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Know the West

Climate changes for wolverine listing

What good can the Endangered Species Act do in a warming world?


Updated 8/6/14

In the dead of winter, female wolverines dig elaborate, multi-chambered dens to raise their young, choosing sites where snowpack lasts well into the spring. But snowpack in the Northern Rockies is almost certain to decline as the climate warms, jeopardizing their chances for successful reproduction. There are fewer than 300 wolverines in the Lower 48, and models show that they could lose 31 percent of their habitat by 2045 and 63 percent by 2085. And so, in February 2013, the U.S. Fish and Wildlife Service proposed adding the "mountain devils" to the endangered species list.

The science behind the proposal has not changed, but the agency's position on it has. Mountain-Prairie Regional Director Noreen Walsh advocated against a speculative listing in a memo released by environmentalists in July, citing uncertainty as to exactly why wolverines need a persistent snowpack to reproduce and how its loss would harm the animals. Though scientists recommended listing wolverines as threatened, agency leader Dan Ashe defended her position – a strong indication of which way the final decision, due in early August, will go.

Wolverines would have been the first species in the Lower 48 thrust onto the endangered species list by climate change. A listing would have helped validate the use of climate models to develop strategies to protect animals against future threats. And it would have been unusual because, unlike most of the species the act safeguards, wolverines, though rare, are not thought to be declining.

Idaho, Montana and Wyoming – the states that anchor the animal's range in the Lower 48 – dreaded the prospect of a listing and the public-land restrictions it could bring, while environmentalists cheered it on. In practical terms, though, would formal protections really help wolverines? Can a law that was designed to rescue species from discrete, localized threats also protect them from the more diffuse hazards of a warming world?

The Endangered Species Act has helped prevent the extinction of many species of plants and animals by removing specific threats to their survival, often only in areas designated as "critical habitat." Closing forest roads in prime grizzly habitat, for instance, helped keep poachers and stressful traffic at bay. Prohibiting the hunting or poisoning of wolves after they were reintroduced to the Northern Rockies allowed populations to rebuild. Restricting timber harvests in the Pacific Northwest took pressure off the northern spotted owl.

But the Fish and Wildlife Service can't simply rope off high mountain niches, exclude greenhouse gases and preserve the snow that wolverines depend on. Polar bears, bearded seals and ringed seals are already listed due to disappearing sea ice, yet carbon emissions continue to rise, and the Arctic is still melting.

The Center for Biological Diversity, which has sued for greater wolverine protection, wants the Fish and Wildlife Service and the National Marine Fisheries Service to include specific emissions targets in the plans they create to recover species threatened by climate change "to raise awareness about what these species need," says Shaye Wolf, the center's climate science director. But using the act to reduce greenhouse gases would be politically and practically impossible, argues J.B. Ruhl, a Vanderbilt University professor specializing in endangered species law. Scientists couldn't prove that a particular coal-fired power plant is responsible for the demise of polar bears, for instance. Plus, the idea has never had support in the agencies or the White House.


Still, listing species threatened by climate change isn't pointless. Recovery plans lead to basic conservation measures, such as long-term, range-wide monitoring of endangered populations and their habitats. Such unglamorous science is crucial to understanding what can be done to help at-risk species; it's not being done for wolverines, which are elusive and scarce, thus difficult and expensive to study. Insufficient funding for wolverine research also means that any decline in the population or devastating habitat changes might not be noticed until it's too late.

Additionally, the act includes an allowance for the introduction of "experimental" populations, which carry fewer land-use restrictions than existing populations that are declared endangered or threatened. In Colorado, wildlife managers have discussed introducing an experimental wolverine population for years. Trapping and poisoning wiped out wolverines in Colorado in the early 20th century, but its mountains could provide a snowy stronghold into the future. Now, however, the state is reluctant to reintroduce a species that could later become officially endangered.

Though few species have been listed primarily because of impending climate change, 66 percent of recovery plans now recommend action to cushion the impacts of warming. Of those, about 17 percent mention reducing greenhouse gas emissions, about half recommend monitoring, and most suggest actions to help species adapt, according to Wolf. These are incremental steps, but necessary to maintain the act's relevance in a warming world.

In the future, the Fish and Wildlife Service could take more creative approaches, like setting aside critical habitat that may not be ideal today, but could be essential tomorrow.  Another option is to protect corridors that would allow species to move to friendlier climes as their current homes become less hospitable. The Endangered Species Act, explains Ruhl, hasn't solved traditional problems such as urban sprawl or invasive species – but it's helped species survive them. Similarly, the act must be used to address the effects, if not the causes, of a warming planet. "I think fundamentally this is about trying to help species to adapt to climate change," he says.  "That's what the Endangered Species Act can help us do best."