07:49 PM

Last 250-300 Wolverines in Lower-48 Denied Protection


August 12, 2014

Contact: Melanie Gade, Defenders of Wildlife: mgade@defenders.org; 202-772-0288

Last 250-300 Wolverines in Lower-48 Denied Protection

WASHINGTON – The U.S. Fish and Wildlife Service today denied protections for the rare wolverine under the Endangered Species Act (ESA), potentially jeopardizing the species’ long-term survival in the lower-48 states. Although the Service proposed to list wolverines as “threatened” in 2013 citing a primary threat of reduced habitat and range from climate change, the agency today said wolverines do not warrant a listing due to uncertainty about the effects of climate change on the animals, a claim disputed by conservation groups.

Defenders and other groups filed the original petition to list the species in July 2000, citing numerous threats to the species’ survival including the species’ small population size, low genetic diversity, and direct and indirect impacts from trapping, winter recreation, and habitat alteration. The petition was filed before climate change was understood to present a serious threat to the wolverine, leading conservation groups to reassert today that, without or without climate change, wolverines face enough threats to warrant listing.

Defenders of Wildlife President and CEO Jamie Rappaport Clark issued the following statement:

“The Service made the wrong call today in denying protections for wolverines under the ESA. The Service is ignoring the numerous serious threats to wolverines, including the species’ low genetic diversity and impacts such as trapping and winter recreation. These serious threats are made worse by loss of snowpack across much of the West – habitat needed for this snow-dependent species.

“The wolverine is in dire need of protection under the ESA, regardless of one’s opinions about the science of climate change. The number of wolverines in the lower-48 is incredibly low with only a few dozen females able to produce offspring in any year. Are we really willing to deny any sort of federal protection for a species whose low numbers make it one of the rarest in the continental U.S.?”

Background: Wolverines have one of the lowest successful reproductive rates known to mammals. Scientists estimate the effective population size – the portion of the population that contributes to future generations and thus a measure of the population’s genetic health – to be estimated at 35.

Wolverines are rare, wide-ranging members of the weasel family that exist in high-altitude mountain ranges. They are found primarily in Montana, Idaho, Wyoming, and north-central Washington. Individuals have been recently photographed in Utah, Colorado, and California but these are not breeding populations.

Wolverines were denied federal protection under the Bush administration twice. The Obama administration delayed action for wolverines in 2010, saying that other imperiled species took precedence.

On February 4, 2013, the Service proposed to list the wolverine in the lower-48 as threatened, citing the likelihood of habitat loss caused by climate change as a primary threat to the species. In February 2014 the Service delayed the final decision by six months to address concerns from states including Idaho, Montana, Wyoming, and New Mexico.


Defenders of Wildlife is dedicated to the protection of all native animals and plants in their natural communities. With more than 1.1 million members and activists, Defenders of Wildlife is a leading advocate for innovative solutions to safeguard our wildlife heritage for generations to come. For more information, visit www.defenders.org.