Forest Carnivore Conservation

and Management in the Interior

Columbia Basin: Issues and

Environmental Correlates

United States

Department of

Agriculture

Forest Service

Pacific Northwest

Research Station

United States

Department of the

Interior

Bureau of Land

Management

General Technical

Report

PNW-GTR-420

July 1998

Gary W. Witmer, Sandra K. Martin, and Rodney D. Sayler
Authors

GARY W. WITMER is a wildlife research biologist, USDA/APHIS National Wildlife Research

Center, 1716 Heath Parkway, Fort Collins, CO 80524-2719; and SANDRA K. MARTIN is an adjunct

wildlife faculty and RODNEY D. SAYLER is an associate professor of wildlife, Washington State

University, Department of Natural Resource Sciences, Pullman, WA 99164-6410. This document is

published by the Pacific Northwest Research Station under agreement no. 95-06-54-18.
Forest Carnivore Conservation and Management

in the Interior Columbia Basin: Issues and

Environmental Correlates

Gary W. Witmer, Sandra K. Martin, and Rodney D. Sayler

Interior Columbia Basin Ecosytem

Management Project: Scientific Assessment

Thomas M. Quigley, Editor

U.S. Department of Agriculture

Forest Service

Pacific Northwest Research Station

Portland, Oregon

General Technical Report PNW-GTR-420

July 1998
Abstract

Witmer, Gary W.; Martin, Sandra K.; Sayler, Rodney D. 1998. Forest carnivore conservation and

management in the interior Columbia basin: issues and environmental correlates. Gen. Tech. Rep.

PNW-GTR-420. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest

Research Station. 51 p. (Quigley, Thomas M., ed.; Interior Columbia Basin Ecosystem Management

Project: scientific assessment).

Forest carnivores in the Pacific Northwest include 11 medium to large-sized mammalian species

of canids, felids, mustelids, and ursids. These carnivores have widely differing status in the region,

with some harvested in regulated furbearer seasons, some taken for depredations, and some protected

because of rarity. Most large carnivores have declined in numbers or range from human encroachment,

loss or modification of forest habitat, accidental deaths (e.g., mortality from vehicles), illegal kills, and

our inability to adequately monitor and protect populations. Efforts to reverse these trends include

new approaches to reduce conflicts with humans, research to better define habitat needs, formation

of expert carnivore working groups, and use of Geographic Information System models to predict

specific impacts of habitat modifications. Long-term preservation of large carnivores in the region

is problematic unless we reduce forest fragmentation and conflicts with humans and improve our

ability to quantitatively integrate population dynamics with landscape level habitat requirements.

Keywords: Coyote, gray wolf, bobcat, lynx, mountain lion, fisher, marten, river otter, wolverine,

grizzly bear, black bear, conservation, management, carnivores, late successional forest, wilderness,

roads, disturbance, fragmentation, conservation biology, geographic information systems, forest

management, animal damage.
Contents

1 Introduction

2 Coyote (Canis latrans)

4 Gray Wolf (Canis lupus)

6 Bobcat (Lynx rufus)

8 Lynx (Lynx canadensis)

10 Mountain Lion (Felis concolor)

13 Fisher (Martes pennanti)

15 American Marten (Martes americana)

18 River Otter (Lutra canadensis)

19 Wolverine (Gulo gulo)

22 Black Bear (Ursus americanus)

24 Grizzly Bear (Ursus arctos)

27 Conclusions

31 Acknowledgments

31 English Equivalents

32 Literature Cited

42 Appendix A

48 Appendix B

49 Appendix C

51 Appendix D
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Document continues on next page.
Introduction

Carnivores were selected for specific attention

by the Interagency Interior Columbia Basin Ecosystem Management Team because of viability

concerns. Carnivores are key species in wildlife

communities; they provide, in their role as top

predators in the trophic webs, a gauge of the

health of entire systems because of their ultimate

dependence on other populations and processes.

Carnivore interactions with prey populations

create dynamics crucial to the balance of these

systems and their long-term sustainability. Forest

carnivores also are vulnerable to habitat alteration and exploitation and have a long and

complex historical relation with humans (Clark

et al. 1996c, Kellert et al. 1996). These species

are variously managed as harvested furbearers,

unprotected depredatory animals, or protected

or endangered species (Keiter and Locke 1996).

If the needs of large, far-ranging carnivores are

met, often the needs of many more species lower

on the trophic scale will also be met—the socalled umbrella effect (Noss et al. 1996, Peterson

1988). Some large carnivores present special

problems to managers because of depredation,

public safety issues, and competition with other

wildlife resources. Several carnivores in the

Western United States have declined dramatically

in the last century and a half and are listed as

threatened or endangered species, or are considered sensitive by land management agencies

(Noss et al. 1996). Portions of the Pacific Northwest hold the largest wildland areas in North

America with most carnivore species still present

(Clark et al. 1996c).

We do not know nearly enough about forest

carnivore species to adequately provide for their

needs and eliminate conflicts with humans. These

species are mostly far ranging, elusive, shy and

inconspicuous, occur in low densities, and are

active mainly at night (Kucera and Zielinski

1995). We know little about their status and

distribution, partly because they currently are

not harvested at anywhere near historical levels.

This makes the study and management of forest

carnivores problematic at best. The numerous

research needs for these species are detailed by

many investigators (Clark et al. 1996b, Kucera

and Zielinski 1995, Peterson 1988, Quigley and

Hornocker 1992, Ruggiero et al. 1994).

As the process of ecosystem management continues, specific land management issues must be

identified and considered as they affect conservation and viability of wildlife. Some of the tools

that will be needed for assessment, modeling,

and monitoring include Geographic Information

Systems (GIS) and associated databases. Attributes relevant to the ecology of selected species

that can be identified from satellite imagery used

to develop existing USDA Forest Service GIS

databases need to be identified. Those attributes

that should be available—but not yet are—also

should be identified.

Eleven medium- to large-sized carnivore species

present in the interior Columbia basin (referred

to throughout as “the basin”) were selected by

the Interior Columbia Basin Ecosystem Management Team for the identification of issues surrounding conservation and population viability.

The species included canids (coyote, gray wolf),

felids (bobcat, lynx, mountain lion), mustelids

(fisher, marten, river otter, wolverine), and ursids

(black bear, grizzly bear). The current state of

scientific knowledge of the ecology and management of each species was surveyed through

review of recent literature. Issues surrounding

conservation of the species in the region were

identified by (1) a panel of experts that convened

briefly in December 1994 to address the topic;1

(2) current conservation assessments, reviews and

scientific literature; (3) our personal knowledge

and background; and (4) outside review of this

document. Key environmental correlates were

identified as factors that affect the distribution

or viability of each species. Those correlates that

could be identified on currently available GIS

were listed with the relevant conservation issue.

Additionally, correlates that probably are important to viability of the species, but which cannot

currently be tracked on GIS, were distinguished.

Several conservation issues intersected the ecology of more than one species of those evaluated,

1 The panel included Keith Aubry, USDA Forest Service,

Olympia, WA; Vivian Banci, Ministry of Environment,

Victoria, BC; Gary Koehler, Washington Department of

Fish and Wildlife, Olympia, WA; Len Ruggiero, USDA

Forest Service, Missoula MT; and John Weaver, Missoula,

MT.

1
and these are identified and discussed. The continuing need for more and better information, and

the tools to gather that information, is notable,

particularly for many of these forest carnivore

species. Many of these species are rare, difficult

to census and study, and yet very important in

their roles in the function of ecosystems and their

values to humans.

Coyote (Canis latrans)

Ecology

Coyotes occur throughout most of North

America, including the entire interior Columbia

basin (appendix A). They use almost all types of

habitats where prey are available (Bekoff 1982,

Voight and Berg 1987). Their range and densities

have increased over historical levels because of

increased forest clearing, agriculture, and livestock production, and the control of wolves

(Canis lupus) and other more specialized carnivores (Toweill and Anthony 1988, Voight and

Berg 1987, Witmer and deCalesta 1986). Their

range is limited in the far north by snow and

arctic conditions; to the south, their range has

extended in recent dacades to Panama in Central

America.

Home range sizes are quite variable, but average

from 4-12 km2 (Bekoff 1982, Voight and Berg

1987). Coyotes are social animals, and groups

will actively defend their territory from other

coyotes. Coyotes can disperse over large

distances, often 100+ km (Harrison 1992).

Coyotes are omnivores and their diet varies by

area and season in relation to prey, carrion, and

fruit availability (Bekoff 1982, Voight and Berg

1987). Lagomorphs and rodents typically comprise a large part of the diet, but fruit in late

summer and fall, carrion in winter and spring,

and young ungulates in spring through early

summer can be significant components. Coyotes

readily take livestock as prey, and substantial

coyote control efforts to reduce depredations

continue in the Western States (USDA 1994).

Coyote densities range widely (up to 2/km2

) and

are closely related to prey abundance (Bowen

1982, Clark 1972, Mills and Knowlton 1991,

Nellis and Keith 1976).

Coyotes are habitat generalists and occur in most

habitats, especially where there is a mix of cover

and open areas supporting abundant and diverse

prey (Bekoff 1982, Voight and Berg 1987). Fragmentation of habitat and forests by humans undoubtedly has resulted in the increased range and

densities of coyotes in North America, as coyotes

readily take advantage of new habitat and prey

opportunities. No habitat elements, other than

prey base, have been found to be critical to

coyotes. They use a variety of den sites: brushcovered slopes, steep banks, rock ledges, thickets,

hollow logs, and dens of other animals (Bekoff

1982). Coyotes are active primarily from dusk to

dawn (Bekoff 1982). During daylight, they avoid

large open areas and traveled roads (Roy and

Dorrance 1985).

Coyotes have a high reproductive potential, often

reaching sexual maturity in one year and usually

bearing a litter of five to six young per year.

Coyotes are subject to various mortality factors,

but in most situations, humans are the primary

mortality agent. Annual mortality in adults is

usually about 40 percent but can be as high as

70 percent in pups and yearlings (Gese et al.

1989, Voight and Berg 1987). Coyotes respond

to high mortality rates with increased pregnancy

rates and litter sizes (Voight and Berg 1987).

Coyotes cannot compete well with wolves or

mountain lions (Felis concolor) (which kill or

force coyotes from their home ranges), but

coexist with bobcats (Lynx rufus) (Major and

Sherburne 1987, Voight and Berg 1987, U.S.

Fish and Wildlife [USFWS] 1996, Witmer and

deCalesta 1986). They are intolerant of foxes

(Vulpes spp.), killing the foxes or forcing them

out of occupied home ranges (Major and

Sherburne 1987). They compete with all forest

carnivores for carrion and other mammalian prey.

2
Coyote Issues in the Basin

Coyotes are common throughout the Western

United States. Their numbers in most states are

stable or increasing, despite intensive control

efforts in livestock production areas (USDA

1994). Coyotes are habitat and diet generalists,

filling niches vacated or made more available

by lowered numbers and ranges of other forest

carnivores. Currently, coyotes come into conflict

with human interests more so than any other

forest carnivore. Two issues are of concern to

the conservation and management of coyotes

in the basin.

Issue 1: Increased range and densities of

coyotes—While most forest carnivore species

have declined in range and numbers because

of habitat alteration and other human activities,

coyotes have responded positively to human

activities. Because coyotes compete with other

forest carnivores for carrion, small mammals,

young ungulates, and fruits, increasing densities

of coyotes can be considered detrimental to

declining populations of other forest carnivores.

If conditions for other larger, forest carnivores

are improved, coyote range and densities should

decline because they do not compete well with

larger carnivores.

Key environmental correlates—The following

information is available on basin GIS:

• Ungulate ranges

• Forest cover, structure, interspersion

• Road density

• Human density

• Large carnivore ranges (grizzly bear [Ursus

arctos], mountain lion, wolf)

The following information is not currently

available on basin GIS:

• Ungulate densities

• Small mammal ranges, densities

• Livestock grazing areas, densities

• Garbage dumps, landfills

Issue 2: Increased conflicts between coyotes

and humans—As the range and densities of

coyotes have increased, conflicts with humans

have increased. Responding to a greater mix of

habitats and more diverse and abundant food

sources, coyotes have increased their tolerance

and association with human habitations. This has

resulted in increased predation on livestock and

pets, consumption of garden and field crops,

disease hazards, and attacks on humans. This

pattern will probably continue as the human

population and their activities expand into what

once were remote areas.

Key environmental correlates—The following

information is available on basin GIS:

• Human density

• Road density

• Forest cover, structure, interspersion

• Agricultural areas

The following information is not currently

available on basin GIS:

• Homesite density

• Garbage dumps, landfills

• Livestock grazing areas, densities

3
Gray Wolf (Canis lupus)

Ecology

The gray wolf originally was found

throughout most of the Northern

Hemisphere north of latitude 20o N.

(Mech 1974). In recent history, the

gray wolf occupied most of the North

American continent, with the primary

exception of Baja California and the

southeastern coastal plain of the

United States (Paradiso and Nowak

1982). Thus, wolves once were one

of the most widely distributed of all

land mammals (Nowak 1983). In the

United States, breeding wolf populations currently are found in Alaska, around

Lake Superior, and in the northern Rocky

Mountains (Van Ballenberghe 1992). In the

interior Columbia basin, established packs of

naturally occurring wolves are found only in

western Montana. Experimental releases to

establish new breeding populations have

occurred recently in central Idaho and Yellowstone National Park (appendix A; USFWS 1996).

It appears that these releases will be successful in

establishing breeding wolf packs (USFWS 1996).

