Climate change threatens wolverines; protections proposed

Citing shrinking mountain snowpacks as a result of climate change, federal wildlife officials are proposing to list wolverines as threatened under the Endangered Species Act.

The animal, which resembles a small bear with a bushy tail, needs deep mountain snow to reproduce. Females give birth from mid-February through March in dens they excavate in alpine snow, typically using them until late April or early May.

Global warming, which will diminish snowfall and cause earlier spring melt, could reduce wolverine habitat in the lower 48 states by 31% over the next three decades and by 63% over the next 75 years, according to the proposed listing by the U.S. Fish and Wildlife Service.

The agency estimates there are 250 to 300 wolverines in the contiguous United States, with the bulk of them living in the northern Rocky Mountains. There is also a small population in the North Cascades range in the Pacific Northwest, one wolverine recorded in the Sierra Nevada in California and one in the southern Rocky Mountains.

A scavenger-predator with an excellent sense of smell, the wolverine dines on a range of food, including carrion, small animals and fruit. Among its common names are mountain devil and skunk bear.

The species range is not restricted by vegetation but wolverines are expected to move to higher elevations to find deep snow as climate change reduces and fragments suitable habitat.

Trapping and predator control virtually eliminated the species from the lower 48 states in the early 20th century. The existing population is believed to have originated with wolverines that crossed the border from Canada. Wolverines are also found in Alaska. The proposed listing would apply only to the population in the contiguous states.

Listing would likely outlaw wolverine trapping in Montana, where it is legal, and could allow reintroduction of the species to alpine regions where it is not currently found.

The proposed listing was made in response to a legal settlement with the Center for Biological Diversity that requires the wildlife service to take action on hundreds of species considered for protections under the Endangered Species Act. A petition to list the wolverine was denied under the George W. Bush administration.