Wolverines are prey generalists, and commonly feed on small and mid-sized mammals and ungulate carrion. They may opportunistically kill adult ungulates. For an animal of their size, wolverines use very large activity areas (77 to 770 square miles).
Anthropogenic sources (trapping or hunting) appear to be the most significant causes of wolverine mortality. Predators include gray wolves, cougars, and other wolverines.
Washington's wolverine population is small, largely restricted to the North Cascades, and is an extension of a larger population in southern British Columbia. Climate change is considered a likely threat to the species in Washington.
Description and Range
The wolverine is the largest terrestrial member of the weasel family, with females weighing 18-27 pounds and males weighing 26-44 pounds. Wolverines are stocky with short, rounded ears, small eyes, a bushy tail, and large feet that are useful for travelling through snow.
Their fur is dark brown, but has tawny colored bands that run down both sides of its body to its tail.
Wolverines occur in the remote mountainous areas of the Cascades and in northeastern Washington. A population of 13 wolverines has been studied in the North Cascades from 2005 to 2013, and wolverines have recently been detected near Mount Adams and in the Goat Rocks Wilderness in the South Cascades. However, the existence of a breeding population in that region has not yet been determined.
The statewide population is probably less than 20 animals, but it appears to be relatively stable.
Wolverines commonly occur in boreal forest, taiga, and tundra ecosystems. In Washington, they occupy alpine and subalpine forest habitats, especially within North Cascades National Park and the wilderness areas of Okanogan-Wenatchee National Forest.
Denning sites are commonly located in north and northeastern facing cirque habitats. Dens are typically associated with a passage through deep snow to a space within talus or under a fallen tree or other large woody debris.