winter 
furbearer track surveys (MTFWP 2010, p. 2, Attachment 8, pp. 2-3). A 
Montana habitat model based on 30 years of fisher presence data (the 
majority being harvest data) conservatively estimates that there is 
high habitat suitability capable of supporting 216 individuals 
concentrated in the Bitterroot Mountains along the Idaho border, the 
Swan and Flathead River drainages, and the Whitefish and Cabinet 
Mountains just south of the Canada border (MTFWP 2010, Attachment 8, 
pp. 2-3; Montana Natural Heritage Program (MTNHP) 2010a, entire; 2010b, 
    Most of the recent USNRMs fisher survey effort has targeted the 
Coeur d'Alene, St. Joe, Clearwater, and Lochsa areas of northern and 
north-central Idaho. In 2006 and 2007, 10 individual fishers were 
identified in an area of approximately 8,951 km\2\ (3,456 mi\2\) of 
potentially suitable habitat in the St. Joe and Coeur d'Alene areas, 
north and south of Interstate 90 in northern Idaho (Albrecht and 
Heusser 2009, pp. 6, 8, 15). The St. Joe and Coeur d'Alene projects 
were not intended to elucidate fisher presence in the entire area of 
potentially suitable habitat, but simply to detect the presence of 
fisher; therefore, traps were placed in areas highly likely to support 
fisher (Albrecht and Heusser 2009, p. 19). Thirty-four fisher were 
identified in a 1,295-km\2\ (500-mi\2\) (one fisher per 38 km\2\ (14.7 
mi\2\)) area of the Lochsa River corridor of north-central Idaho during 
a targeted live-trap study between 2002 and 2004 (Schwartz 2010, 
unpublished data). Thirty individual fishers were captured in the 
Clearwater area north of the Lochsa River in north-central Idaho 
between 2007 and 2010 (Sauder 2010, unpublished data). Based on genetic 
data, it appears that individuals in these areas of north-central Idaho 
and fishers in west-central Montana represent a single population 
(Schwartz 2007, p. 924) (Figure 2). We have no additional information 
on the Lochsa River or Clearwater surveys to determine if these reports 
are indicative of comprehensive population numbers. No habitat 
suitability or capacity model is available for Idaho.

Evaluation of Listable Entities

    Under section 3(16) of the Act, we may consider for listing any 
species, including subspecies, of fish, wildlife, or plants, or any DPS 
of vertebrate fish or wildlife that interbreeds when mature (16 U.S.C. 
1532(16)). Such entities are considered eligible for listing under the 
Act (and, therefore, are referred to as listable entities), should we 
determine that they meet the definition of an endangered or threatened 
species. In this case, the petitioners have requested that the fisher 
in the USNRMs be considered as a DPS of a full species for listing as 
endangered or threatened under the Act. We concluded in our 90-day 
finding on the petition that there is support for a DPS of fisher in 
the USNRMs (75 FR 19925), and we analyze this possibility further in 
the following section after reviewing the best available information.

Distinct Vertebrate Population Segment

    Under the Service's DPS policy (61 FR 4722, February 7, 1996), 
three elements are considered in the decision concerning the 
establishment and classification of a possible DPS. These are applied 
similarly for additions to, or removal from, the Federal List of 
Endangered and Threatened Wildlife. These elements include:
    (1) The discreteness of a population in relation to the remainder 
of the species to which it belongs;
    (2) The significance of the population segment to the species to 
which it belongs; and
    (3) The population segment's conservation status in relation to the 
Act's standards for listing, delisting, or reclassification (i.e., is 
the population segment endangered or threatened).
    In evaluating the distribution of fisher and the geographic extent 
of a possible DPS in the USNRMs, we examined information cited in the 
petition (Defenders et al. 2009, pp. 11-24), published range maps, 
published works that included historical occurrences, unpublished 
studies related to fisher distribution, and other data submitted to us 
subsequent to the request for information published in the 90-day 
finding for fisher (75 FR 19925). Fisher distribution in the USNRMs and 
extended area was discussed in detail in the preceding ``Distribution'' 
    Under the DPS policy, a population segment of a vertebrate taxon 
may be considered discrete if it satisfies either one of the following 
    (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.
    (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.
    Western Montana and north-central to northern Idaho broadly 
encompass the area under consideration for a fisher DPS in the USNRMs. 
The population area includes the contemporary (1960s reintroductions to 
present) distribution of fisher in the USNRMs and is best circumscribed 
by geological features and the distribution of habitat known to support 
fisher. The distribution of fishers in the USNRMs is bounded by the 
southern Bitterroot Range north of Lemhi Pass in Montana, east and then 
north along the Continental Divide including forested areas east of the 
Divide to the Rocky Mountain Front, north along the eastern boundary of 
Glacier National Park, west along the Boundary Mountains and northern 
Whitefish Range in northern Montana, west to the southern Selkirk and 
southern Purcell Mountains to the Idaho boundary with Washington, south 
along the forested areas of northern Idaho bounded on the west by the 
Palouse and Camas Prairie regions, south along the Western Mountains 
and North Payette River to the Boise Mountains, northeast along the 
Salmon River to the southern

[[Page 38516]]

Bitterroot Range north of Lemhi Pass in Idaho (Figure 2). The northern 
geographic extent of the fisher distribution roughly coincides with the 
border of the United States and Canada at 49 degrees north latitude. 
The fisher distribution in the USNRMs is the southern extent of the 
taxon's known range in the Rocky Mountains.
    Fishers in the USNRMs are physically or geographically separate 
from other fisher populations. The range of the fisher in the West 
Coast Range of Washington, Oregon, and California is separated from the 
USNRMs by distance, natural physical barriers, including the 
nonforested high desert areas of the Great Basin in Nevada and eastern 
Oregon and the Okanogan Valley in eastern Washington, major highways, 
urban and rural open-canopied areas, and agricultural development (69 
FR 18770; Lofroth et al. 2010, p. 47). Occupied areas in the USNRMs are 
150 to 200 km (93 to 124 mi) from the closest edge of the West Coast 
fisher DPS abutting the unoccupied Okanogan Valley of Washington (69 FR 
18770, Lofroth et al. 2010, p. 33). Occupied areas in the USNRMs are 
approximately 418 km (300 mi) from the closest occupied area of the 
West Coast DPS in the southern Cascade Mountains of southwest Oregon or 
the Olympic Peninsula in Washington (National Park Service (NPS) 2009, 
entire; Lofroth et al. 2010, p. 47). There is no evidence to indicate 
that fisher in the USNRMs were recently, or historically, connected to 
other fisher population centers in the United States (Gibilisco 1994, 
p. 64; Proulx et al. 2004, p. 57). Maps of historical and recent fisher 
distributions show no connection in the contiguous United States 
between occurrences in the USNRMs and the fisher populations in the 
Midwest and Great Lakes area, which occur approximately 1,126 km (700 
mi) away, across mostly nonforested areas of unsuitable habitat 
(Hagmeier 1956, p. 151; Douglas and Strickland 1987, p. 313; Gibilisco 
1994, p. 64; Proulx et al. 2004, p. 57).
    There is no indication that a population of fisher exists in a 
large geographic area of southern Alberta or southern British Columbia 
in Canada to the north of the USNRMs (see ``Distribution'' section). 
Individual fishers have been identified near the international boundary 
and observed using areas in both Canada and the USNRMs (Fontana et al. 
1999, p. 19; Albrecht 2010, unpublished data; Giddings, 2010 pers. 
comm.). We believe that the detections in extreme southern Canada 
represent wandering individuals, or individuals in the USNRMs whose 
home ranges include suitable habitat patches coincidental to the 
border, because the closest concentration of fishers in Canada is over 
200 km (125 mi) north of the USNRMs through patchy habitat of low 
suitability (Weir 2003, p. 14; Weir and Lara Almuedo 2010, p. 36). The 
lack of suitable habitat in southeastern British Columbia likely 
contributed to the failure to reestablish a fisher population there in 
the early 1990s (Fontana et al. 1999, p. 1; Weir et al. 2003, pp. 24-
    We have no direct confirmation that fishers are moving between the 
USNRMs and larger population centers in Canada; however, it is likely 
there is some interaction between transient individuals from the larger 
population areas. Reports of transient or juvenile fishers moving 
linear distances up to 135 km (84 mi) are known from other parts of the 
fisher's range (Weir and Corbould 2008, p. 48), although shorter 
distances of up to 107 km (66 mi) are more common (York 1996, p. 55). 
It is unlikely that transient individuals provide a functional 
connection between Canada population centers and the USNRMs. 
Individuals traveling longer distances are subject to a greater risk of 
mortality, and very few establish the stability of a home range (Weir 
and Corbould 2008, p. 44) required for successful long-term 
recruitment. Because the intervening areas appear unable to support 
resident fishers, and we believe that the only fishers using these 
areas are transient individuals attempting to move between population 
centers, we have concluded that the USNRMs fisher population is 
markedly separate from those to the north.
Summary for Discreteness
    We conclude that the fisher in the USNRMs is markedly separated 
from other populations of the same taxon as a result of physical 
factors, and thus meets the definition of a discrete population 
according to the Service's DPS policy. Because the entity meets the 
first criterion for discreteness (marked physical separation), an 
evaluation with respect to the second criterion (international 
boundaries) is not needed.
    If a population segment is considered discrete under one or more of 
the conditions described in the Service's DPS policy, its biological 
and ecological significance will be considered in light of 
Congressional guidance that the authority to list DPSs be used 
``sparingly'' (see Senate Report 151, 96th Congress, 1st Session) while 
encouraging the conservation of genetic diversity. In making this 
determination, we consider available scientific evidence of the 
discrete population segment's importance to the taxon to which it 
belongs. Since precise circumstances are likely to vary considerably 
from case to case, the DPS policy does not describe all the classes of 
information that might be used in determining the biological and 
ecological importance of a discrete population. However, the DPS policy 
describes four possible classes of information that provide evidence of 
a population segment's biological and ecological importance to the 
taxon to which it belongs. As specified in the DPS policy (61 FR 4722), 
this consideration of the population segment's significance may 
include, but is not limited to, the following:
    (1) Persistence of the discrete population segment in an ecological 
setting unusual or unique to the taxon;
    (2) Evidence that loss of the discrete population segment would 
result in a significant gap in the range of a 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.
    A population segment needs to satisfy only one of these conditions 
to be considered significant. Furthermore, other information may be 
used as appropriate to provide evidence for significance. Below we 
address conditions 1, 2, and 4. Condition 3 does not apply to fishers 
in the USNRMs because North American fishers are distributed widely 
within their historical range in Canada and the eastern United States.
Unusual or Unique Ecological Setting
    The fisher is a forest-dependent species, and marked separation 
from fishers in other geographic locations may be indicated by 
variations in forest types or ecological conditions influencing forest 
characteristics. Fishers in the western portion of the range (West 
Coast, western Canada, and the USNRMs) generally inhabit landscapes 
dominated by conifer forests, whereas fishers live in more dense, 
lowland forests with higher proportions of deciduous trees in the 
Northeast and upper Midwest United States and Canada (Allen 1983, pp. 
2-3; Arthur et al. 1989b, p. 687; Powell 1993, p. 89; Buskirk and 
Powell 1994, p. 285; Jones and Garton 1994 p. 377;

[[Page 38517]]

