Wolverine - Gulo gulo- facts, video
| Video | Sound | Defenders At Work | Take Action |
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.
Fast Facts
Male wolverines are typically 30-40% larger than females.
Height: 16 inches (.41m) (males); 14 inches (.36m) at shoulders (females)
Length: 31-44 inches (.8 - 1.1m) (including its bushy tail)
Weight: 25-55 lbs (11-18 kg) (males), 15-30 lbs (7-14 kg) (females). Exceptionally large males can weigh over 70 lbs (31 kg)
Lifespan: 10-12 years.
Diet
Wolverines are known for scavenging dead animals like caribou or moose but are also very capable of killing their 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
Did You Know?
Wolverine fur is thick, oily, and hydrophobic, which means it's resistant to frost.
To blend in with their snowy environment, wolverine kits are white when they are born.
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! See a wolverine range map >>
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 more than 500 miles in 42 days.
Watch A Wolverine At Play
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 dig dens eight feet or deeper into the snow in the middle of winter, often in remote alpine cirques at or above treeline.
Global Warming and Other Threats
Wolverine habitat is being threatened by global warming. As climate change causes rising temperatures, more of the wolverine’s mountain top habitat is being lost, forcing them to higher elevations. This will shrink their ranges to only the highest mountaintops. The impacts of global warming are also seen in the female wolverine’s denning. Wolverines need areas that maintain deep snow from February to early May for their dens so they can provide insulation for their kits. With less snow and smaller habitat, food and denning areas are becoming scare.
Defenders at Work
Defenders worked in cooperation with the Forest Service and Glacier National Park to support crucial wolverine research. By tracking wolverines with radio-collars we learned what habitat they prefer, what they eat, and where they den and raise young. We now can use this information and use it to better help and protect the wolverine. Learn more >>
Wolverines still survive in the western U.S. but are at risk due to low breeding numbers. They face threats from habitat loss and habitat fragmentation and more and more areas of wolverine denning habitat are disturbed by snowmobiles and helicopter skiing. Currently Montana and Alaska still allow wolverines to be trapped.
Reasons For Hope
Because wolverines are solitary creatures and require such large tracts of land to live, very little is know about them and what they need to survive. With more research, we can better understand them, their needs, and how better to protect them.
In June of 2009 remote cameras photographed a wolverine on the slopes of Mount Adams in Washington State and another was seen in Colorado at the Rocky Mountain National Park.
In August of 2009 a wolverine was spotted on the slopes of the Pioneer Mountains in Idaho.
Legal Status/Protection
Defenders Success Story
Defenders challenged the March 2008 decision by the Fish and Wildlife Service to not protect wolverines under the ESA. In a settlement agreement filed with the court in June 2009, the Fish and Wildlife Service agreed reconsider whether to add the wolverine population in the lower-48 states to the list of species protected by the Endangered Species Act. The new listing determination is due by December 2010, and will follow an updated status review on the wolverine. Learn more >>
- On the IUCN Red List, the wolverine is currently listed as near threatened.
- In March 2008, the Fish and Wildlife Service decided not to protect wolverines under the Endangered Species Act. FWS said that the United States does 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 wolverine is legally trapped in Montana and Alaska.
- Learn more about legal status and protection for wolverines >>
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.
