Researchers Investigated Ancient Squirrel Poop Frozen in Permafrost and Found Enlightening Details About the Animal’s Ecosystem

Up to 700,000 years ago, ground squirrels in modern-day Canada collected tons of helpful genetic information on their bygone environment through their diet

Margherita Bassi | Daily Correspondent

June 10, 2026 2:47 p.m.

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When most people imagine paleontologists at work, they likely envision researchers investigating giant dinosaur fossils or a long-frozen woolly mammoth. Sometimes, however, the best snapshots of ancient landscapes come from significantly less dramatic remains.

In a study published yesterday in the journal Nature Communications, researchers investigated frozen ground squirrel poop unearthed in Canada’s Yukon Territory that dates back up to hundreds of thousands of years ago. The region’s permafrost preserved not just the ancient feces (called coprolites) but also a shocking amount of genetic information from other forms of life that shared these ground squirrels' landscape, including woolly mammoth DNA.

The coprolites, recovered from the ancient dens of Urocitellus ground squirrels, are between 30,000 and 700,000 years old and yielded environmental DNA from other species of plants, microbes, insects and large mammals. While the habitat and ecology captured in the poop are long gone, Urocitellus ground squirrels are still around.

Today, Arctic ground squirrels (Urocitellus parryii) are common in the Yukon. As opportunistic feeders, they can feast on different foods, including plants, fungi, insects and even meat. “The squirrels hibernate for about eight months of the year and in the four months that they’re conscious, they really need to get out there and eat and bring as many resources as they can back to their burrow,” Tyler Murchie, a co-author of the study and expert in ancient DNA at McMaster University, tells New Scientist’s Chris Simms.

The series of events that saw mammoth genetic information end up in the ancient squirrel poop, however, likely excludes ground squirrels actively hunting mammoths, University of Maine paleoecologist Jacquelyn Gill, who did not participate in the study, tells Science News’ Bethany Brookshire (though if they were all as committed as the squirrel from the Ice Age franchise, they probably could). These rodents were likely scavenging.

“It could have been a component of the diet. They could have been chewing on bone for [the] calcium source,” Brookshire tells the outlet.

The collected environmental DNA is some of the oldest ancient DNA ever recovered and sequenced, and it allowed the team to reconstruct over 18 mitochondrial genomes from horses, steppe bison, woolly mammoth and ground squirrels. The team also found evidence of other rodents and predators such as grey wolves.

Furthermore, their results challenge previous assumptions about ancient squirrels. Before the study, researchers broadly theorized that roughly 700,000-year-old fossil ground squirrel remains in central Yukon were the same species as those that currently live in northern and southern Yukon. However, the study revealed an Arctic ground squirrel lineage from that time period that doesn’t exist in the Yukon anymore. Its relatives live in western Siberia.

The work recorded “a snapshot in time” that sheds more light on this bygone ecosystem than just fossilized skeletons would be able to, Kelsey Witt, a computational biologist at Clemson University who also did not participate in the study, tells the New York Times’ Kate Golembiewski.

“Science is sometimes at its best when it takes something ordinary, weird or even funny, and shows that it contains a much larger story,” Murchie says to Popular Science’s Laura Baisas. “In this case, squirrel poop can turn out to be a window into deep time, climate change, extinction, evolution and ecosystems that no longer exist.”

Genetic information preserved in ancient poop can even inform what the future will bring. “We can look at genes under selection due to climate change in the past and that may help us think about how animals today may, or may not, adapt to our current warming climate,” Hendrik Poinar, a senior author of the study and director of the McMaster Ancient DNA Centre, says in a statement.

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Margherita Bassi is a freelance journalist and trilingual storyteller. Her work has appeared in publications including BBC Travel, Discover magazine, Live Science, Atlas Obscura and Hidden Compass.