Relationships among grizzly bears, roads and habitat in the Swan Mountains, Montana

Relationships between grizzly bears, habitat, and roads were investigated between 1990 and 1994 in the Swan Mountains, Montana. Relationships were examined at three levels of resource selection. Differences existed between habitat and road features within, and those outside, the multi-year composite female grizzly bear home range. Using logistic regression, large resource selection probability functions were obtained for the subalpine zone within multiple-use lands having no roads. Selection probability was zero for private lands and declined as total road density increased. Within seasonal ranges, most grizzly bears favoured low temperate and temperate elevation zones over the subalpine zone during all seasons. Relative to forested habitats, avalanche chutes were positively selected for during all seasons, but especially in spring. Shrub lands and cutting units were important to most bears during summer and autumn. Grizzly bears were more closely associated with higher total road densities during spring than during other seasons. When in low temperate habitats, most bears used habitats with lower total road density than occurred randomly. Seasonal use by grizzly bears of areas within a 0.5 km buffer surrounding roads was evaluated. Most grizzly bears exhibited either neutral or positive selection for buffers surrounding closed roads and roads receiving 10 vehicles per day. Between 1988 and 1994, eight grizzly bears were killed by humans. These deaths were directly influenced by road access and unnatural food sources. These deaths, in addition to natural mortality, were too great to promote local population growth.

[1]  Liping Xu,et al.  [Response of maize emergence rate and yield to soil water stress in period of seeding emergence and its meteorological assessment in central area of Jilin Province]. , 1988, Ying yong sheng tai xue bao = The journal of applied ecology.

[2]  R. Ellis,et al.  Responses of Grizzly Bears to Logging Truck Traffic in the Kimsquit River Valley, British Columbia , 1987 .

[3]  David W. Hosmer,et al.  Applied Logistic Regression , 1991 .

[4]  Gary C. White,et al.  Analysis of Wildlife Radio-Tracking Data , 1990 .

[5]  Anne Lohrli.  Chapman and Hall , 1985 .

[6]  F. Bunnell,et al.  Tests of hypotheses for sexual segregation in grizzly bears , 1995 .

[7]  David J. Mattson,et al.  The Effects of Developments and Primary Roads on Grizzly Bear Habitat Use in Yellowstone National Park, Wyoming , 1987 .

[8]  L. Mech.  Wolf Population Survival in an Area of High Road Density , 1989 .

[9]  Bryan F. J. Manly,et al.  Resource Selection by Animals , 1993, Springer Netherlands.

[10]  Timothy L. Manley,et al.  Road and Trail Influences on Grizzly Bears and Black Bears in Northwest Montana , 1990 .

[11]  William J. Paul,et al.  WOLF DISTRIBUTION AND ROAD DENSITY IN MINNESOTA , 1988 .

[12]  P. Zager,et al.  Logging and Wildfire Influence on Grizzly Bear Habitat in Northwestern Montana , 1983 .

[13]  R. Mace,et al.  Local Food Habits of the Grizzly Bear in Montana , 1986 .

[14]  Richard D. Mace,et al.  ESTIMATING GRIZZLY BEAR POPULATION SIZE USING CAMERA SIGHTINGS , 1994 .

[15]  P. Krausman,et al.  Clarification of a technique for analysis of utilization-availability data , 1984 .

[16]  D. Mattson.  Human impacts on bear habitat use , 1990 .

[17]  S. J. Press,et al.  Choosing between Logistic Regression and Discriminant Analysis , 1978 .

[18]  Southeastern Forest Experiment Station.  General technical report , 1985 .

[19]  Montana.,et al.  Grizzly bear recovery plan , 1982 .

[20]  James L. D. Smith,et al.  Home ranges of sloth bears in Nepal: implications for conservation , 1995 .

[21]  P. Martín.  Factors Influencing Globe Huckleberry Fruit Production in Northwestern Montana , 1983 .

[22]  R. Thiel,et al.  Relationship between Road Densities and Wolf Habitat Suitability in Wisconsin , 1985 .

[23]  R. C. Belden,et al.  Feasibility of Translocating Panthers into Northern Florida , 1993 .