Even low levels of backcountry recreation linked to fewer wolverines, study finds

Skiers, snowshoers and snowmobilers heading into the backcountry are having a bigger impact on wolverines than previously understood, according to a new study.

New research across the Columbia and Rocky Mountain ranges, including Banff National Park, found areas with more recreation and roads had fewer wolverines living there.

Researchers already knew wolverines stayed away from people. But the study suggests the impact goes beyond simply avoiding someone walking on a trail.

“Recreation is not as benign as we thought in the past,” said study author Mirjam Barrueto.

Barrueto and her team at the University of Calgary, working with Parks Canada, studied wolverines across 80,000 square kilometres. She chose the area because it was particularly good habitat for the animals.

Based on earlier research, scientists expected the area could support roughly 500 to 600 wolverines.

The study results show that only about 300 are living there.

The study found winter activities had more of an impact than summer activities.

“Winter recreation generally has a much bigger footprint because in summer you cannot really go anywhere unless there’s a trail, and there’s not that many trails in our study area,” she said. “In winter, everything is covered with snow. Skiers, snowmobilers, heli-skiers, can essentially go everywhere.”

Barrueto said she was surprised by just how far people reach into the backcountry, which she had thought of as remote wilderness.

Female wolverines can be particularly vulnerable to disturbance while raising their young, she said, as they give birth in the winter and den in specific areas. If disturbed, they may leave places where they’ve stored food, or waste their energy avoiding people instead of taking care of their kits.

Barrueto says one solution is to find these areas and temporarily keep people out during those sensitive winter months. 

Female wolverine numbers also dropped as the number of roads increased; the same was not true for males.

Jason Fisher, a wildlife ecologist and professor at the University of Victoria who was not involved in the study, says the study area is mostly undisturbed land, which is what makes the findings a big deal.

“We rely on the Rocky Mountains. and the national parks in particular, as an anchor for wolverine populations,” he said. “And the fact that they’re doing so poorly inside this area that’s supposed to be protected is really quite alarming.”

Previous research found wolverines may start avoiding an area if as few as three or four groups pass through over a couple weeks.

That means it isn’t necessarily the number of people that matters, says Barrueto. Even a small amount of human activity can be enough to reduce the number of wolverines living in the area.

“Whether you have 100 people per day or a thousand people per day, for this particular animal, they’re already gone,” Barrueto said.

Keeping people on established trails rather than building new ones or going off-trail, she says, would help give wolverines the space they need. 

Fisher said protecting habitat is only part of the picture.

Wolverines also die from trapping, hunting and collisions with vehicles, and he said those deaths need to be better managed because the population has little room for additional losses.

“We can save things,” Fisher said. “But we need to make those decisions right now and start getting serious about wolverine conservation.”

Wolverines, he says, have survived in these mountains for thousands of years.

“Just an astounding animal that is hanging on after the ice age,” Fisher said. “And I’d like to see them hang on a whole lot longer.”