Matrix of winter recreation effects on wildlife

Authors(s): J. W. Caslick and E. Caslick

Publication: Effects of winter recreation on wildlife of the Greater Yellowstone Area: a literature review and assessment. Report to the Greater Yellowstone Coordinating Committee. Yellowstone National Park, Wyoming.

Publisher: YCR, Natural Resources

Publication Date: 0000-00-00

Type:

Location: Yellowstone National Park Wyoming

Abstract: SNOWMOBILING Bald Eagles ??? ?Since bald eagles apparently require freedom from human disturbance during the early stages of nesting. . . no habitat alterations, especially campgrounds, campsites or trails, should be made within 1 to 2km of a bald eagles nest? (Swensen 1975:121). ??? in Grand Teton National Park, in reference to the RKO bald eagle nesting territory, ?at the time of nest initiation there is still ample snow for snowmobiling on the plateau adjacent to the territory. This activity at or above the level of the nest could be inhibiting nest initiation or disrupting incubation during the early stages: (p. 64); recommended that a buffer zone of ?1 km or any reasonable distance deemed necessary to minimize any possible disturbance by snowmobiles (p. 80); observed adults in close association with three territories along the Snake River on the earliest eagle observation flight (Feb. 26, 1979) (Harmata 1996). ??? in Greater Yellowstone, bald eagles will persist only if there is ?adequate habitat available to avoid humans? and management of wintering and migration habitat also should be considered (p. iv); ?Eagles shifted their activity patterns to periods when their presence would be least obvious to humans: very early morning and evening? (p. 13); ?Snowmachines and all terrain vehicles are especially disturbing, probably due to associated random movement, loud noise and operators are generally exposed . . .? (p. 12); The cumulative effects of many seemingly insignificant or sequential (human) activities may result in disruption of normal behavior of wildlife. ?The importance and pertinence to bald eagle behavior cannot be overstated.? (p. 14) (Harmata 1996). ??? ?Sensitivity of nesting bald eagles to human activity generally diminishes in the following temporal order: nest site selection>nest building>egg laying>incubation>brooding> fledging? (p. 37). This indicates that disturbance in winter may be influential nesting chronology, since nest site selection occurs ?year round?, nest building occurs ?October through April? and egg-laying occurs ?28 February through 10 April? (p. 37) in the Greater Yellowstone area (Harmata 1996). ??? in Glacier National Park, the greatest threat to bald eagles was human disturbance; certain areas should be protected from snowmobiling (Shea 1975) (M.S. Thesis). ??? in Grand Teton Park, snowmobiling could be inhibiting nest initiation or disrupting incubation at the RKO bald eagle nesting territory and a recommended buffer zone of ?1km or any reasonable distance deemed necessary to minimize any possible disturbance by snowmobiles.? During investigators first flight in 1979 on Feb. 26, adult eagles were observed in close association with 3 territories along the Snake River (Alt 1980:80) (M.S. Thesis). ??? human disturbance of an avian scavenger guild, includes bald eagles (Skagen et al. 1991). ??? in Yellowstone and Grand Teton Parks, bald eagles reside year-round. ?Resident bald eagles begin defending territories in late January, display courtship in February, and begin laying eggs and incubating in March. They are sensitive to disturbance by humans from late winter through spring and early summer. Wintering bald eagles depend on three major types of food: waterfowl, carrion, and fish. . . .About 20-40 bald eagles, including 14 nesting pairs spend part of the winter in Yellowstone: (USDI National Park Service 1990:12). Bears ??? a grizzly bear den was abandoned after snowmobile disturbance (Jonkel 1980). ??? in Yellowstone Park, black bears began denning between late October and mid-November. The winter dormancy period terminated primarily between late March and the end of April (Barnes and Bray 1967). ??? in Yellowstone Park?s Firehole, Madison and Gibbon River drainages, grizzly bears emerged from hibernation and traveled to elk and other native ungulate winter areas between March and early May (Cole 1972). ??? in Grand Teton and Yellowstone Parks, ?Bears usually emerge from dens in mid-March, but they may emerge earlier depending on elevation, slope, aspect, weather conditions, and the individual bear?s age, sex, condition