Ricketts et al. 1999, pp. 156, 160, 170). Fishers of the West Coast 
population (Washington, Oregon, and California) inhabit forest 
environments unusual in comparison to the rest of the taxon, and are 
unique from other parts of the range based on the unusual forest 
environment (69 FR 18777). Not only are the forests of the West Coast 
fishers lacking the broadleaf forest component common in the eastern 
range, but the coastal climate of wet winters and cool, dry summers 
produces distinctive forests of sclerophyllic (leathery-leafed) 
evergreen trees and shrubs found nowhere else in the range (Smith et 
al. 2001 pp. 17-18; 69 FR 18777).
    In addition to differences of forest type between the USNRMs and 
eastern North America and the U.S. West Coast, fishers in the USNRMs 
occupy forest areas that differ due to influences of climate and 
precipitation patterns from fisher population areas in western Canada. 
Forested areas of western Montana and central-to-northern Idaho are 
temperate, coniferous forests influenced by dramatic elevation 
gradients that produce several types of vegetation zones (Ricketts et 
al. 1999, pp. 213-214, 250-251; Bailey 2009, p. 89, plate 1). 
Topographic relief produces localized climate effects which add to the 
vegetation variability within this region (Ricketts et al. 1999, pp. 
213-214). Locally variable in predominant tree species or assemblages 
of species, this temperate zone encompasses the USNRMs extending north 
along the Continental Divide into southwestern Alberta and southeast 
British Columbia (Ricketts et al. 1999, pp. 213-214).
    The northern areas of the USNRMs are heavily influenced by maritime 
moisture patterns, and in addition to the predominating Pseudotsuga 
monziesii, Pacific tree species such as Thuja plicata (western red 
cedar), Tsuga heterophylla (western hemlock) and Abies grandis are 
present (McGrath et al. 2002, entire; U.S. Forest Service (USFS) 2009, 
p. 1). Severe winters with heavy snowfall are usual and summers are 
usually dry; precipitation is highly variable within the zone averaging 
between 510 to 1,020 mm (20 to 40 in.) per year primarily falling as 
snow in fall, winter, and spring (USFS 2009, p. 1). In the southern 
part of the USNRMs, maritime conditions decrease along latitudinal and 
altitudinal clines in the mountains of central Idaho and the Bitterroot 
Range in west-central and southwest Montana (McGrath et al. 2002, 
entire). A. grandis, P. monziesii, and western spruce/fir forests, 
Larix spp. (larch), Pinus ponderosa and Pinus contorta (lodgepole pine) 
characterize the mountain forests of the Idaho Batholith (Ricketts et 
al. 1999, p. 250; McGrath et al. 2002, entire). Hardwood trees, 
selected for fisher denning in other parts of the range, are not 
significant parts of the landscape in the USNRMs (reviewed by Powell 
1993, pp. 55-56; Heinemeyer and Jones 1994, p. iii; reviewed by Lofroth 
et al. 2010, pp. 101, 108-109). The absence of hardwoods may be a 
limiting factor to fishers in the region (Heinemeyer and Jones 1994, p. 
iii), or an indication of successful adaptation to resources not used 
elsewhere. Both of these points are speculative as there is little 
information available describing natal den selection or successful 
reproduction in the USNRMs.
    Fishers in British Columbia and Alberta are associated most 
commonly with the Sub-boreal Spruce and Boreal White and Black Spruce 
Biogeoclimatic Zones in the central to northern areas of the provinces 
(Weir and Lara Almuedo 2010, p. 36; Meidinger et al. 1991, p. 211; 
Delong et al. 1991, p. 239). The Sub-boreal Spruce Zone is a heavily 
forested montane region with uplands dominated by Picea engelmannii x 
glauca (hybrid white spruce) and Abies lasiocarpa; Pinus contorta is 
common on drier sites (Meidinger et al. 1991, p. 210). The climate of 
the Sub-boreal Spruce Zone is continental and characterized by severe, 
snowy winters and relatively warm, moist, and short summers (Meidinger 
et al. 1991, p. 210). Mean annual precipitation ranges from 415 to 
1,650 mm (16 to 65 in.) with less than half of that falling as snow in 
winter (Meidinger et al. 1991, p. 210). The Boreal White (Picea glauca) 
and Black (Picea mariana) Spruce Zone is a relatively dry zone with 
very long, very cold winters with short summer growing seasons, and 
annual precipitation averages between 330 and 570 mm (13 and 22 in.), 
with 35 to 55 percent falling as snow (DeLong et al. 1991, p. 238). P. 
glauca, P. mariana, P. contorta, and A. lasiocarpa are major tree 
species in these zones (DeLong et al. 1991, p. 238). Both the Sub-
boreal Spruce and Boreal White and Black Spruce Zones have a 
representative deciduous tree component of Populus tremuloides 
(trembling aspen), Betula papyrifera (paper birch), and Populus 
balsamifera spp. Trichocarpa (black cottonwood) (DeLong et al. 1991, p. 
238; Meidinger et al. 1991, p. 212; Weir and Corbould 2008, p. 5), all 
of which are tree hardwood types selected by fisher for reproductive 
dens (Weir and Lara Almuedo 2010, p. 37).
    Topographic relief in the USNRMs produces localized variations in 
vegetation and seasonal snowfall not widely seen in the western Canada 
population. It is hypothesized that fisher distribution on the 
landscape is limited by deep snow (Krohn et al. 1995, p. 103; Krohn et 
al. 1997, p. 226). If this is correct, then the precipitation in the 
USNRMs, the majority of which falls as snow and is heavily influenced 
by topography, could lead to geographic partitioning and an overall 
less optimal habitat within the region. There are observations of 
fishers using areas with deep, fluffy snow in the USNRMs, which also 
could indicate an adaptation to local conditions, but the relationship 
between using or avoiding certain snow conditions has not been 
evaluated statistically. Fishers in Idaho have some of the largest home 
ranges recorded for the species (reviewed by Powell and Zielinski 1994, 
p. 58; IOSC 2010, p. 4; reviewed by Lofroth et al. 2010, p. 68), 
possibly indicating suboptimal forest resources often found in 
peripheral populations (Wolf et al. 1996, p. 1147). The limited 
availability of hardwood tree types used for denning in other areas of 
the range also may indicate a local adaptation to different den 
structures in the USNRMs and the selection of less optimal structures 
based on necessity.
    More information is needed to elucidate important ecological 
relationships for fishers in the USNRMs. Therefore, we do not conclude 
that the fisher in the USNRMs is significant to the taxon as a whole 
based on ecological differences alone, but the observed differences 
indicate that fishers in the region are subject to suboptimal habitats 
and pressures typically seen in important peripheral populations. 
Strong selective pressures in peripheral populations may induce 
adaptations that may be important to the taxon in the future.
Significant Gap in the Range of the Taxon
    The loss of the fisher in the USNRMs would result in a significant 
gap in the range of the taxon and contribute to the extensive range 
retraction and fragmentation that has occurred since European 
settlement of North America (Gibilisico 1994, p. 60). The USNRMs 
represent one of only three historical peninsular reaches of the range 
in the United States connecting with Canada and the southernmost 
extension of the taxon's distribution in the Rocky Mountains (Gibilisco 
1994, p. 60; Proulx et al. 2004, p. 57). Range retraction in the 
eastern United States south of the Great Lakes has isolated populations 
in New England and northern Atlantic States from Minnesota and 
Wisconsin, although the eastern United States populations retain 
connectivity to

[[Page 38518]]

Canada (Gibilisico 1994, p. 60; Proulx et al. 2004, p. 57).
    Fisher populations in the western United States are isolated from 
each other and the closest Eastern population in the Great Lakes area, 
and have lost a connection or have a severely diminished capacity to 
connect with larger population areas in Canada (Gibilisco 1994, p. 64; 
Zielinski et al. 1995, p. 107; Aubry and Lewis 2003, pp. 86, 88; Weir 
2003, pp. 19, 24, 25; Weir and Lara Almuedo 2010, p. 36). Extirpation 
of the USNRMs population would significantly impact representation of 
the species by shifting the southern boundary of the western range of 
the taxon over 965 km (600 mi) to the north. Only three individually 
isolated fisher populations in Oregon and California, two being native 
populations (Aubry and Lewis 2003, p. 88; Lofroth et al. 2010, p. 47), 
would be left in the entire southwest range of the taxon at a distance 
of over 800 km (500 mi) from populations in Canada (Weir and Almuedo 
2010, p. 36). The recent fisher introduction to Washington's Olympic 
peninsula is not considered here because its establishment as a self-
sustaining entity has not been demonstrated.
    The retention of a fisher population in the USNRMs is significant 
to the taxon because of its situation at the periphery of the range. 
Populations at geographic margins, defined as peripheral populations, 
may be of high conservation significance and important to long-term 
survival and evolution of species (Lesica and Allendorf 1995, p. 756; 
Fraser 2000, p. 49). Populations at the periphery tend not to be given 
conservation priority because of their existence in lower quality 
habitats, and these populations are presumed to be least likely to 
survive a reduction in range (Wolf et al. 1996, p. 1147). This 
presumption is based on an existing theory that the cause of a species' 
range contraction is erosion that commences at the periphery where 
population numbers are low and progresses to the center where optimal 
habitats support higher population numbers (Lomolino and Channell 1995, 
pp. 336, 338). Upon closer examination, population persistence is not 
biased toward larger, less isolated or more central regions of a 
species historical range. Of 245 vertebrate species experiencing 
geographic range contraction, 98 percent retained some species presence 
in peripheral populations, 68 percent retained greater periphery than 
core, and 37 percent of species retained no core but remained in 
peripheral populations (Channell and Lomolino 2000, p. 85). Peripheral 
populations are likely to be in suboptimal habitats and subject to 
severe pressures that result in genetic divergence, as seen in USNRMs 
fisher populations, either from genetic drift or adaptation to local 
environments (Fraser 2000, p. 50). Because of their exposure to strong 
selective pressures, peripheral populations may contain adaptations 
that may be important to the taxon in the future. Lomolino and Channell 
(1998, p. 482) hypothesize that because peripheral populations should 
be adapted to a greater variety of environmental conditions, then they 
may be better suited to deal with anthropogenic (human-caused) 
disturbances than populations in the central part of a species' range.
    We conclude that the loss of the USNRMs fisher population would 
result in a significant gap in the range of the taxon by shifting the 
southern boundary of the western range over 965 km (600 mi) to the 
north, leaving only three individually isolated populations in the 
entire southwestern range of the taxon. Thus, the USNRMs population 
meets the definition of significant in our DPS policy.
Marked Genetic Differences
    Fishers in the USNRMs represent a native lineage that escaped 
extirpation early in the 20th century (Weckwerth and Wright 1968, p. 
977; Schwartz 2007, p. 924). Close to half of the USNRMs fishers 
sampled have a unique mitochondrial haplotype [a group of alleles (DNA 
sequences) of different genes on a single chromosome that are closely 
enough linked to be inherited usually as a unit]--Haplotype 12--found 
nowhere else in the range of the taxon (Drew et al. 2003, p. 57; Vinkey 
2003, p. 82; Vinkey et al. 2006, p. 269). Mitochondrial DNA is 
associated with the energy-producing structures within cells called 
mitochondria, and is inherited through the maternal line. Individuals 
with Haplotype 12 are significantly divergent from all other haplotypes 
in having an additional variation (Haplotype B) within a genetic 
structure associated with the mitochondria called Cytochrome b, while 
all of the other 11 mitochondrial haplotypes have the Haplotype A of 
the Cytochrome b region (Vinkey 2003, p. 79; Vinkey et al. 2006, p. 
268; Schwartz 2007, p. 923). Unique genetic haplotypes common to the 
native lineage are expected, considering the peripheral location of the 
population and a history of severe population reduction and isolation 
(Lesica and Allendorf 1995, p. 754, Vinkey 2003, p. 82). Locally 
adapted populations evolve traits that provide an advantage and higher 
level of fitness under the local environmental conditions or habitat 
than genotypes evolved elsewhere (Kawecki and Ebert, 2004, p. 1225), 
and the unique genetic characteristics may have factored into 
sustaining a rare population in the USNRMs. The forces that shape 
adaptation are often strongest in the periphery of the range, and 
populations situated here may be better suited to deal and adapt to 
changes in their environments (Lomolino and Channell 1998, p. 482). It 
is the intent of the DPS policy and the Act to preserve important 
elements of biological and genetic diversity. The loss of the native 
fisher lineage in the USNRMs would result in the loss of a unique and 
irreplaceable genetic identity and the local adaptation and 
evolutionary potential that goes with it. Thus, we conclude that the 
USNRMs fisher differs markedly from other members of the taxon in 
genetic characteristics, and this difference is significant to the 
conservation of the species.
Summary for Significance
    We conclude that the fisher population in the USNRMs is significant 
because its loss would result in a significant gap in the range of the 
taxon, and its genetic characteristics differ markedly from those of 
other fisher populations.
Determination of Distinct Population Segment
    Based on the best scientific and commercial information available, 
we find that the fisher in the USNRMs is both discrete and significant 
to the taxon to which it belongs. Fishers in the USNRMs are markedly 
separated from other populations of the same taxon as a result of 
physical factors, further supported by quantitative differences in 
genetic identity. The loss of the fisher in the USNRMs would result in 
a significant gap in the range of the taxon and the loss of markedly 
different genetic characteristics relative to the rest of the taxon. 
Because the fisher in the USNRMs is both discrete and significant, it 
qualifies as a DPS under the Act.

Distinct Population Segment Five-Factor Analysis

    Since the fisher in the USNRMs qualifies as a DPS, we will now 
evaluate its status with regard to its potential for listing as 
endangered or threatened under the five factors enumerated in section 
4(a) of the Act.
    Section 4 of the Act (16 U.S.C. 1533) and implementing regulations 
(50 CFR part 424) set forth procedures for adding species to, removing 
species from, or

[[Page 38519]]

reclassifying species on the Federal Lists of Endangered and Threatened 
Wildlife and Plants. Under section 4(a)(1) of the Act, a species may be 
determined to be endangered or threatened 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; or
    (E) Other natural or manmade factors affecting its continued 
    In making this finding, information pertaining to the USNRMs fisher 
DPS in relation to the five factors provided in section 4(a)(1) of the 
Act is discussed below. In making our 12-month finding on the petition 
we considered and evaluated the best available scientific and 
commercial information.
    In considering what factors might constitute threats to a species, 
we must look beyond the exposure of the species to a particular factor 
to evaluate whether the species may respond to that factor in a way 
that causes actual impacts the species. If there is exposure to a 
factor and the species responds negatively, the factor may be a threat 
and, during the status review, we attempt to determine how significant 
a threat it is. The threat is significant if it drives, or contributes 
to, the risk of extinction of the species such that the species 
warrants listing as endangered or threatened as those terms are defined 
in the Act. However, the identification of the factors that could 
impact a species negatively may not be sufficient to compel a finding 
that the species warrants listing. The information must include 
evidence sufficient to suggest that these factors are operative threats 
that act on the species to the point that the species may meet the 
definition of endangered or threatened under the Act.
    We are required by the Act to assess threats information that may 
occur within the foreseeable future. We define foreseeable future as a 
timeframe in which impacts can be reasonably expected to occur. Where 
future projections are not available, it is assumed that current trends 
will continue unless information exists to the contrary. Our evaluation 
of the fisher in the USNRMs follows.

