A wolf in Yellowstone National Park. Photo courtesy of Yellowstone National Park

The federal government's proposal to discontinue protection for the gray wolf across the United States could have the unintended consequence of endangering other species, researchers say.

As written, scientists assert, the proposed rule would set a precedent allowing the U.S. Fish and Wildlife Service (FWS) to declare habitat unsuitable for an endangered animal because a threat exists on the land – the exact opposite of the service's mandate to impose regulations that reduce threats against imperiled species.

The FWS has "conflated threats with habitat suitability" by stating that U.S. land currently unoccupied by wolves – most of the country that historically served as wolf habitat – is now unsuitable because humans living in those regions won't tolerate the animals, the lead scientist said. This claim runs counter to existing research, which the service did not cite in its explanation of the rule.

"The Fish and Wildlife Service is supposed to detail what the threats are and if they're substantial enough, they're supposed to list a species and put in place policies to mitigate the threats," said Jeremy Bruskotter, associate professor in The Ohio State University's School of Environment and Natural Resources and lead author of the paper.

"Here, they're saying that they recognize the threat of human intolerance and instead of mitigating the threat, they're just going to say the land is unsuitable."

Were this rule to stand, he said, "Anytime the U.S. Fish and Wildlife Service finds that something is in the way of a species' recovery, they can just say the habitat is unsuitable for the species and disregard the threat altogether."

FWS proposed removing the gray wolf (Canis lupus) from the list of threatened and endangered species in June. The rule covers most of the continental United States where wolves historically existed, before being exterminated by people in the late 19th and early 20th centuries. Public comments closed Dec. 17, and will be analyzed and considered before the service issues a final rule.

The critique is published online in the journal Conservation Letters.

Congress passed the Endangered Species Act in 1973. The act expanded on previous legislation by providing for the protection of any species in danger of or threatened with extinction throughout all or a significant portion of its range.

The act's language is critical to what follows: In determining whether a species has recovered, the law requires FWS to declare it is no longer endangered in all or a "significant portion of its range." The gray wolf has recovered in the northern Rockies and upper Great Lakes.

The proposed rule, however, discounts the other 85 percent of the wolf's historic range, which stretches across northern states from the west coast through New England and as far east as mid-Texas in the southern half of the country.

"So what the service is saying is that wolves are going to be called recovered in most of the United States despite the fact that very few wolves live outside these two recovered areas," Bruskotter said. "Wherever they are now, that's their range – which means taking the historic and geographic component out of the listing process."

He and colleagues suggest that this practice not only disregards the law, but "specifically creates incentive to destroy habitat in advance of a listing and do things that aren't good for endangered species."

The law also requires the service to consider the "best available science" in assessing whether threats have eased and a species is recovered. Instead of citing the dozens of studies that suggest human support for wolf restoration is high, the service simply ignored this research and claimed that these areas are unsuitable because of human intolerance. When federal protection is lifted, species management falls to the states.

"That process is not the best available science," Bruskotter said.

Bruskotter acknowledged that FWS is under enormous pressure from the opposing sides of a highly contentious fight about wolves: hunters and livestock producers on one side and wildlife advocates on the other. But that pressure doesn't relieve the service of its duty to act on behalf of endangered species as the law requires, he said.

"The law is supposed to help the protected species, not just describe the threats to that species. But to construct this delisting rule, they've had to interpret policy and science in every case in a way that either disregards threats to wolves, or treats them as insurmountable," he said. "They're doing the opposite of what the act requires."

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