The wolverine is the largest land-based member of the weasel family and roams the most rugged and beautiful areas of the Rocky Mountains and North Cascades in the western United States. These animals are also exceedingly rare, with scientists speculating that fewer than 300 wolverines may live in the U.S., possibly far fewer. Only 35 wolverines are estimated to successfully breed in the Rocky Mountains—a critically low number.

Why They’re Important

Wolverines are primarily scavengers, feeding off old or sick animals that die in the cold. But they can also take down much larger animals, even elk and moose under the right circumstances such as extreme snow, providing carrion for other species. Wolverines are a vital part of the ecosystem in their own right, but also a great ambassador of the wild places they inhabit.

Major Threats

Wolverines rely on deep spring snow to rear their young, so they are especially vulnerable to the loss of their alpine habitat due to climate change. One study suggests that wolverines may lose two-thirds of their habitat by the end of the century. They are also threatened by trapping, habitat loss and fragmentation, and disturbance from winter recreation activities. Given the low numbers of wolverines and the fact they are spread over such a vast area, each of these threats can have a major impact on wolverine recovery.

What Defenders Is Doing to Help Wolverines

Defenders of Wildlife has been fighting to protect wolverines under the Endangered Species Act since 2000. We’ve also recruited and trained volunteer “citizen scientists” to document wolverines using snow-tracking and remote cameras and we help increase appreciation for these animals by supporting the Wolverine Network, a coalition and website for sharing information on wolverine research, management and conservation.