Wolverine
Gulo gulo
Called “skunk bear” by the Blackfeet Indians, the wolverine is the largest terrestrial member of the weasel family. It has a broad head, small eyes and short rounded ears. The wolverines have glossy dark brown fur, a light face mask and a stripe running down both sides of its body. It is powerfully built and has short legs with wide feet for traveling across the snow.
Height 14 inches at shoulders (females); 16 inches
(males)
Length 31-44 inches (including its bushy tail)
Weight 25-40 lbs (males), 15-30 lbs (females). Males are typically 30-40% larger than females.
Lifespan 10-12 years
Diet
Known for scavenging dead animals like caribou or moose but is also very capable of killing its own meal, including ground squirrels and snowshoe hares.
Population
Fewer than 500 wolverines remain in the lower 48 states, according to the latest estimate by the U.S. Fish and Wildlife Service.
Range
Wolverines prefer scattered trees at high elevations. Historically they occurred from Maine to Washington down to the Rocky Mountains and Sierra/Cascades. In the lower 48 states, wolverines now occur only in Wyoming, Idaho, Montana, Washington and may still occur in the Great Lakes region. Wolverines were believed to be extirpated from California, but a remote camera caught one on film in February 2008!
Behavior
Wolverines have been documented traveling great distances, often going right over mountains instead of taking the easy way around. One male wolverine near Yellowstone traveled 250 miles in 19 days.
Reproduction
Mating Season May through August
Gestation Egg
implantation is delayed, following which is a 30-40-day gestation
period
Litter Size 2-3 kits
The females use dens, often on rocky hillsides
above timberline. The baby wolverines are white when they are born.
Threats
Trapping and habitat disturbance due to snowmobiling and heli-skiing activities and habitat loss.
Legal Status/Protection
The wolverine is legally trapped in Montana and Alaska.
In March 2008, the Fish and Wildlife Service decided not to protect wolverines under the Endangered Species Act*. They said we do not need to protect wolverines in the lower-48 states, because wolverines are not endangered in Canada. Defenders of Wildlife is now challenging this decision, because we believe that America should protect its own wildlife, not rely on other countries to save them. We are optimistic that we will succeed, and soon gain wolverines the protections they need and deserve.
* The Endangered Species Act requires the US federal government to identify species threatened with extinction, identify habitat they need to survive, and help protect both. In doing so, the Act works to ensure the basic health of our natural ecosystems and protect the legacy of conservation we leave to our children and grandchildren.
How You Can Help
- Help wolverines and other wildlife by adopting an animal at our Wildlife Adoption Center.
- Take Action for Wildlife at our Wildlife Action Center.
For additional information
Visit Defenders' Imperiled Species: Wolverine pages for more information about what Defenders is doing to help.
Navigating the Arctic Meltdown: Wolverines
Audio courtesy of Jeff Copeland, USDA Forest Service, Rocky Mountain Research Station.
