Elk have returned to their historic winter range in the Gros Ventre River drainage, and one theory for their reappearance is the targeted killing of resident wolves.
One winter ago, Wyoming wolf biologist Ken Mills dubbed the red, gray and lavender-capped valley climbing east out of Jackson Hole the most wolf-dense landscape in Wyoming outside Yellowstone National Park. At the time, nearly three dozen wolves running in five packs had home ranges in parts of the Gros Ventre.
Then came the exodus. Last winter, elk either didn’t return or fled the Gros Ventre, and the wolves mostly followed their prey.
In the aftermath of the unprecedented outflow of elk — just 86 animals were detected during midwinter surveys — big-game hunting outfitters and a high-ranking Wyoming Game and Fish Department official lobbied the agency’s commission to dial up hunting pressure on Gros Ventre wolves.
Managers capitulated, redrawing boundary lines and upping the maximum quota of wolves that could be hunted from nine to 15 animals. Meanwhile, state biologists’ remote game cameras detected thousands of elk pouring back into the Gros Ventre last spring — dispelling fears of an elk population crash.
Fast forward one winter to the present, and the Gros Ventre wolf-elk dynamics look entirely different.
“One factor, I think, is that we do have a lot fewer wolves on the landscape this year, especially in the Gros Ventre,” Game and Fish wildlife biologist Aly Courtemanch told the News&Guide. “Five, maybe six wolves at the most in the Gros Ventre.”
As for the elk, the ungulates have mostly stayed put on three state-run feedgrounds spurring off the snowed-over Gros Ventre Road.
The elk count came in at 2,136, a 25-fold increase over last year and the most tallied in five years, a span marked by steady decline. The sudden onset of a severe winter is another likely factor for the stark reversal in wapiti whereabouts, Courtemanch said: Elk could have essentially become stranded.
Just two small wolf packs tried to make a living up the Gros Ventre this winter: three animals that remained from the Togwotee Pack and a yet-to-be named pair that’s been living near the Red Hills, Mills said.
The wolf biologist explained that the precise accounting for what happened to the wolf packs will be laid out in Game and Fish’s annual monitoring report, which has not been completed, but he provided an overview of what went on in one corner of the ecosystem.
The abrupt collapse of the valley’s wolf population can be traced to mankind, but also natural competition-related causes, Mills said. Hunters killed all 15 wolves that Game and Fish permitted.
When the state agreed to ratchet up hunting pressure on wolves in the Gros Ventre, officials essentially combined three hunt units into one. That combined zone also includes the Upper Green River basin, where a handful of the wolves were killed. The Upper Green packs rarely traveled as far west as the Gros Ventre and its three elk feedgrounds, Mills said.
The dominant pack in the lower Gros Ventre a winter ago with 12 members — the Slate Creek Pack — winked out.
“The Slate Creek Pack last winter broke into three different groups, none of them reproduced, and by the end of the year they just weren’t there,” Mills said. “There was mortality, there weren’t any pups, and that’s not sustainable for a pack, really.”
Relative newcomers to the Gros Ventre, the Slate Creek Pack formed from animals that broke off the National Elk Refuge-dwelling Pinnacle Peak Pack in the winter of 2015-16. Its demise three years later came from killing cattle and in turn being killed by wildlife officials, and also from human hunting, which killed the breeding female. Another wolf from the pack was poached, and one lost Slate Creek wolf was deemed to have died from “wounding loss” related to hunting, Mills said.
“That was it,” he said, “combo’d with the pack not having pups and the pack fracturing.”
Meanwhile, the Gros Ventre’s other formerly large and dominant wolf pack left its old home range farther up the river. The Lava Mountain Pack’s departure is attributed to competing with Slate and Togwotee packs for a vastly diminished prey base last winter. As recently as four years ago — before wolf hunting returned to the landscape — the pack was the largest in not just Wyoming but the American West, at 24 animals.
