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Sizes of home ranges are largely determined by distribution of food. Rapid digestibility of high-quality food and rapid mass gain are essential if winter dormancy is to be a viable strategy (Bunnel and Hamilton, 1983; Hamer and Herrero, 1987). Where food is abundant, such as at salmon streams, berry patches, carrion, and garbage dumps, brown bears congregate in high densities and their home ranges become reduced (Craighead, 1979; Hamilton and Bunnel, 1987; Stonorov and Stokes, 1972). Size of home range is also influenced by age, sex, social status, condition of animal, foraging habits, distribution and availability of food and cover, topography, location of day beds and dens, and proximity of mates (Craighead, 1979; LeFranc et al., 1987; Murie, 1985; Roth, 1983). Females have smaller home ranges than males which may lessen the female's chance of encountering aggressive males and thus increase security for herself and her young. Upon mating, young females tend to stay near the maternal home range. Home ranges of mature males usually encompass home ranges of several estrous females, thus increasing the probability of breeding. Larger males may also have greater energy needs and wander farther in search of food (Craighead and Mitchell, 1982). Subadult males tend to disperse far from maternal ranges, possibly due to low social status and aggression from adults of both sexes. Sizes of home ranges (km2) of adult males and females, respectively, in North America are: Kodiak Island, 24, 12; Alaska Range, 710, 132; western Brooks Range, 776, 220; eastern Brooks Range, 702, 382; northern Yukon, 286, 121; interior British Columbia, 297, 79; Jasper National Park, 916, 244; Yellowstone ecosystem, 828, 384; Mission Mountains, 1,398, 133; and Cabinet/ Yaak ecosystem, 1,290, 430 (LeFranc et al., 1987).
Population density is affected by topography, cover, food abundance, and spacing behavior. Densities are: Kodiak Island, 1/1.5- 4 km2; Alaska Peninsula, 1/16 km2; Denali National Park, 1/24-38 km2; eastern Brooks Range, 1/83-304 km2; northern Yukon, 1/48 km2; interior British Columbia, 1/18-32 km2; Jasper National Park, 1/86-102 km2; Cabinet Mountains, 1/44 km2; Yellowstone ecosystem, 1/50 km2 (LeFranc et al., 1987); Norway, 0.6-7.9/ 1,000 km2 (Mysterud and Falck, 1989); Gorski Kotar, Yugoslavia, 1/10 km2 (Frkovic et al., 1987); mountainous regions of Ural, Altai, and eastern Siberia, 4-6/100 km2 (Vereschagin, 1976); Okhotsk Sea, 1/10 km2; and Kamchatka, 0.6/10 km2 (Kistchinski, 1972).
Source: Pasitschniak-Arts, Maria. Ursus arctos Mammalian SpeciesNo. 439, Ursus arctos (Apr. 23, 1993), pp. 1-10.
Sizes of home ranges are largely determined by distribution of food. Rapid digestibility of high-quality food and rapid mass gain are essential if winter dormancy is to be a viable strategy (Bunnel and Hamilton, 1983; Hamer and Herrero, 1987). Where food is abundant, such as at salmon streams, berry patches, carrion, and garbage dumps, brown bears congregate in high densities and their home ranges become reduced (Craighead, 1979; Hamilton and Bunnel, 1987; Stonorov and Stokes, 1972). Size of home range is also influenced by age, sex, social status, condition of animal, foraging habits, distribution and availability of food and cover, topography, location of day beds and dens, and proximity of mates (Craighead, 1979; LeFranc et al., 1987; Murie, 1985; Roth, 1983). Females have smaller home ranges than males which may lessen the female's chance of encountering aggressive males and thus increase security for herself and her young. Upon mating, young females tend to stay near the maternal home range. Home ranges of mature males usually encompass home ranges of several estrous females, thus increasing the probability of breeding. Larger males may also have greater energy needs and wander farther in search of food (Craighead and Mitchell, 1982). Subadult males tend to disperse far from maternal ranges, possibly due to low social status and aggression from adults of both sexes. Sizes of home ranges (km2) of adult males and females, respectively, in North America are: Kodiak Island, 24, 12; Alaska Range, 710, 132; western Brooks Range, 776, 220; eastern Brooks Range, 702, 382; northern Yukon, 286, 121; interior British Columbia, 297, 79; Jasper National Park, 916, 244; Yellowstone ecosystem, 828, 384; Mission Mountains, 1,398, 133; and Cabinet/ Yaak ecosystem, 1,290, 430 (LeFranc et al., 1987).
Population density is affected by topography, cover, food abundance, and spacing behavior. Densities are: Kodiak Island, 1/1.5- 4 km2; Alaska Peninsula, 1/16 km2; Denali National Park, 1/24-38 km2; eastern Brooks Range, 1/83-304 km2; northern Yukon, 1/48 km2; interior British Columbia, 1/18-32 km2; Jasper National Park, 1/86-102 km2; Cabinet Mountains, 1/44 km2; Yellowstone ecosystem, 1/50 km2 (LeFranc et al., 1987); Norway, 0.6-7.9/ 1,000 km2 (Mysterud and Falck, 1989); Gorski Kotar, Yugoslavia, 1/10 km2 (Frkovic et al., 1987); mountainous regions of Ural, Altai, and eastern Siberia, 4-6/100 km2 (Vereschagin, 1976); Okhotsk Sea, 1/10 km2; and Kamchatka, 0.6/10 km2 (Kistchinski, 1972).
Source: Pasitschniak-Arts, Maria. Ursus arctos Mammalian SpeciesNo. 439, Ursus arctos (Apr. 23, 1993), pp. 1-10.