Posted by Andrea West - February 10, 2009 - Mammals - No Comments

Wolverine kit, early spring in the Rockies. Photo (c) Daniel C. Cox/NaturalExposures.com

Fearless But Vulnerable
Historically, wolverines ranged south from Canada and Alaska, through the mountainous regions of the West to southern California, Utah, and Colorado. Today, healthy populations of wolverines inhabit remote, high-elevation areas of the North Cascades in Washington, and the northern Rocky Mountains in Idaho, Montana and Wyoming. There are between 250-300 wolverines left in the contiguous United States today.

Wolverines historically lived in Colorado until 1919, but were wiped out by poisoning and trapping targeted against coyotes and other predators. In the spring of 2009, Colorado welcomed the arrival of M56, a lone wolverine who traveled 500 miles from Wyoming to Colorado’s Rocky Mountain National Park and who is thought to be Colorado’s first wolverine in over 90 years.

Natural History
Wolverines are small (13-40 lbs), relatives of badgers and river otters.  Despite their appearance, wolverines are not related to bears but are actually the largest member of the weasel family. They live in high mountains in remote areas and avoid people, sharing habitat with mountain goats and lynx.  Wolverines are opportunistic feeders – they are primarily scavengers, feeding on almost any available carcass, but will also prey on small mammals (and the occasional full-grown game species) and browse for berries and other plant material. Wolverines are tougher than one would think for their size – they have been known to chase wolves, mountain lions, and bears away from fresh kills. Wolverines birth their young in dens dug deep into the snow in mid-February, and need that snow to remain in place through mid-spring, when its kits are weaned and can safely travel on their own. Current climate change projections indicate areas of the western U.S. with persistent spring snowpack are likely to recede by 50% during the next century. Colorado’s Rocky Mountains are likely to retain much of their spring snowpack, because of their high elevation, which could provide an important refuge for wolverines in the West.

Conservation Status
-Forest Service Sensitive Species
-Colorado Division of Wildlife Endangered Species
-Endangered Species Act Candidate Species

Action Taken
In February of 2013, the U.S. Fish and Wildlife Service announced its proposal to protect wolverines in the lower-48 states as a threatened species under the Endangered Species Act, citing the threats posed to their habitat by climate change.  A related proposal to designate Colorado as an experimental population area for wolverines enables Colorado Parks and Wildlife to renew conversations with stakeholders about reintroducing the elusive animals to Colorado. The primary threat to wolverines, warranting their protection under the Endangered Species Act, is climate change.

Read More
Wolverines One Step Closer to Endangered Species Act Protection