and behavioral patterns. . .The late winter to early spring period is a crucial feeding time. . .winter-killed carrion. . .is an important source of protein. . .bears. . .must feed undisturbed in preferred areas to meet nutritional requirements. . .Adult females and young grizzlies, especially, need carrion and suffer most from its exclusion for their diet. . .When adult females are excluded on a regular basis from carrion sources, higher mortality and lower fecundity rates can be expected? (USDI National Park Service 1990:15). Bighorn Sheep ??? on winter range, may be debilitating to winter-stressed sheep (Berwick 1968) (M.S. Thesis). ??? heart rates of unrestrained bighorn sheep varied inversely with distance from a road, in Alberta (MacArthur et al. 1979). ??? cardiac and behavioral responses of bighorn sheep to human disturbance (MacArthur et al. 1982). Bison ??? in Yellowstone Park, snow packed roads used for winter recreation in the interior of the park appeared to be the major influence in major changes in bison numbers and distribution in the park, in the past decade. Roads provided energy-efficient travel that resulted in energy saving within traditional foraging areas, range expansion, major shifts among previously semi-isolated subpopulations, and a mitigation of winterkill and enhancement of calf survival. Effects will ultimately occur on an ecosystem level (Meagher 1993). ??? in Yellowstone Park, ?Bison were frequently observed traveling in the packed and groomed snowmobile trail and habitually used the trail as part of their intricate network of trails during the winter months? (Aune 1981:34). Elk ??? in Yellowstone Park, resulted in average flight distance of 33.8 m (Aune 1981) (M.S. Thesis). ??? in Montana, additional stress from snowmobiles in winter is undesirable (Aasheim 1980). ??? in Idaho, road closures allowed elk to remain longer in preferred areas (Irwin and Peek 1979). ??? forest roads evoke an avoidance response by elk (Lyon 1983). ??? in Rocky Mountain Park, quantified responses of elk to human activities, in winter; nonhunted elk were not significantly affected by on-road visitor activities (Schultz and Bailey 1978). Mule Deer ??? after habituating to an all-terrain vehicle (ATV) for 12 weeks, harassment of radiocollared females by the ATV altered feeding, altered spatial use, and decreased production of young the following year (Yarmaloy 1988). ??? elicited motor responses (in sagebrush winter range) when closer than 133m; moved at similar velocities when disturbed by snowmobiles or persons afoot; moved shorter horizontal distance when disturbed by snowmobiles than when disturbed by persons afoot; became more sensitive in moving away from disturbances, as the controlled trials progressed. Test disturbances did not prevent adult females from producing fawns later that year. (See Freddy et al. 1966 in ?SNOWSHOEING? section.) (Used 18 radio-collared adult females, Colorado.) (Freddy et al. 1966). ??? in Yellowstone Park, resulted in average flight distance of 28.6m (Aune 1981). ??? recommended that snowmobiles remain more than 470m from mule deer, in winter, in Colorado (Freddy et al. 1986). White-tailed Deer ??? altered spatial rise, Minnesota (Dorrance 1975). ??? increased home-range sizes, Minnesota (Dorrance 1975). ??? displaced animals from the vicinity of snowmobile trails, Minnesota (Dorrance 1975). ??? routing snowmobile trails away from deer concentration areas was suggested (Eckstein et al. 1979). ??? appeared to force deer into less-preferred habitats where nighttime radiant heat loss was increased, Wisconsin (Huff and Savage 1972). ??? reduced home-range sizes, Wisconsin (Huff and Savage 1972). ??? was detrimental to energy-conserving behavioral adaptations for winter survival, Minnesota (Moen 1978). ??? provided trails that deer used, probably reducing energy expenditures, Maine (Richens and Lavigne 1978). ??? caused energy expenditures to deer in wintering areas, expenditures calculated, New York (Severinghaus and Tullar 1975). ??? effects on distribution in south-central Minnesota (Kopischke 1972). ??? snowmobile trails enhanced deer mobility and probably reduced deer energy expenditures; snowmobile disturbance did not cause abandonment of preferred bedding and feeding sites, caused deer responses varying from running out of sight to remaining in place (Lavigne 1976) (M.S. Thesis). ??? in responses to snowmobile activity, were more pronounced in a hunted than in an unhunted population of deer (Dorrance et al. 1975). ??? established snowmobile trails