Wolverine

High country denizens

In Washington, wolverines (Gulo gulo) favor habitat conditions that occur at or above treeline, which are among the wild areas Conservation Northwest works to protect. Throughout North America they frequent alpine meadows, boreal forests, and tundra. Wolverine were once nearly lost from our state, but they being seen more and more in the North Cascades of Washington: near Mount Baker, high above the Methow Valley, and in and around the Alpine Lakes Wilderness. We've also captured this elusive animal on film through the rare carnivore remote camera project, which volunteers operate every summer and fall.

Read more on wolverines by research wildlife biologist Keith Aubry.

Solitary and shy

Wolverines are solitary animals and need a lot of space and peace and quiet to thrive. They were probably never very numerous on the landscape, but by the early 1900s they were lost from most of their historical range across much of the US, due probably to high levels of human-caused mortality and low or nonexistent movement from neighboring populations back into areas from which they were lost. Mortality factors included incidental or intentional captures by trappers, poison-baiting aimed at other carnivores, and persecution from people who feared for their safety or who didn’t want wolverines around to raid their traplines or spoil their cabins or food stores.

Today in the lower 48 states, wolverines are found only in Washington, Idaho, Montana, and Wyoming. They are classified as a “species of special conservation concern” by the US Fish and Wildlife Service, though they can still be legally trapped in Montana. The wolverine is considered a candidate species for listing as threatened or endangered by the state of Washington, and a sensitive species by the Pacific Northwest Region of the US Forest Service.

Extremely elusive, they are shy around humans or human activity. Powerful runners, they can cover great distances in their search for carrion, including ungulates killed by winter and other food. Their wide-ranging travel also makes it difficult for biologists to capture and study them. Wolverines are  slow to reproduce and females birth kits only every several years. These challenges have led to much debate and controversy on the current numbers of wolverines.It's hard to know. Still, it is estimated that fewer than 1,000 remain in the lower United States.

Who they are

• Wolverines have thick brown fur with a light stripe that travels along each side from the shoulders to the base of the tail. One of the early names for them was "skunk bear."
• The largest land-based animal of the weasel family (the sea otter is larger!), the wolverine weighs 15 to 40 pounds.
• Wolverines are predominantly scavengers of the dead carcasses (carrion) of large mammals (including mountain goat, deer, elk, moose, and caribou), but they also prey on marmots, ground squirrels, snowshoe hares, and other small mammals, and sometimes take advantage of other food sources, such as insects or berries.  However, they are capable of hunting and killing animals five times their own body weight, if snow conditions give them a predatory advantage.
• Wolverines are solitary, except during mating season, which occurs once every two years between the months of June to August.

Long-term protection

Many conservationists and wildlife biologists view the wolverine as a species in trouble which needs protection.

In 2000, conservation groups, including Conservation Northwest, petitioned the federal government to protect the wolverine as a "threatened" species under the Endangered Species Act. That petition was denied and we filed a lawsuit in federal court to overturn the government’s decision.

In September 2006 the US District Court for Montana directed the Fish and Wildlife Service to conduct a full status review of the wolverine and issue a final determination of whether the species should be listed as threatened or endangered.

In March 2008 the agency  to list the wolverine, maintaining that healthy populations over the border in British Columbia made listing unnecessary. A petition to list all wolverine populations in the lower 48 under the Endangered Species Act was denied in March 2008 and petitioners, including Conservation Northwest, filed a notice of intent to sue over that decision. The Endangered Species Act was written to protect known species on American lands, and we shouldn't rely on Canada. We'll continue to push for protection for the wild and wiley wolverine.