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 fisher 
habitat including: (1) Timber Harvest and Forest Management, (2) 
Development and Roads, (3) Climate Change, and (4) Fire and Disease. 
Climate change is discussed under Factor A, because the primary impact 
of climate change on fishers is expected to be through changes to the 
availability and distribution of fisher habitat. Many of these impact 
categories overlap or act together to affect fisher habitat.
Timber Harvest and Forest Management
    Industrial timber harvest in the inland Northwest United States 
(Interior Columbia River Basin), including Idaho and western Montana, 
did not occur until the early 20th century (Hessburg and Agee 2003, pp. 
40-41). Prior to 1900, logging in Idaho and Montana supplied timbers 
only to local concerns such as mining and railroad development, and did 
not become important to national markets until after other forested 
areas (e.g., Great Lakes region) had been depleted (Hessburg and Agee 
2003, p. 40). Early industrial logging used selective practices, taking 
only large, high-grade or salvage logs (Hessburg and Agee 2003, pp. 41-
42). By 1940, many inland northwest areas containing dry forest types, 
typically of ponderosa pine, were intensively logged by this method; 
moist or mesic forest types favored by fishers in the Flathead Valley 
and Whitefish Mountains in Montana and the Coeur d'Alene area of 
northern Idaho were also affected (Lesica 1996, p. 34; Hessburg and 
Agee 2003, pp. 41-42). The balance of forested areas in Idaho and 
Montana showed little or no logging activity up to 1940 (Hessburg and 
Agee 2003, p. 42).
    Historical fisher population numbers are not known, but reports of 
their presence declined in the 1920s to a point that the fisher was 
presumed extirpated in the USNRMs (Williams 1963, p. 8; Weckwerth and 
Wright 1968, p. 977; Brander and Books 1973, p. 52). Fishers in the 
USNRMs avoid dry forest types (Schwartz 2010, unpublished data), and 
because local subsistence logging and early industrial logging were of 
limited geographic scale and selected for dry forest types, it is 
unlikely that this contributed directly to the fishers' apparent demise 
across the USNRMs area. Other factors or combination of factors, 
discussed in subsequent sections, may have had more influence on past 
fisher population reductions.
    From the 1930s, timber harvest continued (Hessburg and Agee 2003, 
p. 41) while native fishers maintained an undetected refugium likely, 
in the Selway-Bitterroot Mountains straddling the border of Montana and 
Idaho (Vinkey et al. 2006, p. 269). Timber harvest was increasing in 
the USNRMs as fisher reintroductions (later realized to be population 
augmentations) were occurring in the late 1950s and early 1960s. 
Clearcutting practices, which removed all overhead cover in the harvest 
area, increased on private and public lands, and large areas of private 
timberland were converted to plantation forestry which emphasized 
clearcutting and even-aged forest regeneration management practices 
(Hessburg and Agee 2003, p. 41). With plantation or rotational 
forestry, the large tree components and coarse woody debris are 
suppressed or not allowed to accumulate to the point that they supply 
denning or cold weather resting sites (Weir 2003, p. 16). From 1938 to 
present day, low-elevation timberlands have been depleted of large, 
older trees considered late-seral or old-growth type, and the mid-
elevation habitats retain only small amounts (DellaSala et al. 1996, p. 
213; Lesica 1996, p. 37). The majority of presettlement upland old-
growth forest was in the drier forest types of ponderosa pine/Douglas 
fir/western larch, which are subject to frequent low-intensity 
underburns that reduce ladder fuels (forest fire fuels that provide 
fire connectivity from understory to midlevel or canopy fuels) and more 
shade-tolerant vegetation in the understory (Green et al. 1992, p. 2). 
However, fishers are known to avoid these forest types and they 
represent only minor components of areas used by fishers (Jones and 
Garton 1994, pp. 377-378; Schwartz 2010, unpublished data).
    In general, timber harvest and management over the last century has 
resulted in the loss of old forest and large- and medium-diameter trees 
that historically were widely distributed in forest structures other 
than old growth forest (Hessburg and Agee 2003, p. 45); still, the 
amount of land covered by forest in the USNRMs is similar to historical 
times (Hessburg et al. 2000, p. 60). Timber harvest, together with fire 
exclusion, has produced younger, homogenously structured forest 
patches, especially in dry forest types, with more canopy layers and 
more understory vegetation than historically due to fire suppression 
(Hessburg and Agee 2003, pp. 45-46). Fragmentation of managed 
landscapes has increased due to more numerous and smaller patches of 
various forest types, while roadless and wilderness areas have retained 
a simpler less fragmented structure (Hessburg et al. 2000, p. 78). From 
a landscape perspective, the departure from historical old-growth 
structure is most

[[Page 38520]]

pronounced in the northern areas of the USNRMs, with a concurrent shift 
to increasing old-forest multistory stages in the southern areas 
(Wisdom et al. 2001, p. 184).
    As a result of timber harvest and management practices, forest 
structures and quantities of large trees across the USNRMs have been 
affected. It is unclear how this has impacted fisher populations. There 
is no information regarding fisher population numbers within the region 
before European settlement, and no region-wide population numbers or 
trends are available today to allow a comparison of the impacts of 
changes to the landscape over time on fisher populations. Fishers were 
so rare as to be considered extirpated before large-scale harvesting 
occurred. Fifty years after the introduction of 78 animals to 9 areas 
in Idaho and Montana between 1959 and 1962 (reviewed by Vinkey 2003, p. 
55), concurrent with decades of post-introduction timber harvest, 
fishers, half of which are of native lineage, persist on the landscape 
in a wider distribution than they did before augmentations (Vinkey 
2003, p. 82; IOSC 2010, pp. 7, 10; MTFWP 2010, Attachment 4). Although 
there is little information elucidating the density of fisher 
populations in the USNRMs, the contemporary distribution of fishers 
appears to be similar to the historically depicted distribution in 
Idaho and Montana (Gibilisco 1994, p. 64) (Figure 1).
    We are not concluding that a cause and effect relationship exists 
between increased timber harvest or treatment and increasing fisher 
distribution. The existing state of the USNRMs landscape is conducive 
to supporting fisher, but it is unknown if the system has the capacity 
to support, in the long term, a self-sustaining population or 
subpopulations in a metapopulation dynamic. Fisher home ranges in Idaho 
and Montana are larger than most other areas in the taxon's range 
(reviewed by Powell and Zielinski 1994, p. 58; reviewed by Lofroth et 
al. 2010, p. 68; IOSC 2010, p. 4), and this large size could be the 
result of fragmentation or low-quality habitat (Powell and Zielinski 
1994, p. 60), either naturally occurring or human-produced. Timber 
harvest and management have significant potential to alter the 
suitability of a landscape for fishers; conversely, management of 
forests using mechanical means or fire can assist in creating 
conditions that foster larger trees, create snags, increase woody 
debris, or open densely stocked areas to provide habitat for fisher 
prey species. Fishers in the USNRMs evolved in forest types where fire 
frequency and intensity was mixed, and windthrow was common, resulting 
in a complex and intricate landscape mosaic of young, mixed-age, and 
late-seral components (Jones 1991, p. 111; Arno et al. 2000, pp. 225-
227). Thus, the result of silviculture treatments or harvest may 
resemble the natural disturbances and the succession that follows 
(Powell and Zielinski 1994, p. 64).
Current and Future Timber Harvest and Management
    Commercial timber harvest, management for timber production, and 
the use of forestry techniques to protect, restore, and enhance forest 
ecosystems are ongoing activities in the USNRMs and are expected to 
continue. Fourteen national forests comprise approximately 65 percent 
of the land area and 72 percent of the forest types known to be used by 
fishers in the USNRMs (U.S. Department of Agriculture (USDA) 2009, 
entire). Timber harvest or manipulation for either timber production or 
other resource objectives is stated in each forest's Land and Resource 
Management Plan, which provide direction for a 10- to 15-year period. 
National forests are subject to a multi-use mandate and maintenance 
``in perpetuity of a high level of annual or regular periodic output of 
the various renewable resources,'' including timber (PL 104-333), and 
other legislative mandates for forest health or fuels reduction (e.g., 
Healthy Forests Restoration Act (Pub. L. 108-148)), which may require 
manipulation of forested areas. Planning directives specify lands for 
timber production for long-term sustained yields; however, silviculture 
(forest removed or treated) acres on all forests in the USNRMs has 
generally declined over the past 15 years, including a significant 
reduction in clearcutting (USDA 2010a, entire; USDA 2010b, entire). The 
USFS actions are regulated and relevant authorities are discussed in 
the ``Factor D'' section below.
    State-owned forestry lands comprise approximately 6 percent of the 
forest types preferred by fishers in the USNRMs area. Timber harvest is 
an activity expected to continue on State trust or endowment lands in 
both States of Idaho and Montana, because of the responsibility to 
maximize long-term financial returns to public schools and other trust 
beneficiaries (Idaho Board of Land Commissioners 2007, p. 3; Montana 
Code Annotated 2009a, entire). Forest resources are evaluated for 
management of a sustainable harvest on 5- to 10-year review schedules 
(Idaho Board of Land Commissioners 2007, p. 18; Montana Department of 
Natural Resources and Conservation (MTDNRC) 2010, p. 3). Private lands, 
including commercial timber operations with the primary objective of 
maximizing fiber production, comprise approximately 22 percent of the 
fisher forest types. The extent of timber harvest operations are driven 
by market forces and difficult to predict (Morgan et al. 2005, p. 2), 
but it is reasonable to conclude that management to maximize wood 
production (e.g., pre-thinning of stands), harvest, road construction 
and maintenance, and other activities will continue into the future.
    We expect the current timber management and silviculture activity 
to continue on national forest lands guided by management plans. The 
effects of present and future forest management and timber harvest on 
the capacity of the USNRMs to support fishers may be influenced by many 
factors, including the location, scale, and juxtaposition of treatments 
to previous disturbances; the suitability of an area to provide fisher 
habitat under natural conditions; and the habitat needs of fishers. The 
habitat ecology of fishers in the USNRMs is not well understood. Forest 
patches with high densities of large trees, canopy covers exceeding 40 
percent, and riparian areas appear to be important; however, 
information is lacking regarding fishers' requirements for patch size 
and connectivity (Jones and Garton 1994, pp. 380, 385-386). Although 
some information is available from other regions, habitat requirements 
for successful denning and rearing of young in the USNRMs are not 
known. Fishers have been described as using ``old-growth'' forest types 
disproportionally to their occurrence (Thomas et al. 1988, p. 255); 
however, there also has been a lack of clarity in the use of the term 
``old-growth'' in forest ecology literature, and description of forest 
characteristics at any particular successional stage vary by geographic 
region, forest type, and local conditions (Green et al. 1992 errata 
2008, p. 2). Therefore, without specific parameters, basing a loss of 
fisher habitat on trends of ``old-growth'' or even ``larger trees'' may 
be misleading.
    Late seral or mature forest elements such as snags and overhead 
cover are important habitat features for fishers throughout their 
range. These mature forest conditions may take many decades to hundreds 
of years to develop, and national forest management direction is 
revised over short time periods relative to forest succession. National 
forest lands that support fishers today reflect natural processes and 
silviculture actions

[[Page 38521]]

spanning numerous planning periods as well as actions taken before 
comprehensive national forest management was mandated in 1976 (16 U.S.C 
1601-1614). Given the history of forest management and planning, we do 
not expect significant changes in the availability of mature forest 
habitats through future forest planning cycles.
    The species continues to occupy its presumed historical range 
despite habitat alterations that have occurred within that range, 
although fisher densities may be different. Fishers in the USNRMs have 
been observed to use roadless areas of forests, national forest lands 
managed for multiple purposes, and State forests and industrial forests 
managed primarily for commercial timber production (J. Sauder, IDFG, 
unpublished data cited in IOSC 2010, p. 4), although it is unclear how 
fishers are using these environments, or the relative importance of 
each to supporting individuals or fisher populations. We expect that 
fishers' use of lands managed for timber production or multiple uses 
will occur in the future under conditions fostered by the continuance 
of current management. Therefore, we conclude that the best available 
scientific and commercial information does not indicate that current or 
future forest management practices and timber harvest threaten the 
fisher now, or in the foreseeable future.
Development and Roads
    The USNRMs region encompasses large tracts of public lands with 
little or no development, wilderness areas, and numerous municipalities 
of varying size, low-density rural development, rail lines, road 
networks and other human developments. Most of the development and 
infrastructure, including national forest roads, have been on the 
landscape for decades (Baker et al. 1993, p. 2; Havlick 2002, p. 11). 
Higher density development and road networks are situated in broad, 
open, lower-elevation intermountain valleys or lower montane areas, and 
most human activity and dwellings adjacent to public lands occur in dry 
woodlands or dry forest (Hessburg and Agee 2003, p. 47). Development in 
most cases is not far from public lands--primarily national forest. 
Mesic forest types and riparian corridors preferred by fishers are 
generally found at low to mid-elevations, and these highly productive 
habitats often coincide with areas that receive above average levels of 
human use (Carroll et al. 2001, p. 962). Where development and roads 
coexist with these areas, habitat could be lost directly by replacement 
with infrastructure or removal of cover, and fishers could be impacted 
by increased susceptibility to direct mortality from vehicle 
collisions, and increased exposure to disease from pets and animals 
such as raccoons associated with human development (Ruediger 1994, p. 
3; Carroll et al. 2001, p. 969; Brown et al. 2008, p. 23). We have no 
information that disease is a problem for fishers in the USNRMs, and 
reports of fisher mortality due to vehicle collision are few (Vinkey 
2003, p. 32; Giddings 2010, pers. comm.) (see Factor C discussion 
    The secondary effects of human activity and infrastructure, and 
roads or road use, in causing fisher avoidance or inhibiting movement 
on the landscape are unclear. It is reported that fishers in California 
more often used areas with a greater than average density of low-use 
roads (Dark 1997, p. 50), and, in Maine, fishers seldom traveled in the 
vicinity of roads or powerline corridors (Coulter 1966, p. 61). 
Conversely, Arthur et al. (1989b, p. 687) found that fishers in Maine 
were fairly tolerant of human activity, including low-density housing, 
farms, roads, and gravel pits, if forest canopy cover was maintained in 
the vicinity. Roads in forested areas of the USNRMs are often 
constructed along riparian corridors or forested valley bottoms, which 
are habitats fishers prefer. Targeted surveys for fishers are often 
conducted near roads because of the ease of access and likelihood of 
detecting fisher in a preferred habitat. Fishers do not avoid areas 
adjacent to a minor State highway that traverses National Forest land 
in Idaho (Schwartz et al. 2007, p. 6), and other targeted survey 
efforts for fishers in northern Idaho have successfully detected 
fishers in the vicinity of roads (Schwartz et al. 2007, p. 6; Albrecht 
and Heusser 2009, p. 8). This would imply that fishers are not 
displaced from suitable habitat by the presence of roads or road use. 
Roads and landscape features such as rivers have been implicated in 
increasing mortality risk to dispersing fishers, but fishers have 
dispersed across, and did not appear to be affected by roads, lakes or 
rivers in other parts of the range (York 1996, p. 46; Fontana et al. 
1999, pp. 17; Weir and Corbould 2008, p. 44).
    Roads constructed on public lands to provide access for resource 
use and extraction have been implicated in increasing access for 
trappers that target fishers or that may accidentally trap them 
(Hodgman et al. 1994, p. 598). The closure of roads to provide grizzly 
bear (Ursus arctos) habitat security is a possible reason for the 
reduction in fishers harvested in Montana's Flathead and Swan Valley 
(Giddings 2010, pers. comm.). Recent changes in the USFS' travel 
management direction (70 FR 68264, November 9, 2005), require that 
national forest roads are managed in a manner compatible with wildlife 
resources. Accordingly, implementation of seasonal or permanent road 
closures to benefit the threatened grizzly bear has likely provided 
benefits to fishers in many parts of the USNRMs.
    Rapid housing growth has occurred in close proximity to public 
lands in the Rocky Mountain region since the 1990s, with much of it 
situated in areas already considered wildland-urban interface and 
impacted by development (Alig et al. 2010, p. 9). Additional 
residential development adjacent to public lands is expected to 
increase by 10 to 42 percent in some areas of the USNRMs by 2030 (Stein 
et al. 2007, p. 8). The sale of private nonindustrial lands (i.e., 
family-owned forests) currently managed for timber is a likely source 
for additional residential development (Alig et al. 2010, pp. 6-7), 
although it is uncertain if a significant quantity of these lands is 
mesic forest or dry forest type less suitable for fishers.
    There is a trend of large, industrially managed or corporate forest 
properties being divested for real estate development across the United 
States that is expected to continue into the future. Although large 
areas of industrial forest are predicted to be lost nationwide through 
2050, most of this loss is due to urbanization in the southern United 
States (Alig et al. 2010, pp. 14-15). We know that fishers utilize 
industrial forests in the USNRMs (IOSC 2010, p. 4). The availability of 
industrial forest lands for other uses will likely improve conditions 
for fishers in Montana, where over 1,253 km\2\ (484 mi\2\) of low-
elevation commercial forest, originally intended to be sold for 
development purposes was instead purchased for conservation and 
sustainable forestry by State, Federal, and conservation organizations 
(MTFWP 2010, Appendix 13, entire; The Nature Conservancy 2010, entire).
    Dwellings, roads, and other infrastructure have been on the 
landscape for decades, and areas currently developed will see an 
increase in the density of development over the next 20 years. It is 
unknown if fisher habitats that are currently or potentially suitable 
will be affected directly by future development. The proximity and 
availability of public lands may moderate a loss of habitat if it 
occurs, but the impact to fishers is uncertain because of a lack of 
understanding of how fishers use the lands at the interface of public 
and private ownerships. Increased road traffic and

