Wolverine walking in snow (G. gulo)

The wolverine is the largest land-dwelling species of the weasel family.

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It’s so rare, that many of the biologists who study the critter have never seen one in the wild.

But a few weeks ago, a camera mounted about a mile from Mammoth Hot Springs in Yellowstone National Park to study cougars known to pass that way, caught a few seconds of a passing wolverine.

“I’ve been here since ’97 and I’ve never seen one myself,” said Yellowstone wildlife biologist Dan Stahler. “I’ve covered a lot of terrain in the park in my career. I’ve seen tracks every couple of years, but it’s always neat to actually see images of them.”

The park posted the short trail cam video clip on its Facebook page. The park said although it has been using trail cameras to monitor a variety of species since 2014, this is the first time the cameras caught a wolverine.

“We’re pretty excited to see the footage of a wolverine sauntering by our cameras,” Stahler said. “The park put out a social media blast and it’s amazing how fast things like that get picked up. Everyone’s excited about rare animals that are charismatic like the wolverines.”

Stahler said because there are only an estimated 300 wolverines in the lower 48 states — most of them in the West — keeping track of them is a challenge.

“That’s a very low number for any species,” he said. “It’s not uncommon for a male wolverine — based on GPS studies — to have a home range of over 500 square miles. Females can have smaller home ranges of about 100 miles.”

Hearing the news of the recent wolverine sighting in Yellowstone has caught the attention of Idaho wildlife biologists. Wolverines are on Idaho’s list as a “species of greatest conservation need.”

Matt Proett, Idaho Fish and Game regional wildlife biologist, said one of his tasks this winter has been to install 12 baited camera traps in the Centennial Range area next door to Yellowstone to see if the elusive wolverine is wintering there. The traps are also designed to catch a bit of hair from the critter as it passes by to sniff the bait. This allows biologists to cross-reference genetics to see if different individuals are visiting the bait.

“In our state wolverine plan, the Centennial Range has been classified, as far as habitat, as one of the highest for conservation reasons,” Proett said. “Previous researchers have suggested that it’s an important area because you have an east-west mountain range that connects your Greater Yellowstone Area spanning across the desert and goes to all your central Idaho mountain ranges. It’s suggested as important for population connectivity and genetic dispersal.”

Although wolverines have been occasionally observed in eastern Idaho, so far, no wintering wolverines have been discovered with the traps.

“We know we’ve got them around,” Proett said. “We’re just trying to understand what those observations mean. Are they dispersing critters as opposed to year-round residents? We’re just trying to get a better picture as to what’s going on out there.”

Stahler said the animal’s propensity for moving around makes it difficult to figure out. Wolverines can easily cover 15 or more miles in a day.

“On the topic of how many wolverines we have in Yellowstone, the answer is we have no idea,” Stahler said. “It’s fair to consider that we have several individuals that consider part of Yellowstone as a year-round home range. It could be more than that, but probably not.”

Stahler is also tasked with keeping tabs on another extremely rare animal in Yellowstone: lynx. He admits that he’s never even seen its tracks in the park.

“There were a few individuals documented in the early 2000s,” he said. But it’s thought that Yellowstone isn’t the best lynx habitat. … That would be another amazing thing to get on our cameras as well.”

To see the wolverine video, go to facebook.com/YellowstoneNPS/videos/399150214715661.

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