Called "skunk bear" by the Blackfeet Indians, the wolverine is the largest terrestrial member of the weasel family.

© Paul Nicklen / National Geographic Stock

It has a broad head, small eyes and short rounded ears. The wolverine has glossy dark brown fur, a light face mask and a stripe running down both sides of its body. It is powerfully built and has short legs with wide feet for traveling across the snow.

Diet

Wolverines are known for scavenging dead animals like caribou or moose but are also very capable of killing their own meal, including ground squirrels and snowshoe hares.

Population

It is estimated that fewer than 300 wolverines exist in the lower 48 states, according to the latest estimate by scientists, possibly fewer. Only 35 wolverines in the Rocky Mountains have been calculated to be successfully breeding.

Range

Wolverines prefer scattered trees at high elevations. Historically they occurred from Maine to Washington down to the Rocky Mountains and Sierra/Cascade Mountains. In the lower 48 states, wolverines now occur only in Wyoming, Idaho, Montana, Washington and may still occur in the Great Lakes region. Wolverines were believed to be extirpated from California, but a remote camera caught one on film in February 2008!

Behavior

Wolverines have been documented traveling great distances, often going right over mountains instead of taking the easy way around. One male wolverine near Yellowstone traveled more than 500 miles in 42 days.

Reproduction

Mating Season May through August
Gestation Egg implantation is delayed, following which is a 30-40-day gestation period
Litter Size 2-3 kits
The females dig dens eight feet or deeper into the snow in the middle of winter, often in remote alpine cirques at or above treeline.