New study confirms ATVs on back country trails harmful to bears

Grizzly bears tend to avoid back country trails where all-terrain vehicles and dirt bikes are operating, new University of Alberta research shows.

That could potentially hamper efforts to increase bear populations in the province, said Andrew Ladle, who has a PhD in ecology and is lead author on the study.

"Many of these trails provide rich food sources for bears, so if they are using them less frequently they may have decreased access to high-quality food," said Ladle.

The study is the first to look at the effects of ATVs and dirt bikes on grizzly bear and black bear activity on trails, he said Thursday.

"We had expected bears to leave areas where there was motorized activity altogether," said Ladle. "Instead, we found that the bears are still in the area and simply using these trails less frequently."

Grizzly bear is threatened species

This is particularly significant for grizzly bears, which are listed as a threatened species in Alberta, he said.

The "increased stress levels" and limited access to quality food could prevent bears from breeding, said Ladle.

"Although this isn't associated with a direct influence on mortality, it can potentially affect grizzly bear reproduction," he said.

The study compared data from trail cameras in 192 locations in Jasper National Park, where ATVs are not allowed, and outside the park boundary, where they are.

The data was gathered from June 15 to Aug. 25, 2014.

In areas outside the park where heavy ATV use overlaps with high-quality grizzly bear habitat, provincial officials may want to rethink how access to those areas is controlled, he said.

His recommendation comes with a caution.

"In order to take drastic changes in access management, and so forth, I do believe additional evidence would be required," said Ladle.

The paper was published Thursday in the academic journal PLOS.