Even with the extensive distribution and use of

diverse habitats and prey by wolves, their home

range sizes differ considerably among regions.

The limited comparisons that may be drawn

from different studies support this expectation.

Investigators have reported home ranges varying

from 94 km2 in Minnesota to about 13 km2 for

a wolf pack in Alaska (Mech 1970). The smaller

home ranges (about 125 km2

) occur in forested

habitats with high deer (Odocoileus spp.) populations, and the larger annual ranges (about 500

to 1400 km2

) are found for wolves preying on

bison (Bison bison), moose (Alces alces), or

caribou (Rangifer spp.) (Carbyn 1987). Summer home ranges are smaller because breeding

and activities focused at den sites with pups; in

winter, packs move across larger areas. Wolves

can travel and disperse over very large distances

(Carbyn 1987, Paradiso and Nowak 1982). Wolf

densities differ widely because of variation in

their prey base. Wolf densities have been estimated for areas from the size of Isle Royale,

Michigan (546 km2

), to the Northwest Territories

(1248000 km2

) (Paradiso and Nowak 1982). The

highest densities of about one wolf per 26 km2

occur in forested regions of Minnesota; much

lower densities of about one wolf per 150 to

500 km2 are found in the northern parts of their

range in Alaska and Canada.

Gray wolves specialize in their prey but primarily eat ungulates and beaver (Castor canadensis)

(Carbyn 1987). Prey smaller than beaver typically

do not form large parts of the wolf diet, although

snowshoe hares (Lepus americanus), squirrels,

and microtine rodents may be taken during some

periods of the year when particularly abundant.

Beaver are taken more heavily during summer,

depending on their availability in a region. In

general terms, ungulates comprise about 85 to

95 percent of the wolf diet and wolf populations

cannot be sustained without populations of deer,

moose, elk (Cervus elaphus), bison, or caribou.

Domestic livestock, including cattle and sheep,

are taken as well. Wolves also feed on carrion.

As habitat generalists, wolves are not restricted

to specific habitats. The only conspicuous unoccupied habitats are desert areas having few

ungulate prey and tropical rain forests (Carbyn

1987).

Although denning sites may be limited in tundra

areas, it seems highly unlikely that they would

be so in forested or prairie regions throughout

the rest of the wolf range. Dens often are within

500 m of water on elevated knolls in forested

areas, but dens have been found in rock crevices,

beaver lodges, hollow logs, and underneath tree

stumps (Carbyn 1987). After several weeks, pups

4
are moved to a succession of activity sites farther

away from the den, known as rendezvous or

home sites. Thus, it is unlikely that availability

of suitable denning or rendezvous sites places

any major restrictions on wolf distribution

throughout most of the range.

Natural mortality factors include starvation, disease, intraspecific aggression, predation, and

injuries received while attempting to kill large

prey (i.e., moose). In most areas of North

America, humans are the primary mortality

factor for adult wolves. About 80 percent of

the mortality of radio-marked wolves in northcentral Minnesota was caused by humans (Fuller

1989). Human-caused mortality may be limiting

population growth in Wisconsin and Michigan

(Peek et al. 1991, Weise et al. 1975). There is no

harvest season on wolves in any state within the

Columbia basin.

Offsetting the susceptibility to human-caused

mortality is a high capacity for reproduction

and population growth. In the wild, females may

reach sexual maturity at 22 months, although

wolves often do not breed until their third year

or later. Average litter size is about 6; range 1 to

11 (Mech 1974). Survival rates from birth to 5 to

10 months of age may range from 6 to 43 percent.

Survival from this point to age 17 months may

be about 55 percent, and annual survival after

age 17 months may be about 80 percent (Mech

1970). Annual survival rates may differ substantially, depending on the relative importance of

disease, starvation, and human-caused mortality.

Gray Wolf Issues in the Basin

Humans are the major predators and source of

mortality for mature wolves, whether wolves are

legally protected in an area or not. Consequently,

the only major issues facing both natural and

reintroduced wolf populations in the basin are

whether humans will allow the wolves to survive

by not killing them directly. Of secondary importance is the maintenance of adequate ungulate

populations as a prey base. Other environmental

factors such as denning or rendezvous sites are

unlikely to be limiting to populations.

Studies in Ontario and the north-central United

States demonstrate a strong inverse relation

between road density and wolf populations

(Paquet and Hackman 1995, Thiel 1985). Wolf

populations are either absent or low when road

densities exceed about 0.58 km/km2

. Hunting,

trapping, poisoning, and predator control

programs are the most common sources of

human-caused mortality. Mortality associated

with highways has now become a primary source

of mortality in the Canadian Rocky Mountains,

and increased road development and human

settlement may be threatening the security of

recently recovered populations in this area

(Paquet 1993). Major highways also may be

barriers to movements and dispersal of wolves,

which further isolates subpopulations from

each other. Three issues are of concern to wolf

conservation and management in the basin.

Issue 1: Maintenance of large, remote areas

with limited accessibility to humans—Wolves

are able to survive in large areas of forested or

open habitats, such as prairie and tundra, where

there is limited human access. Increased human

access into wolf habitats seems to limit population growth or occurrence because of legal and

illegal killing and accidental mortality. Both the

short- and long-term survival of gray wolf populations in the basin depend on maintaining large

land areas with limited road access. Because

wolves are persecuted more on private lands,

large areas of public lands and designated

wilderness are important to conserving wolf

populations in the basin. Such areas will be the

foci of restored or recovered wolf populations.

Key environmental correlates—The following

information is available on basin GIS:

• Human density

• Road density

• Agricultural lands

1. Grazing lands

2. Croplands

• Wilderness and large roadless areas

5
The following information is not currently

available on basin:

• Hunter use days

Issue 2: Shooting, trapping, poisoning, and

predator control activities—Wolves come into

conflict with humans primarily over livestock

and perceived competition for game animals.

Livestock producers and a large segment of the

public in regions occupied by wolves have negative attitudes about wolves. Consequently,

human-caused mortality is significant, even

when wolves are legally protected, and affects

the potential for wolf population growth and

viability. Wolves also may be killed accidentally

during coyote control activities.

Key environmental correlates—The following

information is available on basin GIS:

• Agricultural lands

1. Grazing lands

2. Croplands

The following information is not currently

available:

• Density of cattle, sheep, and other domestic

livestock

Issue 3: Maintenance of adequate ungulate

prey populations—Wolf populations depend

on ungulates as their primary source of prey.

Excluding associated human-caused mortality,

wolves benefit from dense ungulate populations,

which the wolves follow seasonally as ungulates

move from summer to winter ranges. Wolves

may limit ungulate populations, although their

ability to regulate them is controversial. Protection and management of ungulate wintering

ranges is important to provide concentrations of

prey during times of the year when food is most

limited. Abundance of carrion through natural

processes (e.g., disease) also is an important

food source for wolves.

Key environmental correlates—The following

information is available on basin GIS:

• Ungulate ranges

The following information is not currently

available:

• Prey availability

1. Average annual ungulate density

2. Ungulate density on their wintering range

• Ungulate harvest

Bobcat (Lynx rufus)

Ecology

The bobcat is the most widely occurring felid in

North America (Anderson 1987). The species

occurs throughout the interior Columbia basin

(appendix A). It is widely distributed across the

Lower 48 States and Mexico, but its ecological

niche throughout Canada and Alaska is occupied

by the lynx (Lynx canadensis), which is better

adapted to the deep snows of boreal forest winters

(McCord and Cardoza 1982). The range of the

bobcat has expanded owing to some human

activities; however, recent intensive forestry

and agriculture (Midwestern States) or dense

human settlement (Middle Altantic States) has

eliminated or restricted the range of bobcats in

some regions (Rolley 1987).

Bobcats are territorial and, for the most part,

live solitary lives (Anderson 1987, McCord and

Cardoza 1982). The home ranges of females

typically do not overlap much, but male home

ranges may overlap with females or other males.

There also are transients—individuals without an

established home range that may move as much

as 6+ km every few days (McCord and Cardoza

6
1982). Females are only about half the size of

males and typically have home ranges two to

three times smaller. Home range sizes are highly

variable, usually 1 to 100 km2

, but can be as

large as 200 km2 and are usually larger in more

northerly areas (Anderson 1987, McCord and

Cardoza 1982).

Bobcats are opportunistic predators, feeding on a

wide array of prey: mice, voles, rats, lagomorphs,

beaver, squirrels, deer, birds, insects, fish, and

reptiles may be consumed (McCord and Cardoza

1982, Toweill 1982). Lagomorphs are probably

the main prey item over most of the range of

the bobcat, but there may be distinct regional

differences: deer are commonly fed on in

winter in the Northeastern States (Anderson

1987, Rolley 1987) and the mountain beaver

(Aplodontia rufa), a burrowing rodent, is heavily

used in the Oregon Coast Range (Witmer and

deCalesta 1986). Although bobcats may feed on

deer as carrion, their ability to kill adult deer is

well documented (McCord and Cardoza 1982).

In some cases, bobcats have had a substantial

impact on game populations because of the

amount of predation on deer fawns or pronghorn

antelope (Antilocapra americana) calves

(McCord and Cardoza 1982). Some livestock

depredation occurs—especially with lambs,

goats, and poultry—but the problems usually are

localized and relatively minor (Anderson 1987,

Rolley 1987).

Bobcats are adapted to a wide variety of habitats,

but use “broken and rugged country” to a large

extent (McCord and Cardoza 1982). A mixture

of forested area with openings provides cover

and an adequate prey base (Rolley 1987). Rock

piles and rocky ledges and outcrops provide

important natal dens and shelters, although

brush piles and hollow logs or trees also are

used (McCord and Cardoza 1982, Rolley 1987).

Deep snow (15 cm) restricts the movements of

bobcats (Anderson 1987). Unlike many of the

larger forest carnivore species, bobcats are

fairly compatible with moderate levels of

human activities and development (McCord

and Cardoza 1982).

Relatively few bobcats live to 9 or 10 years

of age in the wild (McCord and Cardoza 1982).

They have moderate reproductive potential;

females are sexually mature at 1 or 2 years of

age and usually have one litter per year of two to

three young (McCord and Cardoza 1982, Rolley

1987). Mortality rates can be relatively high for

kittens and juveniles, especially if prey is not

abundant (Anderson 1987, McCord and Cardoza

1982). Various mammalian and avian predators

can take young bobcats, and adults can be killed

by mountain lions and coyotes. Cannabalism

occurs with bobcats (Anderson 1987, Zezulak

and Minta 1987). Quills from porcupines

(Erethizon dorsatum) also kill some bobcats

(Anderson 1987). Mortality rates in adult bobcats are relatively low (about 3 percent per year),

and harvest by humans accounts for most of that

(McCord and Cardoza 1982, Rolley 1987). Populations can be overharvested, and because of the

inclusion of bobcats in a CITES (Convention

on International Trade in Endangered Species)

appendix, populations and harvests are closely

monitored by state wildlife agencies (Anderson

1987, Gluesing et al. 1986, Rolley 1987). Abundant coyote populations may limit the range and

distribution of bobcats (Anderson 1987), although

the two species can coexist where there is good

habitat and an abundant prey base (Witmer and

deCalesta 1986).

Bobcat Issues in the Basin

Bobcats are widespread in forested and rangeland

areas of the Western United States. A mixture of

habitats and an adequate and diverse prey base

provides for their needs. Bobcats are compatible

with most human land uses. State wildlife agencies must continue to monitor bobcat populations

and harvests to avoid overharvest and to comply

with CITES requirements. Because the habitat

needs of bobcats are easily met and because there

are no serious conflicts between humans and bobcats, no specific issues of concern to conservation

and management of bobcats in the basin were

identified.

7
Lynx (Lynx canadensis)

Ecology

The lynx is holarctic in distribution and

ranges across Alaska and Canada (McCord

and Cardoza 1982, Quinn and Parker

1987). It is absent in unforested areas in

the far north. In the Lower 48 States, lynx

are found in limited areas of north-central

and northeastern Washington, western

Montana and Wyoming, and northern

Colorado (appendix A). In the Midwestern

and Eastern United States, lynx occur at

the northern edge of the country, contiguous with lynx range in Canada that skips

the southern prairies but follows forested

regions to the east. Lynx distribution has

not changed dramatically since historical

times but has receded from historical southern

limits, where its occupancy may have been

somewhat tenuous (Quinn and Parker 1987).

Home range sizes for lynx are reported as about

16 to 20 km2

, with those of males being somewhat larger than those of females (Quinn and

Parker 1987). Home ranges often overlap, but

lynx avoid interaction through temporal separation (Brand et al. 1976, Keith 1974, Nellis

et al. 1972). Factors that contribute to the size

and shape of lynx home ranges include prey and

lynx densities and physiography (Koehler and

Aubry 1994). Lynx often travel 5 to 10 km per

day and may disperse over 100+ km (McCord

and Cardoza 1982).

Lynx are highly dependent on snowshoe hares

as prey but also take voles, mice, squirrels, and

grouse (Quinn and Parker 1987). Snowshoe hares

are particularly important during winter; greater

diversity of diet is available in summer (Koehler

and Aubry 1994). Despite this greater diversity,

snowshoe hares still make up the majority of diet

biomass (Brand et al. 1976). Lynx can thrive on

a diet of only snowshoe hares but will switch to

other prey when hare density declines. Lynx

occasionally will take ungulate prey, especially

young caribou or moose (Saunders 1963). In

Washington, Koehler (1990) found that tree

squirrels represented 24 percent of food items

in lynx diet.