[[Page 38522]]

human presence and recreational demands on public lands may increase 
the risk to fisher of vehicle collisions and displacement from suitable 
habitats near areas of high human use. Reports of fishers' responses to 
human activity and the presence of roads are mixed and, therefore, 
difficult to conclude with certainty. Habitat loss and increased direct 
mortality resulting from increasing human development are a concern 
but, based on the available information, do not rise to a level of 
threat to the USNRMs fisher now, or in the foreseeable future.
Climate Change
    We know of no element of the fisher's ecology or physiology that 
would be directly affected by changes in climate. Predicted climate 
changes could impact forested environments upon which fishers depend; 
therefore, we address climate change under Factor A.
    Climate is influenced primarily by long-term patterns in air 
temperature and precipitation. The Intergovernmental Panel on Climate 
Change (IPCC) concluded that climate warming is unequivocal, and 
evident from observed increases in global average air and ocean 
temperatures, widespread melting of snow and ice, and rising global 
mean sea level (IPCC 2007a, pp. 30-31). Continued greenhouse gas 
emissions at or above current rates are expected to cause further 
warming (IPCC 2007a, p. 30). Eleven of the 12 years from 1995 through 
2006 rank among the 12 warmest years in the instrumental record of 
global average near-surface temperature since 1850 (Independent 
Scientific Advisory Board (ISAB) 2007, p. 7; IPCC 2007a, p. 30). During 
the last century, mean annual air temperature increased by 
approximately 0.6 [deg]C (1.1 [deg]F) (IPCC 2007a, p. 30). Warming 
appears to be accelerating in recent decades, as the linear warming 
trend over the 50 years from 1956 to 2005 (average 0.13 [deg]C or 0.24 
[deg]F per decade) is nearly twice that for the 100 years from 1906 to 
2005 (IPCC 2007a, p. 30). Climate change scenarios estimate that the 
mean air temperature could increase by over 3 [deg]C (5.4 [deg]F) by 
2100 (IPCC 2007a, pp. 45-46). The IPCC also projects that there will 
likely be regional increases in the frequency of hot extremes, heat 
waves, and heavy precipitation, as well as greater warming in high 
northern latitudes (IPCC 2007a, p. 46). We recognize that there are 
scientific differences of opinion on many aspects of climate change, 
including the role of natural variability in climate. In our analysis, 
we rely primarily on synthesis documents that present the consensus of 
a large number of experts on climate change from around the world, as 
well as the scientific papers used in those reports, to represent the 
best available scientific information. Where possible, we used 
empirical data or projections specific to the western United States, 
which includes the Northern Rocky Mountain region, and have focused on 
observations or expected effects on forested ecosystems.
    Specific regional projections for the Interior Columbia Basin and 
the USNRMs are warmer temperatures, with more precipitation falling as 
rain than snow, diminished snowpack and altered stream flow timing, 
increase in peak flow of rivers, and increasing water temperatures 
through the 21st century (to 2099) (Hansen et al. 2001, p. 769; ISAB 
2007, pp. iii, 15-16). The consequences of these projections are 
unclear and could result in positive, negative, or neutral impacts to 
fisher habitat and populations. Fisher habitat could expand due to 
warming temperatures extending the growing season and increased 
atmospheric carbon dioxide escalating vegetation growth and extending 
forest area (Millar et al. 2006, pp. 48-49). It is hypothesized that 
climate change will produce greater tree species richness over much of 
the coterminous United States because of the current relatively greater 
species richness in warmer climates (Hansen et al. 2001, p. 774). The 
potential habitats of dominant rainforest conifers (e.g., western 
hemlock and red cedar that fishers use in the USNRMs) are expected to 
decrease west of the Cascades but expand into mountain ranges of the 
interior West (ISAB 2007, p. 26). If the hypothesis that fishers are 
limited by deep winter snow is correct (Raine 1981, p. 74; Krohn et al. 
1997, p. 226), decreased winter snowfall could increase the habitat 
available to fishers.
    Changes in temperature and rainfall patterns are expected to shift 
the distribution of ecosystems northward (IPCC 2007b, p. 230) and up 
mountain slopes (McDonald and Brown 1992, pp. 411-412; IPCC 2007b, p. 
232). Predicted climate shifts over the next century could result in 
the loss of alpine and subalpine spruce-fir forests, for example, 
forcing competition for prey between fishers and predators that are now 
occupying higher elevation niches (e.g., lynx) (Koehler 1990, p. 848; 
Ruediger et al. 2000, p. 3), or novel predator-prey interactions could 
evolve (ISAB 2007, pp. 26, 28). Increasing temperatures without 
additional moisture could stress vegetation, alter riparian systems, 
increase fire risk, and increase the susceptibility of forest 
vegetation to disease (Westerling et al. 2006, p. 943; ISAB 2007, pp. 
19, 25). Riparian areas are used extensively by fishers in the USNRMs 
(Jones 1991, pp. 90-93). Changing water regimes or decreased flow could 
decrease the productivity of riparian species and affect vegetation 
structure necessary for prey and security cover. The potential effects 
of climate change on the health of riparian systems could be 
exacerbated by the demands from increasing human population, 
development, and land use (Hansen et al. 2002, p. 159).
    Projected changes of climate could result in a wide range of 
potential outcomes for fishers and their habitat. The effects to 
fishers in either the short or long term in a focused geographic area 
cannot be reasonably discerned without a specific aspect of the 
species' ecology or physiology linked to a confidently projected 
climate change variable (e.g., water temperature tolerance of fish, or 
early snowmelt reducing wolverine denning). Increasing temperatures and 
drought could affect fire frequency and intensity and the 
susceptibility of forest vegetation to disease, but climate change 
itself does not represent a threat to fishers now or in the foreseeable 
Fire and Disease
    Fire disturbance was an integral force in shaping the Northern 
Rocky Mountains forest ecosystem well before European settlement of the 
region (Lesica 1996, p. 33). Lower, drier elevations were prone to 
frequent, low-intensity burns, while cool high-elevation forests were 
subject to intense stand-replacing events at intervals up to 300 years 
(reviewed by Hessburg and Agee 2003, p. 27). The grand fir/hemlock/
cedar forests known to support fisher today in Idaho have a history of 
highly variable mixed-intensity fire regimes. Fire severity and return 
intervals varied widely ranging from low-intensity fires with 16-year 
return intervals, to high-severity fires with 500-year return intervals 
(reviewed by Hessburg and Agee 2003, p. 27). Pre-European settlement 
forests would likely have been in a shifting mosaic of different 
successional stages, with 4 to 46 percent of the landscape of trees 
older than 200 years old (reviewed by Lesica 1996, p. 37). A fire 
history from 1650 to 1900 reveals that local fires or no fires occurred 
in most years. Occurring less often were extensive regional fire events 
in warm, dry summers that were preceded by warm springs: Eleven of 
these events occurred in the 20th century (Morgan et al. 2008, p. 723). 
One of the largest regional fires

[[Page 38523]]

of the 20th century occurred in 1910, consuming over 11,675 km\2\ (4507 
mi\2\) in northern Idaho and scattered locations in northwest Montana 
(Morgan et al. 2008, p. 721). Regional fires in the early 1900s 
consumed more mesic forest than regional fires in later years (Morgan 
et al. 2008, p. 725). It has been suggested that the 1910 and 1934 fire 
events, in combination with overharvest by the fur industry, 
contributed to the fisher population decline (Jones 1991, p. 1).
    Active fire suppression by humans in the mid-20th century has been 
implicated in the accumulation of forest vegetation believed to 
contribute to more fire-prone conditions today (Hessburg and Agee 2003, 
pp. 44, 46). However, a remarkable period between 1935 and 1987 was the 
longest period of low fire activity of the previous 250 years, and the 
lack of large fire activity was more a factor of cooler, wet climate 
conditions than fire suppression action (Morgan et al. 2008, p. 726). 
An abrupt change occurred in the 1980s from a fire regime of infrequent 
large fires of short duration, to more frequent longer burning fires 
(Westerling et al. 2006, p. 942). The shift was associated with 
unusually warm springs, longer summer dry seasons associated with 
reduced winter precipitation, and early spring snowmelt (Westerling et 
al. 2006, p. 943), a climate pattern seen with historical regional fire 
    Since the 1980s, the Northern Rocky Mountains have seen the largest 
absolute increase in large wildfire activity in the forest types least 
affected by previous fire exclusion: Mesic mid-elevation and high-
elevation forest types (Westerling et al. 2006, p. 943). Climate model 
projections indicate decreased snowpack, earlier snowmelt, and 
increasing temperatures contributing to longer fire seasons (Westerling 
et al. 2006, p. 943). Moisture patterns are more difficult to predict 
than temperature (Global Climate Change Impacts 2009, p. 135; Dai 2011, 
p. 16). Because many climate models predict higher precipitation levels 
associated with climate warming, the interaction between precipitation 
and temperature increase can be quite complex. If temperatures increase 
without compensating moisture patterns or amounts, the predicted warmer 
springs and summers could produce conditions favorable to the 
occurrence of large fires in the future, regardless of past trends 
(Westerling et al. 2006, p. 943). If this occurs, increased fire 
frequency and intensity in forests could increase the likelihood of 
direct fisher mortality, diminish the capacity of the landscape to 
support fisher, and increase isolation of small fisher populations on 
the landscape.
    Diseases that affect forest structure and composition could impact 
fisher habitats by reducing cover or altering prey availability. Bark 
beetle (Dendroctonus spp.) eruptions have been affecting forest 
structure for millennia, but recent drought and increased winter 
temperatures have contributed to unprecedented rates of beetle 
infestations in lodgepole and ponderosa pine in the western United 
States (Brunelle et al. 2008, pp. 836-837). Lodgepole forests in 
British Columbia are a significant habitat type for fishers in British 
Columbia, and these forests have experienced widespread mortality from 
beetle infestation (Weir and Corbould 2010, p. 409). Infestations are 
widespread in forested areas of Idaho and western Montana (MTDNRC 2009, 
entire; Idaho Department of Lands 2010, entire), but the affected 
forest types are a small component of fisher habitat in the USNRMs 
(Jones and Garton 1994, pp. 377-378). Mortality of the overstory occurs 
in affected stands, but fisher use may not be affected if sufficient 
secondary structure remains (Weir and Corbould 2010, p. 409). Over 
time, affected trees or stands could provide standing (vertical) rest 
and den sites as well as contributing to downed woody debris in the 
understory (Simard et al. in press, p. 2). Standing beetle-killed trees 
have been considered a significant fire hazard which could fuel larger, 
landscape fires (Bentz et al. 2010, p. 611). Recent studies indicate 
that this concern could be overstated as neither torching nor crowning 
would be expected to increase with dead standing trees with retained 
needles, and the likelihood of sustaining an active crown fire in dead 
stands significantly decreases with tree collapse (Simard et al. in 
press, pp. 2, 28).
    Disease processes are natural forces in shaping forest environments 
and may be important in providing denning or resting structures for 
fishers. We have no information that the current bark beetle epidemic 
is negatively impacting fisher habitat or fishers in the USNRMs. An 
increase in incidence of forest diseases or novel diseases also could 
accompany a changing climate, but as with fire, the threat to fisher 
habitats is difficult to predict. Based on the available information, 
climate driven events such as regional fires or disease and insect 
infestations do not rise to the level of threat to the fisher now or in 
the foreseeable future.
Summary of Factor A
    The fisher is a forest-dependent species that evolved in the USNRMs 
in a complex landscape mosaic shaped by fire, tree disease, and 
windthrow. In the USNRMs, younger forests provide foraging habitat, but 
abundant mature and old trees that provide extensive canopy cover for 
resting and possibly denning are also considered important elements to 
support fishers on the landscape. Fisher populations were greatly 
reduced to the point they were believed extirpated in the USNRMs in the 
early 20th century. Human occupation and commercial timber harvest 
occurred at low levels early in the century, and anthropogenic 
alteration of fisher habitat is an unlikely cause of the species' 
population collapse in this region. Over decades, fisher populations 
resurged, with the help of augmentations, concurrently with natural 
climate events such as drought and fire, and also the permanent or 
long-lasting effects of development and timber harvest that potentially 
alter the important mature forest structure.
    Fourteen national forests comprise approximately 72 percent of the 
forest types known to be used by fishers in the USNRMs, State forestry 
lands 6 percent, and private lands including industrial timber lands 
comprise approximately 22 percent (USDA 2009, entire). Commercial 
timber harvest, management for timber production or fuels reduction 
(such as pre-commercial thinning), prescribed burning, recreation and 
road maintenance and use are ongoing in the region and we expect these 
activities to continue. Fishers have been observed to use roadless 
areas of forests, national forest lands managed for multiple purposes, 
and State forests and industrial forests managed primarily for 
commercial timber production. It is unclear how fishers are using these 
environments, or their relative importance to supporting individuals or 
fisher populations. However, habitats supporting fishers today reflect 
past and current forest management, silviculture, and natural 
processes, and we do not expect future changes in the management of 
forest conditions to significantly vary from current direction.
    Based on the limited available survey information, the contemporary 
distribution of fishers is similar to the historically depicted 
distribution in Idaho and Montana, despite alterations that have 
occurred within its range. Current fisher population numbers or trends 
are unknown. The existing state of the USNRMs landscape is conducive

