low kitten production and low lynx density overall (Aubry et al. 2000).
Recent analyses suggest only mild cycles in southern hare populations, with peaks 8-11 years
apart. Even during a peak, hare abundance is much lower in the south (1-2 hares/ ha) than in the
north (4-6 hares/ ha) (Hodges 2000b).
Limiting Factors
Lynx in Wyoming and surrounding states experience different ecological pressures than do
their counterparts to the north, and are thus subjected to different limiting factors. The main limit
on southern lynx populations is the rarity and fragmented nature of suitable habitat (Beauvais
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 17 of 43
2000). Conifer forest in general is restricted to discontinuous mountain ranges, and late-seral
forest, which provides the best habitat for hares, red squirrels, and lynx in southern mountains, is
more rare and isolated still. Furthermore, timber harvesting and associated disturbances like road
building have preferentially targeted the flat, late-seral stands preferred by lynx. This has further
fragmented suitable lynx habitat, and roads and snow-machine trails have increased the ability of
generalist carnivores (e.g., bobcats, coyotes, mountain lions) to prey upon and compete with lynx
in formerly snowbound areas in the winter.
Some studies suggest that densities of 1.1 – 1.8 hares/ ha are necessary for lynx population
persistence (Steury and Murray 2004), and such densities are exceedingly rare in the contiguous
U.S. Field observations of lynx in the Central and Southern Rocky Mountains suggest an
unusually heavy reliance on alternative prey such as red squirrels, ground squirrels (
Spermophilus
spp.), and blue grouse (
Dendrogapus obscurus
).
In general, human-caused mortality and disturbance is a major limiting factor on population
expansion of most large mammalian carnivores in the Rocky Mountains (e.g., Beck 1991,
Anderson et al. 1992, Wieglus et al. 1994, Mace et al. 1996; see also Noss et al. 1996). Given the
rather high rates of human-caused mortality recorded in southern lynx populations, it is reasonable
to assume that lynx are no exception to this generalization.
Metapopulation Dynamics
A number of factors suggest that southern lynx populations are arranged as metapopulations:
habitat that is fragmented on both regional and local scales, with suitable patches embedded in a
matrix of unsuitable-but-traversable environments, and a species with very high mobility
(McKelvey et al. 2000a). Persistence of lynx in the contiguous U.S. may depend rather heavily on
regular importation of individuals dispersing out of larger populations to the north, and as such the
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 18 of 43
maintenance of connectivity between northern and southern populations is of critical management
importance (Schwartz et al. 2002). For Wyoming and Colorado, this translates into maintaining
connectivity between populations in those two states, and also between lynx populations in
Canada and Montana, and Montana and Wyoming.
Genetic Concerns
Peripheral populations of lynx have less genetic variation than core populations, as measured
by fewer mean numbers of alleles per population and lower expected heterozygosity (Schwartz et
al. 2003). Although surprising because of the lynx’s ability to move long distances, these results
can be explained by the fact that peripheral populations often have smaller population sizes and
limited opportunities for genetic exchange. This further suggests that connectivity between
northern (core) and southern (peripheral) lynx populations is important in maintaining genetic
diversity, and therefore increasing the viability, of southern populations.
There is some indication that lynx and bobcat can hybridize; three putative lynx from
Minnesota contained DNA from both bobcats and lynx, and samples from Maine and New
Brunswick show similar blending. All suspected hybrids had lynx mothers (Pilgrim and Schwartz
2004).
Food Habits
Food Items
Primary lynx prey is the snowshoe hare. In Canada, Alaska, and Washington snowshoe hares
comprised 35-97% of lynx diet (Koehler and Aubry 1994). Secondary prey includes red squirrels,
ground squirrels, grouse, porcupine (
Erethizon dorsatum
), beaver (
Castor canadensis
), muskrat
(
Ondatra zibethicus
), deer mice (
Peromyscus
spp.), voles (
Microtus
spp.), shrews (
Sorex
spp.),
and even some fish. Deer (
Odocoileus
spp.) and moose (
Alces alces
) occasionally appear in lynx
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 19 of 43
diets, mostly as carrion (Tumlison 1987, Ruediger et al. 2000). In Washington, the only state in
the contiguous U.S. for which such data are available, the annual lynx diet was 79% hares, 24%
tree squirrels, 3% ungulates, and 3% grouse (Koehler 1990). In northern populations red squirrels,
voles, and other small mammals are a larger component of summer and fall diets, whereas
snowshoe hares clearly dominate the winter diet (Anderson and Lovallo 2003).
The relative rarity of hares in southern mountains requires lynx to rely more heavily on other
prey there (Hodges 2000b). Red squirrels are an especially important prey in the south, as they are
in the north during troughs in the hare population cycle. Lynx appear to use non-hare prey to a
greater degree in summer than in winter in both northern and southern forests, although data are
scarce (Aubry et al. 2000, Mowat et al. 2000). In areas of patchy lynx habitat lynx are more
opportunistic and may feed occasionally on white-tailed jackrabbits, black-tailed jackrabbits (
L.
californicus
), sage grouse (
Centrocercus urophasianus
), and Columbian sharp-tailed grouse
(
Tympanichus phasianellus
columbianus
) (Quinn and Parker 1987, Ruediger et al. 2000).
Foraging Strategy
Lynx are most active between dawn and dusk, although they can seek prey any time of day.
Their primary strategy is stalk-and-pounce; sometimes they will ambush from a branch or other
high perch (Tumlison 1987). The chase typically covers a distance of 20 – 50 m. Family groups
(female and kittens) occasionally forage cooperatively, with the young flanking the adult by 15 to
40 paces in heavily wooded sites. The young rejoin the female and follow in her tracks when
crossing clearings. Lynx often rest in day beds near centers of hare activity.
Foraging Variation
In northern populations diet composition and foraging behavior varies in a rather
straightforward manner with hare abundance. Both lynx and coyotes fed on hares in the Yukon
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 20 of 43
during cyclical highs and showed a clear functional response to changes in hare density (Mowat et
al. 2000). After the hare decline, lynx increasingly foraged for squirrels. Relative frequency of
red squirrels in lynx scats was 25 – 36%, and other small mammals was 23 – 25%, during hare
lows. Hares showed up in scats in these years at a frequency of 38 – 60%, compared with 85 –
94% frequency during cyclical high hare populations. Kill rates varied from 0.3 to 1.2 hares per
day. Hunting success for lynx preying on hares declined past the point when hares started
increasing, and hunting success continued to increase for lynx hunting red squirrels, suggesting
that lynx became skilled at killing red squirrels during hare lows (O’Donoghue et al. 1998). This
has implications for lynx in southern populations: individuals may learn and become skilled at
foraging on alternate prey.