Lynx are found in boreal forest habitats throughout their range (Quinn and Parker 1987). In the

southern portions of their range, lynx are associated with boreal forest typically found in higher

elevations of montane regions (McCord and

Cardoza 1982). Lynx habitat in the mountains

of the Western United States consists of early

successional forest, used as foraging habitat

because of its value to the snowshoe hare, and

late successional forest, containing optimal sites

for denning (Koehler and Aubry 1994). Lynx

use hollow logs, stumps, deadfalls, and caves for

dens (McCord and Cordoza 1982). Lynx require

a mosaic of seral stages of forest connected by

stands suitable for travel cover; foraging habitat

must be near den sites. This habitat is described

as intermediate seral stage forest.

Like bobcats, lynx have a moderate reproductive

potential: females are sexually mature at 1 or

2 years of age and usually have one litter per

year of three to four young (McCord and Cardoza

1982, Quinn and Parker 1987). The bobcat has

expanded its range north since historical times,

and evidence suggests lynx densities will

decrease where bobcats increase (Quinn and

Parker 1987). Several other major competitors

for snowshoe hares exist in the southern limits

of lynx range and include coyotes, foxes, and

raptors; all contribute to the lowered availability

8
of hares to lynx. Roloff2 contends that natural

balance of these predators and prey populations

would be of no concern, but that many of the

competing predators respond positively to

human-induced habitat alteration, and community relations thus are influenced by human

activities to the detriment of the lynx. Lynx may

benefit, however, from alteration of forest habitat

to early seral stages, which provides optimal

habitat to snowshoe hare. Koehler and Aubry

(1994) also state that in undisturbed environments, the lynx may have an advantage over

many potential competitors because it is well

adapted to deep snows at high elevations, but

roads and snowmobile trails increase access

for lower elevation predators to these formerly

remote lynx areas, and thus increase the potential

for competiton. Direct predation on lynx is rare,

but wolves have been documented as predators

on lynx in Scandinavia and Russia (McCord and

Cardoza 1982).

Lynx Issues in the Basin

The largest populations of lynx in the conterminous United States occur in northern Washington and Montana (Koehler and Aubry 1994).

These populations are isolated naturally by the

montane distribution of boreal forests at these

latitudes, and by the distribution of the primary

prey of the lynx, the snowshoe hare, which is

found at lower densities than further to the north.

A number of other predators compete with lynx

at the southern limits of its range for snowshoe

hares, and some of these predators respond

positively to human-induced habitat alteration.

Increased competition for prey will have a

negative impact on lynx. All these factors

increase the vulnerability of lynx populations.

Two issues are of concern for lynx conservation

and management in the basin.

2 Roloff, G. 1995. Canadian lynx (Felis lynx) in Idaho:

habitat conservation assessment and conservation strategy.

13 p. Unpublished report. On file with: Idaho Department

of Fish and Game, 600 S. Walnut, P.O. Box 25, Boise, ID

83707.

Issue 1: Conservation of appropriate mosaics

of seral stages in boreal forest habitat—Lynx

require early seral stage boreal forest habitats, but

stands may not support many snowshoe hares for

10+ years after clearcutting and may not become

optimal hare habitat for an additional 20 years

postharvest (Koehler and Aubry 1994). Snowshoe

hares prefer densely stocked stands of smalldiameter trees. Preferred stands, with highest

hare densities, had reported tree densities of

6,000 to 22,000 stems/ha throughout the range of

the snowshoe hare (Koehler and Aubry 1994).

Only relatively small patches of late-successional

forest are needed to provide denning opportunities

for lynx, but these must be connected by adequate

travel habitat to foraging habitat. Frequent, small

patches of habitat alteration that mimic natural

patterns of disturbance are proposed by Koehler

and Aubry (1994) as a model for lynx habitat

management. Landscape-level planning of the

optimum mix of stand ages is necessary for lynx

conservation, and planning for delay in development of quality, even as foraging habitat, will be

required. Catastrophic wildfire would eliminate

the mix of seral stages that create optimal lynx

habitat, and fire management plans should

recognize this hazard.

The ranges of lynx, bobcats, and coyotes may

overlap, and competition for snowshoe hares

may be of significant concern (Koehler and

Aubry 1994). Alternate prey might alleviate

competitive pressure.

Key environmental correlates—The following

information is available on basin GIS:

• Boreal forest type

1. 10 percent of area (drainage) in

late-successional forest

2. 30 to 50 percent of area in early

successional forest (10 to 30 years old,

≥ 6,000 stems/ha)

3. Remainder of area in intermediate age

classes, with continuity between these 3 types;

that is, no lengthy, wide stands <10 years old

that could serve as barriers to movement

• Fire hazard rating

9
The following information is not currently available on basin GIS:

• Log piles, blowdowns

• Deer fawning areas

• Tree squirrel density

Issue 2: Harvest and human disturbance—

Lynx are protected in most states of the interior

Columbia basin, but they are classified as furbearers in Idaho and Montana (Koehler and

Aubry 1994). Trapping mortality may be critical

in reducing lynx populations below threshold

limits, particularly when populations may be

low naturally because of declining or naturally

low prey populations (Brand and Keith 1979,

McCord and Cardoza 1982). Where lynx are

legally protected, an increase in roads through

lynx habitat increases human access and humanlynx encounters, as lynx also use roads for

hunting and travel (Koehler and Aubry 1994).

Increased road density therefore leads to increases in poaching, road kill, and incidental

mortality of lynx. Additionally, increased

snowmobile use in key lynx habitat may allow

access by other, competing predators.

Key environmental correlates—The following

information is available on basin GIS.

• Road density

1. ≤1.6 km/2.6 km2

2. Highway location and density

The following information is not currently

available on basin GIS:

• Off-road motorized recreational

vehicle use areas

Mountain Lion (Felis concolor)

Ecology

At one time the range of the mountain lion was

perhaps the most extensive of any terrestrial

mammal in the Western Hemisphere, extending

from the southern Yukon of Canada to the tip

of Chile (Dixon 1982, Lindzey 1987). Its range

has declined dramatically in the Eastern and

Midwestern United States; however, it is still

relatively widespread in the Western States,

including the interior Columbia basin (appendix

A; Dixon 1982, Lindzey 1987). The range of

this large, solitary, mobile predator originally

corresponded closely to that of major prey

species—in particular, with the ranges of

ungulates such as mule deer (Odocoileus

hemionus) and white-tailed deer (O. virginianus)—irrespective of habitat or cover type.

There has been a reduction in portions of its

range because of conflicts with livestock and

native ungulate management. More recently, the

removal of bounties, restrictions on mountain

lion harvests, and increasing deer populations

have resulted in increases in the distribution and

densities of mountain lions (Dixon 1982, Lindzey

1987).

Mountain lions are territorial with large home

ranges because of their size and food requirements. Home ranges sizes can be from 120 to

10
1000 km2 for males and 32 to 1000 km2 for

females (Dixon 1982, Lindzey 1987, Seidensticker et al. 1973). Home ranges may overlap

between males and females and between residents

and transients, although resident males seldom

overlap (Lindzey 1987, Seidensticker et al. 1973).

The size of the home range also is related to the

seasonal pattern and density of prey; seasonal

ranges often are much smaller than the annual

range (Dixon 1982, Seidensticker et al. 1973).

Mountain lions (except females with kittens)

are very mobile and can move 10+ km in a day;

young animals may disperse as far as 50+ km

(Lindzey 1987).

Mountain lions are almost exclusively carnivorous, feeding mainly on ungulates (deer, elk,

moose) but also on a variety of smaller mammals, such as porcupines, jackrabbits (Lepus

spp.), snowshoe hares, beaver, ground squirrels

(Spermophilus spp.), marmots (Marmota spp.),

and other small rodents (Dixon 1982, Lindzey

1987). An adult mountain lion will kill, on average, one ungulate every 7 to 10 days; very young

and very old ungulates are most vulnerable

(Dixon 1982, Lindzey 1987). It is not clear

whether mountain lions can regulate ungulate

population densities, although some researchers

speculate that they do (Anderson 1983). Where

available, some mountain lions will prey on

cattle (mainly calves) and sheep (all ages; Dixon

1982, Lindzey 1987). Losses from lions are

rarely significant among all losses across the

domestic livestock industry, although losses

for individual operators may be substantial.

Dispersing young males and older, injured

adult lions seem to account for most of the

depredations. Mountain lions have strong

predatory instincts, and surplus killing and

caching of carcasses is reported (Dixon 1982,

Holt 1994). They also feed on carrion when

and where available (Anderson 1983).

Although mountain lions occupy a wide variety

of habitats and elevations, they seem to prefer

open or mixed forest and shrubby cover types

(Dixon 1982, Lindzey 1987). Within these types,

steep rugged areas with rocky cliffs or ledges are

preferred. Females use a variety of sites in which

to give birth (caves, shallow nooks in rock cliffs,

boulder piles, brush thickets, uprooted trees, or

fallen logs) and require only cover to keep out

heavy rain and hot sunlight (Dixon 1982, Lindzey

1987). Most adult mountain lions avoid roaded

areas, recently logged areas, and areas of human

activity (VanDyke et al. 1986a, 1986b). Increased

sightings and conflicts with lions in urban and

suburban settings may be due to dispersing

juveniles from expanding lion populations.

Mountain lions are long-lived (12+ years) and

have a moderate reproductive potential. Females

are sexually mature by 2.5 years and may bear a

litter of two to three kittens every year, although

birthing occurs every other year in some areas

(Dixon 1982, Lindzey 1987, Lindzey et al. 1994).

Mountain lions can die from several causes (injuries sustained while capturing prey, starvation,

accidents, disease, intraspecific fighting), but

human-caused mortality is usually the largest

source (Anderson 1983, Dixon 1982, Lindzey

1987). As with many mammalian species, the

very young and the very old have the lowest

survival rates. Resident adult lions had an average 74 percent annual survival rate (range 52 to

100 percent) in a study conducted in southern

Utah (Lindzey et al. 1988). Mountain lions in

areas of good habitat can respond relatively

quickly with density increases when hunting

pressures are removed (Ross and Jalkotzy 1992).

Mountain lions compete with other forest carnivores for prey, but they are probably rarely

killed or injured by other carnivores. Wolves are

known to kill mountain lions (Boyd and Graham

1992, Paquet and Hackman 1995). Mountain

lions will kill smaller carnivores such as bobcats, coyotes, and foxes (Boyd and O’Gara

1985, Lindzey 1987).

11
Mountain Lion Issues in the Basin

Mountain lions are widespread in forested,

mountainous areas of the Western United States.

To maintain viable populations, lions require

areas of abundant prey and cover and relatively

little human activity. Overharvest by humans

is a concern in some areas; however, where lion

harvests have ceased or been severely restricted

and ungulate prey densities have grown, increased

lion densities have rapidly occurred with an increase in conflicts with humans. Two issues are

of concern to conservation and management of

mountain lions in the basin.

Issue 1: Provision of appropriate habitat and

adequate prey—Mountain lions can thrive in

many habitats and on several prey species. Where

humans are present and alter habitats or prey

abundance, or overharvest lions, lion population

density may decrease and become vulnerable to

local extirpation. Regulation of lion harvest,

maintenance of tree and shrub cover, and

provision of an abundant and diverse prey

base will provide the needs of mountain lions,

especially in rugged, remote forested areas. It

is important to not overharvest, or otherwise

substantially reduce, important prey populations

(especially ungulates). Adequate corridors for

dispersal and interaction of subpopulations must

be provided to maintain population viability

(Beier 1993, 1995). Highways can reduce the

effectiveness of forested corridors as dispersal

routes (Paquet and Hackman 1995). Mountain

lion requirements for dispersal corridors have

not been well studied or defined; however, they

appear to be easier to meet than those for other

large, far-ranging forest carnivores, such as

grizzly bears and wolves.

Key environmental correlates—The following

information is available on basin GIS:

• Forest cover, structure, interspersion

• Ungulate ranges

• Physiography (slope, elevation)

• Forested corridors

• Highways

The following information is not currently

available on basin GIS:

• Ungulate densities, harvests

• Mountain lion harvest units, limits

Issue 2: Reduction of conflicts with humans—

Many sociopolitical pressures affect the management of mountain lion populations (Mansfield

1994). Many people want to have mountain lion

populations nearby, and urban-suburban and

recreational expansion into mountain lion

habitats is increasing with resultant increases

in attacks on humans and livestock (Paquet and

Hackman 1995). Precautions, such as not letting

a lone individual hike ahead of the group and

responding aggressively to a lion encounter,

must be taken to reduce the increasing number

of attacks on humans (Beier 1991, Hanson 1995).

Key environmental correlates—The following

information is available on basin GIS:

• Human density

• Road density

• Agricultural lands

The following information is not currently

available on basin GIS:

• Livestock grazing areas, densities

• Campgrounds, recreational developments

• Trail locations, densities

12
Fisher (Martes pennanti)

Ecology

Fishers occur only in North America. The

southern extent of their range from Illinois

to Virginia was severely restricted by the

early 1900s by habitat loss induced through

logging, fire, and settlement (Douglas and

Strickland 1987). Trapping further reduced

fisher populations on their shrinking range.

In the interior Columbia basin, fishers occur

primarily in the Cascade Range and Rocky

Mountains (appendix A).

Home range sizes in Idaho average 83 km2 for

male fishers and 41 km2 for females (Jones 1991)

and probably reflect true space requirements for

the species in the northern Rocky Mountains

(Heinemeyer 1993). In California, Buck et al.

