They tumble over the snow, bundles of fur on the grow: two wolverine kits, three months old, the first ever documented on a wildlife camera south of I-90.
The photos recovered last week from the camera mounted outside a wolverine den in the William O. Douglas Wilderness delighted researchers hoping to detect a return of the charismatic carnivore to the south Cascades.
A breeding female recently photographed on the same wildlife camera was the first good sign. Then photos just recovered of the romping kits showed the family is alive and well.
“It tells us wolverines are starting to claw their way back to the south Cascades,” said Jocelyn Akins, conservation director of the Cascades Carnivore Project, a nonprofit studying the return of the wolverine and other rare carnivores to their home ground in Washington.
Wolverines were exterminated in Washington in the 1880s and early 1900s by trappers that regarded them as a nuisance because the wily wolverine stole their bait and their catch. Poisoned and trapped, wolverines were eliminated from Washington by the mid-1900s, said Cathy Raley, wildlife biologist at the Pacific Northwest Research Station of the U.S. Forest Service in Olympia.
A collaborative effort by multiple agencies and partners has been underway since the early 2000s to understand the status of wolverines in Washington.
After a few confirmed sightings, the question remained whether these were animals just passing through the state, or if Washington had a resident population – and even a reproducing one.
During a 10-year field study begun in 2006, the first confirmed dens were found in the North Cascades, as well as reproducing wolverines, Raley said. But it wasn’t until the recent discovery of the den in the William O. Douglas that scientists knew for sure the animals also had successfully recolonized the south Cascades.
The wolverines in Washington are all descendants of those in the Coast Range of southwest British Columbia, Raley said, and are genetically distinct from wolverines in the Rocky Mountains of Idaho and Montana.
The 10-year field study revealed in a 2016 report the lives of 14 tracked wolverines – including startling information about just how wide-ranging wolverines are in their habitat. One female traveled 483 kilometers from the Pasayten Wilderness in the North Cascades into British Columbia, before perishing in a fight with a cougar, perhaps over a deer carcass found with the wolverine’s body.
Somewhere along the way she also crossed the Fraser River, maneuvering with ease through snow and over peaks along the way.
“They just go right over everything, they are adapted to the rugged terrain, and the cold. They thrive in winter, and high-elevation areas,” Raley said. “That is the wolverine’s world, where they do best.”
Females use deep snow for their dens, typically locating them under tumbled logs of an avalanche chute or boulders stacked with as much as 10 feet of snow.
Akins said the wolverines tracked in their study also used deep snow to cache meat, keeping it fresh. “We called it the ‘refrigerator hypothesis.’?”
The number of wolverines in the state remains very low, perhaps just 100 to 200, Akins said. That is one reason monitoring is so important. “We are collecting data because without shining a spotlight on them, they could go extinct before our eyes without us even knowing it, because they live in such remote areas, with rare human visitation.”
Research last summer as part of the Western States Wolverine Conservation Program confirms the wolverine is present in much, but not all of its original range, said Robert Long, senior conservation scientist with the Woodland Park Zoo, who collaborated with other partners on a survey last summer of where wolverines exist in the West. Some areas, such as Colorado, have yet to document the carnivore’s return, Long said.
Climate change is the new threat for the wolverine; deep snows that persist even into late spring – their denning season – is essential for survival.
“Their dens are not dug into the earth, so if there was no snow they would have no protection,” Akins said.
The wolverine’s powerful neck and jaws enable them to dig out food even in deep snow, going deep to get at the carcass of a mountain goat fallen from a cliff, for instance, or even just a pile of bones. Wolverines are the only animal in their studies known to crack the skull wide open of a bait animal in their camera-survey station to get at the brain, Akins said.
Just tracking the wolverine in its territory is a terrifically tough task. It does have sublime rewards, though, of being in some of the state’s most beautiful and remote terrain, and sometimes sharing space with so rare an animal.
Akins was in her tent exhausted after the most recent trip to the wolverine den, getting the photos of the kits. It was about 1:30 in the morning when she heard something close by, sniffing powerfully.
In the morning, she discovered wolverine tracks all around the stinky socks she had hung outside, a few feet away.
“I was totally thrilled. It was incredible to me, it was just right there.”