Lynx have broader diets and use a wider range of habitats in summer than winter in northern
populations. Summer diets there contain less snowshoe hare and more alternative prey, including
red squirrels, small mammals, ground squirrels, ducks, passerines and other birds, ungulates, and
carrion (Mowat et al. 2000). Riparian willow stands were used more in winter, but no other
changes were observed between winter and snow-free times in the Yukon (Mowat and Slough
2003).
Community Ecology
Predation
The predatory relationship between the lynx and the snowshoe hare is well-known and well-
studied in northern populations. The tightly linked cycles of the 2 species were first illustrated by
fur harvest records of the Hudson’s Bay Company in the 1800s (Elton and Nicholson 1942). Lynx
densities at peak cycle can be 15-times higher than in the cycle trough, an amplitude much greater
than is known for any other predator (Bulmer 1974). The generally accepted explanation for the
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 21 of 43
cycles is that high hare densities reduce winter forage, which reduces hare reproductive success
and initiates a hare decline. Predation on hares by lynx and other predators accelerates the decline
until hares become extremely rare. Lynx numbers trail those of hares, and bottom-out a year or 2
following the hare crash in response to low hare abundance. This allows winter hare forage to
recover, which slowly results in increasing hare density. Climate may also play a driving role in
the cycles, including a possible link with the North Atlantic Oscillation (Stenseth et al. 1999).
Whereas hares in northern populations may fluctuate 10 to 25 fold, in southern populations
their fluctuations are typically much weaker (Hodges 2000a, 2000b).
Competition
Competition with lynx from other predators takes two forms, exploitation and interference
(Buskirk et al. 2000). Exploitation competition involves potential competitors for food, especially
snowshoe hares, such as coyotes and raptors. Interference competition involves direct aggression
and may include attacking and killing. Coyotes, mountain lions, and bobcats are all exploitative
and interference competitors with lynx. All 3 of these carnivores are also more widespread and
abundant than they were 50 years ago in the southern portion of lynx range (Buskirk et al. 2000).
Mountain lions are known to kill lynx in Montana (Squires and Laurion 2000). Bobcats are
typically larger and more aggressive than lynx; on Cape Breton Island bobcats are the suspected
cause of lynx disappearing from lower elevations (Parker et al. 1983).
Coyotes may be particularly important competitors in southern mountains (O’Donoghue et al.
1998, Buskirk et al. 2000). Coyote use of lynx habitat is likely increasing as snowmobiles and
other agents extend compacted trails into areas where deep snow formerly prevented coyote travel
(Koehler and Aubry 1994, Buskirk 2000, Buskirk et al. 2000, Bunnell et al. 2004; but see also
Kolbe et al. 2004). This effect likely extends to other generalist predators as well.
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 22 of 43
Parasites and Disease
Ectoparasites and endoparasites have been described for lynx but do not appear to pose a
management problem (Tumlison 1987). A number of diseases, including panleucopenia, rabies,
coccidiosis, and mycoplasmosis, are known to infect lynx at rather low levels. Serological surveys
of 215 lynx from six sites in western North America revealed low disease prevalence, suggesting
rare contact between free-ranging lynx and common feline pathogens (Biek et al. 2002). All six
sites did show serologic evidence for feline parvovirus, and it was more common in southern
populations. Plague was the cause of death of four of the Colorado lynx (Colorado Division of
Wildlife 2004).
Symbiotic and Mutualistic Interactions
There is no information to suggest important symbioses involving lynx.
Conservation Concerns
In northern populations there has not yet been a substantial amount of habitat alteration, and
lynx populations are rather stable and under no great degree of conservation concern (Quinn and
Parker 1987). In Canada the species is endangered only in New Brunswick, and has been
extirpated from Prince Edward Island and mainland Nova Scotia. Fur trapping can be the single
largest mortality source, and thus is a critical management factor, in northern populations
(Ruggiero et al. 2000).
Knowledge of historic lynx distribution in the southern portion of their range is poor
(Fitzgerald et al. 1994), but they appear to have regularly bred in the Central Rocky Mountains
and regularly occurred, with possibly sporadic breeding, in the Southern Rocky Mountains. It is
generally accepted that lynx have declined in these areas over the past 50 - 100 years as their
already naturally-fragmented habitat was further fragmented by anthropogenic forces, most
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 23 of 43
notably timber harvesting, road building, and increased shooting and trapping pressure (Reeve et
al. 1986, Quinn and Parker 1987). Most states allowed harvest of lynx up until the 1970s, but this
has largely been abandoned as lynx numbers declined. In contrast to northern lynx populations fur
trapping is probably not a major pressure in the south, although the effects of accidental capture of
lynx in traps set for bobcats, coyotes, and other southern furbearers should be analyzed more
closely.
Lynx in the southern portion of their range are ecologically distinct from lynx in the north.
Naturally-fragmented habitat, more habitat disturbance, higher dependence on non-hare prey, and
substantially more interactions with generalist carnivores all challenge the management and
conservation of southern populations. The below discussion will focus on these southern
dynamics, with only occasional and brief reference to northern populations.
Conservation Status
USDI Fish and Wildlife Service
The Canada lynx was proposed for listing as threatened under the ESA on 8 July 1998
(Federal Register Volume 63, No. 130). On 24 March 2000 the final rule listing the contiguous
United States Distinct Population Segment (DPS; Colorado, Idaho, Maine, Michigan, Minnesota,
Montana, New Hampshire, New York, Oregon, Utah, Vermont, Washington, Wisconsin, and
Wyoming) was issued (Federal Register Volume 65, No. 58) (USDI Fish and Wildlife Service
2000). The main factor noted as threatening this DPS was the inadequacy of existing regulatory
mechanisms. In 2002 the U.S. District Court for the District of Columbia remanded for further
consideration the determination that the Northeast, Great Lakes, and Southern Rockies do not
constitute a significant portion of the range of the DPS. The remand notice found that the lynx is
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 24 of 43
not endangered throughout a significant portion of its ranges, and does not warrant reclassification
to “endangered” (USDI Fish and Wildlife Service 2003).