(1979) found male fishers have home ranges

of 18 km2

, and female home ranges average

3.6 km2

. These studies represent the extent of

available research to date into fisher home ranges

in the Western United States. Home ranges of

fishers frequently overlap, although there may

be temporal separation of adults of the same sex

(Coulter 1966, de Vos 1951, Kelly 1977, Powell

1977). Fishers probably can disperse 40+ km.

Fisher diet is varied throughout the range of

the species (Martin 1994). The most important

fisher foods reported in the literature include

snowshoe hares, porcupines, deer, passerine

birds, and a variety of vegetation. Redback

voles (Clethrionomys spp.), red squirrels

(Tamiasciurus hudsonicus), and shorttail

shrews (Blarina brevicauda) also have been

reported in fisher diets. Seasonal changes in

fisher diets have not been documented with

clarity, although it is likely that this opportunistic

predator exhibits seasonality in diet (Martin

1994). In Idaho, mammalian prey had the highest

frequency of occurrence in the diet of fishers, and

included snowshoe hares, red squirrels, redback

voles, and beaver (Jones 1991). Similarly, diets

of fishers in Montana were dominated by snowshoe hares and carrion, with a variety of small

mammals also representing large portions of the

diet (Aune and Schladweiler 1993, Roy 1991).

Carrion may be a seasonally important food item,

particularly during winter.3 Additionally, prey

switching was observed in Idaho by Jones (1991),

where fishers frequently took red squirrels more

often in winter, when voles probably were less

available.

Fishers usually are found in mixed forests with

a diversity of tree species and ages. The diverse

diet of the fisher probably requires a mix of forest

habitat types for optimal habitat (Arthur et al.

1989). Johnson (1984) reported that fishers in

Wisconsin often used areas of interspersion, most

likely because prey were more diverse at habitat

edges.

Fishers select habitats with relatively high canopy

cover (Powell 1982). Fishers preferred closed,

multilayered fir stands in northwestern California,

and avoided hardwood stands (Buck et al. 1979).

Fishers have used diverse forest habitats in

Washington, but these also have relatively high

canopy cover (Aubry and Houston 1992). In

Idaho and Montana, mesic forest habitats at low

or mid elevations are important fisher habitat

(Jones 1991, Heinemeyer 1993). Deep snow

accumulation, as typically occurs at high

elevations, appears to limit fisher movements

and distribution (Arthur et al. 1989, Aubry and

Houston 1992, Heinemeyer 1993). Riparian

corridors are especially important habitat, serving

as travel corridors and providing rich habitat

for fisher prey (Buck et al. 1979, Jones 1991,

Heinemeyer 1993).

3 Heinemeyer, K.; Jones, J. 1994. Fisher biology and

management in the Western United States: a literature

review and adaptive management strategy. 109 p.

Unpublished report. On file with: Department of

Agriculture, Forest Service, Northern Region. Federal

Building, P.O. Box 7669, Missoula, MT 59807.

13
Fishers have a moderate reproductive potential;

they are sexually mature at 1 or 2 years of age,

usually have one litter per year of three young,

and remain sexually active to 8+ years of age

(Douglas and Strickland 1987, Strickland et al.

1982b). Fishers may compete for food with

coyotes, foxes, bobcats, lynx, martens, wolverines

(Gulo gulo), and weasels (Mustela spp.) (Powell

and Zielinski 1994). Martens and fishers are the

most likely direct competitors, as both are capable

of hunting arboreally. Sympatry has been documented in Idaho and California (Powell and

Zielinski 1994). Fishers may have a competitive

advantage because of their larger size, although

the smaller marten can specialize on voles

(Martin 1994), and it is difficult to accurately

predict the impact of sympatry and competition

on populations. Management objectives for

both species for a single land unit may conflict,

however.

Fisher Issues in the Basin

The status of the fisher in the Western United

States is poorly known but generally perceived

as precarious and declining (Powell and Zielinski

1994). This is a serious issue alone, but it also is

a component of the larger problem of the decline

of biological diversity (Wilson 1988). Recovery

of species of concern must necessarily focus on

the population level, because this is the scale at

which genetic variation occurs and because population are the constituent elements of communities

and ecosystems.4 Systematic habitat alteration

and overexploitation have reduced the historical

distribution of fishers in suitable habitat in the

interior Columbia basin to isolated and fragmented populations. Current populations may

be extremely vulnerable to local and regional

extirpation because of their lack of connectivity

and their small numbers. Four issues are of

concern to fisher conservation and management in the basin.

4 Weaver, J. 1993. Lynx, wolverine, and fisher in the

Western United States. 132 p. Unpublished report. On

file with: U.S. Department of Agriculture, Forest Service,

Northern Region, Federal Building, P.O. Box 7669

Missoula, MT 59807.

Issue 1: Conservation of late successional

forest at low to mid elevations—The range

and population levels of the fisher have declined

substantially in the past century, primarily the

result of trapping pressure and habitat alteration

through logging (Powell and Zielinski 1994).

Additionally, large-diameter logs and snags are

critical habitat features for fishers, providing

maternal and natal dens, and these features are

particularly vulnerable to decline in availability

in harvested forest landscapes. Finally, conservation of fishers will require areas of suitable

habitat large enough to hold a minimum number

of contiguous fisher home ranges. Past decades

of timber harvest in many areas of the basin

have fragmented forest habitat, thereby reducing

the contiguous area and creating barriers to

movement.

Fishers probably can tolerate small patch cuts

or other small-scale disturbances, provided these

occur in a larger matrix of relatively dense, closed

canopy, late successional forest (Powell and

Zielinski 1994). Such openings might even

increase the value of habitat by providing a

diversity of prey, which will support a diverse

diet for fishers.

Key environmental correlates—The following

information is available on basin GIS:

• Coniferous forest

1. ≥20 percent of unit mature forest

2. ≥40 percent additional heterogenous aged

forest

The following information is not currently

available on basin GIS:

• Coarse woody debris

1. Medium to high fuel loadings

2. Large logs

Issue 2: Maintenance of links between populations—Fishers can travel relatively long

distances, and daily movement of 5 to 6 km

has been documented repeatedly (Johnson 1984,

Jones 1991, Kelly 1977, Roy 1991). Barriers

to movement may include large nonforested

openings and highways. Maintenance of links

between individuals and populations will require

elimination or reduction of these barriers.

14
Key environmental correlates—The following

information is available on basin GIS:

• Nonforested habitat

• Highway location and density

Issue 3: Maintenance of riparian corridors for

use by individuals and populations—Riparian

corridors are documented as important habitat

for fishers in several studies. They provide travel

routes and often are found at the lower elevations

fishers prefer within a given area. The high canopy cover and structural complexity of riparian

habitat support relatively abundant and diverse

populations of small mammals and birds, and

these sites may be important prey patches for

fishers.

Key environmental correlates—The following

information is available on basin GIS:

• Riparian corridors (≥3d order streams

available only)

The following information is not currently

available on basin GIS:

• Riparian corridors, 1st and 2d order streams

Issue 4: Trapping pressure and human

disturbance—Fishers are formally protected

in Washington and Oregon, and the trapping

season has been closed in Idaho, although fishers

do not have special status in that State (Powell

and Zielinski 1994). Montana has had a trapping

season for fishers with a quota of 20 animals.

Fishers have relatively low fecundity, with

females typically giving birth to only two young

per year. Population sustenance and growth

depend, then, on long-term adult survivorship

(see footnote 4). This survivorship rate is

imperiled in commercially exploited populations.

Key environmental correlates—The following

information is available on basin GIS:

• Road density ≤1.6 km/2.6 km2

The following information is not currently

available on basin GIS:

• Allowable fisher harvest by area

• Recent harvest data by area

American Marten

(Martes americana)

Ecology

The American marten occurs only in North

America but is closely related to three Eurasian

species of Martes. Its geographic distribution

ranges to the limit of trees in the Canadian and

Alaskan north and as far south as northern New

Mexico. In the Western United States, marten

distribution is closely associated with latesuccessional mesic coniferous forest. The

distribution of martens in Washington and

Oregon has been reduced in recent decades,

apparently the result of habitat alteration by

logging (Buskirk and Ruggiero 1994). Martens

occur in portions of the Cascade Range and

Rocky Mountains within the interior Columbia

basin (appendix A).

Numerous studies using both mark-recapture

techniques and radio telemetry have found

similar sizes for marten home ranges: male

home range sizes reported in studies conducted

in the Western United States are from 0.8 to

4.9 km2 (Burnett 1981, Hawley and Newby

1957, Martin 1987, Spencer 1981). In these same

studies, home range sizes for females are roughly

half the size of male home ranges and range from

0.7 to 3.4 km2

. Home ranges frequently overlap

both between and among sexes. Martens may

disperse 40 to 60+ km (Strickland and Douglas

1987).

15
Voles are the most important food item in the

diet of American marten throughout their range

(Martin 1994). Diets vary tremendously and

often include shrews, deer mice (Peromyscus

maniculatus), red squirrels, heather voles

(Phenacomys intermedius), northern flying

squirrels (Glaucomus sabrinus), northern

pocket gophers (Thomomys talpoides), fish,

ungulates (as carrion), and Douglas squirrels

(Tamiasciuris douglasii). Diet is influenced

by seasonal availability of some food items.

Insects and fruit are eaten when available.

Marten prefer mature, mesic coniferous forests,

with high structural diversity in the understory

layers (Buskirk and Powell 1994, Buskirk and

Ruggiero 1994). Structural diversity is contributed by coarse woody debris, the lower

branches of living trees, and shrubs. These

features provide resting sites for martens,

subnivean access to prey habitat in winter,

and predator avoidance cover (Buskirk and

Ruggiero 1994). Forests lacking structural

diversity, especially at ground level, are used

little or not at all by martens. Preference for

late-successional mesic forests is even more

pronounced in winter, although martens are

not migratory and home ranges do not shift

(Campbell 1979, Soutiere 1979, Steventon

and Major 1982). Dependence on access to

subnivean prey provided by the complex

structure of these forests, and the need for

thermally superior coarse woody debris as

resting sites in cold temperatures, may limit

habitat use by martens to these forest types

in winter (Buskirk and Powell 1994).

Martens have a moderate reproductive potential;

like fishers, they are sexually mature at 1 or 2

years of age, usually have one litter of three

young per year, and can be sexually active to

12+ years of age (Strickland et al. 1982a).

Martens are vulnerable to predation because

of their relatively small size, and predator

avoidance cover has been noted as important

to optimal marten habitat by many researchers.

Raptors and owls are considered potential

predators on martens (Buskirk and Ruggiero

1994). Fishers also have been documented as

predators on martens (deVos 1952, Raine 1981).

Fishers are likely to be important competitors

with martens for prey, where the two mustelids

are sympatric, as both feed on a variety of voles

and other small mammals. Both mustelids are

capable of arboreal hunting, as well, and may

compete for squirrels. Sympatry of these two

mustelids is documented in Idaho and California

(Powell and Zielinski 1994).

Marten Issues in the Basin

Marten populations are among the least compromised of all mustelids in the interior Columbia

basin, though the current range of the species

is reduced from historical limits throughout the

United States (Buskirk and Ruggiero 1994).

The range of the marten has been especially

fragmented in the Cascade Range as a result

of habitat alteration by forest harvest. Marten

range in the Rocky Mountains seems to be

similar to historical distribution. Three issues

are of concern to marten conservation and

management in the basin.

Issue 1: Conservation of late successional

forest—Research throughout the range of the

marten has demonstrated the negative effects

of timber harvest activities involving the substantial modification or removal of overhead

canopy across large areas (Strickland and Douglas

1987, Strickland et al. 1982a). Thompson and

Harestad (1994) reviewed 10 studies of marten

habitat selection and found that martens consistently use early seral stage forests (shrub, sapling,

and pole stage areas) relatively less than their

availablility might indicate. They found that in

all studies, only overmature stands are consistently preferred. Timber harvest reduced the value

of forest habitat to martens through removal of

overhead cover, removal of large-diameter coarse

woody debris, and the conversion of mesic sites to

xeric conditions (Buskirk and Ruggiero 1994).

Additionally, catastrophic loss of late successional forest from wildfire is a concern because

of the negative impact it would have on the conservation of martens and other wildlife associated

with these habitats.

Little evidence yet exists to document the effects

of forest fragmentation on martens. Relatively

small home range sizes and tolerance of home

range overlap suggest that martens may be capable of persisting in fragmented landscapes with

blocks of forest large enough to accommodate

16
multiple home ranges. Martens will not, however,

travel far from substantial overhead forest cover,

and thus direct links among remaining suitable

habitat blocks are essential. Little is known about

the effects on martens of increased edge and the

reduction of forest interior that occurs with fragmentation. If these factors are detrimental to

martens, it would further strengthen the need for

conservative management of the forest landscape

harboring marten populations. Large blocks of

contiguous late successional forest provide suitable habitat, and it is unknown at what point

fragmentation eventually creates unsuitable

habitat (Buskirk and Ruggiero 1994).

Large-diameter snags, logs, and stumps provide

important resting sites for marten (Martin and

Barrett 1991). These authors recommend that

snags and logs ≥80 cm be preserved for martens

in any timber harvest. Coarse woody debris also

provides habitat for prey species. Timber harvest

typically reduces the density of large-diameter

woody debris and the potential population from

which these features are recruited.

