Collaring studies show worrisome survival rates for wildlife in Northwest Colorado this winter |

Collaring studies show worrisome survival rates for wildlife in Northwest Colorado this winter

Suzie Romig
Steamboat Pilot & Today
State wildlife biologists say last year’s elk calves are among the animals at the highest risk of not surviving this winter. This pair was photographed in February in Moffat County.
Colorado Parks & Wildlife/Courtesy photo

North Routt County residents John and Nancy Johnson have seen a bull elk bedded down only 20 yards from County Road 129 for about two weeks.

After 23 years of watching wildlife in the county, the couple know that a bull elk staying in one place closer to humans is unusual, and they contacted Colorado Parks and Wildlife.

“Twenty yards from the road is not normally where they bed down, and you see him nibbling on bushes,” Nancy Johnson said. “They are not getting a lot of nourishment from the bushes.”

Johnson thought Parks and Wildlife officers might leave a bale of hay to help the bull elk survive, but that is not the way statewide wildlife management works.

Collaring studies show concern for mule deer survival this winter across Northwest Colorado, especially for last year’s fawns. These mule deer were photographed in Moffat County in March 2023.
Colorado Parks & Wildlife/Courtesy photo

“(Parks and Wildlife) said, ‘Let nature take its course unless they get tangled in something,'” Johnson said. “You see an animal that’s obviously very hungry and getting low on energy, it’s just hard to see. Normally, they move a little bit; he hasn’t.”

Parks and Wildlife Area Wildlife Manager Kris Middledorf said Monday, April 3, that the mortality rate for deer, elk and pronghorn across Northwest Colorado will likely be high this winter due to abundant snow. Officials are especially concerned about the heavy snow at lower elevations, where the animals normally find winter refuge and food.

As a result, Parks and Wildlife staff have proposed large reductions in hunting licenses this year, which must be approved by the Parks and Wildlife Commission.

“From an observational or non-empirical standpoint, the district wildlife managers in Routt County have euthanized or picked up more dead animals this winter than any of the past winters that I have been here (since 2016),” Middledorf said. “All of our wildlife managers and biologists are extremely busy working on this issue along with other duties related to wildlife management.”

Animals with larger fat reserves, a more durable body size or longer legs have the best chance for survival this winter, wildlife officers say. Last year’s fawns or calves are at the highest risk, followed by pronghorn, deer, elk and then moose, wildlife biologists say.

“We are seeing elk more dependent on brush this year because that’s available to them, but it’s less nutritious,” said Darby Finley, a wildlife biologist for Colorado Parks and Wildlife in the Meeker area.

Parks and Wildlife has radio collar tracking studies underway for mule deer from the White River herd and elk in the Bears Ears herd that will help quantify the animals’ survival rates this winter. The agency has collared about 150 mule deer throughout the Yampa River corridor, Finley said.

State wildlife officials urge drivers across Northwest Colorado to slow down and scan the roadsides when driving, especially near dawn and dusk. This winter in Moffat County, wildlife managers have responded to four incidents involving vehicle collisions with groups of 10 or more pronghorn. This photo was taken in March in Moffat County.
Colorado Parks & Wildlife/Courtesy photo

Finley’s highest level of concern for mule deer fawn this winter is based on the collaring study, which shows 35% to 40% of the fawns may survive to adulthood compared to the normal rate of 64%. The average survival rate for an adult doe is 82%, but Finley estimates a doe survival rate of about 70% by the end of this year.

“We are seeing an increase of rate of mortality in recent weeks in mid-March,” Finley said. “It’s always concerning when you lose that many from a population standpoint. It’s Mother Nature at work unfortunately on years like this.”

Nathaniel Rayl, a Parks and Wildlife researcher based in Grand Junction, said approximately 75 elk calves and 40 adult elk females have been collared since the Bears Ears herd study began in 2019.

Rayl emphasized that the elk study results are preliminary with research ongoing, but he estimated up to two-thirds of elk calves may be dead by the end of winter, while one-quarter or more of adult elk females may die.

That compares to the higher annual baseline elk survival rates of 70% to 85% for calves and 90% for adult females.

Both researchers are most concerned about the survival of last year’s deer fawns and elk calves, then for undernourished and stressed adult females, and then survival rates of fawns and calves born this spring. The fawning time for mule deer, which often give birth to twins, is the first two weeks in June. Underweight mothers can produce underweight babies that are so weak they cannot stand to feed. Some overstressed does may also die during fawning or calving.

Parks and Wildlife staff emphasize that residents and drivers across Northwest Colorado can help wildlife survive by slowing down and scanning the roadsides, especially near dawn and dusk. This winter in Moffat County, for example, wildlife managers responded to four incidents involving vehicle collisions with groups of 10 or more pronghorn.

Residents are also being asked to remove any possible wildlife entanglement hazards such as Christmas lights, clothes lines, swings or nets that may further stress animals already facing difficulties foraging for food.

Humans should always give wildlife abundant space, minimize disturbances on winter rangeland and keep dogs on leashes or under full control, Parks and Wildlife officials advise.

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