The USFWS plans to establish a Recovery Team and develop a Canada lynx Recovery Plan
(
http://www.r6.fws.gov/endspp/lynx/recovery.htm
). No timeline is provided at this time. USFWS
can propose delisting of a species when it determines that a listed population has recovered and
there are reasonable assurances that it will not be threatened again when ESA protections are
removed (16 U.S.C. §1533(a)). The USFWS is also currently developing critical habitat
designations.
Reintroductions of lynx have occurred in New York in the late 1970s and in Colorado starting
with releases in the late 1990s and continuing to present. The New York effort failed (McKelvey
2000). The Colorado project has been successful to date, with six dens found and 16 kittens born
in 2003, and another seven kittens found in 2004 (Colorado Division of Wildlife 2004). As noted
earlier, individuals from the Colorado reintroduction have colonized mountains of southern
Wyoming, with successful reproduction documented in winter 2003-2004 in the state.
USDI Bureau of Land Management
The lynx does not appear on the Sensitive Species List of the BLM - Wyoming State Office
because this list explicitly excludes species already designated by the USFWS as endangered or
threatened.
USDA Forest Service
Similar to the situation with the BLM, the Sensitive Species lists of the USDA Forest Service
explicitly exclude species already designated by the USFWS as endangered or threatened.
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 25 of 43
State Wildlife Agencies
The Wyoming Game and Fish Department (WGFD) classifies the lynx as a furbearer with no
harvest allowed; i.e., it is a protected species. In their Native Species Status system the WGFD
ranks the lynx as NSS1, which indicates populations are greatly restricted or declining with
extirpation possible and/ or ongoing significant loss of habitat.
State Natural Heritage Programs
The Wyoming Natural Diversity Database (WYNDD; University of Wyoming) ranks the lynx
as
G5 / S1
with a Wyoming Contribution Rank of
Low
. The “G5” indicates that the species is
demonstrably secure at the continental scale; “S1” indicates a very high probability of extinction
from the state. The Wyoming Contribution Rank indicates that because Wyoming forms a rather
small part of the lynx’s continental range Wyoming populations contribute little to the persistence
of the species as a whole in North America (Keinath et al. 2003).
Biological Conservation Issues
Abundance
Lynx are so cryptic and occur at such low densities in Wyoming and surrounding states that it
is difficult to assess their abundance. Reliable trapping data are available for only four U.S. states
(Minnesota, Montana, New Hampshire, and Washington), with fairly large numbers of lynx
reported from Minnesota and Montana (McKelvey 2000). For other states, including Wyoming,
available data can be used only to infer some degree of presence.
Most of the historic and recent Wyoming lynx records are from the northwestern and western
mountains (Reeve et al. 1986; WYNDD, unpublished data). Recent field data suggest that lynx
currently occupy these ranges (Squires and Laurion 2000, Murphy et al. 2004; WYNDD,
unpublished data), and lynx from the recent Colorado reintroduction have colonized portions of
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 26 of 43
the Medicine Bow and Sierra Madre ranges in southern Wyoming. The USFWS (USDI Fish and
Wildlife Service 2003) believes that most lynx in Wyoming are dispersers from source
populations to the north (and now south, assuming continued success in Colorado), with little
reproduction occurring within the state itself.
Throughout most of the species’ range the local abundance of Canada lynx clearly varies with
snowshoe hare density. It is thought that this occurs in a rather dampened fashion in Wyoming
and surrounding states, such that the highest possible densities in southern populations may be
comparable to some of the lowest recorded densities in northern populations.
Trends
Abundance Trends
Quantitative estimates of lynx abundance trends in Wyoming are unavailable due to lack of
data, but it is generally accepted that lynx numbers here have declined as anthropogenic impacts
on boreal forests have increased. The persistence of southern populations may always have
depended on regular importation of individuals from the north; this dependence may be greater
now as habitat quality in the south has declined. In general, population peaks in northern
populations can generate waves of dispersers that can supplement southern populations in
following years, but the dynamics of such dispersal are not well-understood (Mech 1980,
McKelvey 2000). Extremely low hare densities to the north can also send dispersers southward,
as individual lynx abandon formerly adequate home ranges in search of more prey (McKelvey
2000).
The recent lynx reintroduction in Colorado has provided a new regional lynx source, and
individuals from Colorado have colonized mountain ranges in southern Wyoming. The extent to
which Colorado continues to serve as a lynx source is a major management question.
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 27 of 43
Population Extent and Connectivity Trends
Based on limited trend information and a general knowledge of lynx natural history it is
reasonable to assume that human development of lynx habitat has decreased and fragmented the
species’ distribution relative to historic levels in Wyoming and surrounding states. The recent
reintroduction in Colorado has clearly countered this trend and, as stated above, the extent to
which Colorado continues to serve as a lynx source is a major management question.
Because Wyoming populations may depend highly on importation of dispersers from outside
of the state, regional connectivity of lynx habitat is a key issue for Wyoming managers. Lynx can
traverse low-elevation environments during dispersal, especially if timbered ridges and forested
riparian corridors are available. However, such environments are heavily disturbed throughout the
region; in fact, in general low-elevation environments are more disturbed than true lynx habitat at
higher elevations.
Habitat Trends
The distribution of lynx in the U.S. is clearly tied to the distribution of boreal forest, and such
habitat is naturally fragmented across Wyoming and surrounding states. Timber harvesting, road
building, mining, and urbanization have further fragmented suitable lynx habitat here, especially
considering that the late-seral stands preferentially targeted for timber harvest probably provide
the best lynx habitat in the region. Loss and fragmentation of lynx habitat is expected to continue
as human populations and development increase.
Range Context
Lynx populations in Wyoming and Colorado are at the southern end of the species’ current and
historic range. From a conservation standpoint this is a vulnerable position; in the long term,
persistence in these areas may depend mostly on natural or human-mediated dispersal of
individuals from outside population centers.
