'Huge Mortality': Winterkill Hitting Wildlife In Northern Rockies Hard
Grizzlies are out and wildlife is severely stressed. States issue warnings that recreationists need to be smart and, most importantly, respect space of animals or they could perish
Animals that make it through winter are left extremely fatigued and malnourished in spring months like April and into early May. The number of winterkilled animals is already significant in the Northern Rockies and the toll is expected to markedly rise. Here a haggard-looking bull elk in Yellowstone takes a rest in deep snow. Photo courtesy Jacob W. Frank/NPS
by Todd Wilkinson
It’s been a long winter for people, and a grim one for wildlife and livestock in the interior West, exacerbated by recent snowstorms.
Whether a person is feeling stir crazy, gung-ho to catch a few last hurrahs with their favorite snow sports, heading out to look for shed horns or taking a hike with the dogs, it’s important to remember that many wild denizens are severely stressed and pushed to the brink of total exhaustion.
Although it’s technically spring, April is typically the hardest month of survival for a range of species, particularly ungulates that include elk, deer, moose, bighorn sheep, pronghorn (antelope), and bison, says Julie Cunningham, veteran biologist with Montana Fish Wildlife and Parks.
In all three of the Northern Rocky Mountain states which converge to form Greater Yellowstone and in neighboring states like Colorado and higher elevation areas of Utah, wildlife officials are noting how deep snow, combined with thawing and freezing cycles, has created a layer of ice that prevents weakened and nutrition-challenged animals from reaching natural ground forage. Not only is the number of winterkilled wildlife high already in Montana, Wyoming, and Idaho but it is expected for keep rising, just like water levels in rivers as the snow melts. In Wyoming, pronghorn and mule deer in western areas of the state, including the Upper Green River Basin near Pinedale and the flanks of the Red Desert and Wind River Range, have been hit especially hard.
About half a million pronghorn live in the western part of the state and biologists say that some sub-populations could suffer mortality figures, caused by winterkill and animals succumbing to diseases like mycoplasma, of 50 percent or higher. As an indication, at the end of March, Game and Fish reported this in a press release: “Of the 83 adult female pronghorn wearing GPS collars at the beginning of winter, approximately 50 percent of those animals have been lost to either pneumonia or the winter conditions. Adult pronghorn mortality in the Sublette herd is typically around 20 percent.”
Photos above: Whether from harsh winter conditions or an outbreak of disease, pronghorn and mule deer in western Wyoming have already died in significant numbers and more is yet to come, officials say. Photos courtesy Wyoming Game and Fish
Where mule deer are concerned, Game and Fish wrote in late March, “looking at GPS-collared animals in the Wyoming Range mule deer herd, of the 128 does wearing collars at the beginning of winter, 35 percent currently have been lost. In an average year, adult deer mortality is approximately 20 percent. And of 92 juvenile deer collared, 90 percent of those animals have died to date. Again, with winter showing little sign of subsiding, those numbers, which are already well above average, are sure to keep climbing.”
Wyoming Game and Fish announced that hunting quotas for some wildlife areas have been adjusted, some dramatically downward, because of winterkill projections. "After considering the ongoing impacts of winter and the overwhelming public concern, wildlife managers modified their recommendations in areas with extreme mortality," the agency announced Friday, April 7.
Winters of high mortality can ripple forward because it's not just the loss of adults in a population but reproduction can take a hit, too. No one knows yet if Wyoming's beleaguered greater sage-grouse population, already beset by habitat loss and drought in the southern portion of Greater Yellowstone the last few years, will again suffer declines in breeding and production of young but this time due to lack of winter survivorship in adult birds. Wyoming has the largest greater sage grouse population remaining in the US and the fate of the species here is considered a bellwether.
"Looking at GPS-collared animals in the Wyoming Range mule deer herd, of the 128 does wearing collars at the beginning of winter, 35 percent currently have been lost. In an average year, adult deer mortality is approximately 20 percent. And of 92 juvenile deer collared, 90 percent of those animals have died to date."
Indeed, it's important to point out that the biggest predator on wildlife herds is not wolves; far from it, animals are succumbing to the natural elements. Check out the drone footage video below from Colorado that shows a mature bull elk so fatigued it could no longer move through deep snow.
Brian Nesvik, director of Wyoming Game and Fish said at a recent meeting in Pinedale that the department is thinking of postponing the start of antler hunting season until May 1, including on the National Elk Refuge in Jackson Hole where gathering the headgear of ungulates is an annual tradition. Nesvik said the reason is to prevent humans from adding stress to wildlife. Every spring male ungulates—elk, deer and moose—shed or "drop" their antlers and new ones grow in summer.