Key environmental correlates—The following

information is available on basin GIS:

• Contiguous late successional coniferous forest

1. ≥60 percent of unit

2. Relatively low fragmentation

• High average canopy closure (≥60 percent)

• Fire hazard rating

The following information is not currently

available on basin GIS:

• Coarse woody debris

1. Large (≥81 cm diameter, 10 m length),

intact, moderately decayed logs

2. Large (≥81 cm diameter, 4.3 m tall), intact,

moderately decayed snags

3. Slash piles

4. Squirrel middens

• Understory (woody stem density)

Issue 2: Maintenance of links between populations—Martens will not use habitat with

minimal canopy cover. Forested travel corridors

are essential for maintaining links among individuals and populations. Paved roads may not be

significant barriers to movement, but mortality

caused by vehicles on highways is documented

(Martin 1987, Spencer 1981). This mortality

factor may be incidental, but if populations

decline and viability is at risk, any source of

mortality will be a concern.

Key environmental correlates—The following

information is available on basin GIS:

• Nonforested habitat

• Road type, location and density

Issue 3: Trapping pressure and human disturbance—Martens are trapped commercially

in most states of the basin (appendix C). The

species is considered sensitive by the State of

Oregon, and receives specific attention during

management planning and implementation by

the USDA Forest Service at most National Forests

in the basin. These plans and regulations differ

with Forest Service Region, but all identify the

need to maintain late successional forest habitat

to support viable marten populations. The need to

coordinate habitat management with population

management, to ensure population viability, will

require interagency cooperation.

Key environmental correlates—The following

information is available on basin GIS:

• Road densityall roads, ≤1.6 km/2.6 km2

The following information is not currently

available on basin GIS:

• Allowable marten harvest by area

• Recent harvest data by area

17
River Otter (Lutra canadensis)

Ecology

River otters range from Florida to Alaska, but

have been extirpated from more than one-third

of their historical range, which included most

of the North American continent (Melquist and

Dronkert 1987). Extirpation has occured most

dramatically in the central portion of the continent, and in the Southwestern United States. In

the interior Columbia basin, river otters occur

widely, but at low densities, in various river

systems (appendix A).

River otters depend on aquatic and semiaquatic

habitats, and their home ranges reflect this dependence in shape and size. Home range sizes

ranged from 8 to 78 km2 in Idaho (Melquist

and Hornocker 1983) and were reported as 20 to

57 km2 in Colorado (Mack 1985). Overlap of

home ranges among and between sexes was

extensive in the Idaho study. River otters may

travel 10+ km per night (Toweill and Tabor

1982).

Fish are the most important prey of river otters

(Melquist and Dronkert 1987, Melquist and

Hornocker 1983, Toweill and Tabor 1982).

Additionally, otters consume crustaceans,

reptiles, amphibians, birds, insects, and mammals. Competition with other mammals for food

has not been documented (Melquist and Dronkert

1987, Melquist et al. 1981). In Idaho, negative

impacts of river otters on prey populations of fish

were not found (Melquist and Hornocker 1983).

Aquatic habitats associated with areas ranging

from coastal intertidal zones to freshwater

streams and lakes provide river otters with

suitable habitat (Melquist and Dronkert 1987,

Toweill and Tabor 1982). River otter density

seems to be related conversely with pollution

levels and associated human density (Toweill

and Tabor 1982). In the northern regions of

their continental range, otters are limited by the

availability of winter habitat, which is defined

by open water that provides access to foraging

areas (Reid et al. 1994). Riparian areas adjacent

to water also are important components of river

otter habitat. One key factor is the riparian zone’s

attraction to beavers, who create lodges and dam

pools that provide habitat for many prey of the

otters. The dependence of river otters on beavers

for both provision of den sites (abandoned beaver

lodges) and creation of prime habitat (dammed

pools) is noted by many researchers (Bradley

1994, Melquist and Dronkert 1987, Melquist

and Hornocker 1983, Reid et al. 1994).

River otters have a low to moderate reproductive potential; they usually have a litter of three

young but may not breed every year (Toweill

and Tabor 1982). They usually mature sexually

by age 2 and may live 10 to 15 years in the wild

(Melquist and Dronkert 1987). Although no predator is documented as having significant impact

on river otter populations, several carnivores are

reported to have killed river otters; these include

bobcats, coyotes, foxes, mountain lions, wolves,

and black bears (Toweill and Tabor 1982).

River Otter Issues in the Basin

A rising concern for the conservation of aquatic,

riparian, and wetlands habitats bodes well for

the river otter throughout North America. Many

wildlife agencies have conducted reintroduction

programs for otters in recent years, as well

(Melquist and Dronkert 1987). Counteracting

forces, including habitat loss and water pollution,

will continue to work against otter conservation;

river otter fur has been highly prized by fur

trappers for centuries, and trapping will continue

to have direct impact on harvested populations.

River otters are harvested in most states of the

basin (appendix C). Three issues are of concern

to river otter conservation and management in

the basin.

Issue 1: Conservation of aquatic and riparian

habitat—River otters cannot use relatively

food-poor small mountain streams in forested

areas of the Western United States and thus

are dependent on adequate habitat along larger

18
waterways. Beavers create important habitat

features and suitable habitat (pools) for river

otters, and conservation of this species will

also benefit otters.

Key environmental correlates—The following

information is available on basin GIS:

• Rivers, lakes, estuaries, ≥3d order streams

The following information is not currently

available on basin GIS:

• Water quality

• Coarse woody debris

1. Large hollow logs

2. Log piles

• Beaver density

Issue 2: Maintenance of links among

populations—River otters have been

documented as dispersing 42 km overland

in Idaho (Melquist and Hornocker 1983).

Barriers in the form of inhospitable habitat

are not known. Although most movement of

river otter in Idaho followed streams, ridges

separating drainages also were traversed by

otters carrying radio telemeters.

Key environmental correlates—Because

information is limited, there are no specific

environmental correlates that can be used

to monitor habitat for support links among

otter populations at this time. It is possible

that the presence of beaver and year-round

open water might serve as correlates.

Issue 3: Trapping pressure and human disturbance—Human-related mortality causes

include trapper harvest, road kills, accidental

trapping, and poaching (Melquist and Dronkert

1987). Human activities that lead to water

pollution also may impact river otters, both

indirectly (through the food chain) and directly.

Several studies have documented significant

levels of mercury, DDT, and PCBs in river

otters, and Henny and others (1981) believe that

a decline in otter populations along the Columbia

River in Oregon was caused by PCB poisoning.

Key environmental correlates—The following

information is available on basin GIS:

• Road density ≤1.6 km/2.6 km2

The following information is not currently

available on basin GIS:

• Water quality

• Allowable river otter harvest by area

Wolverine (Gulo gulo)

Ecology

The wolverine is circumpolar in distribution,

and is found in the arctic tundra and across

forested Alaska and Canada in the north. The

continental range of the wolverine extends

through boreal montane habitats at the southern

limits of its range in eastern and central Canada,

the Northwestern United States, and south

along mountain ranges to Arizona and New

Mexico (Hash 1987, Wilson 1982). Current

range has receded from the historical extent

of the species in North America, with notable

declines in eastern Canada and the prairie provinces. In the Western United States and the interior Columbia basin, wolverines occur widely

at very low densities, but only in northwestern

Montana are wolverine populations considered

to be healthy and thriving5 (appendix A).

5 Butts, T. 1992. Wolverine (Gulo gulo) biology and

management: a literature review and annotated bibliography. 106 p. Unpublished report. On file with:

U.S. Department of Agriculture, Forest Service,

Northern Region, Federal Building, P.O. Box 7669,

Missoula, MT 59807.

19
Reported home range sizes for wolverines

generally are large. Wolverines are capable of

sustained travel, and coverage of 30 to 60 km

in a few days is documented (Wilson 1982).

Home ranges for males in northwestern Montana

averaged 422 km2 and for females, 388 km2

(Hornocker and Hash 1981). Lactating females

in the same study had considerably smaller home

ranges of 100 km2

. Similarly large home ranges

of hundreds of square kilometers have been

reported in Alaska (Magoun 1985). In a study in

the Yukon, Banci (1987) found markedly smaller

home ranges than in Alaska or Montana and

theorized that the wolverines had localized

access to adequate food and mates. Home range

sizes of wolverines in Idaho were reported as

80-700 km2 for females and more than 2000 km2

for resident males.6 Some researchers have

found evidence of intrasexual territoriality in the

wolverine (Magoun 1985, Powell 1979), but

Hornocker and Hash (1981) found only temporal

segregation of wolverines in Montana, with

extensive overlap of home ranges.

A large proportion of the wolverine diet is a

variety of ungulates, primarily taken as carrion

(Banci 1987, 1994; Hash 1987; Rausch and

Pearson 1972; Wilson 1982). Ungulate carrion

seems to be particluarly important to wolverine

diet in late winter and early spring. Wolverines

also can kill ungulate prey, as well as smaller

animals, including marmots and ground squirrels,

and ptarmigan (Lagopus spp.) and other birds

(Hash 1987, Magoun 1985, Wilson 1982).

The noted importance of ungulate carrion to

wolverines probably requires long scavenging

treks and may be one factor leading to the large

home ranges reported by researchers. Hornocker

and Hash (1981) report that wolverine density

was greatest in their Montana study area where

ungulate diversity was highest. The same area

also supported snowshoe hares, hoary marmots

(Marmota caligata), and a variety of small

mammals. Winter range of wolverines was

focused on ungulates winter range in the area.

6 Copeland, J.; Harris, C. 1994. Wolverine ecology and

habitat use in central Idaho. 26 p. Unpublished report.

On file with: Idaho Department of Fish and Game,

600 S. Walnut, P.O. Box 25, Boise, ID 83707.

Many authors define wolverine habitat worldwide as boreal forest and tundra ( Hash 1987,

Wilson 1982). Wolverines occupy mixed coniferous forest habitats in coastal regions from

southeastern Alaska to southern British Columbia, in the Cascade Range and Sierra Nevada,

and in the Rocky Mountains (Hash 1987). The

wolverine is found in boreal forest across Canada

in middle and southern latitudes; tundra is the

predominant vegetation type in the northern

range of the species. The majority (70 percent)

of locations of wolverines carrying radio telemeters in a study in Montana were in forests

with medium to low canopy cover (Hornocker

and Hash 1981). Wolverines selected forests

dominated by subalpine fir (Abies lasiocarpa

Hook. (Nutt.)), and rarely used dense young

timber, burned areas, or wet meadows. Copeland

and Hudak7 report that wolverines in Idaho prefer

mature montane forest in association with subalpine rock and scree habitats. Wolverines use

a variety of habitat features as dens, including

exposed tree roots, rock piles, caves, and log

falls (see footnote 5). Female wolverines used

subalpine talus sites for natal dens in Idaho

(see footnote 6).

Wolverines are associated with remote areas

with little disturbance by humans ( Groves 1988,

Hash 1987). Hornocker and Hash (1981) report

that wolverines are reluctant to cross large openings, including clearcuts. Although wolverines

reportedly avoid areas of human habitation, they

may cross these areas during their travels, usually

under cover of night (Hash 1987). Banci (1994)

notes that wolverines feed at community garbage

dumps in the Canadian north and that they occupy

logged forests in British Columbia. Banci (1994)

suggests that some as-yet-unknown combination

of factors dictate wolverine presence, and lack

of human activity alone is not adequate to define

suitable wolverine habitat.

7 Copeland, J.; Hudak, H. 1995. The wolverine (Gulo gulo)

in Idaho: Habitat conservation assessment and conservation

strategy. 21 p. Unpublished report. On file with: Idaho Department of Fish and Game, 600 S. Walnut, P.O. Box 25,

Boise, ID 83707.

20
Wolverines have a low-to-moderate reproductive

potential, reaching sexual maturity at 1 or 2 years

of age and usually bearing a litter of two to three

young per year (Wilson 1982). Poor breeding

success and high juvenile mortality may contribute to low reproductive output (Hash 1987).

Wolverines have no known natural predators,

and the main causes of mortality are humaninduced ones (Banci 1994, Hash 1987, see

footnote 7). Wolverines probably benefit from

predatory activities of other large carnivores and

garner ungulate carrion from those kills. Some

direct mortality of wolverines by wolves and

mountain lions has been documented, but it

likely is a minor mortality factor (Banci 1994,

Hornocker and Hash 1981, see footnote 6).

Wolverine Issues in the Basin

In all states of the interior Columbia basin except

Montana, the wolverine is legally protected from

harvest because it is considered rare (see footnote 5). Montana continues to classify the wolverine as a furbearer, and an annual harvest is

allowed. Total annual harvests over the past 30

years have averaged between 10 and 15 animals,

with as few as 5 taken in one year (1991) and as

many as 58 (1976). The USDA Forest Service

considers the wolverine a sensitive species, with

population viability a prime concern. The low

densities of the wolverine and its dependence

on remote habitat continue to make this species

vulnerable to local and regional extinctions. Some

authors suggest that there is no justification for

any continued harvest of wolverines in the Lower

48 States because the minimal current harvest

offers little economic or recreational return and

only adds to negative pressures on the species

(Wilson 1982, see footnote 5). Wolverine populations in northwestern Montana have a good

probablility of persistence in the near future,

because of their continuity with protected areas

in Canada (Banci 1994). Populations in other

areas within the basin, including Idaho and

Oregon, are more isolated and thus more vulnerable to extinction. Three issues are of concern

to wolverine conservation and management in

the basin.

Issue 1: Maintenance of large, remote areas

of habitat—The wolverine’s dependence on

suitable habitat in remote areas, with little or

no human disturbance, is notable. Additionally,

wolverines appear capable of repopulating habitat

from suitable refugia (Allen 1987, Hash 1987).

