Wolverines, one of the West’s most elusive high-country predators may soon find a place on the endangered species list because of climate threats to the deep snow and frigid temperatures they need to survive.
The U.S. Fish and Wildlife Service announced Friday a proposal to list wolverines as a threatened species. It also proposed establishing a nonessential population area for any wolverines reintroduced into portions of the southern Rocky Mountains.
A listing decision will likely have limited impact on land activities in Wyoming. Wolverines and humans have little interaction because the animals live in such high, wilderness terrain. Hunting and trapping of wolverines would become illegal under the proposal, but Montana is the only state that allows trapping, said Shawn Sartorius, a fish and wildlife biologist for the Fish and Wildlife Service.
Wolverines have been protected from hunting and trapping in Wyoming by state law since 1973. As with more well-known species such as polar bears, the biggest threat to wolverines is habitat loss because of climate change.
“When we list something, we not only look at the current situation, but we are required to project what threats may exist in the future,” Sartorius said.
“This is an unusual case in which the species is actually doing pretty well right now … But now we have information that shows wolverine habitat is likely to be directly impacted by climate change.”
Studies show wolverine habitat will reduce significantly over the next 30 years and very significantly over the next 70 or 80 years. Wildlife officials hope a listing will bolster wolverine numbers before their habitat dwindles, Sartorius said.
Wolverines live at or above the timberline and require deep snow and freezing temperatures into late spring. They make their dens 20 feet deep in snow-covered boulder fields and avalanche wreckage. They rarely reproduce every year and live in only small, isolated pockets high in the Rocky Mountains.
Humans essentially eradicated them by the 1930s in the lower 48 through hunting, trapping and poison. New populations started forming in the 1950s from wolverines from Canada, Sartorius said.
Officials roughly estimate about 250 to 300 wolverines live in the lower 48, but Sartorius stresses the number is only a guess. Until the mid-2000s, wildlife officials knew very little about wolverines.
Fewer than 30 wolverines currently live within Wyoming, mostly in the Wind River Range, Tetons and Absarokas, said Bob Oakleaf, nongame coordinator for the Wyoming Game and Fish Department.
The proposal also includes the possibility of reintroducing wolverines into areas in Colorado. It does not require reintroduction, but establishes a nonessential status in some of those areas to give states more freedom to bring the animal back. If wolverines are reintroduced into Colorado, their range could include sections of Albany and Carbon counties, Sartorius said.
As a nonessential population, those reintroduced wolverines would not be afforded the same protections as the already existing populations in northwest Wyoming. The classification is the same used by the Fish and Wildlife Service to reintroduce black-footed ferrets into Shirley Basin.
A possible wolverine listing brings resources and public attention to the elusive animal, said Kylie Paul, Rockies and Plains representative with Defenders of Wildlife.
“Increasing their population to help sustain them longer into the future is what we can do now,” she said.
The Fish and Wildlife Service decided in 2010 wolverines qualified for listing under the Endangered Species Act but had other priorities. A final decision on the listing will come within one year.