Tracking Wolverines in the Cascades

Citizen scientists are protecting the small but ferocious predators

By Megan Hill

August 12, 2020

It’s been five months to the day since the researchers strapped two trail cameras to trees just off Hart’s Pass Road. On this snowy June day, I'm braving the drive so I can trail a wildlife biologist. The narrow, unpaved route, carved from cliffs in 1893 to access gold and silver mines in Washington State’s North Cascades, crawls to the highest drivable point in the state. At more than 6,000 feet, views open across talus fields to snow-bound slopes and glacier-encrusted Silver Star Mountain. 

Snow clings to the north-facing slopes well into June here, making it prime habitat for the elusive wolverine—the predator I’m here to seek evidence of. I’m trailing biologist David Moskowitz, cofounder of the Cascades Wolverine Project (CWP). His cameras have been operating since January, when researchers from the nonprofit arrived here by snowmobile and on skis to install the cameras and the bait—deer legs with hunks of flesh, hair, and meat. They’re strapped to trees above a gun brush, with bristles designed to snag the fur of anyone who comes by for a snack.

The memory card from the first camera we check holds 3,000 photos. Being careful to maintain appropriate physical distancing (we’re in the throes of the coronavirus pandemic), I strain to look over Moskowitz’s shoulder as he scrolls through each one. Moskowitz never waits until he’s back home to check the pictures. “It’s like Christmas,” he says. Plus, the camera will help him know whether he needs to take a closer look for any hairs on the gun brush.

Most of the photos capture a snowshoe hare, which spends a lot of time hopping around the tree throughout the winter, as snow piles higher and higher. A squirrel, a deer, a black bear, and a deer mouse all make appearances. Cute, but not entirely revelatory. Then, we see the lynx. “Whoa,” Moskowitz exclaims like a kid opening a present he’s waited six months to unwrap. “That’s a big detection.” We’re at the very southern edge of the Canada lynx range. It’s a rare sighting, but not exactly the one we’re after.

The second camera doesn’t turn up a wolverine either, but overall, it’s been a successful third season of sightings for CWP. The organization—whose efforts combine wolverine monitoring with citizen science and public education—collected some 40 wolverine observations from the public, following an expanded effort to engage winter backcountry visitors. Moskowitz says that only about 10 of those are likely legitimate, but still, that’s significant considering only 30 to 40 wolverines, by scientists’ estimate, roam Washington. The organization’s 11 cameras captured multiple detections of wolverines, fishers, and Canada lynx during this year’s observation season, which runs January to June. 

The wolverine’s binomial name is Gulo gulo, Latin for “gluttonous glutton.” The small, badger-like creatures, known for their round ears and thick fur, are impressive animals, capable of violence that seems outsized for their 30-pound bodies. Thanks to strong jaws, large teeth, and sharp claws, though, single wolverines can bring down prey as large as a caribou—though they largely scavenge carrion for their meals. They’re members of the mustelid family, which includes martens, weasels, badgers, and otters. Each solitary animal patrols up to 500 square miles of snowy territory, in a relentless quest for the next meal. The curved claws on their large paws help them float over snow and bite into ice, enabling them to scale thousands of feet of sheer mountains in minutes. 

The wolverine’s binomial name is Gulo gulo, Latin for “gluttonous glutton.”

“There is something extraordinary about a solitary animal roaming the winter mountains—climbing peaks, traversing ridgelines, and belly-sliding down powder bowls—that is both a stunning expression of wild nature and a familiar story not unlike the human tendency to seek challenge and play in sublime places,” says CWP cofounder Stephanie Williams, who is also a biologist and mountain guide.

Wolverines’ historic ranges include northern Eurasia and North America. In the US, government-sponsored eradication programs and habitat loss in the early 1900s largely eliminated the animal from the Lower 48. But they’ve held on in Alaska and in western, central, and northern Canada. Beginning in the 1960s, they started making their way back to the US, crossing the border into Washington, Idaho, Montana, and Wyoming. Now, an estimated 250 to 300 wolverines roam south of Canada—a stable population, though likely less than half the carrying capacity, or the number the environment can support. The species—which plays an important role in the ecosystem as predators that keep prey animal populations in check, furthering biodiversity—faces a range of threats, from loss of habitat to roads and other development, resource extraction, recreation, and climate change. 

Wolverines rely on deep snowpack lasting into May—a condition that will diminish as the planet warms. “Every wolverine den needs to be subnivean,” Moskowitz says. If current climate change models hold, by 2050 wolverines may lose one-third of their current range in the Lower 48. Without crucial denning conditions, wolverines could face extinction. 

Despite these realities, the animal is not listed for protection under the Endangered Species Act. Conservation groups sued the US Fish and Wildlife Service in 2016, and a Montana federal district judge ordered the agency to grant wolverines legal protection. In March, the groups sued again, in an attempt to force the agency to act, saying the service failed to list the wolverine as directed by the ruling. In July, the service agreed to decide on the listing status by the end of August. Meanwhile, monitoring efforts continue throughout the Cascades and the Rocky Mountains, informing protection efforts and tracking wolverine numbers. 

