Epic wolverine journey ends in North Dakota

Wildlife managers at the North Dakota Game and Fish Department knew the dead wolverine was special even before they performed a necropsy. It was the first wolverine (Gulo gulo) reported in the state in almost 150 years; a rancher had killed it legally in late April for harassing cattle and then given its carcass to the agency. But the managers weren’t expecting to find a radio transmitter in its abdomen.

The transmitter identified the wolverine as “M56,” an animal that traveled at least 2,000 miles and nearly inspired a reintroduction program in Colorado, says Bob Inman, carnivore and fur bearer coordinator for Montana Fish, Wildlife and Parks, whose team implanted the transmitter seven years ago. Colorado is part of the wolverine’s historic range, but until M56 crossed into the state in 2009, no wolverines had been documented there for nearly a century.

“Had we been able to move female wolverines down there, M56 could have been part of founding new populations in that historical area,” said Inman. “But because of the political red tape, we weren’t able to get that done.”

Wolverines, the largest members of the weasel family, are solitary, cold-loving creatures that defend huge mountainous territories. A range like the Tetons might hold as few as five or six, says Inman, and males like M56 often travel between mountain ranges in search of mates and resources.

Inman and his colleagues first encountered M56 in Wyoming, just south of Yellowstone National Park. They implanted a radio transmitter in the wolverine’s abdomen and attached a GPS collar to its neck, then tracked it from an airplane as it journeyed across Wyoming and into the mountains of Colorado. Less than two weeks after it entered the state, a wildlife photographer snapped its portrait, marking the first documented wolverine sighting in Colorado in 90 years, says Inman.

M56’s arrival rekindled interest in reintroducing wolverines to Colorado, a prospect managers first discussed in the 1990s. They had already mapped out areas they thought might make good wolverine habitat, and M56 seemed to agree, spending much of its time in those areas over the next several years.

“We learned a lot from the time that he was here,” said Eric Odell, Species Conservation Program Manager at Colorado Parks and Wildlife. “We learned that Colorado has habitat that will sustain wolverines.”

But while wildlife managers were eager to provide M56 with mates, they couldn’t muster enough support from stakeholders such as ranchers and ski resorts. The problem, according to Inman and Odell, was that wolverines were — and still are — candidates for protection under the Endangered Species Act (ESA). No one minded the idea of having wolverines on the landscape. But if the species were listed, industries that shared public land with the wolverines could suddenly find themselves facing new restrictions and litigation. The ESA has mechanisms to protect stakeholders from introductions of listed species, but there are no such mechanisms for candidate species. So the idea was put on hold, and after three and a half years in Colorado, M56 moved on.

For several years, no one knew what had happened to the wolverine. Its distinctive collar had come off on the journey to Colorado, and the batteries in its radio transmitter eventually died. When it turned up on the necropsy table in North Dakota, no one dreamed it was the same animal that had made headlines years earlier in Colorado.

Its long journey emphasizes the need for far-flung agencies to work together, says TWS member Bob Lanka, a wildlife biologist with the Wyoming Game and Fish Department and the Central Mountains and Plains Section representative to The Wildlife Society’s Council. Recently, state, federal and tribal agencies have all risen to the challenge, uniting for a new program to monitor wolverines across their range in the lower 48 states. The Western States Wolverine Conservation Project will set out 140 bait stations across four states, with camera traps and combs to collect hair for DNA analysis. The first stations were placed in Wyoming last winter, says Lanka; more will be placed next winter in Montana, Idaho and Washington. The team will also map out the pathways wolverines need to disperse between mountain ranges, which could be crucial areas to protect.

“In order for us to be effective at conserving this species, we have to think bigger than single states,” said Lanka. “I think this one animal, M56, is kind of symbolic, and points to the need for doing collaborative conservation.”

Header Image: This 2009 photo of M56 in Colorado’s Rocky Mountain National Park marked the first documented wolverine sighting in the state in nearly a century. ©Ray Rafiti