After the U.S. Fish and Wildlife Service announced on Thursday that wolverines would be denied long-sought protection under the Endangered Species Act, several environmental groups—including the Idaho Conservation League—have declared intent to sue the agency.
Wolverines, also known as “skunk bears,” once roamed as far south as New Mexico, but hunting and trapping pressure nearly wiped out the species in the U.S. by the early 1900s. Today, fewer than 300 wolverines live in Idaho, Montana, Washington and Wyoming. According to the handful of conservation groups challenging Fish and Wildlife’s decision, the species could face further habitat loss and potential extinction in the continental U.S. without a “threatened” or “endangered” listing to unlock recovery efforts.
“Scientists estimate that 78 percent of wolverine habitat will be lost by the end of the century unless steps are taken to reduce the greenhouse gas emissions that contribute to global warming,” Idaho Conservation League spokesman Brad Smith wrote in an email to the Idaho Mountain Express on Monday.
Typically found in high, remote terrain, the wolverine—a solitary carnivore and scavenger—requires a particularly large territory of up to 300 square miles. The animals also depend on deep, lasting snowpack, as females build dens in the snow around February to raise their young and use the shelters through mid-May.
Current climate projections suggest that earlier-in-the-season, accelerated snowmelt periods could lead to the wolverine’s extirpation from Idaho and the contiguous 48 states. Other key threats to the animal include commercial and residential development—such as new ski resorts—and motorized recreation, with recent studies showing that heli-skiing and snowmobiling can push wolverines out of their native territories.
“[Opening] up even more wolverine habitat to winter motorized use could spell doom for wolverines in north-central Idaho,” Friends of the Clearwater Executive Director Gary Macfarlane wrote in a Thursday press release.
In 2000, San Francisco-based nonprofit Earthjustice represented Friends of the Clearwater, Idaho Conservation League and six other environmental groups in a collective petition to the Fish and Wildlife Service to add wolverines to the Endangered Species List. The Fish and Wildlife Service responded with a proposal to add the species to the list in 2013, but that offer was withdrawn in 2014 due to “opposition from state wildlife management agencies,” Smith said. Now the same coalition of groups, represented by Earthjustice, is turning to the courts once again to seek protections for the wolverine.
“States will continue to be responsible for managing wolverines in the absence of an ESA listing,” Smith said. “As we have seen, state wildlife management agencies are either unwilling or unable to rise to the challenge.”
In 2016, District Court of Montana Judge Dana Christensen ruled that Fish and Wildlife had violated the Endangered Species Act by withdrawing its 2013 proposal, writing that the wolverine’s susceptibility to climate change “cannot really be questioned.”
Agency officials maintained then—as today—that wolverines are not threatened by climate change in the lower 48 states.
Fish and Wildlife’s Thursday decision was based on a status assessment of the wolverine that the agency completed in 2018. While acknowledging that climate change is “the most significant stressor” of wolverines in the lower 48 states, the nearly 200-page report argues that snowpack in high elevations should remain consistent over the next few decades.
“If wolverines need snow, we think that there’s going to be enough snow out there for them,” said Jodi Bush, Fish and Montana project leader with FWS, in a statement.