Banci (1994) suggests other, currently unknown,

habitat factors act in concert with lack of disturbance to create optimal wolverine habitat, and

our lack of knowledge is a critical problem for

successful wolverine conservation. Successful

habitat management for wolverines may actually

involve managing for many prey species on which

wolverines depend, and Butts (see footnote 5)

noted that wolverine conservation requires ecosystem conservation. A wide variety of habitat

types, supporting a variety of ungulate, small

mammal, and avian prey, therefore are necessary

for viability of individual, and populations of,

wolverines.

Maintenance of forested areas within wolverine

habitat will be necessary to provide security

cover; travel corridors between such areas should

be provided. Any activities affecting or altering

montane boreal habitats may have negative

impacts on wolverines (see footnote 7). Many

types of habitat alteration have probably reduced

the quality of or eliminated wolverine habitat,

including agriculture, cattle grazing, forestry,

oil exploration, human settlement, and human

population growth (Banci 1994). The impression

that wolverines require high-altitude habitat may

be caused by the remaining wolverines in populations stressed by human activities retreating

to the least accessible, currently undeveloped

territory, which is often at high elevations.

Little is known about the continuity or fragmentation of wolverine populations south of Canada,

and little information exists on potential barriers

to movements (see footnote 7). In this vacuum of

knowledge, there is a high probability that habitat

alteration will negatively impact persistence of

wolverine populations. If populations become isolated, susceptiblity to local extinction increases.

Wolverines have low birthrates, with low percentages of females becoming pregnant each year

and small litter sizes (Banci 1987, Hash 1987,

Hornocker and Hash 1981, Magoun 1985, Rausch

and Pearson 1972). Low reproductive output

contributes to the vulnerability of wolverine

populations to local extinction.

21
Recreational development in mountainous areas

may be especially injurious to wolverine conservation. In Idaho, subalpine cirques have been

identified as key areas for wolverines because of

their use for natal denning (see footnote 7). Ski

area development in particular poses a threat

to wolverines, because use of these cirques for

recreational purposes would make them unavailable for isolation-dependent wolverines.

Key environmental correlates—The following

information is available on basin GIS:

• Habitat types

1. Alpine and subalpine types

2. Coniferous forests

• Wilderness and large roadless areas

• Human density

The following information is not currently

available on basin GIS:

• Coarse woody debris

1. Large snags

2. Large logs

3. Log piles

• Rocky habitat

1. Scree and talus slopes

2. Caves

• Trail density

• Off-road motorized vehicle areas

• Rural homesite density

• Recreational developments

• Back-country campgrounds

• Oil, gas, and mining exploration and

extraction sites

Issue 2: Prey populations—Areas of high ungulate density, and especially winter range, are

probably key in identifying suitable wolverine

habitat in mountainous regions. Activities that

decrease ungulate density may negatively impact

wolverines (Banci 1994); these include excessive

hunter harvest and poaching and habitat alteration that decreases quality for ungulates. Livestock losses on grazing allotments may provide

carrion sources for wolverines (see footnote 7).

Key environmental correlates—The following

information is available on basin GIS:

• Grazing allotments

The following information is not currently available on basin GIS:

• Ungulate density and winter range areas

• Ungulate harvest by area

Issue 3: Incidental trapping and predator

control mortality—Wolverines are easily

attracted to lures and baits and, thus, may be

subject to injury or direct mortality as a nontargeted species on trap lines set for species

of similar or larger size than wolverines (see

footnote 7). It is thought that all or most of the

recent legal harvest of wolverines in Montana

has been incidental take in traps set for other

species (Banci 1994). Additionally, use of

sodium cyanide in M-44 delivery systems for

coyote control (Green et al. 1994) may unintentionally impact wolverines.

Key environmental correlates—The following

information is not available on basin GIS:

• Areas and target species of legal harvest

• Areas under predator control with sodium

cyanide

Black Bear

(Ursus americanus)

Ecology

Black bears range throughout much of eastern

and western North America, especially in forested

areas of rugged topography (Kolenosky and

Strathearn 1987, Pelton 1982). Historically,

they have been considered a pest and a threat

to human life and property and, hence, were

extirpated or reduced to very low numbers in

many Eastern and Midwestern States (Pelton

1982). They are considered common in the

Pacific Northwest, Rocky Mountains, and all

Canadian provinces. They occur throughout

the interior Columbia basin except for the open,

semiarid Columbia basin plateau (appendix A).

22
Home range sizes are variable, from 10

to over 100 km2 (Kolenosky and Strathearn

1987, Pelton 1982). Black bears are longlived (20+ years) and usually use the same

areas throughout their lives (Amstrup and

Beecham 1976). Except for sows with cubs,

bears are solitary, so densities are usually

low, about one bear per 2 to 14 km2 (Pelton

1982). Densities and home range sizes are

closely related to food availability.

Black bears are omnivores and their

diet varies seasonally (Kolenosky and

Strathearn 1987, Pelton 1982). In spring,

they feed on grasses, carrion, and in some

areas, on the cambium layer of trees. They

feed on young ungulates and livestock as well.

In summer and fall, they feed on forbs and the

fruits of various trees and shrubs. They also

consume insects when concentrated sources are

available. Bears must put on substantial weight

to survive the 5- to 6-month winter hibernation.

Consequently, they spend much time in energyrich (high fat and carbohydrate levels) areas such

as berry patches, meadows, avalanche chutes,

riparian areas, garbage dumps, and sites where

colonial insects occur (Elowe and Dodge 1989).

Thus, a close relation exists among habitat use,

movements, and behavior by the bears, and plant

phenology (Amstrup and Beecham 1976, Rogers

1987).

Black bears use a variety of habitats but prefer a

mix of forested and open areas (Kolenosky and

Strathearn 1987, Pelton 1982). Open areas with

mesic vegetation are used for foraging, as are

areas with thick, brushy understories and berries

or other mast (Unsworth et al. 1989). Bed sites

are usually in uncut forest stands: coniferous,

mixed, or aspen stands (Irwin and Hammond

1985, Unsworth et al. 1989). Black bears avoid

rock talus areas and sagebrush-grass areas.

Den sites are important for bear survival. Uncut

forest is used and most dens are excavated in the

ground or under the roots of fallen trees (Tietje

and Ruff 1980). Large-diameter snags or downed

logs also may be used (Pelton 1982, Tietje and

Ruff 1980).

Black bears are fairly adaptible and can coexist

with humans if the bears are not overharvested

(Kolenosky and Strathearn 1987, Pelton 1982).

In most cases, hunters are the main source of bear

mortality. Bears are active mostly from dusk until

dawn, thereby minimizing contact with humans

(Amstrup and Beecham 1976, Pelton 1982).

Conflicts are more likely to occur when natural

food sources are poor (Pelton 1982).

Bears have a low reproductive potential. Females

do not have their first litter until they are 3 to 6

years old; typically, a litter of two to three cubs

is born every 2 to 5 years (Pelton 1982, Rogers

1987). Cub mortality rates are often 40 to 50

percent, and this increases to about 60 percent for

subadults, especially males (Elowe and Dodge

1989). Young bears can die from several causes,

but many are killed by adults bears as the young

disperse and attempt to establish a territory

(Kolenosky and Strathearn 1987, Pelton 1982,

Schwartz and Franzmann 1991). Mortality rates

are highest in poor food years (Kolenosky and

Strathearn 1987, Schwartz and Franzmann 1991).

Bears compete with other forest carnivores for

carrion and prey (young ungulates and livestock).

They may be killed or driven off by grizzly

bears or wolves (Gehring 1993, Schwartz and

Franzmann 1991, Smith and Follmann 1993,

Veitch et al. 1993).

23
Black Bear Issues in the Basin

Black bears are widespread and relatively common in the Western United States, although

overharvest by humans is a concern in some

areas. Black bears require certain habitats

and habitat elements to do well, but at higher

densities, they can come into conflict with

humans, especially when humans encroach on

bear habitats. Two issues are of concern to black

bear conservation and management in the basin.

Issue 1: Provision of appropriate habitat

mix—Black bear populations thrive where there

is a mix of forested areas and small openings

that provide foraging sites. Intrusions by roads

or human activities must be minimal. Large

woody debris and snags should be left to provide

foraging and denning opportunities along with

caves and talus slopes (Kolenosky and Strathearn

1987). Steep, north-to-northeast-facing slopes

are important denning areas (McCutchen 1993).

Riparian habitats, meadows, bogs, and valley

bottoms can be especially important foraging

areas and need protection from human development and heavy use.

Key environmental correlates—The following

information is available on basin GIS:

• Forest cover, structure, interspersion

• Riparian habitat, valley bottoms

• Physiography (slope, aspect)

• Ungulate ranges

The following information is not currently

available on basin GIS:

• Ungulate density

• Coarse woody debris, log piles

• Meadows, bogs

• Rock outcrops, caves

Issue 2: Reduction of conflicts with humans—

Black bears will use easily accessible, highenergy food sources, so humans must exercise

caution with garbage dump sites and food storage

in the backcountry (Merrill 1978, Payne 1978).

Backcountry users should be instructed on appropriate actions and behaviors around black bears

(Bromley et al. 1992). Roads, campgrounds,

homes, and recreational developments may bring

humans into contact with bears. Hence, access

to—and human development in—areas of high

black bear densities should be minimized to

reduce conflicts.

Key environmental correlates—The following

information is available on basin GIS:

• Road density

• Human density

The following information is not currently available on basin GIS:

• Trail locations, density

• Campgrounds

• Recreational developments

• Garbage dumps, landfills

Grizzly Bear (Ursus arctos)

Ecology

Grizzly bears once were widespread in North

America, but their current range and numbers

are only about 1 percent of historical levels

(Jonkel 1987, USFWS 1993). The large size of

bears and aggressive encounters with humans

and their livestock resulted in the extirpation of

grizzly bears from much of their historical range

(Craighead and Mitchell 1982). Small populations (in total, about 250 bears) exist in small

areas of the interior Columbia basin—but primarily in the north Continental Divide and

Yellowstone ecosystems—where they are

protected under the Endangered Species Act

(appendix A; Jonkel 1987, USFWS 1993). Their

range and numbers are much larger in western

Canada and Alaska, where grizzly bears are still

harvested in regulated seasons (Horejsi 1989,

Jonkel 1987).

Grizzly bears require large territories because

of their size and food requirements. Home range

sizes of 1400 to 3757 km2 (males) and 285 to

884 km2 (females) are reported (Craighead and

Mitchell 1982, Servheen 1983). Home ranges can

be much smaller and can overlap, especially in

good habitat or at good foraging sites (Jonkel

1987).

24
Grizzly bears are omnivorous and generalist

feeders (Craighead and Mitchell 1982, USFWS

1993). They need to consume large amounts

of high-energy (fats, carbohydrates) and highprotein foods before their 5- to 7-month winter

hibernation (Blanchard and Knight 1991,

Craighead and Mitchell 1982, Jonkel 1987).

Their movements and habitat use patterns are

closely associated with available food sources

and plant phenology (Servheen 1983). In spring,

grasses and carrion are used; in summer, grasses,

forbs, and ferns are used; in fall, tree and shrub

fruits, insects, and grasses are used. Ground

squirrels and other burrowing animals may be

used, especially in spring (USFWS 1993).

Ungulates and livestock (both adult and young)

can be important elements of the diet when and

where available (Peek et al. 1987). Grizzly bears

may influence population sizes of elk and moose

(Ballard 1992, Cole 1972, Larson et al. 1989).

Grizzly bears use a diversity of habitats that provide for travel, security, foraging, and denning

(Jonkel 1987). They also require habitats that

provide a local abundance and sequential availability of foods. Areas for foraging (open forest,

riparian areas, lakeshores, seeps, meadows,

avalanche chutes) interspersed with areas of

forest cover for security and bedding are

essential (Agee et al. 1989, Servheen 1983,

USFWS 1993). Even-aged, second-growth

stands with minimal understory development

provide poor habitat (Peek et al. 1987). These

areas must be relatively free from disturbance

and human activities (Knight et al. 1988,

McLellan and Shackleton 1988). Most grizzly

bears avoid roads and recently logged areas (Peek

et al. 1987). Whitebark pine (Pinus albicaulis

Engelm.; for seed production), subalpine larch

(Larix lyallii Parl.), and subalpine herbaceous

habitats are important to grizzly bears (Agee et al.

1989, Blanchard and Knight 1991). Additionally,

denning sites are very important: typically, winter

dens are excavated on steep, north-to-northeast

slopes above 1370 m in elevation where deep

snows accumulate and human activity and

development does not occur (USFWS 1993).

Grizzly bears are generally long-lived (20+

years), but they have a low reproductive

potential. Typically, females do not reproduce

until they are 5+ years old and produce only

about two cubs every 3+ years (Craighead and

Mitchell 1982, Jonkel 1987). Natural mortality

of bears is relatively low, and humans account

for most adult grizzly bear mortality (Peek et

al. 1987, Wielgus et al. 1994). Additional

mortality occurs from disease, accidents

(especially through poor choice of denning sites),

old age, malnutrition, and infanticide by adult

grizzly bears (Jonkel 1987, Olson 1993). To

maintain or increase populations, it is especially

important to protect females with cubs (Knight

and Eberhardt 1985, Sidorowicz and Gilbert

1981). Grizzly bears compete with other forest

carnivores for food, including carrion (LaFranc

1987). There are some reports of grizzly bears

killing or displacing black bears and wolves from

carcasses or by excavating dens (Haynes and

Baer 1992, LaFranc 1987, Smith and Follman

1993).

