Conclusions:
Grizzly bears avoid high volume roads (25,000 vehicles/day). High quality habitat determines movement decisions relative to roads. Grizzly bears will cross high volume roads to access high-quality habitat. Grizzly bears use areas close to roads more than expected, in particular low-volume roads (10,000 vehicles/day). Prevent loss of habitat connectivity with the following mitigation: maintain high-quality habitat adjacent to roads, install continuous highway fencing and create wildlife passages.
Thresholds/Learnings:
Synopsis: The study examined the relationships among grizzly bears, their habitats and roads in Banff National Park, a protected area characterized by a major transportation corridor. This corridor is comprised of the Trans-Canada Highway and other low-volume roads that provide visitor access to the park. Corridors such as this one constitute a significant linear disturbance in the landscape which are known to significantly affect landscape connectivity, habitat, movement patterns and increased species mortality, leading to decreased populations and species viability for grizzly bear populations.
Three main analyses were undertaken as part of the research and included the spatial distribution of grizzly bears relative to roads, road crossing attributes and road crossing indices. The study took into consideration the quality of habitat for grizzly bears in the lower elevation montane ecozone located in the study area. The study identified two main patterns: grizzly bear avoidance of high volume roads (25,000 vehicles/day) and the importance of high quality habitat in determining movement decisions relative to roads. Specifically, grizzly bears avoided crossing high volume roads; however, were more likely make the crossing to access high-quality habitat. Further, the research found that grizzly bears used areas close to roads more than expected, in particular low-volume roads (10,000 vehicles/day).
The findings suggest that the cumulative effects of linear disturbances within the transportation corridor can limit access to important habitats and negatively affect grizzly bears in the Banff National Park ecosystem. The study recommends that land managers and transportation planners in the Bow Valley prevent loss of habitat connectivity with the following mitigation: maintain high-quality habitat adjacent to roads, install continuous highway fencing and create wildlife passages. Mitigation should seek to address effects of traffic volume and road-crossing decisions and recommendations were informed by research findings and a review of mitigation literature.
