Three months ago at a trailhead in eastern Idaho’s Centennial Mountains, wolverine research technician Kyle Crapster eyed two snowmobilers from across the parking lot as they pulled avalanche safety gear from a sticker-emblazoned truck. He suspected they were heading for the steep, open slopes that help make this area west of Yellowstone National Park, known as Island Park, an international snowmobiling destination.
Wolverines share the snowmobilers’ affinity for isolated alpine terrain with deep snow, and Crapster was part of a research team tracking the movements of both to learn if the traffic impacts the animals. He approached the two men to ask them to take a GPS along on their ride. One of them noticed his clipboard and cut him off before he could start: “I’m not carrying one.”
- Sarah Jane Keller
- Researchers have used small GPS trackers to trace the paths of more than 10,000 snowmobilers and backcountry skiers since 2010.
Fortunately, such rejections are rare. About 90 percent of snowmobilers and skiers approached have taken the GPS units into the mountains. Since 2010, researchers have collected roughly 10,000 GPS tracks in the area. They’ve fitted 23 wolverines with radio-collars in those areas, including two in the Centennials. Eventually, they’ll compare the two datasets to see if the presence of people affects how the animals behave, reproduce and where they choose to live—things that could ultimately affect their survival.
Wolverines are scrappy scavengers, generally weighing between 20 and 60 pounds, with stout legs, snowshoe-like paws and sharp claws that equip them for travel near the treeline. When a three- to four-foot dump overwhelmed the researchers’ snowmobiles in 2011, a GPS-collared wolverine cruised the stormy slopes and ridgelines as briskly as a human striding down a flat, dry trail.
“They are just like a little super animal,” says Kim Heinemeyer, a biologist with Round River Conservation Studies, a research nonprofit co-leading the study with the Forest Service’s Rocky Mountain Research Station.
But wolverines are also vulnerable. So far, their remote lifestyle has protected them from most of the pressures that other charismatic carnivores face, like development, livestock and logging. That, and their natural rarity, has also kept them relatively understudied. While there are thousands of wolverines in Alaska and Canada, plus more in northern Europe and Asia, the Lower 48 probably hosts fewer than 300. But no one knows for sure.
It’s clear that climate change threatens their snowy habitats, so they’ll be considered for endangered listing this August. Yet the effects of increasing numbers of snowmobiles, helicopters, snowcats and skis in wolverine territory are uncertain.
Surprisingly, the Idaho State Snowmobile Association endorses the study. The potential for a listing has raised the stakes for everyone: Snowmobilers hope the study’s findings will prevent large closures, while managers and scientists are optimistic that getting the recreation community involved early on could help wolverines remain relatively uncontroversial, even if listed.
“My hope is that regardless of the results, recreationists take ownership of this animal and become largely self-policing, and we don’t have to force regulations upon them,” says Jeff Copeland, a Forest Service researcher who started the project before retiring to direct the Idaho-based Wolverine Foundation.
Copeland started the project because he wanted to maintain wildlife management’s credibility by avoiding arbitrary closures. He also recognized a rare opportunity to improve the adversarial and often litigious relationship between snowmobilers and the Forest Service. The snowmobile association, in turn, saw that Copeland didn’t have an anti-motorized agenda.
That trust has been crucial. When the project began, researchers weren’t sure how snowmobilers at trailheads would respond. But the ISSA encouraged its members to participate, and some snowmobile rental companies helped distribute GPS units. Local businesses provided beer and pizza discounts to riders that returned GPS units (as opposed to dropping them in pit toilets, which once happened). Yurt and helicopter skiing operators and ski areas have also begun equipping customers with GPS trackers.
Though Heinemeyer is encouraged by early results, the study needs to include more animals to justify policy decisions, and the wolverine’s rarity makes accumulating a large sample tough. A preliminary analysis revealed some snowmobile impact: Wolverines seemed to move more during high-traffic weekends than during the quieter workweek. But it’s not yet known if that creates difficulties finding food, burns too many calories, or hinders survival and reproduction.
“My sincere hope is that if there are any impacts, that we have this group of folks that continue to work together and figure out ways to sustain both winter recreation and wolverines on the landscape,” Heinemeyer says.
There is another problem that makes the study even more relevant. Most researchers agree that female wolverines, which dig snow tunnels to birth kits in late February and March, need deep snowpack lasting until late April and early May, likely to protect their denning kits. “Where you don’t have those (cold, persistently snowy) conditions, you don’t have wolverines,” says Shawn Sartorius, a U.S. Fish and Wildlife Service biologist based in Helena, who is overseeing the endangered species listing decision.
Climate change is the main threat motivating the proposed listing, but the study could help managers if dwindling snowpack means that winter recreation adds stress to wolverines. “Winter recreation is one of the areas where we have more control,” says Ana Egnew, a wildlife biologist on the Payette National Forest. “Climate change is a bigger issue than the Forest Service can take on alone.”
Back in Island Park, Crapster prepares to approach the next truck that pulls in. The driver, a sunburned construction contractor with two teenage boys, is curious about wolverines: where they live, what they eat, etc. He accepts a GPS unit.
“If we’re harming anything, I wouldn’t go there,” he says. “I’m glad that (wolverines) are here.”
This story originally appeared in the June 9 issue of High Country News (hcn.org).