After almost two decades of silence, the North American wolverine (Gulo gulo) is confirmed to be back on the prowl in the mountains of Oregon. Two of the feisty carnivores, dubbed "Iceman" and "Stormy," were caught on remote camera feasting on hunks of bait meat in the Wallowa Mountains -- the first verified wolverine sightings in recorded history in that part of the state.
On April 17, biologist Audrey Magoun and her husband Pat Valkenburg discovered tracks in the snow, marking the first confirmed evidence of Oregon wolverines since a partial skeleton was found in 1992 in Grant County. Then, five days later, Magoun downloaded photos from a remote camera to find two hungry wolverines staring back at her.
“We’ve always thought it was good habitat, and we’ve had reports but nothing we could verify until now,” said Vic Coggins, district wildlife biologist for the Oregon Department of Fish and Wildlife, in a press release. Ongoing survey efforts around the state, which include 14 baited remote camera stations and aerial surveys in the Wallowas, have been fruitless up to this point.
The U.S. Fish and Wildlife Service in December declared wolverines "warranted but precluded" for protection under the Endangered Species Act by species facing more imminent threats. Wolverines are listed as a threatened species by the state of Oregon, and are also state-protected in Washington, California and Colorado, where harming them is illegal. Montana is the only state with an open season on wolverines.
Likely extirpated from the lower 48 in the early 20th century, far-roaming wolverines have wandered down from Canada and resettled in Washington's North Cascades and the Rockies of Idaho, Montana and Wyoming. Some 200-300 wolverines now populate those areas, as well a couple recently documented in western Colorado and California's Sierra Nevada.
As denizens of high mountain areas, wolverines live in naturally fragmented habitat where females dig snow dens to protect their kits. As climate change reduces snowpack, that habitat will become even more disconnected and hard to find, further threatening the species. According to data from the University of Washington Climate Impacts Group and the U.S. Forest Service Rocky Mountain Research Station, cold and snowy wolverine habitat will decrease by 63 percent by 2099. In the 2010 ESA determination, USFWS said, "This habitat reduction is expected to result in reduced numbers of wolverines and reduced connectivity among wolverine populations to the point where maintenance of the wolverine population in the contiguous United States is unlikely."
The sighting in Oregon is encouraging, but now biologists must determine if Iceman and Stormy are actually residents of the Wallowas -- and perhaps part of a larger Oregon wolverine population -- or if they're just passing through.
Nathan Rice is an intern at High Country News.
Remote camera photos of Iceman and Stormy courtesy Oregon Dept. of Fish and Wildlife.