should be kept at least one-half mile from white-tailed deer wintering areas, in New York (Severinghaus and Tullar 1975). Trumpeter Swans ??? in Yellowstone Park ?No future activities should be planned which would increase human use of the north shore of Yellowstone Lake and the Yellowstone River from Fishing Bridge to Alum Creek after 20 October.? At the time of her study, up to 100 trumpeters wintered in Yellowstone, although numbers were usually much lower (p. 109); ?Land management agencies should direct human activities away from wintering and nesting sites. . .Winter activities such as snowmobiling or cross-country skiing will cause most swans to fly if the person can be seen. Snowmobile and ski trails should be routed away from the river courses? (Shea 1979:111) (M.S. Thesis). Subnivian Mammals/Small Mammals ??? increased mortality in small mammals beneath snow-packed trails; snow compaction by snowmobiles resulted in destruction of air spaces, reduced snow depth, increased snow density and increased thermal conductivity. Also a possibility of toxic air trapped in snow (4% carbon dioxide); destruction of wintering of small mammals at even conservative levels of snowmobile use (mammals trapped in the study: meadow vole, short-tailed shrew, white-footed mouse, ground squirrel and spotted skunk), Minnesota (Jarvinen and Schmid 1971). ??? discusses possible effects on small mammals (Aasheim 1980). ??? snowmobile compaction of snow changes the physical and thermal properties and potentially affects animals that live beneath the snow in winter (Corbet 1970). ??? effects on small mammals (Bury 1978). ??? in Minnesota, studied snowmobile use and winter mortality; used traps; meadow vole, short-tailed shrew, white-footed mouse, ground squirrel, masked shrew, spotted skunk, showed increased mortality of small mammals; destroyed subnivian air space, possibly trapped toxic air in snow. Even conservative levels of snowmobiling on trails is destructive to wintering small mammals (Jarvinen and Schmidt 1971; Schmidt 19971, Schmidt 1972). ??? snowmobile use affected snowshoe hare and red fox mobility and distribution, in Ontario, mainly within 76 meters of snowmobile trail; hares avoid snowmobile trails, foxes use them (Neumann and Merriam 1973). ??? discussed impacts of snowmobiles on the subnivian environment (Pruitt 1971). Terrestrial Invertebrates ??? preliminary studies of snowmobile compaction on invertebrates (Marshall 1972). Fish ??? ability to swim diminished by snowmobile exhaust (lab and field studies on fingerling brook trout) (Adams 1975). ??? Baldwin, M.F. 1968 ??? Bury, R.C. 1978. ??? polluted snow effects on freshwater and aquatic organisms (Hagen and Langeland 1973). ??? effects of snowmobiles on fish resources (Doan 1970). ??? ?fish stop swimming in response to ground or sound vibrations? (Gabrielson and Smith 1995:100). ??? detection and reaction of fish to infrasound (Enger et al. 1993). General ??? a literature review of wildlife harassment by snowmobiles. Documents Congressional testimony on impacts of snowmobiles on wildlife and recommends the prohibition of snowmobiles in national parks (Baldwin and Stoddard 1973). ??? in Ontario, snowmobiles caused significant changes in wildlife behavior; snowshoe hares and red foxes were disturbed mainly within 76 meters of the snowmobile trail; hares avoided snowmobiles trails, foxes used them (Neumann and Merriam 1972). ??? motorized recreational activities are generally much more destructive than nonmotorized activities (p. 194); ?the indirect impacts of recreation on wildlife are clearly substantial but even more poorly understood than the direct impacts: (p. 196) (Cole and Landres 1995). ??? lead contamination associated with snowmobile trails (Collins and Snell 1982). ??? contamination of vegetation by tetraethyl lead (Cammon and Bowles 1962). ??? cites snowmobile harassment of ungulates (Curtis 1974). ??? effects on large mammals, medium-sized mammals, small mammals (Bury 1978). ??? effects on fish and wildlife resources (Doan 1970). ??? ?When people intrude into wildlife habitat, stress on wildlife populations is one result. Snowmobile activity is a particular problem as people move into wintering areas where animals may already be stressed? (Anderson 1995:163). SNOWSHOEING/HIKING Bears ??? grizzlies do not actively defend dens from humans (Craighead and Craighead 1972). Bighorn Sheep ??? in California, protection of bighorn sheep includes regulation of hiking and sightseeing (DeMarchi 1975). ??? in California, hikers did not