In Idaho, officials from the Caribou-Targhee National Forest and Idaho Fish and Game recently announced that winter travel and recreation closures in the western part of Greater Yellowstone are being extended until May 1. You can find those areas by clicking here. “This has been a brutal winter and we are asking people to give big game animals plenty of space, and avoid causing them additional stress,” Matt Pieron Regional Supervisor in the Upper Snake Region said in a statement. “Our wildlife will benefit from any relief we can provide them and we appreciate the Forest Service for their efforts.”
Winter range is found predominantly on south facing slopes at lower elevations and is extremely important to elk, moose and deer for survival, the agency notes. Human disturbance during winter months—that includes all kinds of human activity from snowmobilers to skiers and over-snow mountain bikers—can cause animals to expend energy from already low reserves. Even after the snow melts, some ungulates will be so fatigued they still will not make it.
Biologists say it’s vitally important that people keep their dogs on leash and under control or, when headed into the front and backcountry, leave the domestic canines at home altogether.
In recent weeks in Jackson Hole, a resident of Teton Village, Wyoming, home of the Jackson Hole Mountain Resort, was "trampled" by a moose that may have been provoked by her dog. Only a few days later, just south of the town of Jackson, a pet husky was shot and killed after it was seen trying to take down a mule deer.
In recent weeks in Jackson Hole, a resident of Teton Village, Wyoming, home of the Jackson Hole Mountain Resort, was "trampled" by a moose that may have been provoked by her dog. Only a few days later, just south of the town of Jackson, a pet husky was shot and killed after it was seen trying to take down a mule deer.
It is illegal to have your dog accompany you on any trail in Yellowstone and Grand Teton national parks, but other public lands, such as national forests and states, are open. However, it’s also important to know that some public lands, which provide key winter range to wildlife, are temporarily closed to all human use. That includes some bear management units in Yellowstone.
Morgan Jacobsen, spokesman for Region 3 of Montana Fish Wildlife and Parks, which covers a wide swath of southwest Montana, warns that the prolific number of carcasses also means they likely will be scavenged by wild carnivores that includes wolves, mountain lions and hungry grizzly and black bears just out of their dens. Soon, male bears will be joined by protective and hungry females with cubs.
A grizzly is joined by a wolf (at left), coyotes (middle and at right) and ravens on a carcass in Yellowstone. While carcasses represent a smorgasbord for predators and scavengers, they are not always visible to people as they move through the landscape. It is important that people exercise caution because grizzlies might be on a carcass you don't readily see. Photo courtesy Jim Peco/NPS
In mid April 2021, a 40-year-old photographer and outdoorsperson from West Yellowstone, Montana was severely mauled by a grizzly bear and died two days later of injuries. An investigation later revealed that the hiker had unknowingly wandered near the bear that had been feeding on a carcass.
A year ago in late March, a resident of Livingston, Montana was killed by a grizzly as he was out solo searching for shed antlers in the Six Mile Creek drainage of Paradise Valley, bushwhacking off trail, when he apparently surprised a bear likely also in the same area feeding on carcasses.
Carrying bear spray and knowing how to use it, hiking in groups of four or more, making noise on the trail, staying clear of carcasses, and maintaining control of dogs are always highly recommended but they take on special importance now, and as mother bears emerge with cubs, bear managers say.
Human lack of respect—and empathy— for wildlife can take many forms. See at bottom of this story the recent video capturing two men in Big Sky taunting a moose and one of them being charged after he tried to touch it. The incident is reminiscent of the inebriated park visitor in Yellowstone who infamously tantalized a bison and received a 130-day jail sentence
All across Greater Yellowstone, most drainages are reporting snowpack and/or water precipitation in frozen form to be higher than average. The hard winter has resulted in thousands of haggard-looking elk in and north of Yellowstone National Park and more bison leaving park compared to past winters. As a catalyst, and given the state of Montana’s low tolerance for bison leaving the park, around 1200 bison have been killed by indigenous and other hunters just beyond the park boundary. Critics have compared it to a firing line and a needless “slaughter” of bison, including the shooting of pregnant bison mothers.
How much precipitation has fallen in Yellowstone? “If this winter has felt longer and colder than usual, our colleagues at the U.S. National Weather Service have the weather data to confirm your suspicions,” the park shared on social media. “The park received 113-137 % snowpack at various locations, with below-average temps in Mammoth and Old Faithful, ranking this winter as the top 5 and top 3 coldest, respectively, in recorded history.”
