A road-killed mule deer buck that took its last breaths off the side of Gros Ventre Road near Kelly is responsible for the first-ever confirmed case of chronic wasting disease in Jackson Hole.
Chronic wasting disease, or CWD, is a scary, invariably fatal condition that infects elk, deer and moose, and it has the potential to significantly depress wildlife populations over time. It had inched westward across Wyoming toward Jackson Hole for over three decades before officially arriving. Though dreaded, its arrival was entirely expected.
“It’s not much of a shocker,” Wyoming Game and Fish Department Regional Supervisor Brad Hovinga said. “We had found it, essentially, all around us — in Lincoln County and Sublette County and off to the east of us.”
Grand Teton National Park managers first learned of the positive test from Game and Fish’s Wildlife Health Laboratory in Laramie late last week, and results of a confirmation test came in Monday.
The animal that eventually tested positive was removed from the roadside and tissue samples were taken Nov. 5. The buck did not show the emaciation that CWD can eventually wreak on its victims, and outwardly it looked like “any other adult male deer,” said Dave Gustine, Teton park’s fish and wildlife chief.
Because Jackson Hole is a melting pot for migratory mule deer, and also houses resident animals, there’s no saying where the CWD-positive buck came from, though there’s a suspicion it migrated from the east, Gustine said.
A cousin of mad cow disease in bovines and Creutzfeldt-Jakob disease in humans, wasting disease is spread by prions, which are misfolded proteins that can survive outside their animal host and can persist in soil and grasses. There’s no evidence that CWD can be eliminated from a landscape once it’s introduced.
A 2015 study of the Converse County Mule Deer Herd, which has harbored CWD for decades, found the disease was driving down the population by 19 percent annually. There’s no saying how quickly wasting disease will affect Jackson Hole’s ungulates on a population level, or jump species to elk.
“CWD is a very slow-moving disease, so I suspect, based on the current literature, that it would be years, if not decades, before we would see a population-level effect from CWD in deer in western Wyoming,” Hovinga said. “And we’ve not found it in elk, so currently we consider it confined to deer in western Wyoming.”
The nearest elk that has tested positive for CWD was in the Bighorn Basin, in a hunt area that stretches between the Owl Creek Mountains and Cody. A positive moose was once found dead in Star Valley, and otherwise all nearby detections have been deer. On a larger scale, CWD has shown up in 25 states and Alberta, Saskatchewan and Manitoba provinces in Canada.
The elk-feeding program will go on this winter as it always has, Hovinga said.
“We’ll continue doing the things that we had planned,” he said. “It’s not a trigger for anything for Game and Fish, management-wise.”
Conservation biologists, and recently even wildlife managers from Montana, have asked Wyoming officials to phase out the elk-feeding program to diminish the disease’s spread among elk.
National Elk Refuge Manger Brian Glaspell also said that no changes are coming to the feeding program this winter, but that other switches have been flipped. The refuge, he said, will ramp up its biosecurity protocol for staff handling potentially infected animals and its monitoring of animals.
“There’s no definitive way to predict if it’ll make the jump between species or how long that may take,” Glaspell said, “but, anecdotally, if you look at the progression of CWD across the state, it seems like there’s maybe a two- to five-year lag time between deer [contracting it] and elk.”
Surveillance programs in place will ideally detect the species leap once it occurs. Centers for Disease Control and Prevention guidance that Game and Fish passes along to hunters advises against consuming meat from infected animals. Wyoming wildlife managers tested 3,882 animals for CWD last year. Teton park so far this year had sampled 31 elk, 18 deer and two moose.
Teton park, like the other agencies, is not making any major immediate changes as a result of CWD and is emphasizing public education.
“No one wanted to see it here,” said Sue Consolo-Murphy, the park’s science and resource chief. “And now we’ll try to deal with it in the best way we can moving forward.”
One former National Elk Refuge employee called for the agencies to take swift action.
“It’s not surprising that, ‘Hey, we’ve now got chronic wasting disease in Jackson Hole,’” retired biologist and author Bruce Smith said. “And nothing has really been done to try to reduce the impact of CWD being there.
“You need to reduce numbers down to what the habitat can support,” he said. “And then as that happens, the feeding becomes unnecessary. It’s a slow phase out. It’s all doable, and, in the long run, it will be to the advantage of the citizens of Wyoming to have a smaller, healthy elk herd than what’s now on the horizon.”
Jackson resident and Sierra Club employee Lloyd Dorsey made a similar plea.
“That deer was very close to the boundary with the National Elk Refuge,” Dorsey said. “It’s unfortunately come to pass that we now know the disease is in the heart of this world-renowned ecosystem, and this highlights the fact that our wildlife, including the elk herd on state-run feedgrounds and the National Elk Refuge, are at a very high risk of impact from this deadly disease.”