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 28 of 43
Extrinsic Threats and Reasons for Decline
Anthropogenic Impacts
High-impact anthropogenic features such as urban centers, surface mines, interstate highways,
and reservoirs have had obvious negative impacts on lynx populations in the region and will not
be discussed further.
Forest management actions that degrade habitat for snowshoe hares and/or red squirrels will
negatively affect lynx. In southern mountains, where late-seral stands probably provide the best
habitat for hares, squirrels, and lynx, timber harvesting may have the greatest impact in this
context. Clearcut harvesting directly removes lynx habitat; other harvest types such as
shelterwood cutting, seed tree cutting, and diameter-limited prescriptions probably have less
dramatic impacts. Any harvest system that removes a significant number of large live trees,
standing snags, and downed woody debris reduces the quality of current and future lynx habitat at
that site (Koehler 1990, Koehler and Brittell 1990, Ruediger et al. 2000). The preferential siting of
timber harvests in flat landscapes may be especially harmful, because lynx appear to seek out flat
forests in winter to minimize the energetic cost of travel. Stand-replacing fires have the potential
to degrade lynx habitat as well, although it is recognized that wildfire typically removes fine
woody debris and leaves coarse woody debris, a situation opposite to that produced by timber
harvesting.
The increase in road density that accompanies timber harvesting, mineral development, and
other management actions also poses a threat to lynx by increasing den disturbance, incidental
harvest, poaching, access during winter for competing carnivores, and mortality from vehicles
(Koehler and Brittell 1990, Aubry et al. 2000, Buskirk 2000). Lynx are known to follow road
edges for considerable distances, and commonly use roads as home range boundaries (Ruggiero et
al. 2000, Apps 2000). Seven of the lynx translocated to Colorado between 1999 and 2003 were
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 29 of 43
illegally shot (Colorado Division of Wildlife 2004), accounting for 14% of the 51 mortalities; 6
Colorado lynx (12%) were killed by cars. Lynx in New York had 50% mortality from vehicle
collisions. Two highway mortalities of native, wild lynx were documented recently in Wisconsin
and Minnesota (Ruggiero et al. 2000).
Exceptionally heavy livestock grazing in high-elevation forests could affect lynx populations
by reducing forage and cover for snowshoe hare and other lynx prey species, especially if such
grazing takes place in productive aspen stands or riparian willow communities encompassed by
late-seral conifer forest.
Because Wyoming lynx populations likely require continual supplementation of individuals
from outside of the state anthropogenic development of low elevation environments not normally
considered as lynx habitat could have profound impacts. Actions that reduce the likelihood of
lynx moving across low elevation basins could “strand” Wyoming populations. In this region the
largest disturbance to low-elevation travel habitat is probably mineral exploration and extraction,
along with accompanying roads and increased human presence.
Invasive Species
There is no information to suggest that exotic species are currently affecting lynx in the
Central or Southern Rocky Mountains.
Natural Predation
Lynx are vulnerable to predation by bobcats, mountain lions, coyotes, and possibly also
wolves (
Canis lupus
). In general, anthropogenic development of lynx habitat increases the
abundance and distribution of many generalist carnivores, probably to the detriment of lynx.
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 30 of 43
Intrinsic Vulnerability
Habitat Specificity and Fidelity
Current knowledge indicates that lynx are habitat specialists in the Central and Southern
Rocky Mountains: they preferentially occupy large expanses of boreal forest, which are rare and
fragmented at a regional scale, and have a finer-scale requirement for increasingly rare late-seral
conifer stands within those forests. As such lynx are especially vulnerable to habitat disturbances.
Area Requirements
Individual lynx require rather large areas, on the order of 100 - 200 km
2
(10,000 - 20, 000 ha)
for home ranges in Wyoming and surrounding states. The Lynx Conservation Assessment
Strategy (LCAS) defined a lynx analysis unit (LAU) as the smallest scale for evaluation and
monitoring of the effects of management actions on lynx (Ruggiero et al. 2000). An LAU
approximates the size of one animal’s home range, and includes the area required by a female to
raise her young. The size of an LAU is described as 6,500 – 10,000 ha (16,000 – 25,000 acres or
25 – 50 square miles) of primarily boreal forest, with small amounts of other environmental types
such as lakes, alpine tundra, and montane forest.
By any standard such land units are rare in Wyoming, and thus the likelihood of a viable
population residing completely within state borders is rather low. As mentioned previously this
suggests that managers should focus as much effort on maintaining connectivity to lynx
populations in Montana (and, by extension, Canada) and Colorado as they do on maintaining and
improving the quality of lynx habitat in Wyoming. Lynx dispersal into Wyoming from Idaho and
Utah is probably rather low compared that from Montana and Colorado.
Susceptibility to Disease and Parasites
Although lynx can be infected by a number of pathogens, there is no information to suggest
that parasites and diseases are major limits to lynx populations.
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 31 of 43
Dispersal Capability
Lynx can disperse over very long distances, with documented movements of northern animals
reaching 1,000 km (Mech 1980, Slough and Mowat 1996, Poole 1997). During such dispersal
animals travel about 1.7 – 8.3 km per day, similar to the daily movements of resident lynx (Mech
1980).
Lynx transplanted from the Yukon to southwestern Colorado have moved several hundred
kilometers. One such lynx eventually died in western Nebraska, a linear distance of about 800km
from its release site. At least 4 others have ranged into southern Wyoming, 400-600 km from their
release sites (Colorado Division of Wildlife, unpublished data).
Reproductive Capacity
Lynx vary reproductive output in response to prey density. In Alberta 73% of females
conceived in years of abundant snowshoe hares; this dropped to 33% when hares were rare (Brand
and Keith 1979). Lynx also produce large litters (up to 8 kittens) when prey is abundant (Mowat
and Slough 1998). Because prey densities appear to be chronically low (from a lynx perspective)
in southern forests, it is assumed that lynx reproductive output will also be chronically low here.
Of a litter of 4 kittens produced in western Wyoming in 1998, none survived (Squires and Laurion
2000). Of 16 kittens produced in Colorado in 2003, only 6 survived into their second year
(Colorado Division of Wildlife 2003, 2004).
Sensitivity to Disturbance
Lynx can tolerate moderate levels of human disturbance (Aubry et al. 2000), although it is
generally accepted that disturbance to active dens may result in abandonment.
