It’s coldest in the hour before sunrise, but the creatures that make their home in the lands along the Wasatch don’t seem to care. Sage-grouse and mule deer have already started their day without the sun’s warmth, meaning wildlife biologists hoping to study these animals must also start their day in the dark and bundled up against the chill. 

Over the past two months, Summit and Wasatch County wildlife biologists with Utah’s Division of Wildlife Resources have adjusted their schedules and head out into the field to check up on sage-grouse and mule deer for the seasonal count.

They’re looking for population numbers following the winter, tallies that will also help make up an overall picture of the land’s health. 

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For the sage-grouse — a turkey or chicken-like bird native to the area — this is their mating period, said wildlife biologist Aaron Sisson. In March and April, the birds gather in areas called leks, clearings amid sage brush that serve as the males’ strutting grounds.

“It’s a nightclub for sage-grouse,” said Sisson with a laugh. “It’s where they all gather to meet up and get to know each other.”

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Male sage-grouse are known for their mating displays and unique call during these months as they try to impress females. Fanning their feathers and puffing out their white chests, they inflate two yellow pouches in their necks and make a plopping sound like a stone dropped into a still lake. Much depends on their ability to deliver an impressive performance, Sisson said.

“The females literally walk around and look at every male and then pick the male that they liked the best to breed with,” he said. “If one male breeds with a female, he has a 98% chance of all the other females picking him.” 

During this time, biologists are able to get a rough idea of the sage-grouse population coming out of winter. 

“It’s hard to get a population count, but what we do is we use the number of males displaying as an index,” Sisson said. “It’s an indicator of the overall population, and you look to see if there’s more or fewer males per lek each year displaying, and that gives you an idea if the population is increasing or decreasing.”

According to the 2023 count report of these animals, populations continue to trend upward. 

“Statewide lek counts within sage-grouse management areas were up 2.5% from 2022 counts,” the report said. “Greater sage-grouse (Centrocercus urophasianus) leks have been counted in Utah for over half a century, and the Utah Division of Wildlife Resources maintains lek records extending back to 1959.”

Monitoring their populations is a good indicator of the health of the sagelands, Sisson said.

“Sage-grouse are a sage-obligate species, which means without sagebrush they can’t survive,” he said. “So if you have a lot of sage-grouse in an area, it’s a good indicator that your sagebrush system is healthy and productive.”

Like most situations in the wild, there is a domino effect, a circle of impact. Healthy sage plants have a high diversity and attract insects that sage-grouse chicks eat as protein. Without healthy plants, there are fewer insects. Without those insects, chicks aren’t able to grow strong enough to survive the harsh mountain winters.

Encroachment by other brush species, wildfires and land development pose the biggest threat to sagebrush in the Wasatch Back, he said, and therefore the sage-grouse species. As habitat loss affects these animals, “considerable management time, effort and funding is dedicated to the conservation of greater sage-grouse,” the 2023 DWR report said. 

Mule deer, while their populations are doing well overall, have been affected by habitat loss, said Sisson.

“The biggest concern is winter range being developed into housing developments,” he said.

As with sage-grouse, biologists are working to count these animals as well as tag them with collars for GPS monitoring to better understand their migratory patterns.

The northern region is one of the few places in Utah that does mule deer classification in the spring, said wildlife biologist David Smedley, who has been working for the Department of Natural Resources for eight years.

“They got away from it because we have such good data with GPS collars’ survival data,” Smedley said. But sometimes technology fails.

“We had a hard winter on the Cache the last two winters and several winters before that, and your collars showed 0% fawn survival. It isn’t really accurate because you go out and you do count fawns, so it verifies that,” he said. “On a hard winter, you can get a better idea of your fawn survival through the winter.”

These collars are also an index, Smedley said, because their teams only track a minuscule fraction of the larger mule deer population in an area. Besides survival data, they study these animals for other behaviors. 

“There’s a big migration initiative to find out where a lot of big game species are migrating their routes, obstacles, highways, if there’s an issue with the highways,” said Sisson. “It’s helping with planning highways and things like that.”

During the spring, they count bucks, does and fawns, Sisson said, which gives a snapshot of reproduction. 

Their classification windows are mostly coming to a close, the two biologists said, and they’ll send their data in for analysis.

Now that these projects are winding down, their early summer activities will likely include relocating bears and mountain lions that get too close to residential areas, as well as collaring more animals to keep their data current. Mid-July, they’ll start classifying elk, Smedley said. 

Learn more about Utah native species like sage-grouse and mule deer on the Utah Division of Wildlife Resources website at wildlife.utah.gov.