[[Page 38524]]

to supporting fisher, but it is not clear what the capacity of the 
system is to support, in the long-term, a self-sustaining population or 
a metapopulation dynamic of subpopulations. Interpreting the impact of 
past and present forest management, resource extraction, or development 
is complicated by an incomplete picture of how the animals are using an 
altered landscape. Given the available information, it does not appear 
that forest management and timber harvest are threats to the species 
currently or in the foreseeable future.
    Dwellings, roads, and other infrastructure have been on the 
landscape for decades, and currently developed areas likely will see an 
increase in the density of development over the next 20 years. It is 
unknown if fisher habitats that are currently or potentially suitable 
will be affected directly by future development. The proximity and 
availability of public lands may moderate a loss of habitat, if it 
occurs, but more needs to be understood regarding how fishers are using 
the lands at the interface of public and private ownership. An increase 
in traffic on roads, and increased human presence and demands for 
recreation on public lands also, may increase the risk of vehicle 
collision and displacement from suitable habitats in proximity to areas 
receiving high levels of human use. Reports of fishers' responses to 
human activity and the presence of roads are mixed and, therefore, 
difficult to conclude with certainty. Habitat loss and increased direct 
mortality resulting from increasing human development are a concern, 
but, based on the available information, do not rise to a level of 
threat to the population.
    The Northern Rocky Mountain region has a history of local and 
periodic regional fire and tree disease events. Fire and disease will 
continue to shape the forest landscape. While most climate predictions 
through the 21st century include increased temperature and earlier 
spring snowmelt conducive to longer fire seasons, the uncertainty of 
moisture patterns makes regional fire patterns difficult to predict. 
Forests in the USNRMs are vulnerable to an increasing frequency of 
large fires, which could lead to changes in forest composition and 
structure, cause direct fisher mortality, diminish the capacity of the 
landscape to support fisher, and isolate small populations in a matrix 
of unsuitable habitat. Although the potential for changing fire 
frequency and intensity exists, these events cannot be predicted with 
confidence. The current incidence of bark beetle infestation does not 
appear to represent a significant threat to fishers in the USNRMs. An 
increase in incidence of forest diseases or novel diseases also could 
accompany a changing climate, but as with fire, the threat to fisher 
habitats is difficult to predict. Based on the available information, 
climate-driven events such as regional fires that may result from 
projected increases in temperature, earlier spring snowmelt and 
drought, or the increased susceptibility of trees to disease or insects 
due to drought, do not rise to the level of a threat to the fisher in 
the foreseeable future.
    We conclude that the best scientific and commercial information 
available indicates that the fisher in the USNRMs is not now, or in the 
foreseeable future, threatened by the present or threatened 
destruction, modification, or curtailment of its habitat or range to 
the extent that listing under the Act as an endangered or threatened 
species is warranted at this time.

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

    Unregulated overharvest, and the use of strychnine as a trapping 
and general predator control agent, in addition to habitat loss, 
eliminated or greatly reduced fisher numbers across the range by the 
mid-1900s (Douglas and Strickland 1987, p. 512; Powell 1993, p. 77). 
The closure of trapping seasons in the 1920s and 1930s, reintroductions 
and augmentations, and land-use changes helped restore the fisher's 
presence in many parts of its range (Douglas and Strickland 1987, p. 
512; Powell 1993, p. 80; Drew et al. 2003, 59; Vinkey 2003, p. 61). The 
role of land use changes with respect to the increase in fisher 
presence in the USNRMs is less clear (see Factor A section), but the 
regulation of trapping and end to indiscriminate predator control has 
likely had a positive influence. Trapping seasons were reopened in many 
northeastern and Midwestern States, including Montana, between 1949 and 
1985, with accompanying regulations intended to prevent overtrapping 
and population decline (Powell 1993, p. 80).
    Unregulated trapping was a significant cause of severe population 
declines, because fishers are easily trapped (Douglas and Strickland 
1987, p. 523), and where trapping occurs, there is a potential for 
populations to be negatively affected (Powell and Zielinski 1994, p. 
64). Fisher populations can also be sensitive to the effects of 
trapping because of a slow reproductive rate and the sensitivity of 
population numbers to prey fluctuations (Powell and Zielinski 1994, p. 
45). The presence of fishers is closely associated with the 
availability of their prey. In general, fisher populations tend to be 
distributed in small or isolated populations where their habitat or 
prey distribution is fragmented naturally or by human actions. Fishers 
in the USNRMs have some of the largest home ranges recorded for the 
species (reviewed by Powell and Zielinski 1994, p. 58; IOSC 2010, p. 4; 
reviewed by Lofroth et al. 2010, p. 68), possibly indicating a 
fragmented, suboptimal landscape typical of peripheral populations, and 
consequently small populations. Small or isolated populations may be 
more intensely affected by the additional mortality from furbearer 
harvest than are more robust and widespread populations if harvest is 
not adequately regulated (Powell and Zielinski 1994, pp. 45, 66). There 
is also the potential for fisher populations to be seriously affected 
by unintended trapping or incidental trapping for other species, 
including other furbearers (Powell and Zielinski 1994, p. 45).
    Fishers are classified as furbearers under State codes in both 
Idaho and Montana (IDFG 2010, p. 35; MTFWP 2010, Attachment 10, p. 2). 
The fisher also is considered a species of greatest conservation need 
in Idaho. Other furbearer species are legally trapped in the State, but 
trapping seasons for fishers have been closed for over 60 years in 
Idaho (IOSC 2010, p. 12). Fishers are legally trapped in Montana. The 
authority to regulate trapping procedures resides with the States' 
respective fish and wildlife or game commissions (Idaho Administrative 
Code 13.01.16; Montana Code Annotated 2009b), which review and revise 
furbearer trapping regulations every 2 years-most recently for the 2010 
to 2012 seasons in Idaho (IDFG 2010, entire) and the 2010 and 2011 
seasons in Montana (MTFWP 2010, Attachment 10, p. 2). The 2-year rules 
review period has been in effect since at least 1986 in Idaho and since 
2006 in Montana (MTFWP 2007, p. 2; White 2011c, pers. comm.). Within 
this 2-year period, game commissions and State wildlife agencies have 
authority to close seasons, change season lengths, adjust or implement 
quotas, and apply other means to reduce impacts to intentionally or 
incidentally trapped populations, if it is considered necessary (White 
2011b, pers. comm.; Idaho Administrative Code 2010, 13.01.16; MTFWP 
2010, Attachment 10, p. 7). Based on the current trapping regulations, 
fisher will not be targeted, but legal trapping will occur for other 
species during the 2-year period in

[[Page 38525]]

Idaho, and legal trapping for fishers will be subject to the 
established regulations and authority in Montana (see Factor D section 
    Most of the population distribution information for Montana is 
based on specimens from the regulated furbearer trapping program 
started in 1979 (MTFWP 2010, p. 2, Attachment 4, entire; MTNHP 2010b, 
entire). There are 305 specimens, from legal harvest or mortality 
incidental to legal harvest for other species, recorded in MTFWP files 
since 1968 (Vinkey 2003, p. 51; MTFWP 2010, p. 2). Harvest over the 
past 27 years has been most productive in Trapping District 2, which 
includes the 200-km (125-mi) long Bitterroot Divide with Idaho (MTNHP 
2010b, entire), and trapping in Montana over the past 8 years has been 
conducted in this area almost exclusively (MTFWP 2010, Attachment 3, 
entire). The Bitterroot Divide area in west-central Montana is a 
strong-hold for fishers of native lineage that form a population with 
fishers in Idaho (Schwartz 2007, p. 924). Trapping District 2 has a 
five fisher quota, which is filled most years (MTFWP 2010, Attachment 
8, pp. 1, 4). Harvest or other factors may be impacting the fishers in 
Trapping District 1, including the Cabinet Mountains, in the northwest 
corner of the State. The trapping quota has been reduced from 10 to 2 
between 1993 and 1996, and harvest is low and variable (MTFWP 2010, 
Attachment 8, p. 1). A low harvest level could reflect low trapper 
effort, difficult access, variability in prey availability, or a small 
or difficult to detect population. Six of the eight individuals 
captured between 2003 and 2008 were adult (MTFWP 2010, Attachment 3, 
entire), which suggests, but does not conclude, low recruitment. These 
low harvest numbers are consistent with the scarcity of fisher 
detections described in the evaluation of the Cabinet Mountain 
reintroduction effort (Vinkey 2003, p. 33), and possibly indicative of 
a population that is small or difficult to access.
    There is disagreement among researchers as to whether trap 
mortality is additive (operates in addition to) or compensatory 
(compensates for) to natural mortality. Trapping is often the main 
mortality factor for fisher (Krohn et al. 1994, pp. 139-140). Harvest 
directed mainly at juveniles is most likely to be compensatory, as 
juveniles have higher natural mortality than adults (Krohn et al. 1994, 
p. 144). Numerous models are applied to managing harvest quotas to 
sustain populations based on demographic rates, estimated fecundity, 
population density, and spacing patterns (reviewed by Strickland 1994, 
pp. 153-158; Koen et al. 2006, p. 1489). For example, low ratios of 
juveniles to adult females in a harvest could be indicative of 
declining populations (Strickland and Douglas 1981 in Koen et al. 2006, 
p. 1484), which could be compensated for by altering harvest quotas in 
succeeding years. In a single season, harvests take several hundred to 
over a thousand individuals from many trapped populations across the 
North American range of the species (Association of Wildlife Agencies 
2010, entire), and statistical models can be applied to determine 
population trends or changes in demographics. The small harvest in 
Montana (from two to five individuals, depending on the trapping unit) 
defies statistical analysis (Giddings 2010, pers. comm.), and the 
evaluation of trapping effects is based strongly on demographics. 
Juveniles are represented in the harvest over the past 10 years, and 
the predominant portion of the harvest consisting of younger-aged males 
is interpreted as an indication of light trapping pressure (MTFWP 2010, 
Attachment 8, p. 4), which is likely compensatory to natural mortality.
    Fishers have been caught incidentally to trapping for other 
furbearers in Montana and Idaho. Montana records indicate 11 incidental 
mortalities between 1983 and 2009, in addition to legally harvested 
animals (MTFWP 2010, p. 4). Since 1970 in Idaho, 242 fishers were 
trapped incidentally, 37 of those were reported as dead in the trap, 
107 were released alive, and there were 98 trapper reports of fishers 
captured but no indication of their condition (IOSC 2010, p. 12; White 
2011b, pers. comm.). Incidental capture of fishers has progressively 
increased between 2006 and 2010 in Idaho due to unknown reasons, 
resulting in 22 of the 37 mortalities known to have occurred in the 
past 40 years (White 2011b, pers. comm.). In addition, in the past 5 
years, 42 live releases from traps and 37 captures of unknown status 
also were reported (White 2011b, pers. comm.). The IDFG considers the 
``unknown'' fishers to be live releases because it does not make sense 
to report a capture and not a mortality due to the following 
regulations: there is a legal requirement to report all fisher 
captures, there is no penalty for incidental capture, it is illegal to 
possess a killed fisher, and there is a small financial incentive to 
surrender mortalities (White 2011c, pers. comm.). A change in the 
number of ``unknowns'' reported between 2006 and 2008 to a similar 
number of live releases in 2009 and 2010 corresponds with the start of 
a highly publicized fisher habitat ecology project, and is indicative 
of fur trappers' interest in contributing information for the study 
(White 2011b, 2011c, pers. comm.).
    Possible explanations of this recent rise in fisher captures 
include, but are not limited to, population expansion or better 
reporting and awareness, as stated above (IOSC 2010, pp. 12-13; White 
2011b, pers. comm.). Over the past 40 years, Idaho incidental captures 
exhibit a cyclic pattern of distinct highs and lows every 4 to 5 years, 
which persist for 4 to 5 years. This pattern may reflect similar cyclic 
changes in fisher population numbers that are unrelated to trapping 
effects (White 2011b, pers. comm.). The level of incidental captures 
demonstrated between 2006 and 2010 is the highest during the 40-year 
reporting period. Combined with the increase in anecdotal sightings, 
the recent high number of captures may be indicative of an increasing 
and expanding population (White 2011b, 2011c, pers. comm.).
    The number of trapping licenses sold doubled between 2001 and 2008 
in Idaho (IDFG 2008, p. 8), which could mean additional trapping 
pressure and an increased risk of unintended captures. Fishers are most 
often caught incidentally to trapping for American marten (White 2011b, 
pers. comm.). Although hundreds of martens are harvested most seasons, 
the number of trappers targeting marten is comparatively low compared 
to those targeting other species (IDFG 2007, p. 11; IDFG 2008, pp. 9-
11). Marten trapping efforts have remained steady in years with both 
low and high incidental fisher capture (IDFG 2008, p. 10); therefore, 
the total number of trapping licenses sold may not be a good indicator 
of increased trapping pressure on fishers.
    Both Montana and Idaho have a mandatory reporting requirement for 
incidental mortality. Only Idaho requires reporting of animals trapped 
and released. The fate of released animals is uncertain. Lewis and 
Zielinski (1996, p. 295 and references therein) report that live 
fishers are difficult to remove from traps, and suffer broken bones, 
hemorrhage, self-mutilation, and predation as consequences of capture; 
estimated survivability after release for incidentally captured fishers 
is as low as 50 percent in some studies. There are no measures required 
to avoid or prevent accidental capture of fishers in either Montana or 
Idaho. Hence, additional mortality from incidental capture and release 
may not be fully considered in management evaluations.

