Yohimbine as an Antagonist to Ketamine-Xylazine Immobilization in Black Bears
During May-July, 1981-85, 111 black bears (Ursus americanus) were immobilized with ketamine (x̄ = 5.0 mg/kg) and xylazine (x̄ = 2.0 mg/kg). Time from complete immobilization to recovery (walking) ranged from 22 to 140 min. We experimented with yohimbine (0.04-0.35 mg/kg) to counteract immobilization and thereby speed recovery. Eleven bears were given intramuscular injections of […]
Den Selection and Use by Black Bears in Michigan’s Northern Lower Peninsula
I located 51 different black bear (Ursus americanus) den sites (28 of males, 23 of females) in Michigan’s Northern Lower Peninsula between September 1977 and March 1980. During the 3-winter period, 10 radio-tagged males denned in swamp habitat 24 times, lowland habitat 2 times, and upland habitat 2 times; 7 females denned in swamp habitat […]
Winter Denning of Black Bears in East-Central Ontario
One hundred ten dens of 57 black bears (Ursus americanus) were examined in east-central Ontario from 1976 to 1980. Most bears denned within summer range boundaries. Entry dates ranged from 20 September to 29 November. Denning sequence was yearlings, pregnant females, solitary females, females with cubs, adult males, and subadults of both sexes. Bears that […]
Denning Ecology of Brown Bears on Admiralty and Chichagof Islands
From fall 1981 through fall 1985, 58 radio-collared brown bears (Ursus arctos) were followed to winter dens on Admiralty and Chichagof islands in southeast Alaska. One hundred twenty-one dens were located and their site characteristics described. Mean dates of den entry and emergence, 30 October and 2 May, varied between sexes and among years. Mean […]
Denning Ecology of Three Black Bear Populations in Alaska
Between 1978 and 1985, denning ecology of the black bear (Ursus americanus) was studied in the Kenai Peninsula, the Susitna River basin, and Prince William Sound, Alaska. All these populations are near the northern extension of their range. In different years the mean number of days spent in dens varied from 189 to 233 days; […]
Movements and Habitat Use of Japanese Black Bears in Nikko
The Effects of Developments and Primary Roads on Grizzly Bear Habitat Use in Yellowstone National Park, Wyoming
Aerial locations of radio-instrumented grizzly bears (Ursus arctos) were used to analyze effects of human activity associated with developments and primary roads on grizzly bear habitat use in Yellowstone National Park. Grizzly bear occupancy of habitat near human facilities was reduced, efficient foraging strategies were disrupted, and cohorts tending to be subordinate or security-conscious were […]
Responses of Grizzly Bears to Logging Truck Traffic in the Kimsquit River Valley, British Columbia
To assess the impacts of log truck traffic on grizzly bears (Ursus arctos) in Coastal British Columbia, the zone of hauling activity (zha) in the Kimsquit River study area was mapped using the sound levels (dB[C]) recorded at 25-m intervals along 200-m transects perpendicular to the road. The logging road bisected the home ranges of […]
Timber Harvest and Black Bear Population Dynamics in a Southern Appalachian Forest
Habitat capability models are frequently used in long-term land management planning to evaluate the effects of management alternatives on wildlife populations. We believe that the relationships between timber harvest operations and black bear (Ursus americanus) population dynamics in the southern Appalachians make habitat capability models alone inadequate to predict long-term population response to timber harvest. […]
Black Bear Home Range Overlap in North Carolina and the Concept of Home Range Applied to Black Bears
Theoretical and empirical research indicates that territoriality is related to habitat productivity. Female black bears (Ursus americanus) exhibit intrasexual territoriality in northern North America where habitat productivity is low. However, telemetry studies show that adult female black bears in the Southern Appalachian Mountains, where productivity is higher, exhibit considerable home range overlap. This overlap was […]
