Grizzlies rely on wildlife corridors to get around

Many grizzly and black bears are using wildlife crossings in a Canadian national park, researchers report. The animals probably rely on the corridors to avoid busy roads and seek out food.

The effectiveness of wildlife corridors “remains surprisingly unknown,” the study authors write in Conservation Biology. The crossings are intended to help animals navigate fragmented habitat. But these structures are expensive to build, and skeptics wonder whether the investment is worth it.

In Canada’s Banff National Park, 25 wildlife corridors criss-cross an area with a four-lane highway, golf course, and ski resorts. The team set out barbed wire on 20 of the crossings to catch hair samples from the bears. Then the researchers conducted genetic tests on the samples to figure out how many individual bears had passed through.

From 2006 to 2008, 15 grizzlies and 17 black bears traversed the corridors, the team reports. Grizzlies preferred the open crossings, such as overpasses, while the black bears were also comfortable with small culverts. The authors estimate that at least 15-20 percent of the grizzly population and 11-18 percent of the black bear population used the corridors. — Roberta Kwok | 14 June 2013

Source: Sawaya, M.A. et al. 2013. Demographic connectivity for ursid populations at wildlife crossing structures in Banff National Park. Conservation Biology doi: 10.1111/cobi.12075.

Image © Heidi Brand |