Genetic Factors
Lynx and bobcats have hybridized in Minnesota, Maine, and New Brunswick. Pilgrim and
Schwartz (2004) suggest that hybridization may hinder lynx recovery. Human modification of
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 32 of 43
native environments has allowed bobcats to occupy a larger area of North America than
historically, which may increase the potential for hybridization across lynx range.
Small and peripheral populations of lynx have less genetic variation than core populations
(Schwartz et al. 2003). At first glance this suggests that that Wyoming lynx may be somewhat
threatened by detrimental genetic processes. However, continual dispersal of lynx into the state
from northern population centers and from Colorado (lynx released in Colorado were originally
captured in the Yukon) should alleviate these processes to some degree.
Protected Areas
Lynx themselves are protected across Wyoming by their federal listing under ESA and their
non-harvest status within the WGFD. Much lynx habitat in the state falls within USDI National
Park Service units and USDA Forest Service Designated Wilderness. However, the area of most
consistent lynx occupation in Wyoming (the Wyoming and Salt River ranges of west central
Wyoming) is managed as a multiple use landscape, as is most of the low elevation habitat that
lynx must cross to access other mountain ranges and lynx population centers in the region.
Population Viability Analyses (PVAs)
At this time there are no population viability analyses for lynx in the literature. Dr. J. Squires
(USDA Forest Service) is reportedly working on such an analysis for lynx in northwestern
Montana.
Conservation Actions
The federal listing of the Canada lynx under the ESA in 2000 (USDI Fish and Wildlife Service
2000), further supported by the remand notice of 2003 (USDI Fish and Wildlife Service 2003), has
stimulated broad conservation action in the contiguous U.S. As directed by ESA and court orders,
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 33 of 43
the USFWS is presently developing a lynx Recovery Plan and establishing lynx critical habitat in
the contiguous U.S.
The LCAS (Ruggiero et al. 2000) grew out of the listing efforts, and puts forth relatively
detailed criteria for allowable management actions and conservation. All USDA National Forests
with designated LAUs are in the process of amending Forest Service plans to incorporate the
conservation measures from the LCAS. The BLM is currently preparing a statewide
programmatic Biological Assessment for their Resource Management Plans on lynx, and is
considering adopting the LCAS conservation measures in this document.
The reintroduction of lynx into Colorado, and their subsequent dispersal into southern
Wyoming, is the most aggressive conservation action to date for the species in the contiguous U.S.
The success of this effort, still in question, will have a major impact on lynx management and
recovery in the U.S. in general, and in Colorado and Wyoming in particular.
Conservation Elements
Inventory and Monitoring
There are no organized inventories or monitoring efforts for lynx being conducted in
Wyoming. Biologists in federal land management agencies and WGFD commonly record
observations of lynx and lynx tracks on an opportunistic basis, as do other biologists and some
laypersons. Radio-collared lynx that range into southern Wyoming from Colorado are monitored
by the Colorado Division of Wildlife.
Techniques for inventory and monitoring include track surveys in winter, scent stations with
hair snags and track plates, and capture/ radio telemetry. Remotely-triggered cameras are being
used in Colorado to evaluate use of highway underpasses. Further details on inventory and
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 34 of 43
monitoring techniques can be found in Ruggiero et al. (1994), with special attention to Koehler
and Aubry (1994) and the subsequent publication of Zielinski and Kucera (1995).
Habitat Preservation and Restoration
If implemented, the recommendations within the LCAS will promote habitat protection and
enhancement for lynx. In general, minimizing disturbance to late-seral boreal forest, and mid-
seral forest that will soon convert to late-seral stages, will benefit lynx populations in Wyoming.
Managers seeking to promote lynx occupancy and survival should pay special attention to
protecting late-seral stands in flat landscapes, retaining large live trees and existing coarse woody
debris in all stands, and minimizing the density of roads, especially packed roads and trails in
winter. To the extent possible, management actions that benefit prey populations, especially
snowshoe hare and red squirrel, will benefit lynx.
Because long-term lynx presence in Wyoming is likely very dependent on regular importation
of individuals from population centers to the north and south, land managers should focus on
maintaining regional permeability to dispersing lynx. This necessarily requires minimizing
disturbance in key low-elevation environments that connect major mountain ranges. The Green
River Canyon area in northwest Colorado, the Bear Lake area in northern Utah and southeast
Idaho, the Snake River headwaters north of Rexburg, Idaho, the Prior Mountains of south-central
Montana, the Crooks - Green - Ferris - Seminoe - Shirley mountain chain in central Wyoming, and
the Owl Creek - Bridger mountain chain in central Wyoming are obvious sites in this context.
Fine-scale mapping of these sites to identify and plan management of potential lynx movement
paths, such as timbered ridges and riparian corridors, is recommended.
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 35 of 43
Augmentation and Reintroduction
There are no plans to reintroduce lynx in Wyoming. The Colorado Division of Wildlife has
released 167 lynx into central and southern Colorado from 1999 to 2004, and plans to release 50
lynx in 2005 and 15 each in 2006 and 2007. Individuals from past Colorado releases have already
colonized mountains in southern Wyoming, and more are expected to do so in the future.
Information Needs
Rangewide Needs
Much information on lynx ecology comes from northern populations, which are stable in a
conservation sense and quite different from southern populations. More research into northern
populations is certainly warranted, but it is not as high a priority as basic field research on
southern lynx populations.
Wyoming Needs
Basic field studies of lynx in the Central and Southern Rocky Mountains are lacking. In
general, radio-telemetry studies that take an explicitly spatial focus to elucidate population
dynamics and viability in the patchy forests of the Central and Southern Rocky Mountains are
most needed. Good information on home range and habitat selection, especially by reproducing
females, as well as mortality sources and dispersal dynamics would greatly inform management.
Similarly, scat analyses and snow trailing studies that estimate diet and prey selection in southern
forests are needed.
Interactions between lynx and generalist carnivores could be studied in a variety of ways,
including snow tracking and radio telemetry. Such interactions are likely very important to lynx
in this region, and the probability of such interactions likely varies with road density and other
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 36 of 43
landscape metrics. Studies that estimate these relationships could provide valuable information to
land and wildlife managers.