Grizzly Bear Issues in the Basin

Grizzly bears are dominant forest carnivores once

widespread in the Western United States. Conflicts with humans greatly reduced their numbers

and range, and these conflicts continue today.

The bears have specific habitat requirements

that can limit their numbers and range even with

reductions in human-caused mortality. Their

occurrence in the basin is very limited except

for the far eastern fringe (western Montana

and northwestern Wyoming). Three issues

are of concern to grizzly bear conservation and

management in the basin.

25
Issue 1: Provision of habitat needs—Sustaining

a population of grizzly bears requires a very large

(10 000+ km2

) area of appropriate habitat. Appropriate habitat is a mix of closed canopy forest

interspersed with openings. Natural openings,

such as avalanche chutes, meadows, riparian

areas, and shrubby areas, are appropriate for

foraging and for providing sequential food

availability. Whitebark pine and subalpine

larch stands are important forest cover types,

probably because their open canopy nature

provides foraging opportunities while maintaining adequate security cover. Coarse woody

debris, snags, log piles, and caves are important

habitat elements. Steep, rocky, north-to-northeast

facing slopes are important denning areas. Human

developments in—and human use of—important

grizzly bear areas should be avoided to reduce

human-caused mortality and competitive use

of habitats. Relatively few areas will meet these

requirements, but several are identified in the

“Grizzly Bear Recovery Plan” (USFWS 1993;

also see LaFranc 1987).

Key environmental correlates—The following

information is available on basin GIS:

• Wilderness areas and large roadless areas

• Forest cover, structure, interspersion

• Physiography (slope, aspect, elevation)

• Riparian habitat

• Ungulate ranges

The following information is not currently available on basin GIS:

• Ungulate densities

• Burrowing rodent ranges, densities

• Coarse woody debris, log piles

• Meadows, avalanche chutes, shrub fields

• Caves

Issue 2: Prevention of subpopulation isolation

and extinction—Grizzly bears occur in only a

few, small, isolated areas of the basin. Four of

these small populations (north Cascades, Selkirks,

Cabinet-Yaak, and northern Continental Divide)

may have links with Canadian populations,

although the amount of interchange of bears is

not known (USFWS 1993). The other two areas

(Selway-Bitterroot and Yellowstone) are much

more isolated. The continued viability of the two

sustaining populations (northern Continental

Divide and Yellowstone) and the restoration of

populations in the other four areas may depend

on occasional immigrant bears from adjacent

populations to counteract mortality in the local

population and to help maintain genetic viability

(Paquet and Hackman 1995). Consequently, it is

important to maintain linkage zones or corridors

between populations of bears in designated

recovery areas and across the border between the

United States and Canada. This would facilitate

the occasional movement of dispersing bears

among populations. Unfortunately, discussions

(e.g., Craighead and Mitchel 1982, Jonkel 1987,

Paquet and Hackman 1995) of links and corridors

do not give specific attributes for defining effectiveness. Possible links among the six areas of

the basin mentioned above are discussed by the

USFWS (1993). Extensive development and

intensive land uses may limit the effectiveness

of potential links. Additionally, highways may

form barriers to dispersal and increase bear

mortalities (Paquet and Hackman 1995).

Key environmental correlates—The following

information is available on basin GIS:

• Potential links and corridors (between

recovery areas)

• Highways

The following information is not currently available on basin GIS:

• Integration of habitat and other GIS data bases

from Canada and United States sources

26
Issue 3: Reduction of conflicts with humans—

Where grizzly bears and humans coexist, there

will be conflicts and occasional fatalities of

both (Peek et al. 1987). It is best to restrict most

human developments and human uses in—as

well as livestock access to—designated grizzly

bear recovery areas (Knight et al. 1988, Peek et

al. 1987). Backcountry use should be regulated

and users should be instructed on appropriate

actions and behaviors and food storage in grizzly

bear areas (Bromley et al. 1992). Artificial food

sources, such as open garbage dumps, should not

be allowed in or near grizzly bear areas (Martinka

1974, Merrill 1978). Road densities should be

low, preferably <1.6 km/2.6 km2 of habitat in

grizzly bear areas (LaFranc 1987, McLellan

and Shackleton 1988, Peek et al. 1987, USFWS

1993). A cooperative and consistent nuisance

bear control program also is important (USFWS

1993).

Key environmental correlates—The following

information is available on basin GIS:

• Road density

• Human density

The following information is not currently available on basin GIS:

• Livestock grazing areas, densities

• Trail locations, densities

• Campgrounds

• Recreational developments

• Homesite locations, density

• Off-road motorized recreational vehicle use

areas

• Garbage dumps, landfills

Conclusions

The long-term conservation of a representative

carnivore community in the interior Columbia

basin is problematic at best (Clark et al. 1996b,

1996c; Kucera and Zielinski 1995; Noss et al.

1996; Ruggiero et al. 1994). Carnivores, particularly the large carnivores, present unique

conservation problems that will be difficult to

solve. The large size of many of these far-ranging

species, along with their variable specific habitat

and prey base needs, their differing statuses, and

the diverse management approaches used by the

states (summarized in appendices B, C, and D)

all add to the challenge presented. Grizzly bears,

gray wolves, and mountain lions are viewed

negatively by a portion of the public because

of perceived and real dangers to human safety,

economic impacts from livestock depredations,

and negative impacts on game populations

(Andelt 1996, Kellert et al. 1996, Witmer et al.

1995). Regardless of legal status and level of

protection, illegal and accidental killing (e.g.,

highway mortality) of large carnivores can have

a significant impact on survival and population

growth, especially when many of the species

have low-to-moderate reproductive potential. The

long-term survival of large carnivores therefore

rests on developing and implementing a much

broader landscape-level conservation plan to

provide large, remote, or relatively inaccessible

areas for protection from human impacts and

disturbance (Noss et al. 1996, Primm and Clark

1996, Servheen and Sandstrom 1993, Weaver

et al. 1996). Management policy for large carnivores needs to recognize human emotional

reaction to these animals and incorporate strategies to mitigate potential impacts posed by

negative public attitudes, especially toward

large carnivores (Clark et al. 1996b, Kellert

et al. 1996, Primm and Clark 1996).

27
The management hypothesis that needs to be

tested for the basin is that large carnivores can

coexist successfully with humans if the carnivores are provided with enough core areas, linked

with connecting habitats, to maintain productive

populations which can persist over long periods

and inevitable environmental fluctuations. For

nearly all species, there is a knowledge vacuum

concerning minimum viable population sizes

and population sustainability (Noss et al. 1996,

Salwasser et al. 1984). Habitat conservation

plans must be enacted for carnivores in the

basin before we have definitive information

on population viability and the role of metapopulation structure.

Smaller carnivores generally do not face such

highly negative public attitudes but, nonetheless,

have their own conservation challenges and susceptibility to human impacts. Species such as the

marten and fisher require conservation of late

successional forests. Wolverines may be affected

by increasing human disturbance and use of

subalpine communities and accidental mortality

from trapping. Lynx require early seral stage

boreal forest habitats supporting large populations

of snowshoe hare and other small mammals.

Regulated harvest, incidental mortality from

trapping, illegal harvest, and roads may limit

lynx populations, especially during critical

periods when prey are reduced. The river otter

is a habitat specialist dependent on riparian

areas supporting clean rivers and streams

with productive fish populations. Extensive

degradation of water quality and riparian

communities has hurt this species. On the other

hand, large, remote areas with very limited

human activities and human-caused mortality

and a large measure of human tolerance are

required if the larger forest carnivore species—

gray wolf and grizzly bear—are to continue to

exist in the interior Columbia basin.

Some generalist carnivores are of more concern

because they are highly successful and therefore

may cause secondary negative impacts on other

carnivores through competition. Coyote populations have been favored by the eradication of

other large carnivores, extensive modification

of habitats, human settlement, and disturbance

(Quigley and Hornocker 1992, Witmer and

Hayden 1992). High coyote populations may

have negative consequences for recovering

populations of wolves and other carnivores via

competition for prey and carrion. High coyote

population densities and their depredations also

may lead to increasing demand for predator

control programs (USDA 1994). Similarly, high

bobcat population densities may have negative

effects on lynx because of competition for prey

and the more aggressive behavior of bobcats

(Quinn and Parker 1987). Black bear population

densities are high in many areas and, under such

conditions, may lead to conflicts with humans,

especially with human and livestock encroachment into bear habitats and the availability of

artificial food sources. The problem can become

more severe where bears are not adequately

harvested by humans to help lower bear densities

and to maintain their wariness of humans and

human habitations.

Integrated Species Management

This technical analysis of 11 selected carnivore

species in the basin revealed several conservation

themes encompassing many species, although

there was important variation among the overall

species group (appendices A-D). The themes

benefiting several species of carnivores are as

follows:

• Conservation of late successional forest

• Preservation of large, remote, or inaccessible

blocks of habitat with restricted human

development and access

• Preservation or development of lower

elevation riparian and forest habitats acting as

connecting links between regional source

populations

• Maintenance of adequate prey populations

• Reduction and management of negative interactions with humans to reduce availability of

artificial food sources, highway mortality,

illegal and accidental killing, the need for

predator control, and the accidental take of

nontargeted carnivores during harvest seasons

or predator control operations.

28
The practical implementation of these conservation themes for carnivores requires land management on a larger scale than historically

practiced by any Government agency. On-theground implementation of management plans

for many species of carnivores, especially the

larger species, requires coordinated actions

among different state and Federal agencies,

tribes, private landowners, and neighboring

countries (Clark et al. 1996a, Mattson et al. 1996,

Servheen and Sandstrom 1993). The formation

of working groups with representation by diverse

constituencies are a step in the right direction

(Kucera and Zielinski 1995, Servheen and

Sandstrom 1993). There must be effective

cooperation between Canada and the United

States to maintain habitat links and source

populations for some species, such as the lynx,

wolverine, grizzly bear, and gray wolf (Paquet

and Hackman 1995). These links also would help

maintain healthy genetic variation among

subpopulations (Forbes and Boyd 1996, Weaver

et al. 1996). At present, cooperation and

coordinated planning between the United States

and Canada mainly involve grizzly bear and wolf

management; this effort needs to be expanded to

include other carnivore species. Some specific

land management actions that will help develop

improved habitat and population management for

carnivores include:

• Reduced development and use of roads

• Reduction in habitat fragmentation

Increasing development and use of roads, including both forest roads and highways, stand out as

primary factors affecting carnivores (McLellan

and Shackleton 1988, Mech et al. 1988, Paquet

and Hackman 1995, Thurber et al. 1994).

Increased human access to remote areas can

result in higher mortality from hunting, illegal

killing, and accidental deaths among many

carnivores. Highways also act as significant

barriers to movements for some species, although the impacts of roads and other barriers to

animal movements are not well documented in

ways that improve understanding of carnivore

population dynamics. Reduced development,

closure after use, and management of roads in

forest and riparian environments are critical to

carnivore conservation. Large carnivore populations have difficulty persisting when road

access and interactions with the public exceed

threshold levels. Studies of wolves and grizzly

bears suggest that reducing the number of roads

in forest environments is important to the maintenance of normal habitat use patterns and to

lower human-caused mortality.

Development and Use of GIS

Models for Carnivores

Geographic Information Systems have the

potential to be useful in carnivore management

by helping to identify and visualize critical and

potential habitats and changes in habitats, and

to facilitate long-term management planning

(Agee et al. 1989, Servheen and Sandstrom

1993). Although many advantages of using

GIS in landscape-level planning are evident,

current GIS systems have some shortcomings

for conservation planning and carnivore management. Improvements, discussed below, will

greatly increase the value of GIS systems in

carnivore conservation and management.

Many potential environmental attributes useful in

carnivore management are not measured at all,

are not routinely available on GIS systems, or are

not available at the appropriate scale. Carnivores

depend on prey species that fluctuate in distribution and abundance. Information on prey

species is not routinely available or input into

GIS-aided planning for forest management.

Given the opportunistic—and often heavy use

of—ungulate prey and carrion by carnivores,

information on actual or potential ungulate

population densities and distributions should

be a high priority in GIS modeling. Interactions

with humans are the most important cause of

mortality for many carnivores. Consequently,

increased measurement of variables reflecting

human use and impacts on habitats should be

considered as well. These might include campground locations, trails, recreational developments, homesites, landfills, and livestock grazing

allotments. This information would be invaluable

to many aspects of natural resource planning and

environmental impact assessment. Additionally,

many microsite habitats (<0.40 ha) are important

to forest carnivores, but these are rarely incorporated into GIS systems.

29
Identification of actual or potential carnivore

habitat by GIS does not translate into concrete

information about population dynamics. At

present, there is little understanding of the landscape-level population dynamics of carnivores

and their prey (Peterson 1988, Quigley and

Hornocker 1992). Methods of accurately and

economically assessing presence, abundance,

and population trends still are not available for

most carnivore species (Ruggiero et al. 1994).

Current efforts to better document forest carnivore presence by remote photography and track

identification are a step in the right direction

(Zielinski and Kucera 1995). Furthermore, the

conceptual basis for managing populations at

landscape levels is not supported by factual

information on metapopulation dynamics. Design

and subsequent use of corridors or habitat links

by carnivores and other wildlife require technical

information on movements, reproduction, survival, and cover use, which generally do not

exist (Beier 1993, Harrison 1992, Servheen and

Sandstrom 1993, Simberloff and Cox 1987).

Canada is an important source of individuals

dispersing into the United States for some

carnivore species (e.g., grizzly bears, lynx,

wolverines, wolves), and GIS systems on both

sides of the border should be integrated so that

critical management information can be shared

(Forbes and Theberge 1996, Paquet and

Hackman 1995, Servheen and Sandstrom 1993).

