Snowmobilers Keep Caribou Out of Prime Habitat

Field research now confirms what anecdotal evidence previously suggested: snowmobiling causes mountain caribou to abandon high-quality winter habitat. Three winters of surveying a cluster of subalpine ridges failed to find the threatened ecotype of woodland caribou at a popular backcountry recreation destination for snowmobilers. Wildlife biologists spotted 22 animals there during a fourth year, but these were mainly relegated to places that snowmobiles couldn't access.

The area monitored is the wintering grounds for the Hart Ranges caribou herd, located in the mountains 100 km east of Prince George in central British Columbia. The herd also uses four nearby subalpine ridges, separated from the snowmobiling playground and each other by deep valleys. These high-elevation forests receive few, if any, visits from people on snowmobiles.

Each year the March surveys tallied numerous caribou on all four ridges where snowmobilers seldom go. Mountain caribou were counted at an average density of 0.41 animals per square kilometre. The snowmobiling area of 134 km² contains top-quality caribou terrain and researchers would expect to find about 54 caribou there during late winter. Instead, they usually saw none.

It turns out that motorized recreationists and mountain caribou prefer the same type of late-winter habitat. Snowmobilers concentrate their activity in the areas most ideal for the Hart caribou herd. This study provides evidence for the first time that heavy snowmobile traffic can completely displace caribou from prime winter habitat. These results help resolve the contentious issue of whether restricting snowmobile access can contribute to recovering the dwindling populations of this threatened species.