appear to be adversely affecting sheep on Mount Baxter; if numbers of hikers increase, effects should be monitored (Elder 1977). ??? minimizing harassment of sheep should be given top priority among management objectives (Horejisi 1976). ??? in Rocky Mountain Park, visitor use of critical bighorn sheep habitats has been reduced by trail closures (Stevens 1982). ??? impacts of hiking on Desert Bighorns (Graham 1980). ??? in Colorado, hiking influences bighorn sheep distributions and activities (Bear and Jones 1973). Birds ??? see entry for Bald Eagles (Stalmaster and Newman 1978) of this report in section ?Stress Induced by Human Activity. . .? ??? how close certain passerine bird species will tolerate an approaching human (Cooke 1980). ??? in Colorado, in winter, measured flushing responses and distances of American kestrels, merlins, prairie falcons, rough-legged hawks, ferruginous hawks, and golden eagles, when disturbed by humans walking or by vehicles. Walking disturbances resulted in more flushes than vehicle disturbances for all but prairie falcons (Holmes et al. 1983). Elk ??? in Rocky Mountain Park, elk made greater use of areas near roads as the winter-spring study progressed. People approaching animals off-roads usually caused elk to leave open areas; elk exhibited longer flight distances from an approaching person than from an approaching vehicle (Schultz and Bailey 1978). ??? in Rocky Mountain Park, snowshoers and hikers occasionally disturbed elk along trails; did not quantify elk reactions; larger herds had greater flight distances (p.36); deep snow, blowing snow, and falling snow were frequently associated with shorter flight distances (p. 45) (Schultz 1975) (M.S. Thesis). ??? on Colorado winter ranges, deer and elk avoided areas near roads, particularly areas within 200 meters of roads; deer avoided even dirt roads, some of which were used by hikers (Rost 1975) (M.S. Thesis). Moose ??? in Wyoming, moose were tolerant of close observers when no quick motions or loud noises were made (Denniston 1956). ??? in Wyoming, moose moved away when approached on foot within 20-60 feet (Altman 1958). ??? in Yellowstone, moose develop considerable tolerance for human disturbance in areas of heavy tourist pressure, but in a control area visitor disturbance caused moose to run and not return to the area until at least the next day (McMillan 1954). ??? responses of moose to presence of humans (Corbus 1972). Mule Deer ??? in Colorado, deer were interrupted for longer durations by persons afoot than by snowmobiles; recommended that persons afoot remain more than 334m from mule deer, in winter (Freddy et al. 1986). SKIING Bighorn Sheep ??? impacts of ski lifts on Desert Bighorns (Graham 1980). ??? in California, human disturbance associated with a ski resort; where human use was heavy, Desert Bighorns were forced into poorer habitats (Light 1983). Elk ??? in Yellowstone Park, resulted in average flight distance of 53.5m (Aune 1981) (M.S. Thesis). ??? in Yellowstone Park, the median distance at which elk started to move when skiers approached was 400m at Lamar and Stephen?s Creek and 15m at Mammoth. Median flight distances moved from disturbance were 42 times greater at Lamar and Stephen?s Creek than at Mammoth. No evidence of elk habituation or avoidance was associated with repeated disturbances during the study. At Lamar and Stephen?s Creek, elk were displaced from the drainage for at least the duration of human presence and on average returned within 2 days in the absence of human activity. In 5 (of 40) instances, marked elk did not return to the drainages they left when disturbed. Median energy expenditure for movement was 335 Kcal/disturbance (Cassirer et al. 1992) (M.S. Thesis). ??? in Elk Island National Park, Alberta, influence of nordic skiers on elk distribution (Ferguson and Keith 1982). ??? effects of ski area expansion on elk in mountainous terrain (Morrison 1992) (M.S. Thesis). Moose ??? in Elk Island Park, Alberta, the influence of nordic skiing on moose distribution (Ferguson and Keith 1982). Mule Deer ??? in Yellowstone Park, resulted in average flight distance of 52.4m (Aune 1981) (M.S. Thesis). Trumpeter Swans ??? in Yellowstone Park, ?No future activities should be planned which would increase human use of the north shore of Yellowstone Lake and the Yellowstone River from Fishing Bridge to Alum Creek after October 20. Land management agencies should direct human activities away from wintering and nesting sites. . .Winter activities such as snowmobiling or cross-country skiing