Wolves are moving Gros Ventre elk, but not so much killing them


JACKSON — Biologists have had a microscope on the Gros Ventre River drainage for a couple winters now, monitoring how the region’s apex canine carnivores are interacting with their most locally abundant ungulate prey — elk.

Insights are amassing.

Wolves aren’t killing off the elk herd in the broad basin east of Jackson Hole. In fact, none of the dozens of cow elk that have been fitted with GPS collars in the research project have succumbed to wolf predation.

Wapiti are, however, being pushed around the landscape. Preliminarily, wolf numbers appear to be a major environmental influence that causes the elk herd to abandon the Gros Ventre in favor of the National Elk Refuge.

“One of the things we’re really interested in finding out is: Where is that threshold and where is that trigger point in that Gros Ventre area that cause elk to leave?’” Wyoming Game and Fish Department wildlife biologist Aly Courtemanch said. “How many wolves does it take to cause these elk to leave the Gros Ventre? We don’t really know the answer to that. It’s going to take some more years of watching and collecting more data to watch and see, as wolf numbers change, what elk do.”

Courtemanch made those remarks June 11, giving an update of her findings to the Wyoming Animal Damage Management Board, which has financially supported some of the research. Overall, the Gros Ventre elk-wolf project costs an estimated $356,000, and she asked the board to pitch in $28,000. The state-funded board, which was dealing with a drastically reduced budget, later agreed to pay $18,000 to support the research.

For now there are relatively few wolves and thousands of elk sticking around the Gros Ventre and its three feedgrounds during the winter.

That wasn’t always the case. The winter that initiated Game and Fish’s investigation into wolf-elk dynamics came back in 2017-18, when the drainage was tilted toward the predators. The Gros Ventre hosted “28 to 30” wolves divided into several packs at their peak that year; it was considered the most wolf-dense landscape in Wyoming that year outside of Yellowstone’s Lamar Valley.

Elk adapted to that pressure and all but abandoned their traditional winter range. When Game and Fish flew the region classifying elk that winter, it counted just 86 animals in the hundreds of square miles that make up the Gros Ventre.

Urged by big game outfitters and top employees in Cheyenne, the state wildlife agency altered its hunting seasons and dialed up the pressure on wolves during the following two falls. The population of Canis lupus subsequently fell substantially.

“The last couple years, while elk numbers have started to come back up, wolf numbers have gone down,” Courtemanch told the Animal Damage Management Board. “We had seven wolves in the Gros Ventre in winter 2018-19 and then eight wolves last winter.

“It’s kind of obvious what might be going on,” she said. “As wolf numbers go up, elk numbers go down.”

And vice versa. Over the past two wolf-sparse winters, 75% of the Gros Ventre’s GPS-tracked elk have wintered in the drainage rather than abandoning it. The state surveyed about 2,100 Gros Ventre elk each of those winters. The remaining quarter of tracked animals have drifted down toward the lower Gros Ventre, drawn to the National Elk Refuge and the appearance of safety its many thousands of elk appear to offer the herd. Factor in both the elk that stayed and those that left for the refuge, and there’s likely around 3,000 elk total in the Gros Ventre segment of the Jackson Elk Herd.

There’s ample evidence that wolves are not eating themselves out of a home. The Gros Ventre’s marked cow elk are holding up well generally, with a “very high” rate of survival, Courtemanch said. Out of the 41 tracked animals the last two years, five elk have died. Hunters killed two cows. Of the remaining three, one each was killed by a mountain lion, infection and starvation.

“So far we have not had any wolf predation, at least on our collared cow elk,” Courtemanch said.

The complete absence of wolf-related mortality among the research cohort, she noted, may be a product of there being so few wolves the last two winters.

Of course, wolves do eat elk — it’s how they make a living throughout much of their habitat in the northern Rockies. The Gros Ventre’s wolves also appear to depend primarily on elk, according to research from University of California-Berkeley PhD student Kristin Barker.

“Wolves do predominantly eat elk in this area,” Barker told the News&Guide, “and that might just be a function of elk being the most abundant species.”

Barker’s research is investigating how mankind affects wolf movement and distribution — in other words, how human structures and activities, such as feeding elk, influences wolf behavior. It’s too early to report results, she said. In the process, however, she’s using GPS location data to lead her to wolf kill sites, and what she’s finding where the wolves are clustering is elk carcasses.

Wyoming Game and Fish officials have said it’s undesirable to have wolves push most of the elk out of the Gros Ventre. The valley generally sees a skinny snowpack and provides one of the largest swaths of natural winter range in Jackson Hole. It’s also host to ample artificial winter habitat: three historic state elk feeding areas — the Patrol Cabin, Fish Creek and Alkali feedgrounds — which historically have fed the vast majority of the Gros Ventre’s elk.

One of those feedgrounds, Alkali, is being litigated, as is the massive federal feeding area — the 39-square-mile National Elk Refuge — that tends to be the landing pad for Gros Ventre elk when wolf numbers are high.

Recently retired conservation professional Lloyd Dorsey, a longtime Gros Ventre elk hunter, said the agencies should consider that the practice of winter elk feeding might be on its last legs when they’re evaluating whether wolves pushing elk around the landscape is good or bad.

“If indeed the agencies and stakeholders are looking at elk feedgrounds as a constant as they manage wildlife in this region, that premise is not correct,” Dorsey said. “When scientists are looking at numbers of predators in an area, and what influences predation has on elk and other prey species in a given winter range area, the fact that many elk do go to feedgrounds will change in the future.”

The reason Dorsey cited was chronic wasting disease, an infectious, lethal and environmentally persistent cervid sickness that was verified in deer in Jackson Hole for the first time in 2018. Awareness of the threat CWD poses to feedground elk is increasing not just with wildlife scientists and disease experts, he said, but among “all stakeholders.”

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