Wolverine

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 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 terrestrial 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). 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 their kits are weaned and can safely travel on their own. Current climate change projections indicate wolverines could lose up to 63 percent of their snowy habitat in the lower-48 by the year 2085. 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 Parks and Wildlife Endangered Species

Action Taken
In August 2014, the U.S. Fish and Wildlife Service withdrew its proposed rule to list the wolverine as a threatened species under the Endangered Species Act, citing a determination “that the effects of climate change are not likely to place the wolverine in danger of extinction now or in the foreseeable future.”  In response to the decision, Rocky Mountain Wild joined a coalition of 8 other groups to file notice of intention to sue the Service for refusal to protect the species under the Endangered Species Act.

Read More

Federal Agency Ignores Best Available Science In Decision Not To List Wolverine
FWS Withdrawal of the Proposed Rule to List Wolverines under the ESA and Establish an Experimental Population
FWS Proposed Rule to Establish an Experimental Population of Wolverines in Colorado, Wyoming, and New Mexico
FWS Proposed Rule to List Wolverines as a Threatened Species under the ESA
Wolverines One Step Closer to Endangered Species Act Protection