Wolf-killing mountain lion

Biologists documented F109, a Teton Cougar Project research cat, making a rare wolf kill in early November. Here she nurses her three cubs.

Five mountain lion cubs mothered by Teton Cougar Project research animals have met their ends in the jaws of wolves over the past few years.

Now a Jackson Hole female cougar appears to have exacted vengeance.

A lion tracked by the Kelly-based science institute for the past six years is documented to have recently dined on a yearling wolf, Cougar Project biologist Mark Elbroch says.

“What’s nice about this particular incident is that this is a collared mountain lion, and we know for sure that she killed it,” Elbroch said. “This is just a very nice, clear case.”

The wolf-killer, known as F109, is a 101-pound female that lives in the Gros Ventre River headwaters. She’s a “funky-looking, overly feral cat” that’s as smart as they come and near impossible to catch, Elbroch said.

While hiking with colleagues early last month, Elbroch discovered the cached remains of the young wolf while on a routine visit to check a suspected F109 kill site.

A bloody scene, and a surprise

After a 2 1/2-hour uphill hike through snow, the team of biologists came across an ominous sign, Elbroch said.

“There were wolf tracks everywhere,” he said. “Not just one wolf, but a full pack with pups and subadults.

“I was thinking, ‘Oh gosh, this is not good,’ because she had kittens at the time that were small and defenseless,” Elbroch said.

The biologists saw lion tracks, then blood, then a jet black pelt at the base of a subalpine fir tree.

Though dead only a day, the wolf was nearly consumed, Elbroch said.

“You don’t expect it to be a wolf,” Elbroch said. “The one really intact part of the carcass was the skull.

“We were able to clean it off, and there’s no denying what it was,” he said. “It was a wolf born this year.”

That meant the wolf pup was already larger than a normal-size coyote.

While not unheard of, proven cases of lions killing wolves are far from normal, scientific literature shows. Wolves killing lions — evidenced by the Cougar Project’s experiences — is much more common.

Through 2008 there were three reports of cougars killing wolves in North America, Jackson Hole resident and biologist Mike Jimenez wrote in a short entry to The Canadian Field-Naturalist. One of the unlucky lobos was one of the original Yellowstone imports — Wolf B-4.

Top dog sometimes loses

In early 1996, B-4’s radio collar was detected sending out a mortality signal near Drummond, Mont.

In 2003 a cougar-killed female wolf was found in Paradise Valley north of Gardiner, Mont. In 2006 a healthy male wolf killed by a lion was found in Alberta’s Turner Valley.

More recently, in early 2012, a Montana Fish, Wildlife and Parks wolf biologist reported that two of her radio-collared wolves had turned up dead with trauma consistent with a lion attack.

It’s much more common for wolves, a pack animal, to force lions to flee when the two large carnivores cross paths, Elbroch said. Typically, he said, the wolves chase off the lions.

“The scientific conclusion out there is that they interact as competitors,” he said. “Neither one is trying to catch the other as a prey source.”

That F109 and cubs consumed the wolf pup is a case of “interguild predation,” Elbroch said.

Only on one occasion — a fox — has a Teton Cougar Project research animal been documented making a kill and leaving the meat untouched, he said.

Because there was no video, Elbroch isn’t speculating about the encounter between F109 and the wolf pack.

“Perhaps the wolves had challenged F109, or perhaps just one of them wandered too close to her kittens, or perhaps a pup felt like exploring on its own — trying to decipher the absolute pandemonium of tracks was beyond us,” he wrote in a recent NationalGeographic.com blog post.

If the young wolf had wandered from the pack, maybe it appeared an easy meal. Elbroch said mountain lions are opportunistic killers, and they typically are not choosy about prey.

“If it’s a single wolf and everything’s perfect, why not?” he said.

Mike has reported on the Greater Yellowstone Ecosystem's wildlife, wildlands and the agencies that manage them since 2012. A native Minnesotan, he arrived in the West to study environmental journalism at the University of Colorado.

(5) comments

lions andtigers

Is this one of those weight conscious mountain lions who obsessively weighs herself each morning? Really, she can't simply report in as 100 lbs? Would she be 100 if she hadn't eaten that wolf? 101 lbs???

Julie Gallegos

But wait! how can this be? I thought wolves were implacable killing machines that only human hunters can "manage".


You are so right. Wolves, a satanic demi-demon, may only be killed by sociopathic hunters from 1000 yds, not another carnivore in a natural habitat.

Dale Tobiassen

do you really think that a few wolfs being killed by a couple of lions is management?



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