will cause most swans to fly if the person can be seen. Snowmobile and ski trails should be routed away from river courses? (Shea 1979) (M.S. Thesis). Wolves and Grizzly Bears ??? used GIS to analyze observations of radio-collared wolves and grizzly bears in respect to human activity levels on roads, trails and at ski areas (Purves et al. 1992). ??? in Banff, Yoho, and Kootenai Parks, Canada, where winter human use exceeded 10,000 visitors per month, wolves showed aversion to such areas (Purves et al. 1992). General ??? effects of skiing on wildlife in Michigan (Young and Boyce 1971). ENERGY EXPENDITURES BY WILDLIFE FOR LOCOMOTION Bighorn Sheep ??? prediction of energy expenditures by Rocky Mountain bighorns (Chappel and Hudson 1980). ??? energy expenditures resulting from harassment were most damaging when sheep were in poor condition (Geist 1971). Elk ??? in Montana, free-ranging elk herds are generally restricted by snow depths exceeding 46cm (Beall 1974) (Ph.D. Thesis). ??? in Montana, activity, heart-rate and associated energy expenditures (Leib 1981) (Ph.D. Thesis). ??? energy expenditures for several activities were measured using indirect calorimetry with 5 mule deer and 8 elk; energy expenditures for locomotion in snow increased curvilinearly as a function of snow depth and density. ?The additional energy drain on a wintering population on poor range may be an important factor in survival? (Parker et al. 1984:486). Mule Deer ??? see entry for Parker et al. 1984 under ?ELK,? above. ??? in Colorado, when forced from lying to running by persons afoot, increased energy expended from 9 Kcal to 54-127 Kcal; for snowmobiles, this increase was from 2 to 10-25 Kcal (Freddy et al. 1966). White-tailed Deer ??? in New York, snowmobile trails should be kept at least one-half mile from deer concentrations in winter; used energy expenditure calculations to demonstrate danger of snowmobile harassment to winter-stressed deer (Severinghaus and Tullar 1975). ??? analysis of deer responses to environmental changes should be on a sequential basis rather than as an overall average; a deer does not respond the same to equally cold weather conditions in November and March. In March, the fat reserve is depleted, females may be carrying fetuses, and requirements for gestation are increasing rapidly (Moen 1976). ??? in Maine, deer frequently followed snowmobile trials (Richens and Lavigne 1978). General ??? ?While all impacts on animals cannot be documented, it is clear that loss of body reserves has negative effects on the individuals concerned. When combined with other factors such as stressful winters, the animals could die or fail to reproduce. In such cases, populations would decline. When a disturbance occurs over a large region for many years, the population may be unable to continue to reproduce and survive in the area? (Anderson 1995:164). ??? running increased the need of ruminants for food (Geist 1971). ??? morphological parameters affecting ungulate locomotion in snow (Telfer and Kelsall 1979). ??? energetics and mechanics of terrestrial locomotion (Taylor et al. 1981). STRESS INDUCED BY HUMAN ACTIVITY TO WILDLIFE SPECIES PRESENT IN WINTER IN YELLOWSTONE NATIONAL PARK Bald Eagles ??? human disturbance adversely affected wintering bald eagle distribution and behavior. Distribution patterns were significantly changed, resulting in displacement of eagles to areas of lower human activity, simulated disturbances of persons afoot, in Washington state (Stalmaster and Newman 1978). ??? human disturbance is most serious for eagles that depend on large fish or mammal carcasses as their major food source (Anthony et al. 1995). ??? human disturbance is an important factor in nest site selection by bald eagles (Murphy 1965). ??? modeling cumulative effects of humans on bald eagle habitat (Montopoli and Anderson 1991). ??? in Washington state, sensitivity of wintering bald eagles to human disturbance (Russell 1990). ??? human disturbance of an avian scavenging guild; includes eagles (Skagen 1980; Skagen et al. 1991). ??? human activities had adverse effects on distribution and behavior of wintering bald eagles in Washington state; measured flight distances from simulated human disturbances (Stalmaster and Newman 1978; Stalmaster et al. 1993); high levels of human disturbance during winter could increase energy demands and result in increased mortality rates (Stalmaster and Gessaman 1984). Bighorn Sheep ??? harassment led to increased energy expenditures and was most damaging when animals were in poor condition (Geist 1971). ??? at Grand Canyon, studied helicopters and sheep time budgets; frequent alerting affected food intake (Stockwell et al. 1991). ??? in Wyoming, all mountain recreationists may stress sheep that they encounter (Thorn et al. 1979). ??? harassment has significant impacts on individuals and populations and reduces fitness; passive harassment produces no visible response but may have psychological and physiological effects on sheep (Horejsi 1976). ??? in California, human disturbance by recreationists may be limiting sheep populations; measured heart rate responses to harassment (Stemp 1983) (M.S. Thesis). ??? cardiac and behavioral responses of bighorn sheep to human disturbance; heart rates varied inversely with distance from road (MacArthur et al. 1982). ??? in Rocky Mountain Park, disturbance in critical sheep habitats has been reduced by closure of trails (Stevens 1982). Black Bears ??? assessed the effects of recreational activities on denning ecology of 19 bears for 3 winters in Nevada and California; ?data implied that protecting black bear denning areas from human disturbance in winter is important to minimize cub abandonment and needless energetic expenditures by increased winter activity? (Goodrich and Berger 1993). Canada Geese ??? Geese seemed to avoid or leave locations where disturbances restricted feeding (Austin 1988) (Ph.D. Thesis). Coyotes ??? abortion and consumption of fetuses by coyotes following abnormal stress (Gipson 1970). Elk ??? people concentration areas should be one-half mile from elk feeding sites in Wyoming (Ward et al. 1973). ??? positive correlation of man-caused disturbance and elevated heart rates in telemetered elk; highest incidence occurred with loud noises and direct interaction (Ward 1977). ??? nutrition during gestation in relation to successful reproduction (Thorne et al. 1976). ??? in Yellowstone Park, ?recurring long periods of limited areas, such as at campsites, appeared to cause limited shifts in elk distribution? (Chester 1976) (M.S. Thesis). Other Wildlife ??? the physiology of alarm in deer mice (Rosenmann and Morrison 1974). ??? a 40kg unstressed pronghorn in winter would necessarily consume 900 grams dry matter/ day for maintenance and growth. . . 32% higher for animals which were moderately active, and variably increased by cold temperatures (Wesley et al. 1973). ??? how close certain passerine birds will tolerate approaching humans (Cooke 1980). ??? human disturbance of an avian scavenging guild (Skagen 1988; Skagen et al. 1991). General ??? ecosystem behavior under stress (Rapport et al. 1985). ??? ?In contrast to sizeable literature of direct effects on wildlife, very few studies have documented impacts resulting from habitat changes induced by recreational activities; . ..the indirect effects of recreation on animal populations are likely to be substantial, but there is little rigorous documentation of these impacts. For invertebrates, amphibians, reptiles, small birds, small mammals, and many fish, these indirect effects are likely to be more substantial than direct impacts of recreationists? (Cole and Landres 1995:192-93). ??? snow-based recreation may result in facility construction, fragmenting and reducing the availability of critical habitat; of the snow-based recreational activities, ?the impacts of snowmobiling appear to be most pronounced? (Cole and Landres 1995:186). text continued on website

Keywords: Grand Teton National Park, Yellowstone National Park, Animal, passerine , perching , Passiformes, Bird, Aves, Eagle, Bald eagle, Haliaeetus leucocephalus, Nest, Nesting, Human activity, Snake River, Greater Yellowstone Ecosystem, habitat, wildlife, management, migration, behavior, breeding, food, waterfowl, fish, mammal, Ursidae, Ursus arctos horribilis, Bear, Grizzly bear, Black bear, Ursus americanus, den, denning, ungulate, elk, cervidae, Cervus elaphus, wapiti, sheep, bighorn sheep, Ovis canadensis, Bison bison, Bison, Idaho, hunting, deer, mule deer, Odocoileus hemionus, Radio collar, White-tailed deer, Odocoileus virginianus, Swan, Anatidae, Water bird, Trumpeter swan, Olor buccinator, Rodentia, Rodent, Vole, Cricetidae, Meadow vole, Microtus pennsylvanicus, insectivore, Shrew, Soricidae, Sorex, Mouse, Muridae, White-footed mouse, Peromyscus leucopus, Squirrel, Ground squirrel, Sciuridae, Townsend's ground squirrel, Spermophilus townsendi, Richardson's ground squirrel, Spermophilus richardsonii, Spotted skunk, Mephetis mephitis, Mustelidae, Trapping, fish, Pisces, Trout, Brook trout, Salvelinus fontinali