At present, carnivores effectively “drop off the

edge of the world” when GIS modeling does not

cross political boundaries of the United States

and Canada. These situations and problems need

to be addressed for GIS models to be more

effective in carnivore management.

Coexistence and Competition

Among Carnivores

At present, given the highly restricted distributions of many carnivores, it is difficult to

assess the consequences of competition and

predation among different carnivore species. A

full assemblage of carnivores currently exists

in northwestern Montana, Yellowstone, and

possibly in the north Cascades, and it may be

that in areas of adequate size, with low levels

of human impacts, carnivore communities can

still manage to persist and coexist in the United

States. The detrimental consequences of species

interactions (such as grizzly bears killing wolf

pups or black bears, wolves killing mountain

lions, or competition for food) do not seem to be

nearly as important in carnivore management as

is reducing the impacts of the primary carnivore

predator—humans. Food habits overlap extensively for many of the larger carnivores and

they rely on carrion, particularly during critical

periods of winter and early spring. Maintaining

adequate ungulate populations is pivotal to sustaining a full complement of large carnivores.

Coexistence among carnivores may mean lower

population levels for some individual species,

because of negative interactions and competition

for prey and carrion on population levels. These

results are not certain, however, and more information needs to be gathered on predator-topredator interactions (Peterson 1988, Quigley

and Hornocker 1992). The dynamics of natural

processes that produce carrion, including disease

and predation, are not well-documented aspects

of carnivore and wildlife ecology, and the

physical and ecological attributes of regions

supporting full complements of carnivores aren’t

either. The development of a carnivore research

center, such as that proposed for the northern

Rocky Mountain region, would provide the

opportunity for large-scale, long-term field

research in an area where many forest carnivore

species coexist (Paquet and Hackman 1995,

Ruggiero et al. 1994).

Reduction of Human Impacts on

Carnivores

Without doubt, the most important single factor

affecting all carnivore species is negative human

impacts through habitat alterations or direct mortality (Clark et al. 1996a, 1996c; Kellert et al.

1996; Mattson et al. 1996; Paquet and Hackman

1995; Peterson 1988). Reduction of humancaused mortality is a primary concern in carnivore management. In some cases, better harvest

management is required to assure that carnivore

populations are not detrimentally affected by

consumptive uses (Keiter and Locke 1996,

Ruggiero et al. 1994). Individuals of a rare

species, such as the wolf or wolverine, may be

30
harvested incidentally to the intended harvest

of a more common species, such as the bobcat

or coyote. In this situation, regulations, harvest

restrictions, or alternate harvest methods may

be needed to reduce or prevent this occurrence.

Management programs, including better education and communication, to reduce carnivore

conflicts with livestock producers are required to

lessen the need and impacts of predator control

programs (Andelt 1996, Niemeyer et al. 1994,

Witmer et al. 1995). Livestock grazing on public

lands is a highly emotional and sensitive issue in

the West, but the full consequences of trying to

satisfy all demands on public lands is a critical

problem in carnivore management. Large carnivores, in particular, depend heavily on large

blocks of public lands for their future existence.

If managers desire to maintain or enhance carnivore populations, programs to reduce conflicts

between people and carnivores will help offset

the negative attitudes towards carnivores among

livestock producers and other segments of the

public. Illegal and accidental killing of carnivores can be most effectively managed by

influencing the amounts and types of human

access to critical carnivore habitats and regions.

Research to reduce the impacts of predators on

humans and their valued resources continues in

an effort to develop effective, cost-efficient, safe,

and sociopolitically acceptable solutions (Andelt

1996, Fall 1990, Witmer et al. 1996).

Acknowledgments

The authors thank the reviewers of various

portions of this report, including Keith Aubry,

Gary Koehler, Bill Noble, Fred Knowlton, Robert

Naney, and Thomas Quigley. We also thank the

various state wildlife agencies and their furbearer

biologists for information on species status and

harvests in the interior Columbia basin: Washington (Steve Pazzanghero), Oregon (Larry Cooper),

Idaho (Gary Will), and Montana (Brian Giddings).

We especially appreciate the guidance, support,

and review comments of Robert Naney, wildlife

biologist, Okanogan National Forest. The carnivore figures used in the text are reprinted from

Mammals of the Pacific States: California,

Oregon, and Washington, by Lloyd G. Ingles,

with the permission of the publishers, Stanford

University Press, ©1947, 1954, and 1965, by the

Board of Trustees of the LeLand Stanford Junior

University.

English Equivalents

When you know: Multiply by: To find:

Centimeters (cm) 0.39 Inches

Meters (m) 3.28 Feet

Kilometers (km) 0.62 Miles

Square kilometers

(km2

) 0.39 Square miles

Hectares (ha) 2.47 Acres

Kilograms (kg) 2.21 Pounds (avdp)

31
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41
Appendix A

Species Range Maps

Solid line delineates interior Columbia basin; some range

maps cover only the interior Columbia basin.

42
43
44
45
46
47
Appendix B

Summary of Biology, Ecology, and Status by Species

Adult size Reproductive Home range

Species and kilograms potential and km2 Primary habitat Primary prey Status in basin

Coyote Medium High Small Various, suc- Diverse, Unprotected,

10-16 4-12 cessional mix omnivore harvested

Gray wolf Large Moderate Very large Remote Ungulates Protected

20-80 to high 100-1000+ areas

Bobcat Medium Moderate Small Various, suc- Small to medium Harvested

5-25 2-40 cessional mix mammals

Lynx Medium Moderate Small Successional Small to medium Protected or

7-20 16-20 mix mammals limited harvest

Mountain lion Large Moderate Very large Successional Ungulates Harvested

35-80 100-1000 mix

Fisher Small Moderate Moderate Mature forest Small to medium Protected or

2-5 20-80 mammals limited harvest

Marten Small Moderate Very small Mature forest Small mammals Harvested

0.5-1 1-5

River otter Medium Low to Moderate Riparian Fish, Harvested except

5-14 moderate 10-80 habitats diverse in Idaho

Wolverine Medium Low to Large Mature forest All-sized Protected or

15-30 moderate 100+ mammals limited harvest

Black bear Very large Low Moderate Successional Diverse, Harvested

40-140 10-100 mix omnivore

Grizzly bear Very large Low Very large Successional Diverse, Protected

80-250 1500+ mix omnivore

48
Appendix C

Summary of Population Status and Harvest by Species and Area

Species and area Classification Status Harvest no. (period) Harvest trend (period)

Coyote:

Eastern Oregon Predatory mammal Unprotected 4500 (1994-95) Stable or increasing (1985-95)

Eastern Washington Predatory mammal Unprotected 1415 (1994-95) Stable or increasing (1983-94)

Idaho Predatory mammal Unprotected 1825 (1993-94) Stable or increasing (1984-94)

Northwest Montana Predatory mammal Unprotected 1198 (1993-94) Stable (1984-94)

Wolf:

Eastern Oregon Game mammal Protected No harvest —

Eastern Washington Game mammal Protected No harvest —

Idaho Game mammal Protected No harvest —

Northwest Montana Game mammal Protected No harvest Occasional incidental take

Bobcat:

Eastern Oregon Furbearer Regulated harvest 1017 (1994-95) Stable (1985-95)

Eastern Washington Furbearer Regulated harvest 251 (1993-94) Stable or increasing (1983-94)

Idaho Furbearer Regulated harvest 312 (1993-94) Decreasing (1984-94)

Northwest Montana Furbearer Regulated harvest 265 (1994-95) Stable (1991-95)

Lynx:

Eastern Oregon Furbearer Protected (extirpated) No harvest —

Eastern Washington Furbearer Protected No harvest (since 1991) Decreasing (1970-91)

Idaho Furbearer Regulated harvest (quota) 1 (1993-94) Decreasing (1984-94)

Northwest Montana Furbearer Regulated harvest (quota) 4 (1994-95) Decreasing (1984-95)

Mountain lion:

Eastern Oregon Game mammal Regulated harvest 93 (1992) Increasing (1970-92)

Eastern Washington Game mammal Regulated harvest 148 (1994-95) Increasing (1989-95)

Idaho Game mammal Regulated harvest 448 (1993-94) Stable or increasing (1988-94)

Northwest Montana Game mammal Regulated harvest 258 (1993-94) Increasing (1984-94)

Fisher:

Eastern Oregon Furbearer Protected No harvest —

Eastern Washington Furbearer Protected No harvest —

Idaho Furbearer Protected No harvest Occasional incidental take

Northwest Montana Furbearer Regulated harvest (quota) 8 (1994-95) Stable (1984-95)

Marten:

Eastern Oregon Furbearer Regulated harvest 10 (1994-95) Decreasing (1985-95)

Eastern Washington Furbearer Regulated harvest 40 (1993-94) Decreasing (1983-94)

Idaho Furbearer Regulated harvest 364 (1993-94) Decreasing (1984-94)

Northwest Montana Furbearer Regulated harvest 631 (1993-94) Decreasing (1984-94)

River otter:

Eastern Oregon Furbearer Regulated harvest 84 (1994-95) Stable (1985-95)

Eastern Washington Furbearer Regulated harvest 35 (1993-94) Stable or increasing (1983-94)

Idaho Furbearer Protected No harvest Occasional incidental take

Northwest Montana Furbearer Regulated harvest 26 (1994-95) Stable (1984-94)

49
Species and area Classification Status Harvest no. (period) Harvest trend (period)

Wolverine:

Eastern Oregon Furbearer Protected No harvest —

Eastern Washington Furbearer Protected No harvest —

Idaho Furbearer Protected No harvest Occasional incidental take

Northwest Montana Furbearer Regulated harvest 3 (1994-95) Stable (1984-95)

Black bear:

Eastern Oregon Game mammal Regulated harvest About 270 (1992) Stable (1975-92)

Eastern Washington Game mammal Regulated harvest 781 (1992-93) Stable (1984-93)

Idaho Game mammal Regulated harvest 1231 (1993-94) Stable or increasing (1983-94)

Northwest Montana Game mammal Regulated harvest About 750 (1993) Stable (1986-93)

Grizzly bear:

Eastern Oregon Game mammal Protected (extirpated) No harvest —

Eastern Washington Game mammal Protected No harvest —

Idaho Game mammal Protected No harvest —

Northwest Montana Game mammal Protected No harvest Occasional incidental take

50
Appendix D

Summary of Informational Needs and Management Issues by Species

Species

Gray Mountain River Black Grizzly

Needs or issues Coyote wolf Bobcat Lynx lion Fisher Marten otter Wolverine bear bear

Maintain late

successional forest X X

Maintain dispersal

corridors X X X X X

Maintain riparian

habitat X X

Large undisturbed

areas X X X X

Maintain mix of

seral stages X X X

Maintain prey

population X X X

Reduce mortality

from humans X X X XXXX

Reduce conflicts

with humans X X X X X

Succeed with

reintroductions X X

51
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Document continues on next page.
Witmer, Gary W.; Martin, Sandra K.; Sayler, Rodney D. 1998. Forest carnivore conservation

and management in the interior Columbia basin: issues and environmental correlates. Gen. Tech.

Rep. PNW-GTR-420. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific

Northwest Research Station. 51 p. (Quigley, Thomas M., ed.; Interior Columbia Basin Ecosystem

Management Project: scientific assessment).

Forest carnivores in the Pacific Northwest include 11 medium to large-sized mammalian species

of canids, felids, mustelids, and ursids. These carnivores have widely differing status in the region,

with some harvested in regulated furbearer seasons, some taken for depredations, and some protected

because of rarity. Most large carnivores have declined in numbers or range from human encroachment, loss or modification of forest habitat, accidental deaths (e.g., mortality from vehicles), illegal

kills, and our inability to adequately monitor and protect populations. Efforts to reverse these trends

include new approaches to reduce conflicts with humans, research to better define habitat needs,

formation of expert carnivore working groups, and use of Geographic Information System models

to predict specific impacts of habitat modifications. Long-term preservation of large carnivores in the

region is problematic unless we reduce forest fragmentation and conflicts with humans and improve

our ability to quantitatively integrate population dynamics with landscape level habitat requirements.

Keywords: Coyote, gray wolf, bobcat, lynx, mountain lion, fisher, marten, river otter, wolverine,

grizzly bear, black bear, conservation, management, carnivores, late successional forest, wilderness,

roads, disturbance, fragmentation, conservation biology, geographic information systems, forest

management, animal damage.

The Forest Service of the U.S. Department of

Agriculture is dedicated to the principle of multiple

use management of the Nation’s forest resources for

sustained yields of wood, water, forage, wildlife, and

recreation. Through forestry research, cooperation

with the States and private forest owners, and

management of the National Forests and National

Grasslands, it strives—as directed by Congress—to

provide increasingly greater service to a growing

Nation.

The United States Department of Agriculture (USDA)

prohibits discrimination in its programs on the basis

of race, color, national origin, sex, religion, age,

disability, political beliefs, and marital or familial

status. (Not all prohibited bases apply to all programs.)

Persons with disabilities who require alternative

means of communication of program information

(Braille, large print, audiotape, etc.) should contact

the USDA Office of Communications at (202)

720-2791.

To file a complaint, write the Secretary of Agriculture,

U.S. Department of Agriculture, Washington, DC

20250, or call 1-800-245-6340 (voice), or (202)

720-1127 (TDD). USDA is an equal employment

opportunity employer.

Pacific Northwest Research Station

333 S.W. First Avenue

P.O. Box 3890

Portland, Oregon 97208-3890
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