[[Page 38526]]

    The known incidental capture mortality is less than one fisher per 
year over the period of 1970 to 2005 in Idaho, and 1983 to 2009 in 
Montana (MTFWP 2010, p. 4; White 2011b, pers. comm.). Additional 
mortality from the trauma of capture and release and unreported 
captures is likely, but quantification would be speculative. The 
harvested population in west-central Montana is considered stable, with 
the existing trapping pressure, including the reported incidental 
mortality, based on consistent yearly harvest over time and the 
continual presence of a high proportion of juveniles in the harvest 
(MTFWP 2010, Appendix 8, p. 5). Relying on harvest statistics to assess 
the status of the fisher population in the Cabinet Mountain region of 
northwest Montana is not possible based on the lack of recent 
incidental mortalities and limited harvest in the area (MTFWP 2010, 
Appendix 8, p. 4; Appendix 11).
    The impact of the reported level of unintentional mortality or 
capture in Idaho is difficult to conclude based on the available 
information. As stated above, the increase in captures in Idaho could 
reflect an increase of trapper effort for other furbearers. 
Alternatively, increasing captures may result from expanding or 
increasing fisher populations and density-dependent displacement of 
juveniles to less suitable habitats that increase their vulnerability 
to capture. In addition, the number of reported live-released captures 
could be misleading. Released fishers are not tagged or identified in 
any way. Because fishers are easily trapped, it is possible that the 
live-released data represent fewer individuals who are repetitively 
captured. Individuals previously released could be represented in the 
mortality data as well--a consequence of a later capture.
    The recent increased mortality in Idaho may be compensatory to 
natural forces, and thus not affecting population persistence. However, 
without a history of demographic information (sex/age) of the affected 
individuals, it is difficult to assess additive or compensatory 
effects. Because demographic patterns are not available, we look to 
other areas of the range where fisher populations are persisting with 
sustainable, regulated harvest. Although factors affecting population 
dynamics differ between the eastern and western U.S. populations, 
fishers in peripheral populations and small geographic areas in the 
east persist with regulated harvest far exceeding the targeted and 
incidental harvest that occurs in both Montana and Idaho. For example: 
during the 2001-2008 period, 30 to 108 fishers were harvested annually 
in West Virginia, and the annual harvest in Rhode Island was as high as 
97 individuals (Association of Fish and Wildlife Agencies 2010, 
entire). Fishers have been legally harvested in Montana since 1983, 
with the current Statewide quota in place since 1996, and are 
considered stable at levels above the past 5-year mortality occurrence 
in Idaho (MTFWP 2010, Attachment 8, p. 3). Mortality in Montana and 
Idaho may be cumulative in areas of shared population, such as the 
Bitterroot Mountains, but that impact cannot be concluded based on the 
available information.
    Recent incremental increases in incidental capture could be a 
concern in Idaho if the trend continues and there is no evaluation or 
consideration of the potential impacts to local and regional 
populations. The available mortality and incidental capture data lack 
context and could be interpreted in ways that reach a conclusion of 
benign or detrimental effects. The IDFG is conducting a habitat ecology 
study to assist in adjusting management to benefit fishers, with 
results expected over the next 2 years (White 2011b, pers. comm.). By 
studying fishers' habitat use, geographic or timing restrictions can be 
crafted to limit their exposure to trapping for other species. We 
anticipate that the resulting data will also be helpful in elucidating 
the incidence and trends of fisher mortality in the USNRMs.
    The role of overtrapping in reducing fisher populations is well 
known. Trapping regulation, in addition to habitat regeneration and 
population augmentations in some cases, have contributed to recovery 
and persistence of fishers across the species range. Fishers are 
legally trapped in Montana, but trapping seasons for fishers have been 
closed for over 60 years in Idaho. The Montana fisher trapping program 
began in 1983. After a period of adjustment, the current Statewide 
quotas have been in place since 1996. Combined with a low level of 
mortality incidental to trapping for other species, the Montana fisher 
population is considered stable with the existing trapping pressure. 
There is no trapping for fishers in Idaho, but a small number of 
fishers have been captured or killed incidentally to the trapping of 
other species--primarily the American marten--between 1970 and 2005. 
The reported incidental capture and mortality increased between 2006 
and 2010 for unknown reasons; possible explanations include an 
increasing and expanding fisher population or greater exposure to 
trapping or both. These recent incidental captures could be a concern 
if the trend continues and there is no evaluation and consideration of 
the potential impacts; however, efforts are ongoing to elucidate the 
fisher's ecology and devise beneficial management strategies. The 
potential exists for targeted or incidental trapping to negatively 
impact fisher populations, but based on the available information, this 
potential does not rise to the level of threat at this time.
Summary of Factor B
    Trapping is considered one of the most important factors 
influencing fisher populations, and unregulated overharvesting 
contributed to the fishers' severe population decline in the early 20th 
century. Targeted legal harvest occurs in Montana, and accidental 
capture and mortality occur in both Montana and Idaho. If not 
adequately regulated, low levels of harvest-related mortality, added to 
natural mortality, have the potential to negatively impact small, local 
populations. The Montana trapping season is monitored and regulated, 
and there is no information to conclude that the distribution or 
population numbers of fisher are being negatively impacted directly by 
the current trapping regimes. Incremental increases in incidental 
capture could be a concern in Idaho if the trend continues without some 
evaluation of the local and regional population impacts, and 
application of remedial actions, if necessary.
    We conclude that the best scientific and commercial information 
available indicates that the fisher in the USNRMs is not now, or in the 
foreseeable future, threatened by overutilization for commercial, 
recreational, scientific, or educational purposes to the extent that 
listing under the Act as an endangered or threatened species is 
warranted at this time.

Factor C. Disease or Predation

    Mustelids are susceptible to viral-borne diseases, including 
rabies, canine and feline distemper, and plague contracted through 
contact with domesticated or wild animals (reviewed by Lofroth et al. 
2010, pp. 65-66). Antibodies to a number of canine viruses have been 
isolated from fishers in northwest California (Brown et al. 2008, p. 
2). Parasitism by intestinal invertebrates (e.g., nematodes, 
trematodes) is common (reviewed by Powell 1993, p. 72), and evidence of 
other bacterial, protozoan, and arthropod disease agents also have been 
identified in fishers (Banci 1989, p. v; Brown et al. 2008, p. 21). 
Individuals weakened by parasitism or other

[[Page 38527]]

infectious disease processes may be more vulnerable to other sources of 
mortality such as predation. However, little is known about the impacts 
of disease in fishers, and there is no documentation of disease-causing 
widespread population decline (Powell 1993, p. 71; Brown et al. 2008, 
p. 5). There is no information on the incidence of disease specific to 
fishers in the USNRMs.
    Fox, bear, mountain lion, great-horned owls, and bobcat prey on 
fishers, although there is little evidence to indicate that healthy 
adult fishers have many natural enemies except humans (Douglas and 
Strickland 1987, p. 516; Powell 1993, pp. 72-73). Forest fragmentation 
that forces fishers to travel long distances without suitable hiding 
cover may increase their vulnerability to predation by other carnivores 
(Heinemeyer 1993, p. 26; Powell and Zielinski 1994, p. 62). Predation 
of fishers newly translocated to Montana was reported (Roy 1991, pp. 
29, 35; Heinemeyer 1993, p. 26), but this was attributed to the 
relocation techniques used and fitness of the individual animals 
(Powell and Zielinski 1994, p. 62; Vinkey 2003, p. 34). No information 
is available regarding predation of fisher from established populations 
in the USNRMs.
Summary of Factor C
    There is little known about the impacts of disease in fishers, and 
there is no information on the incidence of disease specific to fishers 
in the USNRMs. There is no evidence that healthy adult fishers in 
suitable habitat are subject to excessive rates of predation or that 
fisher populations in the USNRMs are impacted by predation. We conclude 
that the best scientific and commercial information available indicates 
that the fisher in the USNRMs is not now, or in the foreseeable future, 
threatened by disease or predation to the extent that listing under the 
Act as an endangered or threatened species is warranted at this time.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    To the extent that we identify possibly significant threats in the 
other factors, we consider under this factor whether those threats are 
adequately addressed by existing regulatory mechanisms. If a threat is 
minor or the effects uncertain, listing may not be warranted even if 
existing regulatory mechanisms provide little or no protection to 
counter the threat. Numerous mechanisms affect land and species 
management in the USNRMs. These mechanisms could include: (1) Local 
land use laws, processes, and ordinances; (2) State laws and 
regulations; and (3) Federal laws and regulations. Regulatory 
mechanisms, if they exist, may preclude listing if such mechanisms are 
judged to adequately address the threat to the species such that 
listing is not warranted.
    Seventy-two percent of the land area with forests typical of fisher 
habitat types (fir, spruce, hemlock, Douglas fir (Jones and Garton 
1994, p. 377-378)) in the USNRMs is managed by Federal entities within 
national forest or park boundaries (USDA 2009, entire). Approximately 
15,969 km\2\ (6,165 mi\2\) of wilderness areas are incorporated within 
national forest boundaries. Private lands, including tribal and 
commercial timber lands, comprise approximately 22 percent of fisher 
forest types, and the remaining 6 percent is State or local government 
forest (USDA 2009, entire). Fourteen national forests form large areas 
of contiguous forested land area, often sharing boundaries with State 
forest lands occupying lower elevations of intermountain valleys or 
transition areas with woodlands or nonforested areas.
Federal Regulatory Mechanisms
National Forest Management Act
    Federal activities on national forest lands are subject to the 
National Forest Management Act of 1976 (NFMA) (16 U.S.C 1601-1614). The 
NFMA requires the development and implementation of resource management 
plans for each unit of the National Forest System. Implementation rules 
for resource planning have undergone numerous revisions and legal 
challenges. Planning rules amended in 2008 are being reevaluated, and 
an amended 2000 planning rule is currently in place (74 FR 67059, 
December 18, 2009). The 2000 planning rule emphasizes maintaining 
ecological conditions that provide a high likelihood of supporting the 
viability of native and desired nonnative species well distributed 
throughout their ranges within a plan area. Ecological conditions need 
to be maintained to support the natural distribution and abundance of a 
species and not contribute to its extirpation.
    Individual national forests may identify species of concern that 
are significant to each forest's biodiversity. The fisher is considered 
a sensitive species in the USFS Region 1 (western Montana and northern 
Idaho) and Region 4 (central to southern Idaho) (USFS 2005, p. 4; USFS 
2008, p. 6). A sensitive species is a species identified by a regional 
forester for which viability is a concern (USFS Manual (2670.5). The 
USFS' Sensitive Species Policy (USFS Manual (2670.32)) calls upon 
national forests to assist and coordinate with States and other Federal 
agencies in conserving species with viability concerns. Special 
management emphasis is placed on Sensitive Species to ensure their 
viability. The USFS is directed to develop and implement management 
practices to ensure these species do not become endangered or 
threatened. Management is in place at the individual forest plan level 
or through regional direction that addresses habitat needs of fishers. 
The habitat ecology of fishers in the region is not well studied, but 
current management direction addresses forest characteristics known to 
be important to fishers such as the protection of riparian areas, 
retention of elements such as snags and downed woody material, size of 
forest openings, and the retention of canopy cover (Samson 2006, pp. 
15-16; Bush and Lundberg 2008, p. 16).
    National Forests have been managing for old-growth forest since the 
1990s, guided by regional standardized definitions and descriptors 
(Green et al. 1992 Errata 2008, entire). The USFS planning regulations 
require that forest plans identify certain species as Management 
Indicator Species in order to estimate effects of management 
alternatives on fish and wildlife populations (36 CFR 219.20). In 
addition to Sensitive Species status, the fisher is considered a 
Management Indicator Species by the Nez Perce and Flathead National 
Forests to guide vegetation management of old-growth forest (USFS 1999, 
p. 11; USFS 2006, p. 14). Vegetation objectives include maintaining or 
actively restoring landscape composition, structure, and patterns to a 
condition similar to that expected under natural disturbance and 
succession regimes, and managing landscapes to develop larger old-
growth patch sizes, healthy riparian areas with mosaics of tree age and 
size classes, and retention of structural elements such as snags and 
down logs (USFS 1999, Appendix A; USFS 2006, pp. 41-42).
    The habitat ecology of fishers in the region is not well studied, 
but current management direction addresses forest characteristics known 
to be important to fishers (USFS 1999, p. 24 and Appendix A; USFS 
2003a, p. III-7; USFS 2003b, Appendix A; USFS 2006, pp. 41-42; Samson 
2006, entire; Bush and Lundberg 2008, entire). Within the NFMA 
regulatory framework, management direction and requisite monitoring, 
forest management should be consistent with supporting fisher habitat 
where natural ecological conditions allow. If each plan area

[[Page 38528]]

