Wolverine to be Designated a Candidate for Endangered Species Protection
Wolverines found in the contiguous United States warrant protection under the Endangered Species Act, but a rulemaking to propose the species for protection is precluded by the need to address other higher priority species, the U.S. Fish and Wildlife Service (Service) announced Dec. 13. The wolverine will be added to the list of candidates for Endangered Species Act (ESA) protection, where its status will be reviewed annually.
The ESA provides a critical safety net for America's native fish, wildlife and plants. The unprecedented challenge of climate change and its broad, complex impacts on species and habitat make it even more imperative to have an effective, collaborative approach to conserving and recovering imperiled species. This landmark conservation law has prevented the extinction of hundreds of imperiled species across the nation and promoted the recovery of many others.
The Service's determination - also known as a 12-month finding - that sufficient scientific and commercial data exist to warrant protecting the wolverine in the contiguous United States as a Distinct Population Segment (DPS) under the ESA was made after a comprehensive review of the best available scientific information concerning the wolverine and the threats it faces.
This review found that the wolverine in the contiguous U.S. is primarily threatened by the impact of climate warming on its alpine habitat.
The wolverine is a resilient species which was likely extirpated from the lower 48 states during the early 20th century and has re-established populations by moving down from Canada into the North Cascades Range of Washington and the Northern Rocky Mountains of Montana, Idaho and Wyoming.
"The threats to the wolverine are long-term due to the impacts of climate change on their denning habitat, especially important to assist the species in successfully reproducing," said Steve Guertin, the Service's Director of the Mountain-Prairie Region. "If we work with state and other partners to help the wolverine now, we may be able to counter the long-term impacts of climate change on their habitat and keep them from becoming endangered."
Deep snow is required for successful wolverine reproduction because female wolverines dig elaborate dens in the snow for their offspring. These den structures are thought to protect wolverine kits from predators as well as harsh alpine winters. Data and analysis requested from the University of Washington Climate Impacts Group and the U.S. Forest Service Rocky Mountain Research Station predict a reduction of wolverines' cold and snowy habitat of 63 percent by 2099. As wolverine habitat is reduced, the Service expects the remaining habitat will become more fragmented, with distances growing between habitat "islands." Evidence suggests this diminished and fragmented habitat will support fewer wolverines with reduced connectivity between populations. The impact of climate warming may exacerbate the impact of other threats, such as recreational use of habitat, infrastructure development, and transportation corridors.
The primary threat of climate warming has not, so far, resulted in any detectable population-level effects to the species, and the Service's evaluation found that these effects, while serious, are not imminent. As a result, the agency's limited resources must be devoted to work on listing determinations for species at greater risk of extinction. The Service will proceed with proposing those species for protection prior to addressing the wolverine. Any proposal to add the wolverine to the federal list of threatened and endangered species will be subject to public review and comment through a rulemaking process.
The Service will add the wolverine to its list of candidate species and review its status annually. Candidate species do not receive protection under the ESA, although the Service works to conserve them. The annual review and identification of candidate species provides landowners and resource managers with notice of species in need of conservation, allowing them to address threats and work to preclude the need to list the species. The Service is currently working with landowners and partners to implement voluntary conservation agreements covering 5 million acres of habitat for more than 130 candidate species.
The wolverine inhabits arctic, boreal, and alpine habitats in Alaska, western Canada, and the western contiguous United States. South of the Canadian border, wolverines are restricted to areas in high mountains, near the treeline, where conditions are cold year-round and snow cover persists well into the month of May. Most wolverine habitat in the contiguous U.S. - more than 90 percent - is located on federally-owned land, with the remainder being state, private, or tribally owned.
Currently, wolverine populations are restricted to the North Cascades Range in Washington and the Northern Rockies of Montana, Idaho, and Wyoming. Populations once existed in the Sierra Nevada of California and the southern Rocky Mountains in the states of Colorado and Utah. Currently, at least one individual wolverine is known to inhabit the Sierra Nevada and one in the southern Rocky Mountains. Both are thought to be recent migrants to these areas.
The Service's determination was made in response to a petition filed July 14, 2000, by the Biodiversity Legal Foundation, Predator Conservation Alliance, Defenders of Wildlife, Northwest Ecosystem Alliance, Friends of the Clearwater, and Superior Wilderness Action Network. On March 11, 2008, the Service published a 12-month finding that listing of the wolverine in the contiguous United States was "not warranted." In response to litigation, the Service agreed to revisit its previous determination and issue a new 12-month finding by December 1, 2010. This finding alters the previous determination.
A copy of the finding and other information about the wolverine is available online at http://www.fws.gov/mountain-prairie/species/mammals/wolverine or by contacting the Montana Field Office at 406-449-5225.
America's fish, wildlife and plant resources belong to all of us, and ensuring the health of imperiled species is a shared responsibility. We're working to actively engage conservation partners and the public in the search for improved and innovative ways to conserve and recover imperiled species.
To learn more about the Endangered Species program, go to http://www.fws.gov/endangered/.
The mission of the U.S. Fish and Wildlife Service is working with others to conserve, protect and enhance fish, wildlife, plants and their habitats for the continuing benefit of the American people. We are both a leader and trusted partner in fish and wildlife conservation, known for our scientific excellence, stewardship of lands and natural resources, dedicated professionals and commitment to public service.
For more information on our work and the people who make it happen, visit www.fws.gov.