Spring Foraging and Forest Damage by Black Bears in the Central Coast Ranges of Oregon
Damage to trees by black bears (Ursus americanus) is an ongoing problem in west-coastal North America. We studied damage to Douglas-fir (Pseudotsuga menziesii) during spring by comparing food habits of bears between an area with high damage (north, x_N = 29.4 trees damaged/ha, SE = 6.9) and an area with low damage (south, x_S = […]
Brown Bear Habitat Quality in Gorski Kotar, Croatia
The brown bear (Ursus arctos) population in Croatia is a possible source of bears for reintroducing and augmenting disappearing European brown bear populations in western Europe. For successful reintroduction, knowledge about bear habitat quality of both source and target areas is necessary. We developed a habitat suitability index (HSI) model to assess European brown bear […]
Selection of Denning Caves by Brown Bears in Trentino, Italy
We studied 21 brown bear (Ursus arctos) dens in the mountains of the northeast Brenta range in Trentino, Italy. Of these, 2 dens were located during the late 1970s using radio-tracking, 1 den was located in 1989 by a different researcher, and 18 dens were located by the authors between 1988 and 1994. Two dens […]
Brown Bear Use of Ant Mounds in Scandinavia
Brown bears (Ursus arctos) in Scandinavia forage in early spring on ants (Formicidae) they excavate from large ant mounds. We collected information on the selection and handling of ant mounds by bears by following their tracks in snow during 3 consecutive spring seasons in 1970-72 in the Vassfaret area of central southern Norway. The density […]
Black Bear Home Range Dynamics and Movement Patterns during a Gypsy Moth Infestation
During 1985-89 in Shenandoah National Park (SNP), Virginia, a severe gypsy moth (Lymantria dispar) infestation resulted in wide-spread overstory canopy defoliation and a complete acorn crop failure in defoliated areas. We believed canopy opening and food supply alterations would lead to increased black bear (Ursus americanus) movements, especially in the fall as bears searched for […]
Den Use and Social Interactions of Polar Bears during Spring in a Dense Denning Area on Herald Island, Russia
Estimates of the number of polar bear (Ursus maritimus) maternity dens and observations of social interactions were made over 40 days in a dense denning area on Herald Island, Russia, following female emergence from dens. Twenty-six dens were found throughout the accessible areas of the island (density = 6.2 dens/km^2); 11 were concentrated in the […]
Habitat Preferences of Polar Bears in the Hudson Bay Lowlands during Late Summer and Fall
From late July through early November, polar bears (Ursus maritimus) in western Hudson Bay are on shore because the annual ice melts. During this period, bears segregate by age and sex classes into different habitats. We investigated habitat selection using the locations of 1,131 captures made from 1966 to 1994. Adult males, the most dominant […]
Grizzly Bear Habitat Effectiveness Model for Banff, Yoho, and Kootenay National Parks, Canada
Changes in land use are currently accelerating development pressures in the Central Canadian Rocky Mountains. Given the existing and proposed human influences in the region, cumulative effects are a major issue, especially for carnivores. I quantitatively and qualitatively assess the effects of human actions on grizzly bears (Ursus arctos horribilis) and their habitat. Since 1985, […]
Complex Movement and Scale-Free Habitat Use: Testing the Multi-Scaled Home-Range Model on Black Bear Telemetry Data
Black bears (Ursus americanus) use the landscape over relatively coarse scales compared to many other mammals. We analyzed the way these animals relate to their habitat in general terms using a statistical approach. A priori, we conceived of scale-specific and scale-free types of habitat use. The scale-specific model assumes that an individual’s movements are due […]
Preliminary Evaluation of GPS Collars for Analysis of Habitat Use and Activity Patterns of Black Bears
Prototype radiocollars incorporating global positioning system (GPS) receivers were attached to 8 adult female black bears (Ursus americanus) in March (5) and June-July (3) of 1994 in northern Ontario, Canada. Collars contained a 6-channel GPS receiver, an independent very high frequency (VHF) tracking beacon, an activity sensor, and a computer-memory module. The total package weighed […]