Lest skeptics of human-caused climate change draw the wrong conclusion, the park added, “But remember, weather and climate are different. Climate data shows that our winters have been getting milder, with 80-100 more days above freezing than in the 1960s.”
On top of heeding the advisories related to preventing wildlife disturbance in the crucial weeks ahead, Jacobsen with Montana Fish Wildlife and Parks prepared the following answers for frequently asked questions which apply generally to people in all of the Northern Rockies states.
Q: How can I help wildlife this time of year?
A: The best thing residents and recreationists can do to help wildlife is give the animals plenty of space and keep pets from harassing wildlife. This helps wildlife retain the energy they need to survive. Never feed wildlife. Artificially feeding wildlife can lead to disease and is illegal.
Q: How will impacts to wildlife populations be monitored?
A: This time of year is when biologists conduct annual flights and counts of deer, elk, pronghorn, bighorn sheep and other species. These surveys often include classifications of adults and young. This data helps biologists track population recruitment and can influence adjustments to hunting season structures.
Q: An animal has died on my property. What can I do?
A: Wildlife live and die on public and private lands. When an animal dies on private land, it is the landowner’s responsibility to dispose of the carcass if they so choose. Some waste disposal companies may be available to help. If the carcass is removed, it must be taken to a landfill. Dumping carcasses on public land is illegal and can spread diseases, including Chronic Wasting Disease.
An elk in Rocky Mountain National Park in Colorado ill with what was later determined to be Chronic Wasting Disease. One of the vexing problems at this time of year is being able to assess if animals like elk and deer are in rough shape because of a stressful winter or if they have physical symptoms of CWD. Unfortunately, tests that confirm if an animal was sick with always-fatal CWD can only be taken after the animal is dead. Unknown is if hard winters like these, when thousands of stressed ungulates gather around artificial food rations given to them at the National Elk Refuge in Jackson Hole and 22 state-run feedgrounds in Wyoming, leave them more susceptible to catching CWD. Photo courtesy NPS
Q: What should I do if I encounter an animal carcass while recreating?
A: Animal carcasses are a major seasonal food source for bears in some areas. Bears, especially grizzlies, can be defensive of these food sources. For this reason, recreationists should avoid carcass sites. Watch for ravens and other scavengers that may indicate if an animal carcass is nearby. If you find a large carcass on or near a trail on public land, contact the applicable land management agency.
Q: What wildlife mortalities should be reported?
A: There are some circumstances when staff at Montana Fish, Wildlife & Parks may be interested in wildlife mortality reports. FWP staff will determine case by case whether a response is needed. These might include:
Any animal seen alive with unusual symptoms, such as immobility, drooling, staggering, very poor body condition, and drooping head and ears—telltale signs of animals being ill with Chronic Wasting Disease
Multiple sick or dead animals in the same area, particularly among domestic animals
Individual animals recently deceased with evidence of disease, such as abscesses, severe diarrhea, and excessive mucous or puss from eyes and nostrils
Mortalities of bighorn sheep, moose, mountain goats or other rare species
An animal that dies due to possible criminal activity; FWP’s hotline for reporting crimes against wildlife is 1-800-TIP-MONT. In Wyoming, the numbers to call are: 1-877-WGFD-TIP (1-877-943-3847) or 1-307-777-4330 for out-of-state calls. And, in Idaho, the “Citizens Against Poaching” hotline number is (800) 632-5999. In all three states tipsters can remain anonymous.
What wildlife situations does FWP typically not respond to?
Most aspects of natural wildlife behavior and mortality don’t need to be reported. These include:
Live animals that react normally to human presence by leaving the area, even if injured
Animals that appear thin or have rough hair coat during winter and spring but are behaving normally
Individual deer and elk that likely died of natural causes or trauma (e.g. vehicle collision)
About Todd Wilkinson
Todd Wilkinson, founder of Mountain Journal, is author of the book Ripple Effects: How to Save Yellowstone and American's Most Iconic Wildlife Ecosystem. Wilkinson has been writing about Greater Yellowstone for 35 years and is a correspondent to publications ranging from National Geographic to The Guardian. He is author of several books on topics as diverse as scientific whistleblowers and Ted Turner, and a book about the harrowing story of Jackson Hole grizzly mother 399, the most famous bear in the world which features photographs by Thomas Mangelsen. For more information on Wilkinson, click here. (Photo by David J Swift).
