Yellowstone National Park Wolverine Help Page

Wolverine (Gulo gulo)

The Wolverine is one of the rarest animals in Yellowstone National Park and there have been very few sightings. If you happen to see one, if you can, take some pictures (and GPS location if possible) and report your sighting to any ranger or visitor center. "The wolverine is the largest land species of the “mustelid” or weasel family, with adults weighing 17 to 40 pounds. It has thick brown fur, with a lighter brown or blonde “stripe” along its sides. It has large feet for traversing snow and strong jaws to enable it to feed on frozen carrion and bones. The wolverine inhabits boreal forests in the contiguous United States, Canada and Alaska." (US Fish and Wildlife Service)

"The U.S. Fish and Wildlife Service has determined that protecting the wolverine in the contiguous United States as a threatened or endangered species under the Endangered Species Act (Act) is not warranted. However, the Service will continue to seek new information regarding the status of the wolverine and continue to support cooperative conservation efforts to benefit the species in its native range." (US Fish and Wildlife Service) This fact seems hard to believe as the wolverine is probably the rarest animal seen in Yellowstone.

It light of the above paragraph, consider this quote from the US Fish and Wildlife Service: "Wolverines are the largest land-dwelling member of the mustelid family and are extremely rare in the continental United States. They are also extremely rare on the western lowlands of the Refuge (Kenai National Wildlife Refuge). Occasionally wolverine tracks in snow in alpine areas can be seen from an airplane, and if followed, a wolverine can sometimes be observed. Primarily a scavenger, wolverine have powerful jaws for eating the frozen meat of winter-killed animals, and large teeth to crush the bones and skin of carcasses left behind by wolves and bears. Wolverine are solitary animals, coming together only for a brief mating season. Males have territories of up to 240 miles and travel up to 40 miles/day in search of food; females maintain smaller territories of 50-100 miles. Because the species requires expansive tracks of undisturbed wilderness, wolverine have all but disappeared from much of their historical range in the Lower 48." This sure makes one wonder what the real reasoning is for not listing the wolverine as threatened or endangered?

The following information is provided by Yellowstone National Park:

WOLVERINE (Gulo gulo)

Identification

Habitat

• Found in high-elevation conifer forests and alpine tundra; rarely seen.
• Eat burrowing rodents, birds, eggs, beavers, squirrels, marmots, mice, and vegetation; chiefly a scavenger in winter, but has also been known to take large prey such as deer or elk.

Behavior

• Active year-round, intermittently throughout the day
• Breed April to October; 1 litter of 2–4 young each year.
• Den under log jams and uprooted trees in avalanche chutes.
• Solitary except when breeding.

Research

In 2005, researchers began a 5-year field study to gather information about this species in east Yellowstone National Park and the adjoining Shoshone and Gallatin National Forests. Animals are being livetrapped and fitted with radio collars equipped with Global Positioning Systems to track their movement.

If you find only tracks, measure and photograph them carefully, then consult a track field guide for identification. And consider yourself very lucky to see a wolverine in Yellowstone. These rare and elusive animals are very seldomly seen, so even those who study them seldom have an opportunity to see one! If you think you see a wolverine or wolverine tracks, please report them promptly to a ranger or visitor center. Also, if you have a chance, please take photos or video of the tracks (please place something beside the track to help determine size - pen, pencil, comb, etc.) or animal. For animals so rarely recorded, every observation is useful and important.

Rare Animal Report Form (this is an Adobe pdf form)

For current wolverine research and information, please see the Spring 2008 Newsletter (this is an Adobe pdf document).

Also see these page for Yellowstone Animal / Mammal information Animal Page or the Mammal List (this is an Adobe pdf document).

Please Report any Possible Sightings to any Ranger or Visitor Center!

by John William Uhler

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