“They’re still in the Gros Ventre, in essence, but mostly in the Upper Green,” Mills said. “The Lava Mountain Pack moved not because people killed it, but because of a density response to seek out prey in a different area, and that further reduced the wolf density in the Gros Ventre.”
The upstart Kinky Creek Pack, whose home range was deep into the Gros Ventre near the Green River divide, also met its end in 2018. Small at just an alpha male and female plus their litter, the pack fractured after one of the two adults was killed. The radio-collared wolf, found dead with a gunshot wound, will be classified as a “wounding loss” — likely from a hunter though the dead wolf did not count toward the wolf-hunting quotas.
“They had pups,” Mills said, “but we were unable to verify anything remaining in that country.”
By the time Mills led Wyoming’s annual statewide wolf census in late winter, just the Togwotee Pack and the unnamed pair remained. Numbering six a year ago, the Togwotee animals dwindled to three by the time the state’s contracted pilot and Mills were in the air to count wolves. A litter of pups never materialized last spring.
“The Togwotee Pack has shifted into a gap left by the Lava Mountain Pack, and that’s what they’re doing — they’re filling the gap,” Mills said.
It’s tough to pinpoint exactly how much the decline of wolves over the last year influenced elk distribution in the Gros Ventre this winter, but a biological investigation is underway to figure it out.
The remaining two wolf packs are equipped with GPS tracking collars as part of Game and Fish’s monitoring regime, and in the last couple of years biologists have begun capturing and following elk that winter in the valley split by the Gros Ventre River. Two dozen cows were online going into the winter, and of those, 18 wapiti, or 75 percent, stayed in the valley. The balance drifted down to the National Elk Refuge, which was the primary recipient of the Gros Ventre’s itchy-hooved elk a year ago (others wound up near Dubois, the Upper Green, Bondurant and the Buffalo Valley).
Game and Fish isn’t alone in trying to deduce what’s happening.
The University of California-Berkeley has tasked Ph.D. ecologist Kristin Barker, who works under Arthur Middleton, with researching the dynamic system, and her fieldwork is now in its infancy. She’ll investigate the effect of environmental and landscape characteristics implicated in elk movements, like the feedgrounds, and the timing of snowfall and overall winter severity. Barker will also take a close look at how Gros Ventre elk and wolves are spatially interacting. Her days now are being spent at the sites of wolf GPS clusters, seeing what they’re eating and what they’re up to.
“The goal is to test as many hypotheses as we can,” Barker said.
There’s a debate that extends well beyond Jackson Hole about the wisdom of targeting wolves to lessen impacts on natural prey species like elk. In the case of the Gros Ventre, state biologists say that the effect of elk sticking around — whatever the cause — is a good thing.
“We would prefer the herd to be more distributed versus all being on the refuge,” Courtemanch said. “This is what we’d like them to be doing a bit more of.”
As of early March, around 80 percent of the Gros Ventre’s 2,100 or so elk were holed up at the midvalley Patrol Cabin Feedground, but another 400 animals were spending their winters on natural winter ranges, some of which have largely been abandoned in recent years.
“There were numerous times when we were flying along and not seeing any tracks and getting into deeper snow, and I’d be about to tell the pilot to turn around, but then suddenly we’d see elk tracks,” she said. “Sure enough, there’d be elk wintering out in some drainage that we’ve never seen them in before.”
Elk, she said, are more tolerant of areas with deep snow when wolves aren’t around.
Another school of thought is that it’s wrongheaded to intervene by killing wolves for the sake of trying to control where elk winter.
“As for elk moving around the various watersheds in recent winters, that should be an indication of healthy wildlife behavior in a large contiguous ecosystem,” said Lloyd Dorsey, a Sierra Club staffer. “Confining elk to feedgrounds is the opposite.”
Dorsey, a 44-year Jackson Hole resident, hunts elk in the Gros Ventre annually. His experience hiking in the hills last fall felt different.
“I hunted many days up there last fall,” Dorsey said, “and quite different from previous years I never cut a wolf track, never saw a wolf, and I don’t think that I heard a wolf howl.”