Protecting wolverines amid global warming
U.S. proposes to declare species threatened as its snowy mountain refuges are melting
BILLINGS, Mont. — The North American wolverine would receive long-delayed threatened species protections under a Biden administration proposal released Wednesday in response to scientists warning that climate change will likely melt away the rare species’ snowy mountain refuges and push it toward extinction.
Across most of the U.S., wolverines were wiped out by the early 1900s by unregulated trapping and poisoning campaigns. About 300 surviving animals in the contiguous U.S. live in fragmented, isolated groups at high elevations, largely in the northern Rocky Mountains.
Wolverines join a growing number of animals, plants and insects — from polar bears in Alaska to crocodiles in southern Florida — that officials say are at growing risk as increasing temperatures bake the planet, altering snowfall patterns, melting ice and raising sea levels.
In the coming decades, warming is expected to shrink the mountain snowpack wolverines rely on to dig the dens where they birth and raise their young.
The decision Wednesday by the U.S. Fish and Wildlife Service follows more than two decades of disputes over the risks of climate change and threats to the long-term survival of the elusive wolverine. Officials wrote in the proposal that protections under the Endangered Species Act were needed “due primarily to the ongoing and increasing impacts of climate change and associated habitat degradation and fragmentation.”
The wolverines, which resemble small bears, are the largest species of terrestrial weasels. Sometimes called “mountain devils,” they thrive in harsh alpine environments.
Protections for the species were rejected under former President Trump. In 2022, a federal judge ordered President Biden’s adminis tration to make a final decision this week on whether to seek protections.
Republican lawmakers in Montana had urged the administration to delay its decision, saying scientists’ estimates were too inaccurate to make a fair call about the threat to wolverines. The lawmakers, led by hardright Rep. Matt Rosendale, said protections could lead to future restrictions on activities in wolverine habitats, including snowmobiling and skiing.
Rosendale said Wednesday he would seek to revoke threatened species status for wolverines at the earliest chance if the proposal is finalized.
“Whether it’s private property, state property or federal property, if we are limited on the use of that land based upon this status, that’s a taking,” he said. “Is the federal government going to compensate the state for lack of use on stateowned lands? ... I don’t think so.”
In September, government scientists conceded there was some uncertainty about how quickly mountain snowpacks might disappear each spring in areas with wolverines. But they also said habitat loss due to cli mate change — combined with issues including increased development — would likely harm wolverine populations.
“The best available information suggests that habitat loss as a result of climate change and other stressors are likely to impact the viability of wolverines in the contiguous U.S. through the remainder of this century,” they concluded.
Fish and Wildlife Service officials said in documents released Wednesday that they were “not concerned” about the effects of existing developments such as ski resorts since wolverines likely already avoid those areas. But winter recreation could hurt wolverines in the future, they said, as activities such as backcountry skiing and snowmobiling have become more popular in some areas.
The scientists added that some of those losses could be offset if wolverines are able to recolonize areas such as California’s Sierra Nevada and Colorado’s southern Rocky Mountains.
Environmentalists had argued in multiple lawsuits against the Fish and Wildlife Service that wolverines face localized extinction from climate change, habitat fragmentation and a lack of genetic diversity.
The proposal to protect them “gives the wolverine a fighting chance for survival,” said Timothy Preso, an attorney for the group Earthjustice who’s been part of that legal effort.
Another attorney said he still had concerns over legal trapping for other species in areas where wolverines live.
The Fish and Wildlife Service proposal would allow some accidental killing of wolverines as long as trappers report any captures within five days and use “best practices” to avoid the animals.
“I’m not sure that’s possible. Wolverines are scavengers — they go everywhere and eat everything. We’ll be taking a closer look at this provision,” said Matt Bishop with the Western Environmental Law Center.
Wolverine populations are found in remote areas of Montana, Wyoming, Idaho and Washington state.
In recent years, individual animals have been documented in California, Utah, Colorado and Oregon.
However, there’s been “no evidence” that the animals are becoming established and breeding in those states, officials said in Wednesday’s proposal.
The wildlife service received a petition to protect wolverines in 2000, and the agency recommended protections in 2010. The Obama administration proposed protections and later sought to withdraw them, but was blocked by a federal judge who said in 2016 that the snow-dependent animals were “squarely in the path of climate change.”
Protections were rejected in 2020 under Trump, based on research suggesting the animals’ prevalence was expanding, not contracting. Federal wildlife officials at the time predicted that despite warming temperatures, enough snow would persist at high elevations for wolverines to den in mountain snowfields each spring.
They reversed course in September, publishing a revised analysis that said wolverines were “less secure than we described.”
The animals need immense expanses of wilderness to survive, with home ranges of as much as 610 square miles for adult male wolverines, according to a study done in central Idaho.
They also need protection from trapping, according to scientists.
Wolverine populations in southwestern Canada plummeted by more than 40% over the last two decades due to over-trapping, which could affect populations across the U.S. border, scientists said.
Wolverine trapping was once legal in Montana and other states. The animals are still sometimes caught inadvertently by trappers targeting other fur-bearing animals.
At least 10 wolverines have been accidentally captured in Montana since trapping was restricted in 2012. Three were killed and the others were released unharmed. In Idaho, trappers have accidentally captured 11 wolverines since 1995, and killed three of those.