Wolverine Distribution and Ecology in the North Cascades Ecosystem, 2016

Wolverine Distribution and Ecology in the North Cascades Ecosystem, 2016
Final Progress Report

  • Keith B. Aubry, Ph.D. (Lead Principal Investigator), Research Wildlife Biologist, U.S. Forest Service, Pacific Northwest Research Station, Olympia, WA
  • John Rohrer, Supervisory Wildlife Biologist, U.S. Forest Service, Okanogan-Wenatchee National Forest, Winthrop, WA
  • Catherine M. Raley, Wildlife Biologist, U.S. Forest Service, Pacific Northwest Research Station, Olympia, WA
  • Scott Fitkin, District Wildlife Biologist, Washington Department of Fish and Wildlife, Winthrop, WA

The wolverine (Gulo gulo) is one of the rarest mammals in North America and the least known of the large carnivores (Banci 1994). The wolverine is considered a sensitive species in the Pacific Northwest Region by the U.S. Forest Service, and a candidate species for listing as threatened or endangered by the state of Washington.

Wolverines of the North Cascades, 2014

Wolverine Research

The wolverine is among the rarest of the large carnivores in North America and probably least understood. SEEC produced this video to feature the collaborative, transboundary wolverine research of wildlife biologists in Washington State and and the Province of British Columbia.



Wolverines eat a variety of food items. The larger animals they feed on tend to be carrion, that is, already dead when they discover them.  These larger animals include elk, caribou, deer and mountain goats. Wolverines will also eat snowshoe hare, porcupines, marmots, mice, voles, birds, fish and vegetation.

Length: 82 – 130 cm  |  Weight: 6.5 – 16kg  |  Lifespan: 7-12 years


Wolverines in the North Cascades of Washington State appear to be part of a larger population that reside in British Columbia and possibly Alberta. Wildlife biologists in in the U.S. collaborate with their counterparts in BC to study these populations as part of ongoing research related to transboundary species. This study area includes the North Cascades, Skagit and Similkameen watersheds.

This research involves setting live traps baited with road-killed mule deer, beaver or salmon carcasses and monitored electronically as well as visited regularly to ensure the traps are working properly.  Captured wolverines are ear-tagged and fitted with radio-collars to provide general location and movement data. Approximately 1 dozen unique wolverines have been trapped, tagged and monitored over a 4 – 5 year period.


For a graphic illustration of the extensive range of rough country the wolverine travels over, visit page 13 of this report by wolverinefoundation.org. The vast, uninterupted wild space a wolverine requires speak volumes to importance of protected habitat.


Mating season for wolverines is late spring to summer with an average of 1 – 2 kits being born the following winter, into spring. The kits are born white in color, in dens, burrowed deep into the snow in remote alpine locations usually at or just above the treeline.

What threatens wolverines?

The threats to wolverines are ultimately all human initiated.

Climate change affects the wolverines because the available deep snow in their southern habitat regions is slowly diminishing.

Encroachment of human activity disrupts denning wolverines. Outdoor enthusiasts are accessing wild places via snowmobile and backcountry skiing excursions.

As human infrastructure expands into more remote regions, available wolverine habitat becomes more fragmented.  Connected corridors of protected lands are required to enable the wide ranging wolverine to travel between regional wolverine populations.

The recent wolverine work in BC is funded by the Habitat Conservation Trust Fund, the Skagit Environmental Endowment Commission, the BC Ministry of Environment and the BC Conservation Foundation.

For the latest information about wolverine research, connect with the following organizations.

The Wolverine Foundation     Conservation NW