Nevada Fish & Wildlife Office
Pacific Southwest Region

North American Wolverine

(G. gulo)

Wolverine
Class: Mammalia
Order: Carnivora
Family: Mustelidae
Genus: Gulo
Species: G. gulo
  Photo Credit NPS
Size: Adult males weigh 26 to 55 pounds and adult females weigh 17 to 26 pounds. Length 26-42 inches. Lifespan is up to 13 years.
Feed: Prey mainly consists of small to large-sized mammals and the wolverine has been recorded killing prey such as adult deer that are many times larger than itself.
Habitat: North Cascades in Washington and the Northern Rocky Mountains in Idaho, Montana, Oregon (Wallowa Range), and Wyoming.  Individual wolverines have also moved into historic range in the Sierra Nevada Mountains of California and the Southern Rocky Mountains of Colorado.
 

Official Status:

Proposed Protection as Threatend
 

Life History:

Wolverines, an iconic species of the American mountain west, are the largest member of the weasel family.  The species ranges across northern Europe, northern Asia, and northern North America.  Wolverines occur in a variety of habitats but are dependent on cold conditions and deep persistent spring snow for year-round occupancy and reproduction.  In the contiguous U.S., these conditions occur only at high elevations in the Mountain West. 

Wolverine populations were eliminated from the contiguous U.S. in the early 20th Century due to unregulated trapping and predator control campaigns.  Since that time, wolverines have made a remarkable, albeit slow, recovery, largely unassisted by humans.  Currently, wolverines are found in the North Cascades in Washington and the Northern Rocky Mountains in Idaho, Montana, Oregon (Wallowa Range), and Wyoming.  Individual wolverines have also moved into historic range in the Sierra Nevada Mountains of California and the Southern Rocky Mountains of Colorado, but have not established breeding populations in these areas. 

Wolverines are threatened by the loss of cold conditions and persistent spring snow caused by climate warming predicted to occur over the next eighty years.

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Distribution and Habitat:

 

·         Northern Rocky Mountains – Montana, Idaho, Wyoming, Oregon (Wallowa Range)
·         North Cascades – Washington
·         Southern Rocky Mountains – Colorado, Wyoming, New Mexico
·         Sierra Nevada Mountains – California
·         May also occur historically or sporadically – Oregon, Utah, Nevada

 

Threats:

 

An estimated 250 to 300 wolverines now occur in the lower 48 states, where the species has rebounded after broad-scale predator trapping and poisoning programs led to its near extinction in the early 1900s. This was in part due to the states protecting the species from unregulated trapping.

Extensive climate modeling indicates that the wolverine’s snow pack habitat will be greatly reduced and fragmented in the coming years due to climate warming, thereby threatening the species with extinction. Wolverines are dependent on areas in high mountains, near the tree-line, where conditions are cold year-round and snow cover persists well into the month of May.

Wolverines are threatened by the loss of cold conditions and persistent spring snow caused by climate warming predicted to occur over the next eighty years.

 

Actions / Current Information:

 

02/04/2013
  • News Release: The U.S. Fish and Wildlife Service (Service) is seeking your input on a proposal to protect the North American wolverine as a threatened species under the Endangered Species Act (ESA).
     
  • Additional Information
         
    Last updated: April 16, 2014