It is assumed that the telemetry monitoring of lynx recently released into Colorado will
generate much of the information outlined above. Continued support for this research is crucial,
as it will provide the largest and most important body of information for lynx management in
Wyoming. The Colorado work will probably also provide some insight into the low-elevation
environments used by lynx traveling between the Southern and Central Rocky Mountains.
However, new studies will be needed to provide the same information for lynx dispersing between
the Central and Northern Rocky Mountains.
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 37 of 43
Figures
Figure 1. Range of the Canada lynx (
Lynx canadensis
) in North America. Brown indicates areas
of consistent occupation; blue lines encompass the region where lynx occasionally occur as they disperse from more permanent population centers in the vicinity of Wyoming. Note that lynx have recently been reintroduced into the Southern Rocky Mountains of Colorado. Modified from Patterson et al. (2003).
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 38 of 43
Figure 2. Documented observations of Canada lynx (
Lynx canadensis
) in Wyoming (red dots). Data on file at the Wyoming Natural
Diversity Database, University of Wyoming (Laramie, Wyoming, USA).
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 39 of 43
Literature Cited
Agee, J.K. 2000. Disturbance ecology of Northern American boreal forests and associated northern
mixed/subalpine forests. Pages 39-81
in
L.F. Ruggiero, K.B. Aubry, S.W. Buskirk, G.M Koehler, C.J.
Krebs, K.S. McKelvey, and J.R. Squires (editors). Ecology and conservation of lynx in the United States. University Press of Colorado and the USDA Forest Service Rocky Mountain Research Station.
Anderson, A.E., D.C. Bowden and D.M. Kattner. 1992. The puma on the Uncompahgre Plateau, Colorado.
Colorado Division of Wildlife Technical Publication No. 40.
Anderson, E.M. and M.J. Lovallo. 2003. Bobcat and lynx. Pages 758-786,
in
G.A. Feldhamer, B.C.
Thompson and J.A. Chapman (editors). Wild mammals of North America: biology, management, and conservation. Second edition. Johns Hopkins University Press. Baltimore, Maryland, USA.
Apps, C.D. 2000. Space-use, demographics, and topographic associations of lynx in the southern Canadian
Rocky Mountains: a study. Pages 351-372
in
L.F. Ruggiero, K.B. Aubry, S.W. Buskirk, G.M Koehler,
C.J. Krebs, K.S. McKelvey and J.R. Squires (editors). Ecology and conservation of lynx in the United States. University Press of Colorado and the USDA Forest Service Rocky Mountain Research Station.
Armstrong, D.M. 1972. Distribution of mammals in Colorado. University of Kansas Museum of Natural
History Monograph 3:1-415.
Aubry, K.B., G.M. Koehler and J.R. Squires. 2000. Ecology of Canada lynx in southern boreal forests.
and J.R. Squires (editors). Ecology and conservation of lynx in the United States. University Press of Colorado and the USDA Forest Service Rocky Mountain Research Station.
Reid, D.W. Rice and C. Jones. 2003. Revised checklist of North American mammals north of Mexico, 2003. Museum of Texas Tech University Occasional Paper 229:1-23.
Beauvais, G.P. 2000. Mammalian responses to forest fragmentation in the central and southern Rocky
(editors). Forest fragmentation in the Southern Rocky Mountains. University Press of Colorado. Boulder, Colorado, USA.
Beauvais, G.P., D. Keinath and J. Ratner. 2001. Habitat mapping and field surveys for lynx (
Lynx
canadensis
) on lands administered by the USDI Bureau of Land Management in Wyoming. Wyoming
Natural Diversity Database - University of Wyoming. Laramie, Wyoming, USA.
Beck, T.D. 1991. Black bears of west-central Colorado. Colorado Division of Wildlife Technical
Publication No. 39.
Biek, R., A.L. Zarnke, C. Gillin, M. Wild, J.R. Squires and M. Poss. 2002. Serologic survey for viral and
bacterial infections in western populations of Canada lynx (
Lynx canadensis
). Journal of Wildlife
Diseases 38:840-845.
Brand, C.J. and L.B. Keith. 1979. Lynx demography during a snowshoe hare decline in Alberta. Journal
of Wildlife Management 43:827-849.
Brand, C.J., L.B. Keith and C.A. Fischer. 1976. Lynx responses to changing snowshoe hare densities in
central Alberta. Journal of Wildlife Management 40:416-428.
Bulmer, M.G. 1974. A statistical analysis of the 10-year cycle in Canada. Journal of Animal Ecology
43:701-718.
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 40 of 43
Bunnell, K.D., J.R. Flinders, M.L. Wolfe and J.A. Bissonette. 2004. Quantifying the potential impacts of
coyotes and snowmobiles on lynx conservation in Utah and the Intermountain West. Abstract presented at the Western Forest Carnivore Committee Meeting, April 2004.
Buskirk, S.W. 2000. Habitat fragmentation and interspecific competition: Implications for lynx
conservation. Pages 83-100
in
L.F. Ruggiero, K.B. Aubry, S.W. Buskirk, G.M Koehler, C.J. Krebs,
K.S. McKelvey and J.R. Squires (editors). Ecology and conservation of lynx in the United States. University Press of Colorado and the USDA Forest Service Rocky Mountain Research Station.
Buskirk, S.W., L.F. Ruggiero, K.B. Aubry, D.E. Pearson, J.R. Squires and K.S. McKelvey. 2000.
Comparative ecology of lynx in North America. Pages 397-418
in
L.F. Ruggiero, K.B. Aubry, S.W.
Buskirk, G.M Koehler, C.J. Krebs, K.S. McKelvey and J.R. Squires (editors). Ecology and conservation of lynx in the United States. University Press of Colorado and the USDA Forest Service Rocky Mountain Research Station.
Chapman, J.A. and J.E.C. Flux. 1990. Rabbits, hares and pikas: status survey and conservation action plan.
IUCN/SSC Lagomorph Specialist Group. International Union for Conservation of Nature and Natural Resources. Gland, Switzerland.
Colorado Division of Wildlife. 2004. Lynx update 12 April 2004. Available online
http://wildlife.state.co.us/species_cons/lynx.asp
.
