As global warming melts their snowy habitat, wolverines in the contiguous United States will be listed as threatened under the Endangered Species Act, earning them additional federal protections. The move comes after years of legal back and forth over the survival prospects of the animals amid climate change and other human activities.
“Current and increasing impacts of climate change and associated habitat degradation and fragmentation are imperiling the North American wolverine,” says Hugh Morrison, the Pacific regional director of the U.S. Fish and Wildlife Service (USFWS), in a statement. “Based on the best available science, this listing determination will help to stem the long-term impact and enhance the viability of wolverines in the contiguous United States.”
Currently, an estimated 300 wild wolverines remain in the Lower 48 states, inhabiting the Rocky and Cascade mountains of Wyoming, Washington, Montana, Idaho and Oregon. These elusive creatures may look like small, dark-brown bears, but they’re actually the largest members of the weasel family.
Wolverines (Gulo gulo) rely on a snowy, cold environment. The carnivorous predators eat rodents and rabbits, but they’ll also scavenge the carcasses of larger animals. Sometimes, they cache carrion for later, using the frigid temperatures of their high-elevation habitats to refrigerate and preserve the food.
Females build dens in deep snow banks to give birth in February and March, and they remain in the dens with their kits through May. To find snow that will last that long into spring, wolverines typically den at elevations of 7,000 feet or higher.
However, as global temperatures continue to rise, finding places to store food and build dens will become increasingly challenging for the animals, scientists say. The USFWS estimates wolverines could lose 23 percent of their habitat within the next 30 years because of climate change—and 63 percent over the next 75 years.
As snowy areas shrink, their habitat will also become fragmented, making it harder for wolverines to find mates. This, in turn, may lead to inbreeding and a lack of genetic diversity.
Already, roads make it difficult for wolverines in the U.S. and southern Canada to mate with each other, reports the New York Times’ Catrin Einhorn. Human recreation—in the form of backcountry snowmobiling and skiing—is also encroaching on the mammals’ limited habitat.
Wolverines nearly went extinct in the western U.S. in the 1920s because of hunting and trapping for their fur. However, they’ve managed to hang on—and in May, biologists reported a rare sighting of a wolverine in California, the state’s second in 101 years.
Officials have debated for decades whether wolverines in the contiguous U.S. deserve protection. States, farm bureaus, fossil fuel groups and snowmobile associations have opposed protections, while various conservation groups have fought to have wolverines listed under the Endangered Species Act.
In October 2020, under President Donald Trump’s administration, the USFWS determined the animals did not need to be listed. But last year, a federal judge ruled that the agency needed to reconsider.
Now, officials say they’ve reversed positions since three years ago because of new information related to trapping, habitat connectivity, snow, climate change, popularity density and genetic diversity.
Though conservationists applauded the decision, they also cautioned that federal protection may be too little, too late.
“We have not paid enough attention to this critter to give it what it needs,” says Jeffrey Copeland, a retired biologist with the U.S. Forest Service who now serves as a director for the nonprofit Wolverine Foundation, to the Associated Press’ Matthew Brown. “It’s a failure. But in this type of situation, it’s the only tool that we have.”