(national forest) supports a natural distribution and abundance, then 
the large contiguous area of national forest lands comprising the 
USNRMs would have the potential to support a regional population.
National Environmental Policy Act
    As a sensitive species, the USFS is required to consider effects in 
documentation completed under the National Environmental Policy Act 
(NEPA) (42 U.S.C. 4321 et seq.). The NEPA requires Federal agencies to 
consider the environmental impacts of their proposed actions and 
reasonable alternatives to those actions. To meet this requirement, 
Federal agencies conduct environmental reviews, including Environmental 
Impact Statements and Environmental Assessments. The NEPA does not 
itself regulate activities that might affect fishers, but it does 
require full evaluation and disclosure of information regarding the 
effects of contemplated Federal actions on sensitive species and their 
Healthy Forest Restoration Act
    The Healthy Forest Restoration Act of 2003 (Pub. L. 108-148) (HFRA) 
improves the capacity to conduct hazardous fuels reduction projects on 
national forest lands to protect communities within or adjacent to USFS 
boundaries (wildland-urban interface); municipal watersheds at risk 
from fire; areas where windthrow or the existence or imminent risk of 
an insect or disease epidemic significantly threatens ecosystem 
components or resource values; and areas where wildland fire poses a 
threat to threatened and endangered species or their habitat, or where 
the natural fire regimes are important for their habitat.
    Provisions of the HFRA can be used to expedite vegetation 
treatment, such as mechanical thinning or prescribed fire, which could 
be beneficial or detrimental to fishers on national forest lands. The 
USFS and Department of the Interior revised their internal implementing 
procedures describing categorical exclusions exempt from NEPA review to 
expedite hazardous-fuels reduction and vegetation restoration projects 
meeting certain criteria (68 FR 33813, June 5, 2003; 68 FR 44597, July 
29, 2003).
    The HFRA requires authorized projects, including categorical 
exclusions under NEPA, to be planned and conducted consistent with 
resource management plans and other relevant administrative policies, 
such as the USFS' Sensitive Species Policy, and prohibits authorized 
projects in wilderness areas, formal wilderness study areas, and other 
restricted Federal lands (Section 102(d)). Projects conducted to reduce 
fuels could provide a benefit to fishers by creating foraging habitat 
if needed, promoting the growth of larger trees by decreasing 
competition, and reducing catastrophic fire risk. While the reverse may 
be true, the application of the Sensitive Species Policy should direct 
HFRA projects to improve or maintain suitability of habitats for 
The Wilderness Act
    The USFS manages 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. Lower-elevation forest in 
wilderness areas may be important refuges for fishers because of 
limited human access and less fragmentation than managed forests 
(Hessburg et al. 2000, p. 78). For example: The Selway-Bitterroot 
Wilderness in Idaho may have functioned as a refugium for native 
fishers that enabled their survival through the severe population 
decline in the past, and the area appears to be a stronghold for native 
fishers today (Vinkey 2003, pp. 90-91).
National Park Service Organic Act
    The National Park Service 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 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.'' Fishers or sign of fishers 
have been reported in Glacier National Park in northern Montana, but 
recent verified information is lacking. The Park's west side is a mix 
of conifer forests, with maritime-influenced western hemlock and 
western red cedar existing in ``ancient stands in places'' (NPS 2010, 
entire), and likely capable of supporting fishers. The NPS does not 
manage habitats specifically for fishers, but where fishers occur in 
Glacier National Park, they and their habitats are protected from 
large-scale loss or degradation due to the NPS' mandate to ``conserve 
scenery * * * and wildlife [by leaving] them unimpaired.'' Due to the 
limited access to exploitive activities such as timber or furbearer 
harvest, National Parks, as with wilderness areas, may provide refuges 
for fisher populations that are a source of individuals dispersing to 
peripheral areas.
State Management


    Regulatory mechanisms related to fisher conservation in Montana 
apply to State forest and furbearer harvest management. Montana State 
forests with fisher habitat types are situated in the northwest and 
north-central part of the State, often sharing boundaries or 
interspersed with national forest lands in lower elevations of 
intermountain valleys. Timber harvest for revenue generation is 
conducted on an annual basis and includes forest types preferred by 
fishers; forests also are managed to promote a diversity of habitat 
conditions beneficial to wildlife (MTDNRC 2010, p. 1). Fishers are 
managed as a sensitive species ``primarily through managing for the 
range of historically occurring conditions appropriate to the site'' 
(Administrative Rules of Montana (ARM) 2003, 36.11.436). In 2003, 
MTDNRC formally codified mitigation measures specific to forest types 
preferred by fisher for State forest management including: Timber and 
salvage harvest, thinning, prescribed burning, road maintenance, and 
other activities (ARM 2003, entire). Project-level evaluation 
emphasizes large snag and coarse woody debris retention and emulation 
of natural forest patch size and shape to maintain or contribute to 
connectivity with crown canopy closure of greater than 39 percent and 
patch greater than 91 m (300 ft) wide (ARM 2003, 36.11.403). Riparian 
areas, within 100 ft of class-I (fish bearing) streams and 50 ft of 
class-II (non-fish bearing) streams, maintain or are allowed to 
progress to at least 40-percent canopy cover (ARM 2003, 36.11.440). 
There is no specific direction to retain mature or larger trees for 
fisher independent of snag retention, but it is stated that the 
importance of late-successional riparian and upland forest shall be 
considered in meeting the requirements for fishers (ARM 2003, 
    The fisher is classified as a regulated furbearer in Montana (MTFWP 
2010, Attachment 10, p. 2). Montana is the only State in the western 
United States where fisher trapping is still legal. Trapping season is 
open December 1 to February 15, or within 48 hours of a

[[Page 38529]]

quota being reached (MTFWP 2010, Attachment 10, p. 7). There is 
authorization to close the season if conditions or circumstances 
indicate a quota will be reached within 48 hours (MTFWP 2010, 
Attachment 10, p. 7). Two districts are open for trapping--District 1 
in the northwest has a quota of two, including the Cabinet Mountains, 
and District 2 in west-central Montana, including the Bitterroot 
Mountains, has a quota of five; there is a Statewide sub-quota of two 
females (MTFWP 2010, Attachment 10, p. 7). Only one fisher may be taken 
per person per season, and take must be reported within 24 hours to the 
MTFWP (MTFWP 2010, Attachment 10, p. 7). Reporting and surrender of an 
accidental mortality (unintended capture or outside legal season) must 
be done within 24 hours of capture, and only uninjured animals can be 
released from traps (MTFWP 2010, Attachment 10, p. 7). There are no 
penalties for surrendering an accidentally killed fisher, but there are 
penalties and fines for being in possession of an incidentally taken 
fisher (MTFWP 2010, p. 4). There is no regulatory mechanism or 
requirement in place to minimize incidental take of fisher.
    Harvest quotas and seasons are evaluated and set by the MTFWP 
Commission every year, with the general regulations established for 2-
year periods (Montana Code Annotated 2009b; MTFWP 2010, Attachment 10, 
p. 2). Trends in harvest success, demographics (age class/sex), and 
snow track surveys are used to determine the effectiveness of the quota 
system and assist in the State's objective of maintaining current 
fisher population size and distribution (MTFWP 2010, Attachment 8, pp. 
1-3). A consistent harvest and the presence of juveniles are considered 
an indication of a stable population (MTFWP 2010, pp. 1-2). Snow track 
surveys are conducted along fixed routes in some areas of the State 
that do not receive targeted fisher harvest (MTFWP 2010, Attachment 8, 
p. 3); however, track surveys are conducted sporadically and are very 
dependent on snow conditions for usefulness (Giddings 2010, pers. 
comm.). Quotas have been adjusted downward several times since the 
establishment of the regulated trapping program in1983 in response to 
harvest success, demographics of harvested animals, and track survey 
data. Quotas and harvest have been relatively consistent since 1996 
(MTFWP 2010, Attachment 8, pp. 1, 3). We are not aware of any 
established objectives or direction that indicates action thresholds 
for adjusting quotas or practices.


    The fisher is identified as a species of greatest conservation need 
in the Idaho Comprehensive Wildlife Conservation Strategy, which 
recommends actions to determine fisher population trends, landscape and 
regional scale response to habitat disturbance, genetic composition of 
populations, and the relationship between habitat fragmentation and 
movement patterns (IDFG 2005, p. 365, Appendix B, p. 8). Species of 
greatest conservation need are those considered at high risk due to low 
number, declining numbers, or other factors that make them vulnerable 
to extirpation (IDFG 2005, Appendix B, pp. 1, 8). There are no 
identified regulatory mechanisms that apply to habitat management for 
fisher in the State.
    Implementing rules that protect riparian areas from timber harvest 
actions for the Idaho Forest Practices Act apply to operations on lands 
under all management types. Management goals for class I streams 
include the retention of standing conifers, hardwoods and snags within 
15 m (50 ft) on each side, leaving 75 percent of existing shade, and 
within 9 m (30 ft) on each side of class II streams (Idaho 
Administrative Code 2000, 20.02.01).
    The fisher is legally classified as a furbearer in Idaho, but no 
legal season has been open for over 60 years (Idaho Administrative Code 
2010, 13.01.16; IOSC 2010, p. 11). Capture of fishers has occurred, 
primarily incidentally to legally trapped marten during the open season 
from November 1 through January 31 (White 2011a, pers. comm.). There 
are no legislated regulatory mechanisms in place to minimize incidental 
take of fisher, but voluntary trapper education is provided to help 
direct trapping towards the intended species (White 2011a, pers. 
comm.). Marten and other furbearer trapping is conducted under 
Statewide licensure but management occurs at smaller, regional levels. 
There is no limit to the number of Statewide licenses sold, and no 
seasonal quotas for marten are in place (White 2011b, pers. comm.). The 
IDFG Commission has the authority to set bag or possession limits and 
seasons (Idaho Administrative Code 2010, 13.01.16). A mandatory 
furtaker harvest report is required to be submitted to the IDFG by July 
31 to assist with setting season limits (IDFG 2010, p. 38). An 
incidental capture of a fisher that results in mortality requires 
reporting and surrender of the carcass to IDFG within 72 hours; live 
animals require immediate release if they appear unharmed or, if 
animals appear injured, the IDFG is contacted for assistance (IDFG 
2010, p. 36). Trappers are reimbursed $10 for the surrendered carcass 
and are required to report the capture, dead or released alive, on the 
harvest report. We are not aware of a mechanism in place to adjust a 
trapping season while in session, such as closing a unit or area early, 
to accommodate an incidental take of a fisher or fishers. We have no 
knowledge of how the reports of incidental take of a fisher or fishers 
are used to adjust subsequent marten seasons or quotas, or those of 
other target species that fisher could be caught incidentally to, in 
order to avoid additional mortality.
Management on National Forests and State Forests for Other Species 
Benefitting Fisher
    All national forests in the USNRMs have amended their forest plans 
with the Northern Rockies Lynx Management Direction to provide 
protections and conservation for the Canada lynx (USDA 2007, entire). 
Lynx utilize mesic coniferous forests although their range extends to 
higher elevation zones than fishers (reviewed by Ruediger et al. 2000, 
p. 1-3). Lynx similarly prefer to move through continuous forest cover, 
frequently use riparian zones, and target snowshoe hare as a principle 
prey species (reviewed by Ruediger et al. 2000, pp. 1-4, 1-7). Large 
woody debris within mature or older conifer or mixed-conifer sites are 
selected by female lynx for denning, and these elements are known to be 
used by fishers (Jones and Garton 1994, p. 380; reviewed by Ruediger et 
al. 2000, p. 1-4; reviewed by Lofroth et al. 2010, p. 106). Direction 
is in place for national forest lands to provide connectivity for lynx 
travel throughout the USNRMs (USDA 2007, p. 27). Standards and 
guidelines for specific habitat protections are applied in the north 
half of the USNRMs, where habitats are known to be occupied by lynx 
(USDA 2007, p. 29). Specific measures are applied at the scale of a 
female lynx's home range, which is similar to home range sizes reported 
for fisher in the USNRMs and British Columbia (reviewed by Ruediger et 
al. 2000, p. 6-2; reviewed by Lofroth et al. 2010, p. 68). These 
measures include limiting disturbance by timber harvest and other 
activities, maintaining patches conducive to denning and retention of 
coarse woody debris, protecting regenerating areas that provide 
snowshoe hare habitat, and retaining wooded areas (USDA 2007, pp. 8-
    In 1998, the Service issued a biological opinion on the

[[Page 38530]]

implementation of USFS Land and Resource Management Plans as amended by 
the Interim Strategy for Managing Fish-Producing Watersheds in Eastern 
Oregon and Washington, Idaho, Western Montana, and Portions of Nevada 
(INFISH) (Service 1998, entire). The guidelines, developed to protect 
bull trout and other fish habitat, also may provide benefits to fisher 
by protecting riparian corridors, establishing large woody debris 
requirements, and delineating Riparian Habitat Conservation Areas which 
would prohibit timber harvest in most situations. Conservation Areas 
would be established within 91 m (300 ft) slope distance of either side 
of class I streams, to 46 m (150 ft) on both sides of perennial class 
II streams, and within 15 to 30 m (50 to 100 ft) of seasonal or 
intermittent streams and small wetlands (Service 1998, p. 9).
    The USNRMs covers an area that includes all or part of the Northern 
Continental Divide, Selway-Bitterroot, Selkirks, and Cabinet-Yaak 
Grizzly Bear Recovery Zones. Fishers may benefit from the reduction of 
road densities or reduced motorized use of roads on national forest 
lands or the large areas of core habitat within 3rd and 4th order 
watersheds with no motorized travel routes or high use trails within 
the recovery zones (Interagency Grizzly Bear Committee 1998, entire).
    Management direction intended to protect other species listed under 
the Endangered Species Act could provide benefit to fishers on Montana 
State forests. Montana State forests located in the Cabinet-Yaak and 
Northern Continental Divide Recovery Zones for the threatened grizzly 
bear are managed to limit road density and maintain hiding cover near 
roads and adjacent to riparian areas (ARM 2003, 36.11.432-433). 
Retention of coarse woody debris, vegetative cover for landscape 
connectivity, and habitat for a common prey species--snowshoe hare--are 
intended to contribute to Canada lynx (Lynx Canadensis) habitat 
requirements (ARM 2003, 36.11.435). The retention of vegetation and 
minimization of disturbance in riparian areas to protect bull trout 
habitat also could benefit fisher on State forest land.
Summary of Factor D
    In our review of the factors affecting fishers in the USNRMs, we 
found no single factor or accumulated effects of factors that, when 
considered within the foreseeable future, rose to a level significant 
enough to warrant the protections of the Act. There is a concern 
regarding the adequate control of mortality due to capture incidental 
to the trapping of other furbearing animals. The authority exists under 
States' laws to manage trapping programs, specifically for fisher, as 
well as other species. However, we are unaware of any policy or 
management direction that would invoke that authority and apply 
adaptive management or minimization measures to reduce additional 
mortality from unintended harvest. Since we did not consider that the 
threat of incidental mortality, based on the limited information 
available to us, rose to the level of a threat to the species in the 
foreseeable future, it is not necessary to consider the effectiveness 
of the relative regulatory mechanism.
    We conclude that the best scientific and commercial information 
available indicates that the fisher in the USNRMs is not now, or in the 
foreseeable future, threatened by the inadequacy of existing regulatory 
mechanisms to the extent that listing under the Act as an endangered or 
threatened species is warranted at this time. It is unclear that 
regulatory mechanisms in addition to those described are needed for the 
species based on the current understanding of threats.

