DNA Evidence May Point to Larger Bighorn Sheep Population in Grand Teton National Park

by Amy Myers

Grand Teton National Park may have found evidence that its bighorn sheep population is actually larger than officials initially thought. Recently, biologists have been conducting a DNA study that examines the species’ resilience through non-evasive methods.

According to Grand Teton park staff, biologists have kept a close eye on the “small, isolated and vulnerable population” of bighorn sheep in the area for decades. Because of the population’s limited size and current location, the animals have lost traditional migration routes critical to their survival. Now, though, the study has pointed toward evidence of a larger population of bighorn sheep. This could result in greater security for the park’s species.

Previously, biologists have used helicopters to count bighorn sheep present in Grand Teton National Park. With this method, officials counted 60 sheep from 2016 to 2019 and 100 sheep from 2020 to 2021. However, Butler says that this method doesn’t capture the full picture for the population.

“By analyzing the DNA in scat samples collected in the high country of the Tetons in 2020 and processing that data with statistical models, we estimate about 178 bighorn sheep lived in the range that summer,” said National Park Service wildlife biologist Carson Butler.

Biologists Are Cautiously Optimistic About New Bighorn Sheep Findings in Grand Teton National Park

Ultimately, biologists would like to be optimistic about the new evidence. However, Butler clarified that the scientists involved were only halfway through their four-year study on the population. Until they had more information, it is uncertain whether bighorn sheep numbers are truly on the rise.

Still, the new DNA evidence could mean that there’s much more to these animals than scientists initially thought.

“The good news is, there are likely more bighorn sheep than we previously understood,” Butler said. “At the same time, this information should be taken in context. What really matters is the long-term trend. Conservation and stewardship efforts are needed to protect this population into the future.” 

Regardless of the outcome of the study, a greater understanding of this species will result in officials’ ability to protect it.

“It’s amazing these sheep survive at all, given the fact those little lambs and pregnant ewes have to endure brutal blizzards at 10,000 feet with very little to eat all winter long,” said Aly Courtemanch, Wyoming Game and Fish Department wildlife biologist. “Our goal is to continue to build resilience in the herd over the long term.”

“In the long term, good stewardship and continued monitoring is key to sharing the Tetons with these magnificent animals,” added Steve Kilpatrick, former director of the Wyoming Wild Sheep Foundation. “At the same time, we can all appreciate a little cause for optimism.”