Clark, T.W. and M.R. Stromberg. 1987. Mammals in Wyoming. University of Kansas Museum of Natural
History. Lawrence, Kansas, USA.
Ehle, D.S. and D.A. Keinath. 2002. Habitat mapping of lynx analysis units on Bureau of Land
Management lands and surrounding areas in Wyoming. Wyoming Natural Diversity Database - University of Wyoming. Laramie, Wyoming, USA.
Elton, C. and M. Nicholson. 1942. The ten-year cycle in numbers of the lynx in Canada. Journal of
Animal Ecology 11:215-244.
Fitzgerald, J.P., C.A. Meaney and D.M. Armstrong. 1994. Mammals of Colorado. University Press of
Colorado and Denver Museum of Natural History.
Halfpenny, J.C. and G.C. Miller. 1981. Lynx and wolverine verification. Colorado Division of Wildlife
Research Report January 1981:53-82.
Hall, E.R. 1981. The mammals of North America. John Wiley & Sons. New York, New York, USA.
Hodges, K.E. 2000a. Ecology of snowshoe hares in northern boreal forests. Pages 117-162
in
L.F.
Ruggiero, K.B. Aubry, S.W. Buskirk, G.M Koehler, C.J. Krebs, K.S. McKelvey and J.R. Squires (editors). Ecology and conservation of lynx in the United States. University Press of Colorado and the USDA Forest Service Rocky Mountain Research Station.
Hodges, K.E. 2000b. Ecology of snowshoe hares in southern boreal and montane forests. Pages 163-206
in
L.F. Ruggiero, K.B. Aubry, S.W. Buskirk, G.M Koehler, C.J. Krebs, K.S. McKelvey and J.R.
Squires (editors). Ecology and conservation of lynx in the United States. University Press of Colorado and the USDA Forest Service Rocky Mountain Research Station.
Keinath, D., B. Heidel and G. Beauvais. 2003. Wyoming plant and animal species of concern. Wyoming
Natural Diversity Database. University of Wyoming, Laramie, Wyoming, USA. Available online:
http://uwdmnweb.uwyo.edu/wyndd/soc/2003
Koehler, G.M. 1990. Population and habitat characteristics of lynx and snowshoe hares in north central
Washington. Canadian Journal of Zoology 68:845-851.
Koehler, G.M. and K.B. Aubry. 1994. Lynx. Pages 74-98
in
L.R. Ruggiero, K.B. Aubry, S.W. Buskirk,
L.J. Lyon, and W.J. Zielinski (editors). American marten, fisher, lynx, and wolverine in the western
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 41 of 43
United States: the scientific basis for conserving forest carnivores in the western United States. USDA Forest Service General Technical Report RM-254.
Koehler, G.M. and J.D. Brittell. 1990. Managing spruce-fir habitat for lynx and snowshoe hares. Journal
of Forestry 88:10-14.
Kolbe, J.A., D. Pletscher, J.R. Squires and L.F. Ruggiero. 2004. The effect of snow compaction on coyote
and lynx winter ecology. Abstract presented at the Western Forest Carnivore Committee Meeting, April 2004.
Kurten, B., and E. Anderson. 1980. Pleistocene mammals of North America. Columbia University Press.
New York, New York, USA.
Mace, R.D., J.S. Waller, T.L. Manley, L.J. Lyon and H. Zuuring. 1996. Relationships among grizzly bears,
roads, and habitat in the Swan Mountains, Montana. Journal of Applied Ecology 33:1395-1404.
McCord, C.M. and J.E. Cardoza. 1982. Bobcat and lynx (
Felis rufus
and
F. lynx
). Pages 728-766
in
J.A.
Chapman and G.A. Feldhamer (editors). Wild mammals of North America. Johns Hopkins University Press. Baltimore, Maryland, USA.
McKelvey, K.S. 2000. History and distribution of lynx in the contiguous United States. Pages 207-259
in
L.F. Ruggiero, K.B. Aubry, S.W. Buskirk, G.M Koehler, C.J. Krebs, K.S. McKelvey and J.R. Squires (editors). Ecology and conservation of lynx in the United States. University Press of Colorado and the USDA Forest Service Rocky Mountain Research Station.
McKelvey, D.S., S.W. Buskirk and C.J. Krebs. 2000a. Theoretical insights into the population viability of
McKelvey and J.R. Squires (editors). Ecology and conservation of lynx in the United States. University Press of Colorado and the USDA Forest Service Rocky Mountain Research Station.
and topographic use patterns in North Central Washington: a reanalysis. Pages 307-336
in
L.F.
Ruggiero, K.B. Aubry, S.W. Buskirk, G.M Koehler, C.J. Krebs, K.S. McKelvey and J.R. Squires (editors). Ecology and conservation of lynx in the United States. University Press of Colorado and the USDA Forest Service Rocky Mountain Research Station.
Mech, L.D. 1980. Age, sex, reproduction, and spatial organization of lynxes colonizing northeastern
Minnesota. Journal of Mammalogy 61:261-267.
Mowat, G., K.G., Poole and M. O’Donoghue. 2000. The ecology of lynx in northern Canada and Alaska.
and J.R. Squires (editors). Ecology and conservation of lynx in the United States. University Press of Colorado and the USDA Forest Service Rocky Mountain Research Station.
Mowat, G. and B.G. Slough. 1998. Some observations on the natural history and behaviour of the Canada
lynx,
Lynx canadensis
. Canadian Field-Naturalist 112:32-36.
Mowat, G. and B.G. Slough. 2003. Habitat preference of Canada lynx through a cycle in snowshoe hare
abundance. Canadian Journal of Zoology 81:1736-1745.
Murphy, K., K. Gunther, T. Potter, P. Ludgren, T. Jones and J. Halfpenny. 2004. Yellowstone lynx project.
Abstract presented at the Western Forest Carnivore Committee Meeting, April 2004.
Noss, R.F., H.B. Quigley, M.G. Hornocker, T. Merrill and P.C. Paquet. 1996. Conservation biology and
carnivore conservation in the Rocky Mountains. Conservation Biology 10:949-963.
O’Donoghue, M., S. Boutin, C.J. Krebs, G. Zuleta, D.L. Murray and E.J. Hofer. 1998. Functional
responses of coyotes and lynx to the snowshoe hare cycle. Ecology 79:1193-1208.
