Fact Sheet
Wolverine

Threats to Wolverines

Wolverines once inhabited much of the northern United States in greater numbers. By the 20th century, wolverines were mostly killed off in the lower 48 states due to unregulated predator control and trapping. Since then, they have been slowly recolonizing their former territory.

Today, the species is rare, and faces significant challenges to its future in the U.S. Yet, because of their limited numbers, huge individual territories, and remote locations, it is difficult to gather data on wolverines and this poses a challenge to scientists, agencies, and others trying to understand wolverines’ habitat requirements and threats to their survival.  Perhaps in part due to this lack of data, they have yet to be federally protected under the Endangered Species Act.  

Climate Change

Wolverines have eked out a living under tough conditions in the past, but the danger of climate change melting away their snowbound habitat looms large in the near future. Wolverines rely on deep spring snow to rear their young, so they are especially vulnerable to the loss of their alpine habitat due to climate change. Scientists predict that wolverines in the lower 48 states may lose two-thirds of their suitable, snow-covered habitat by the end of the century.

Human Interaction

Wolverine trapping has long been allowed in Montana, where up to five wolverines statewide can be legally trapped each year. Occasionally, across their range they are also accidently caught in traps set for other species. In addition, winter recreation like snowmobiling and backcountry skiing likely disrupts denning wolverines. Further research is needed to confirm the extent of measurable impacts these activities have on the species.

Habitat Fragmentation

Infrastructure development, land management and transportation corridors can fragment wolverine habitat and reduce connectivity. The Lower 48 population is not well-connected to those in Alaska and Canada, but to improve genetic diversity for wolverines we need to increase connectivity between these populations and between ‘island’ mountain ranges. These ‘islands’ also need to be fully occupied by reproductive adults to be resilient against climate change. Reintroductions into former habitats like Colorado will be important to help wolverines reoccupy mountain ranges that will retain snowpack into the future.

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Polar bear, © Tom Schneider
Conservation Issue
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How You Can Help
Tell Secretary Jewell to stop ignoring threats to wolverines and give them full protection before it’s too late!
Success Stories
February, 2013: After more than a decade of work, wolverines are a step closer to the federal protection they deserve!