Relationships among grizzly bears, highways, and habitat in the Banff-Bow Valley, Alberta, Canada

Abstract

Banff National Park and surrounding lands constitute one of the most developed landscapes in the world where grizzly bears (Ursus arctos) still survive. We examine the relationships among roads, grizzly bears, and their habitat in a protected area with low road density but dominated by a major transportation corridor and highway system. We examined grizzly bears' spatial response to roads, road-crossing behaviour, crossing-location attributes, and habitat and temporal patterns of cross-road movements. Grizzly bears used areas close to roads more than expected, particularly roads with low traffic volume (low volume). Habituated bears were closer to roads than wary bears. Males were closer to low-volume roads than females but crossed roads less than females during the berry season. Bears were more likely to cross low-volume roads than high-volume roads and were more likely to cross at points with higher habitat rankings. In addition, bears were more likely to cross high-volume roads when moving from areas with low habitat values to areas with high habitat values. Efforts to prevent loss of habitat connectivity across highways should involve maintenance of high-quality grizzly bear habitat adjacent to roads and should address the effects of traffic volume on the road-crossing decisions of grizzly bears.