Wolverine

Seldom seen hunters

These rare, alpine carnivores (Gulo gulo) favor remote, rugged, snowy landscapes like those found in the Washington's Cascades. They are successful hunters and, like mountain caribou, remnants of an Ice-age environment.

In response to a challenge filed by Conservation Northwest and others, the USFWS recently promised to determine by 2013 whether wolverines deserve full protection under the Endangered Species Act, as an animal in "dire straits" from habitat loss and global warming.

Wolverines are the largest upland members of the weasel family and were once widespread across North America. They are now constrained to remote wilderness regions of the Cascade and Rocky Mountain where heavy snowpack persists well into spring. Washington's Cascades are one of the last places left in the lower 48 where wolverines are known to exist, and our state has experienced a flurry of wolverine activity in recent years. Sightings have been reported from Mount Baker to Mount Adams.

Read more on wolverines by USFS biologist Keith Aubry.

Wolverines are seldom seen. 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 study them; yet, since 2005, federal researchers have been tracking seven wolverines in the North Cascades, learning that Washington’s wolverines have significantly larger home ranges than wolverines elsewhere.

Wolverines 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, following years of heavy trapping, indiscriminate killing by from poison-baiting aimed at other carnivores, and persecution from people. Today, fewer than 500 wolverines survive in the lower 48–mostly in Washington, Idaho, Montana, and Wyoming–and a recent study found that just 35 individuals are breeding successfully.

Needing protection

In 2010, ten years after Conservation Northwest and others filed a petition for wolverines, the US Fish and Wildlife Service decided that this rare carnivore warrants protection under the federal Endangered Species Act. Unfortunately, the agency also said that those protections will be withheld indefinitely due to the backlog of other species awaiting official action.

This is a step in the right direction, but it's not enough for an animal whose time is running out. Real protections, not just "warranted" intentions, are needed if wolverines are to survive in the face of a changing climate, shrinking snow packs, and increasingly fragmented habitat. Conservation Northwest is working to keep their habitat in the Cascades connected to other habitats in the Rockies and British Columbia. We are also monitoring their populations by sending volunteers to put out camera traps and help us with winter tracking.

More about wolverines

• Wolverines have thick brown fur with a light stripe traveling along each side from the shoulders to the base of the tail. One of the early names, Native American names for them translated as "skunk bear."
• The largest land-based animal of the weasel family (the sea otter is larger!), the wolverine weighs 15 to 40 pounds.
• These awesome predators have a keen sense of smell which allows them to find food, for example animals killed by avalanche, deep beneath the snow.
• Wolverines are most often solitary, except during mating season. But as we learn more about them, we see that they will hunt together occasionally and "hang with" siblings.
• Female wolverines rely on deep snow for their dens, digging eight or more feet into the snow to provide warmth and shelter for their kits.
• 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. Like coyotes and other carnivores, they will also eat insects or berries.
• Wolverine are capable of hunting and killing animals five times their own body weight, if snow conditions give them a predatory advantage. they are known to chase away cougars and grizzly bears. Wow.