UBC Theses and Dissertations
The impacts of transportation corridors on grizzly and black bear habitat use patterns near Golden, B.C. Munro, Robin Helen
The focus of the study was on the influence of transportation corridors (Tcorridors), which included the Trans-Canada Highway (TCH), Canadian Pacific Railway, and Highway 95, on the distribution and habitat use patterns of black and grizzly bears near Golden, B.C. The relationship among bears, habitat, and T-corridors was examined using compositional analysis and univariate comparisons in conjunction with a Geographic Information System. During 1994-1997, 40 radio collared grizzly and 24 radio collared black bears were located 1061 and 505 times, respectively. Because the Tcorridors followed major valleys and crossed a mountain pass where slide chutes and riparian areas predominated, I expected bears to be displaced from these habitat types during spring. During spring, 85% of all collared grizzly bears used areas adjacent to Tcorridors less than expected by random use. The habitat analysis further revealed that although slide chutes were selected the majority of bears selected chutes adjacent to corridors less than expected, however, 15% of the radio collared individuals used slide chutes adjacent to T-corridors more than expected. These bears were all among those trapped within a home range radius of the T-corridors and only one of these 6 bears was an adult female. Eighty-eight percent of collared black bears used areas within 500 m of the corridors during the spring. At this time both male and female black bears selected right-of ways and timbered areas more than expected. Use of the rights-of-way increased the black bears' risk of mortality. To reduce mortality of black bear and return bears to a more natural diet, vegetation along the rights-of-way should be replaced with less palatable plant species. Because of the potential for habitat and population fragmentation among the grizzly bears, areas where bears cross the corridors should be identified before the TCH is twinned. If possible, portions of the highway that contain such crossing areas should be protected from further development. If development must proceed, areas along the T C H which have the potential to act as crossing-underpasses for bears should be enhanced to encourage bear use and improve conductivity.
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