Conclusions:
Despite the fact that valuable grizzly habitat tends to coincide with the location of roads, grizzlies strongly avoided roads regardless of traffic volume, suggesting that even a few vehicles can displace bears from adjacent habitats.
Thresholds/Learnings:
Grizzlies strongly avoided areas within 100m of all roads
Synopsis: This study aimed to determine whether grizzly bears were displaced by roads associated with resource extraction industries in the Rocky Mountains. Since many habitats close to roads contained important bear foods, researchers expected bears to frequent these roads, despite the presence of human activity. However, study results indicated that grizzlies strongly avoided roads regardless of traffic volume, suggesting that even a few vehicles can displace bears from adjacent habitats. Roads were used by bears more at night than during the day. In general, roads increased access for legal and illegal hunters, which are a major source of adult grizzly mortality. Roads often follow valley bottoms and pass through riparian area, which are important habitats for grizzly bears. When roads do displace bears, increased pressure is placed on similar adjacent habitats in undisturbed regions.
