About a century has passed since wolverines roamed Colorado’s highlands.
Sure, a fictional group of high school-aged guerrilla fighters of the name “wolverines” haunted Colorado’s mountains in the 1984 action film “Red Dawn.” And Bayfield High School has adopted the wolverines as its official term for students and sports teams alike. But real wolverines – large, scavenging, carnivorous weasels – haven’t called the state home since about 1919.
However, that is likely to change in coming years, and the mammals, which look like a weasel-bear-badger hybrid, are likely coming to the snowy mountains near Durango.
In May, Gov. Jared Polis signed SB24-171, which directs the state wildlife agency to do something nobody in North America has ever done: reintroduce wolverines to their former habitat.
Colorado Parks and Wildlife has identified three release zones that contain large blocks of prime habitat: the northern zones span the region west of Fort Collins and north of Interstate 70; the central zone stretches northeast of Gunnison up toward I-70; the southern zone is comprised of the San Juan Mountains.
Bob Inman, one of the world’s preeminent wolverine experts who was contracted by CPW to help develop a reintroduction plan for the species, said the agency would likely release the solitary animals in all three of the identified zones right off the bat.
“The San Juan range … is probably the most extensive area of wilderness, and so that’s beneficial for wolverines,” he said, given that there are “probably less roads to potentially get in trouble, getting hit by cars and so forth.”
Despite the phonetic similarity of “wolves” and “wolverines,” lawmakers who championed the reintroduction law say the two species are quite different, and that the wolverine reintroduction process will not repeat some of the mistakes made during the wolf reintroduction.
“The only unfortunate thing is that ‘wolverine’ sounds like ‘wolf,’” said state Rep. Barbara McLachlan, who represents the 59th House District.
McLachlan’s district in Southwest Colorado includes a part of the southern release zone identified by CPW, and she was one of the bill’s four prime sponsors.
Wolverine reintroduction was considered in the 1990s, when wildlife officials began planning to reintroduce the Canada lynx.
CPW returned to the idea in 2010 and completed a plan for reintroduction informed by partners and stakeholders, but that was halted because of uncertainty surrounding a federal listing decision, the agency said in a written statement.
As of November 2023, Wolverines have been listed as “threatened” under the Endangered Species Act.
Reintroducing wolverines to the landscape provides a recreational interest for people who may encounter the animals, Inman said. But with fewer than 400 wolverines in the contiguous United States, reintroduction is also important for preserving biodiversity. Colorado holds about 20% of the wolverine habitat in the lower forty-eight, but the species has not regained a paw-hold here despite established populations in Washington, Montana, Idaho and Wyoming.
Wolverines number in the thousands in Canada and Alaska.
The animals, which weigh anywhere between 15 and 40 pounds, have a large individual territory that is up to 20 times larger than that of bobcats and coyotes and about eight times larger than the territory of lynx.
“The main point here is that Wolverines naturally occur at very low densities,” Dave Klute, supervisor of CPW’s species conservation unit told the CPW Commission during a May 1 presentation. “So even in parts of their range where the populations are robust and they’re doing well, they are extremely rare.”
Wolverines eat mostly carcasses of dead animals, although they will turn to active predation on marmots in the summertime.
They “eke out a living,” Inman said.
“They’re also caching specialists – when they find something, they kind of butcher it up, take it apart, and go and take it and stuff it under the rocks, down in the snow and ice, and keep it there,” he said.
Unlike wolves, wolverines are unlikely to prey on livestock, scientists agree.
Sheep would be the first target, Inman said. Predation is possible and “probably will happen at some point,” he said, however he expects it to be uncommon.
CPW hopes to trap wolverines during late fall and early winter months and bring them to a rehabilitation center in Del Norte, where they will undergo examination, treatment and receive GPS collars. Ideally, the agency will release 15 wolverines each year for three years. Biologists estimate the state can provide home to around 100 wolverines.
Colorado’s habitat is not only ideal, unoccupied wolverine habitat, but it is expected to weather the effects of climate change especially well.
The biggest question now facing CPW: Where will the agency get wolverines?
“CPW has begun the process of scoring potential source populations based on two metrics: ecological similarity of the landscape to Colorado and genetics,” CPW spokesman John Livingston said in a written statement. “As CPW develops its reintroduction plan, it will also evaluate political and logistical considerations such as which jurisdictions are willing to participate and how many wolverines they would be willing to provide, etc.”
Inman said that ideally, Colorado will find wolverines that are accustomed to mountain lions. Most wolverines will know how to live and evade bears and wolves, but not all will be familiar with mountain lions.
British Columbia and places in Alberta would be the top of the ideal potential source list, Inman said.
A month after CPW released wolves in Grand County last December, fulfilling a voter mandate passed in 2020, agency Director Jeff Davis went before the commission to apologize for the lack of transparency around the release.
This stumbling block was one of several CPW hit as the Dec. 31 deadline approached.
Toward the end of the 2023 legislative session, lawmakers passed a law mandating that the U.S. Fish and Wildlife Service have a 10(j) rule in place before wolves were released. The rule defines the wolf population as “experimental,” therefore allowing CPW more latitude when it comes to managing the population.
But given the uncertainty of the federal agency’s timeline, wolf advocates raised concerns that a delay in the 10(j) rule could put CPW in the position of violating either the voter mandate to release wolves by the end of 2023, or the new state law.
Ultimately, the rule was in place before wolves were released on Dec. 18.
This time around, legislators aren’t leaving room for the same mistakes.
Wolf reintroduction was the product of a 2020 ballot measure approved by voters, a process that some derisively refer to as “ballot box biology.”
“Ballot box biology is no way to manage the wildlife resource of the state of Colorado,” said state Sen. Perry Will, a former wildlife officer and prime sponsor of the wolverine bill, at a Senate Agriculture and Natural Resources Committee hearing March 21.
The bill was a way to ensure that the state could correct some of the concerns that arose during wolf reintroduction.
“We kind of slowed down on everything,” Rep. McLachlan said.
Unlike the wolf reintroduction, the wolverine reintroduction has no established timeline. And, the 10(j) rule must be in place before the animals are released.
The legislation also ensures that the commission must adopt regulations to pay compensation for livestock that are depredated by wolverines, although this is unlikely. According to the agency, a wolverine killed a sheep in Wyoming in the 1990s, and another killed four sheep and wounded 14 others in one night in 2021 in Utah.
But depredation is not the primary contention that those who oppose the reintroduction hold.
“Wolverines are not a significant concern regarding depredation, but instead pose a significant threat when used to control land management,” warned Colorado Wool Growers Association Executive Director Bonnie Brown at the March 21 hearing.
She argued that the species might be used as a “Trojan horse,” with which activists may leverage permitees off forest service grazing allotments – the kind of controversial permits historically held by ranchers in Southwest Colorado.
CPW says the 10(j) will reduce the regulatory burden associated with consultation for permitting of activities that occur on federal land, including grazing allotments.
The agency expects the study necessary to comply with the National Environmental Protection Act and 10(j) rule will take one to 2½ years.
“I’m confident it can work,” Inman said. “There’s enough food there, there’s enough territory there, that if they’ll stick around, then they should be able to survive and reproduce.”
rschafir@durangoherald.com
