Conserving the Nature of America

News Release

Endangered Species Act Protection for Wolverine Not Warranted

March 10, 2008


Division of Public Affairs
External Affairs
Telephone: 703-358-2220

The U.S. Fish and Wildlife Service has determined that protecting the wolverine in the contiguous United States as a threatened or endangered species under the Endangered Species Act (Act) is not warranted. However, the Service will continue to seek new information regarding the status of the wolverine and continue to support cooperative conservation efforts to benefit the species in its native range.

The wolverine is the largest land species of the Mustelidae, or weasel family, with adults weighing 17 to 40 pounds. In appearance, it has more characteristics of a small bear than a weasel, and feeds primarily by scavenging on carrion. In North America, wolverines occur in a variety of habitats, primarily boreal forests, tundra and western mountains throughout Alaska and Canada, with the southern portion of the range extending into the contiguous United States.

When considering whether to add a species to the federal list of threatened and endangered species, the Service has the authority under the Act to determine whether a portion of a species? or subspecies? population or range can be designated as a distinct population segment.

A distinct population segment (DPS) must be geographically discrete from other populations and also be significant to the survival of the species. "Discrete? refers to the isolation of a population from other members of the species and is evaluated based on specific criteria.

After reviewing the best available scientific and commercial information, the Service has determined that the wolverine population in the contiguous United States is not discrete, because it is not separated from wolverine populations in Canada, and is likely dependent on them to some degree for maintaining genetic diversity.

After determining that the wolverine population in the contiguous United States did not constitute a DPS, the Service analyzed whether it would constitute a significant portion of the range of the North American wolverine subspecies. The Service determined that the contiguous United States population of wolverine does not significantly contribute to the Canadian and Alaskan wolverine populations? ability to maintain their genetic diversity and viability and, therefore, does not warrant further listing consideration.

Assessing historical and recent distribution data, the current range of the wolverine is found to be the northern Cascades in Washington (and possibly Oregon), and the northern Rocky Mountains in Idaho, Montana, and Wyoming. The species was likely driven from the Sierra Nevada and the southern Rocky Mountains with the early westward expansion of settlers.

In 2000, the Service was petitioned by the Biodiversity Legal Foundation and others to list the North American wolverine within the contiguous United States as a threatened or endangered species. In 2003, the Service published a finding that the petition did not present substantial information indicating that listing was warranted. The Defenders of Wildlife filed a lawsuit in 2006 alleging the Service used incorrect standards to assess the petition, and the Montana U. S. District Court ordered the Service to conduct a new status review by February 28, 2008.

This finding will be published in the Federal Register on March 11, 2008.

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