Bears and Research
in the Canadian
Rockies

Bears and
People

 Roads and Habitat Use 
Bears and Roads

A “dynamic tension” exists between attraction to and avoidance of roadside habitats (Gibeau and Herrero 1998) Bears can be attracted to natural or introduced vegetation along road and railway right-of-ways, carcasses of animals that have been killed from collisions with vehicles or trains, or to non-natural attractants such as spilled grain from train cars or trucks. Alternatively, they can be alienated from using quality habitats adjacent to roads because of the disturbance from traffic, people stopping or approaching on foot, and possibly by smells, sounds and other factors associated with them.

Roadside habitat-use research
Munro investigated the impacts of transportation corridors (roads and railways) on grizzly and black bear habitat-use patterns near Golden, British Columbia. Her results showed that in spring, black bears of both sexes used habitats adjacent to major transportation corridors more than was expected, but that female grizzly bears used them less than was expected. She observed that other researchers have also found that black bears exploit roadside habitats more readily than grizzly bears, and noted that these findings support the hypothesis that black bears are more tolerant of human disturbance. (Munro 1999)

Research in the Central Rockies Ecosystem (CRE) supports Munro’s findings that female grizzly bears are especially sensitive to road-side disturbances, as female grizzly bears in the CRE were located further than males from paved roads regardless of habitat quality. The CRE research also showed that:

• the combination of traffic volume and highway configuration overrides a bear’s attraction to high quality habitats for high speed/high volume roads such as the Trans- Canada Highway 
• males exploiting higher quality habitats near roads used cover or darkness
  (Gibeau 2000)

Grizzly bears using roadside habitats in the Flathead River drainage also tended to use roadside habitats (defined as habitats less than 100m from roads) at night, but they used them less than expected even though this habitat contained important bear foods. Unlike adult female grizzly bears in the Golden area or in the CRE, females in the Flathead used roadside habitats significantly more than adult males. (McLellan and Shackleton 1988)

Footnotes and Sources Cited