The North Cascades are a particularly ripe spot for wolverines to thrive, thanks to consistent, deep snowpack and a relatively intact wilderness. Wolverines are an indicator species—a bellwether of ecosystem health. In places like Hart’s Pass and in the chain of snowy peaks rippling south, they’re gradually rebounding—despite sometimes eluding the camera traps. “Wolverines are naturally recovering in the Cascades, which is a heart-warming story during an otherwise dismal global extinction narrative,” Williams says. CWP hopes to keep it that way.

“Wolverines are naturally recovering in the Cascades, which is a heart-warming story during an otherwise dismal global extinction narrative.”

In this part of the Okanogan-Wenatchee National Forest, to the east of North Cascades National Park, lingering spring snow also means the wolverines face competition from winter recreationists. Snowmobilers love it up here too—and just like the wolverines, they increasingly have fewer places to access snow. But the machines are loud and intrusive, and their presence sends wolverines—especially females—scattering. 

An extensive, six-year study published in the journal Ecosphere tracked 24 collared wolverines across 1.1 million hectares in Wyoming, Idaho, and Montana. It found that wolverines avoided areas where backcountry skiing and snowmobiling took place, with snowmobiling having the greatest impact. (Snowmobilers argue that the issue warrants further study.)

“Wolverines are recognized as tough individuals, but as a group they are vulnerable,” Williams says, explaining that wolverines occur in low densities and have low reproductive rates. “It didn’t take much to wipe them out of the Cascades during the 20th century. It will take collective, creative, local, and global effort to see that they are not wiped out again, perhaps before the end of this century, given the rapid loss of spring snowpack and intensifying winter recreation.” 

This part of the country is expected to weather climate change fairly well—but that may actually increase pressure on the region and its wolverines, as snow-reliant recreation in other places becomes increasingly less possible. As time goes on, after all, everyone will be sharing smaller and smaller pockets of terrain.

The very grassroots CWP was born of necessity, Williams says, to fill in gaps left by other agencies. “CWP began [three years ago] at a time when continuous wolverine monitoring in the North Cascades proved to be either too difficult or too expensive for federal and nonprofits to reliably sustain,” she says. Moskowitz and Williams happen to live near regions that needed monitoring, and they had the goods: Both are experienced backcountry recreationalists and biologists; Moskowitz had camera traps from a caribou research project he just wrapped up. 

CWP’s efforts complement those of other organizations, like Cascades Carnivore Project and Conservation Northwest, and federal and state agencies; together, they’re able to cover large portions of the wolverines’ range in the Cascades. “Needless to say, there is a lot of ground to cover when dealing with these intrepid animals, and we all work together to do the best we can,” Williams says. “It’s possible that there are more people studying wolverines in the Cascades than there are wolverines, yet they remain mysterious and elusive.”

Each snapshot of a wolverine—whether contributed by a citizen scientist on a backcountry ski trip, say, or from a camera trap—contributes to the body of knowledge about the animals. CWP doesn’t collar wolverines, but it can often identify individuals by the unique, blond starburst patterns on their black, bristly chests. Genetic samples from gun brushes and reports of paw prints can help too. 

Citizen scientists can submit information about sightings through the CWP website. “This data informs research and engages more people in science and conservation. Plus, it’s fun,” Williams says. “We’ve learned that wolverines are not only an indicator species but also a gateway species in that they draw people toward learning about converging issues of climate change, land use change, and direct exploitation—three of the five major levers of the biodiversity crises listed by the United Nations.”

Photos and samples from CWP’s camera traps are transferred to Conservation Northwest, land managers, advocacy groups, and media. And they’re used by CWP and these other groups in storytelling efforts that aim to build public understanding of wolverines, particularly among backcountry users like snowmobilers. CWP’s public outreach involves presentations, a robust social media presence, and a short film that will be released this fall, online, and perhaps at the Banff Film Festival. 

Though CWP isn’t directly involved in public policy, its work could one day inform policies, development decisions, and recreational allowances. Williams and Moskowitz hope that their effort puts them on the offensive, building an understanding that may help avoid direct conflict between conservationists and recreationists, as is unfolding in Idaho. 

Drawing on the information from the Ecosphere study, Idaho’s Sawtooth National Forest closed 72,447 acres of land—3 percent of the forest—to snowmobilers in December 2018. The Idaho State Snowmobile Association responded with a lawsuit challenging the closure. The outcome is still pending. 

“One of the goals of our project is to be proactive and build interest in conservation into the recreational community before we start getting mandates and lawsuits to limit recreational use up here,” Moskowitz says. “We want to get that community on board so they ideally understand and are invested, and are stakeholders in the conversations. They feel like this is their playground. It’s also the wolverines’ last refuge.”