Back in November, the United States Fish & Wildlife Service (USFWS) added the North American wolverine to its list of threatened species in the Lower 48, giving the elusive mesopredator new protections under the federal Endangered Species Act (ESA). The agency cited habitat degradation spurred on by climate change as its primary justification for making the determination. On Friday, January 26, Montana—a state with a sizable portion of the wolverine’s home range—said it will sue the USFWS in an attempt to get that decision reversed.
The recent wolverine ESA listing is part of a back-and-forth saga dating back more than a decade. At different times since 2013, the USFWS has proposed a threatened status for the species, then withdrawn its listing in response to shifting political winds and changing science. In response to a 2020 withdrawal of yet another proposed wolverine ESA listing, the Center for Biological Diversity (CBD) sued the Department of the Interior, brining the issue back to the forefront. That lawsuit, which the CBD won in 2022, ultimately led to the wolverine’s official ESA listing in November 2023.
Montana FWP says it’ll file its lawsuit in federal district court. “In Montana, wolverines continue to do well and inhabit much, if not all, of their available habitat,” said Montana Fish, Wildlife & Parks (FWP) Chief of Conservation Policy Quentin Kujala, in a press release announcing the agency’s intent to sue. “We work closely with our neighboring states to ensure the continued conservation of these iconic species. Federal protections in this case will only get in the way of good conservation work.”
When the USFWS listed the North American wolverine as “threatened” on November 30, 2023, it cited a climate analysis that predicted a significant amount of snow loss in five mountain ranges in the Northern Rockies—areas where wolverines live and breed—by the year 2100. If those climate models are borne out, the agency’s report in the Federal Register indicated, wolverine populations will suffer because the species is so reliant on spring snowpack for denning, foraging, and reproduction.
“New research indicates that areas characterized by persistent spring snow are likely important for wolverine survival,” the USFWS wrote last fall. “One new study reported wolverines cache food year-round, indicating that warmer temperatures could impact the ability of wolverines to store food resources by decreasing the shelf life of cached food.”
In its press release, Montana FWP took issue with that rationale, saying it “was used despite recent science that shows wolverines are adaptable and able to den and reproduce without snow.” That’s based on a study examining a sample population of 1,589 wolverines in Scandinavia. According to FWP, the study, published in May 2023, “directly refutes the argument that climate change will have a detrimental population-level on wolverines” in the contiguous United States. Instead, FWP says, it found that “wolverine distribution expanded and that reproductive events increased 20 times in areas lacking spring snow cover.”
Potential Implications for Trappers
Wolverine were nearly extirpated from the Lower 48 by the early 1920s. Since then, they’ve managed to repopulate some of their native haunts south of the 48th parallel, migrating back on their own from populations in Canada. Today, there are an estimated 300 wolverines in the contiguous United States.
Hunting and trapping for the species is already outlawed outside of Alaska, and the most recent ESA listing won’t have any impact on those long-standing rules. But some Western trappers worry that new ESA protections for the species could limit or even shut down legal trapping opportunities in areas that overlap with wolverine habitat.
In November 2023, for example, a federal judge in Montana cut wolf trapping seasons in half to protect endangered grizzly bears. And earlier this year, wildlife advocacy groups sued the Idaho Department of Fish & Game, saying its wolf trapping season puts ESA-protected grizzlies at risk. Field & Stream will follow the developing wolverine listing saga as it continues to unfold.