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 42 of 43
Parker, G.R., J.W. Maxell and L.D. Morton. 1983. The ecology of the lynx (
Lynx canadensis
) on Cape
Breton Island. Canadian Journal of Zoology 61:770-786.
Patterson, B.D., G. Ceballos, W. Sechrest, M.F. Tognelli, T. Brooks, L. Luna, P. Ortega, I. Salazar and B.E.
Young. 2003. Digital distribution maps of the mammals of the Western Hemisphere. Version 1.0. NatureServe. Arlington, Virginia, USA.
Pilgrim, K. and M.K. Schwartz. 2004. Hybridization of lynx and bobcats. Abstract presented at the
Western Forest Carnivore Committee Meeting, April 2004.
Poole, K.G. 1997. Dispersal patterns of lynx in the Northwest Territories. Journal of Wildlife Management
61:497-505.
Quinn, N.S.and G. Parker. 1987. Lynx. Pages 683-694
in
N. Novak, J. Baker and M. Obbard (editors).
Wild furbearer management and conservation in North America. Ministry of Natural Resources. Toronto, Ontario, Canada.
Reeve, A., F. Lindzey and S. Buskirk. 1986. Historic and recent distribution of the lynx in Wyoming.
Wyoming Cooperative Fish and Wildlife Research Unit - University of Wyoming. Laramie, Wyoming, USA.
Ruediger, B., J. Claar, S. Gniadek, B. Holt, L. Lewis, S. Mighton, B. Nancy, G. Patton, T. Rinaldi, J. Trick,
A. Vandehey, F. Wahl, N. Warren, D. Wenger and A. Williamson. 2000. Canada lynx conservation assessment and strategy. USDA Forest Service / USDI Fish and Wildlife Service / USDI Bureau of Land Management / UDSI National Park Service. Missoula, Montana, USA.
Ruggierro, L.F., K.B. Aubry, S.W. Buskirk, L.J. Lyon and W.J. Zielinski. 1994. The scientific basis for
conserving forest carnivores: American marten, fisher, lynx, and wolverine in the western United States. USDA Forest Service General Technical Report RM-254.
2000. The scientific basis for lynx conservation: qualified insights. Pages 443-454
in
L.F. Ruggiero,
K.B. Aubry, S.W. Buskirk, G.M Koehler, C.J. Krebs, K.S. McKelvey, and J.R. Squires (editors). Ecology and conservation of lynx in the United States. University Press of Colorado and the USDA Forest Service Rocky Mountain Research Station.
Schwartz, M.K., L.S. Mills, K.S. McKelvey, L.F. Ruggiero and F.W. Allendorf. 2002. DNA reveals high
dispersal synchronizing the population dynamics of Canada lynx. Nature 415:520-522.
Schwartz, M.K., L.S. Mills, Y. Ortega, L.F. Ruggiero and F.W. Allendorf. 2003. Landscape location
affects genetic variation of Canada lynx (
Lynx canadensis
). Molecular Ecology 12:1807-1816.
Slough, B.G. 1999. Characteristics of Canada lynx,
Lynx canadensis
, maternal dens and denning habitat.
Canadian Field-Naturalist 113:605-608.
Slough, B.G. and G. Mowat. 1996. Lynx population dynamics in an untrapped refugium. Journal of
Wildlife Management 60:946-961.
Squires, J.R. and T. Laurion. 2000. Lynx home range and movements in Montana and Wyoming:
preliminary results. Pages 337-350
in
L.F. Ruggiero, K.B. Aubry, S.W. Buskirk, G.M Koehler, C.J.
Krebs, K.S. McKelvey and J.R. Squires (editors). Ecology and conservation of lynx in the United States. University Press of Colorado and the USDA Forest Service Rocky Mountain Research Station.
Stenseth, N.C., K.S. Chan, T. Howell, R. Boonstra, S. Boutin, C.J. Krebs, E. Post, M. O’Donoghue, N.G.
Yoccoz, M.C. Forchhammer and J.W. Hurrell. 1999. Common dynamic structure of Canada lynx populations within three climatic regions. Science 285:1071-1073.
Steury, T.D. and D.L. Murray. 2004. Modeling the reintroduction of lynx to the southern portion of its
range. Biological Conservation 117:127-141.
Meaney and Beauvais –
Lynx canadensis
September 2004
Page 43 of 43
Tumlison, R. 1987. Felis lynx. Mammalian Species 269:1-8.
USDI Fish and Wildlife Service. 2000. Endangered and Threatened wildlife and plants; determination of
threatened status for the contiguous U.S. Distinct Population Segment of the Canada lynx and draft rule; final rule. Federal Register Vol. 65 No. 58:16051-16086.
USDI Fish and Wildlife Service. 2003. Endangered and Threatened wildlife and plants; notice of
remanded determination of status for the contiguous United States distinct population segment of the Canada lynx; clarification of findings; final Rule. Federal Register Vol. 68 No. 128:40076-40101.
Van Gelder, R.G. 1977. Mammalian hybrids and generic limits. American Museum Novitates 2635:1-25.
Ward, R.M.P and C.J. Krebs. 1985. Behavioral responses of lynx to declining snowshoe hare abundance.
Canadian Journal of Zoology 63:2817-2824.
Werdelin, L. 1981. The evolution of lynxes. Annales Zoologici Fennici 18:37-71.
Wieglus, R.B., F.L. Bunnell, W.L. Wakkinen and P.E. Zager. 1994. Population dynamics of Selkirk
Mountain grizzly bears. Journal of Wildlife Management 58:266-272.
Wozencraft, W.C. 1993. Order Carnivora. Pages 279-348
in
D.E. Wilson and D.M. Reeder (editors).
Mammal species of the world: a taxonomic and geographic reference. Smithsonian Institution Press, Washington DC, USA.
Wyoming Game and Fish Department. 1999. Threatened, endangered, and nongame bird and mammal
investigations; Nongame Program, Biological Services Section, annual completion report. Wyoming Game and Fish Department. Cheyenne, Wyoming, USA.
Zielinski, W.J. and T.E. Kucera. 1995. American marten, fisher, lynx, and wolverine: survey methods for
their detection. USDA Forest Service General Technical Report PSW-157.