Factor E. Other Natural or Manmade Factors Affecting Its Continued 

Population Size and Isolation
    A principle of conservation biology is that small, isolated 
populations are subject to an increased risk of extinction from 
stochastic (random) environmental, genetic, or demographic events 
(Brewer 1994, p. 616). Environmental changes such as drought, fire or 
storms have severe consequences if affected populations are small and 
clumped together (Brewer 1994, p. 616). Loss of genetic diversity can 
lead to inbreeding depression and an increased risk of extinction 
(Allendorf and Luikart 2007, pp. 338-343). Demographic changes can 
reduce the effective population size (number of breeding individuals). 
Populations with small effective size show reductions in population 
growth rates, loss of genetic variability, and increases in extinction 
probabilities (Leberg 1990, p. 194; Jimenez et al. 1994, p. 272; 
Allendorf and Luikart 2007, pp. 338-339).
    There is little information to indicate fisher population numbers 
or population dynamics in the USNRMs. Fishers are vulnerable to the 
effects of small populations and isolation based on characteristics of 
their life history. Fishers are known to be solitary and territorial, 
and require large home ranges where landscapes are less than optimal 
(Weir and Corbould 2010, p. 405). This results in low population 
densities, as the population requires a large amount of quality habitat 
for survival and proliferation. Fishers also are long-lived, have low 
reproduction rates, and, though capable of long-distance movements, 
generally have small dispersal distances. Small dispersal distances may 
be a factor of fishers' reluctance to move through areas with no cover 
(Buskirk and Powell 1994, p. 286). Thus, where habitat is fragmented it 
is more difficult to locate and occupy distant yet suitable habitat, 
and fishers may be aggregated into smaller interrelated groups on the 
landscape (Carroll et al. 2001, p. 974).
    Territoriality and habitat specificity compounded by habitat 
fragmentation may contribute to the strong genetic structuring over 
intermediate geographic distances seen in fisher populations in other 
parts of the species' range (Kyle et al. 2001, p. 2345; Wisely et al. 
2004, pp. 644, 646). Higher levels of genetic structuring describe 
populations that are more genetically distinct and have less 
intrapopulation variation, a condition occurring in peripheral or more 
disturbed habitats of a species' range with low effective population 
sizes and limited genetic exchange (Kyle and Strobeck 2001, p. 343). 
Where these conditions exist, species face an increased vulnerability 
to extinction (Wisely et al. 2004, p. 646).
    Small, isolated populations can be at risk from stochastic factors. 
Demographic stochasticity (the chance events associated with annual 
survival and reproduction) and environmental stochasticity (temporal 
fluctuations in environment conditions) tend to reduce population 
persistence (Shaffer 1981, p. 131). Combinations of factors can 
interact to increase the risk of extinction. Trapping pressure, for 
example, if additive to natural mortality, could act by itself or in 
combination with environmental conditions to have significant impact on 
annual survival. Regional fires that have occurred historically in the 
USNRMs could reduce the suitability of large forest tracts for decades, 
reducing habitat and further isolating small populations.
    As stated above, we have little information to indicate the number 
of individuals, population dynamics, or evidence of genetic structuring 
and inbreeding for fishers in the USNRMs. Although we have no 
information on fisher abundance, their home range sizes are large--an 
indication that the availability of resources may be limiting 
population size. Their restricted geographic range, based on isolation 
from larger populations in Canada or the United States, frequently 
correlates with

[[Page 38531]]

small population size (Purvis et al. 2000, p. 1947). Given the 
restricted distribution, the presumably small population size, and 
propensity to aggregate on the landscape, fishers in the USNRMs are 
vulnerable to demographic, environmental, and genetic stochasticity, 
which could impact long-term persistence. The USNRMs fisher population 
resurged from near extirpation in the 1920s with possible assistance 
from augmentations. It is likely that the historical populations were 
never large. Fishers' response to the impacts of a changing landscape 
from human development and timber harvest are uncertain. The species 
appears to have several characteristics related to small population 
size that increase the species' vulnerability to extinction from 
stochastic events and other threats on the landscape. Currently, we do 
not have sufficient information on these environmental or anthropogenic 
threats to know whether they affect small populations to an extent that 
threatens the fisher in the USNRMs. We are unable to quantify a 
foreseeable future for stochastic events that may have disproportionate 
negative effects on small population sizes. We do not anticipate the 
effects of these events on small population size to change, but our 
understanding of these effects may improve over time.
Summary of Factor E
    Based on the best available information, we have no indication that 
other natural or anthropogenic factors are likely to significantly 
threaten the existence of the fisher in the USNRMs. We recognize the 
inherent vulnerabilities of small populations and restricted geographic 
range. The impacts of various potential threats can be more pronounced 
on small or isolated populations, and we have identified numerous 
potential threats occurring on the landscape within the range of the 
fisher in the USNRMs (see Factor A and B section). However, at this 
time we do not have information to indicate that these activities pose 
a threat to the fisher. Additionally, we do not consider a small 
population alone to be a threat to species; rather, it can be a 
vulnerability that can make it more susceptible to threat factors, if 
they are present.
    We conclude that the best scientific and commercial information 
available indicates that the fisher in the USNRMs is not now, or in the 
foreseeable future, threatened by other natural or anthropogenic 
factors affecting its continued existence, or that these factors act 
cumulatively with other potential threats, to the extent that listing 
under the Act as an endangered or threatened species is warranted at 
this time.

Finding--Determination of Status of Distinct Population Segment

    As required by the Act, we considered the five factors in assessing 
whether the fisher in the USNRMs is endangered or threatened throughout 
all or a significant portion of its range. We have carefully examined 
the best scientific and commercial information available regarding the 
status and the past, present, and future threats faced by the fisher in 
the USNRMs. We reviewed the petition, information available in our 
files, and other published and unpublished information submitted to us 
by the public following our 90-day petition finding. We also consulted 
with fisher experts and other Federal and State resource agencies. We 
were able to qualitatively describe a foreseeable future for forest 
management, development, and climate change and discussed how we 
anticipate each factor to change over time. We were unable to project 
specific changes to the species from these foreseeable actions into the 
future because we do not have sufficient data to know how the analyzed 
factors will affect the species.
    The fisher is a forest-dependent species that evolved in the USNRMs 
in a complex landscape mosaic shaped by climate driven events such as 
fire, drought, and forest diseases. Fisher populations were greatly 
reduced to the point they were believed extirpated in the USNRMs in the 
early 20th century due to unregulated overharvest and indiscriminate 
predator control. Although current comprehensive fisher population 
numbers and trends are not known, fisher populations have resurged from 
previous lows concurrently with the effects of human development and 
timber harvest and the regulation of harvest. The USNRMs landscape 
supports fisher, but it is unknown if the system has the capacity to 
support a population long term. Interpreting or projecting the impacts 
of forest management, development, and resource extraction is 
complicated by a lack of knowledge of fisher habitat ecology in the 
region, and mixed reports of how fishers respond to human disturbance. 
Fisher habitats could be vulnerable to the climate change effects of 
increased temperature and earlier spring snowmelt predicted to produce 
longer fire seasons. An increase in incidence of forest diseases or 
novel diseases also could accompany a changing climate. Although the 
potential for changing fire and disease regimes exists, these events 
are dependent on complex patterns of moisture availability and cannot 
be predicted with confidence.
    Targeted legal harvest of fishers occurs in Montana and accidental 
capture and mortality occurs in both Montana and Idaho. Low levels of 
additional mortality from harvest to natural mortality have the 
potential to negatively impact small, local populations if not 
adequately regulated. There is no indication that the distribution or 
population numbers of fisher are being negatively impacted directly by 
the current trapping regimes in Montana. Recent increases in incidental 
capture and associated mortality could be a concern in Idaho if the 
trend continues without some evaluation of the local and regional 
population impacts and remedial actions applied, if necessary.
    A restricted geographic range like the fisher's in the USNRMs 
frequently correlates with small population size, and it is likely that 
the historical populations were never large. Given the restricted 
distribution, the presumably small population size, and propensity to 
aggregate on the landscape, fishers in the USNRMs are vulnerable to 
extinction from stochastic events and other threats on the landscape 
which could impact long-term persistence. Fishers' response to the 
impacts of a changing landscape from human development, timber harvest 
and climate change are uncertain. As stated above, trapping pressure, 
if additive to natural mortality, could act by itself or in combination 
with environmental conditions to have significant impact on annual 
survival. Currently, we do not have information on these threats to an 
extent that allows us to know whether small population size allows for 
other environmental or anthropogenic factors to create a threat to the 
fisher in the USNRMs.
    Our review of the best available scientific and commercial 
information pertaining to the five factors does not support the 
assertion that there are threats of sufficient imminence, intensity, or 
magnitude to indicate that the fisher in the USNRMs is in danger of 
extinction (endangered) within the foreseeable future (threatened), 
throughout all or significant portion of its range. Therefore, we find 
that listing the fisher in USNRMs throughout its range as an endangered 
or threatened species is not warranted at this time.
    In making this finding, we recognize that the fisher in the USNRMs, 
despite not being warranted for listing as endangered or threatened, 
may benefit from increased management emphasis

[[Page 38532]]

due to its need for forest cover and susceptibility to capture and 
mortality from furbearer harvest. We recommend precautionary measures 
to protect the species be continued where they are in place and 
expanded where they are not. We recommend and encourage additional 
research to improve the understanding of the species, so that our 
responses to future potential threats can be better understood.

Significant Portion of the Range

    Having determined that the fisher in the USNRMs is not in danger of 
extinction or likely to become so within the foreseeable future 
throughout all of its range, we must next consider whether there are 
any significant portions of the range where the fisher in the USNRMs is 
in danger of extinction or is likely to become endangered in the 
foreseeable future.
    The Act defines an endangered species as one ``in danger of 
extinction throughout all or a significant portion of its range,'' and 
a threatened species as one ``likely to become an endangered species 
within the foreseeable future throughout all or a significant portion 
of its range.'' The term ``significant portion of its range'' is not 
defined by the statute. For the purposes of this finding, a portion of 
a species' range (fisher in the USNRMs) is ``significant'' if it is 
part of the current range of the species, and it provides a crucial 
contribution to the representation, resiliency, or redundancy of the 
species. For the contribution to be crucial it must be at a level such 
that, without that portion, the species would be in danger of 
    In determining whether a species is threatened or endangered in a 
significant portion of its range, we first identify any portions of the 
range of the species that warrant further consideration. The range of a 
species can theoretically be divided into portions in an infinite 
number of ways. However, there is no purpose to analyzing portions of 
the range that are not reasonably likely to be significant and 
threatened or endangered. To identify only those portions that warrant 
further consideration, we determine whether there is substantial 
information indicating that: (1) The portions may be significant, and 
(2) the species may be in danger of extinction there or likely to 
become so within the foreseeable future. In practice, a key part of 
this analysis is whether the threats are geographically concentrated in 
some way. If the threats to the species are essentially uniform 
throughout its range, no portion is likely to warrant further 
consideration. Moreover, if any concentration of threats applies only 
to portions of the species' range that clearly would not meet the 
biologically based definition of ``significant'' (i.e., the loss of 
that portion clearly would not reasonably be expected to increase the 
vulnerability to extinction of the entire species to the point that the 
species would then be in danger of extinction), such portions will not 
warrant further consideration.
    If we identify portions that warrant further consideration, we then 
determine their status (i.e., whether in fact the species is endangered 
or threatened in a significant portion of its range). Depending on the 
biology of the species, its range, and the threats it faces, it might 
be more efficient for us to address either the ``significant'' question 
first, or the status question first. Thus, if we determine that a 
portion of the range is not ``significant,'' we do not need to 
determine whether the species is endangered or threatened there; if we 
determine that the species is not endangered or threatened in a portion 
of its range, we do not need to determine if that portion is 
    Applying the process described above for determining whether a 
species is threatened in a significant portion of its range, we 
considered status first to determine if any threats or potential 
threats acting individually or collectively threaten or endanger the 
species in a portion of its range. We have analyzed the threats to the 
degree possible, and determined they are essentially uniform throughout 
the species' range. The limited information available for the fisher, 
such as the lack of population numbers and dynamics, and an incomplete 
knowledge of tolerances to disturbance and habitat needs, does not 
allow us to determine what portion of the range if any, would be 
impacted to a significant degree more than any other.

Conclusion of 12-Month Finding

    We do not find that the fisher in the USNRMs is in danger of 
extinction now, nor is it likely to become endangered within the 
foreseeable future, throughout all or a significant portion of its 
range. Therefore, listing the species as endangered or threatened under 
the Act is not warranted at this time.
    We request that you submit any new information concerning the 
status of, or threats to, the fisher in the USNRMs to our Montana 
Ecological Services Field Office (see ADDRESSES section) whenever it 
becomes available. New information will help us monitor this species 
and encourage its conservation. If an emergency situation develops for 
the fisher in the USNRMs or any other species, we will act to provide 
immediate protection.

References Cited

    A complete list of references cited is available on the Internet at 
http://www.regulations.gov and upon request from the Montana Ecological 
Services Field Office (see ADDRESSES section above).


    The primary author of this document is staff of the Montana 
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT 
section above).


    The authority for this action is the Endangered Species Act of 
1973, as amended (16 U.S.C. 1531 et seq.).

    June 14, 2011.
 Gabriela Chavarria,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2011-16349 Filed 6-29-11; 8:45 am]