This news article is based on the open-access journal article (Murchie et al., 2026) published in Nature Communications. The journal article is published under a CC BY-NC-ND 4.0 license. The publication figures are not reproduced here. The ground squirrel photo above is a public-domain U.S. Fish and Wildlife Service image.

---

---

---

Introduction: When Squirrels Ate Woolly Mammoths... Sort Of

Picture an Ice Age ground squirrel wandering across the mammoth-steppe with one question on its mind: what is for lunch? Grass? Seeds? An insect? Maybe a little mammoth?

That last option sounds ridiculous until you look at a new ancient-DNA study from Yukon, Canada. Researchers analyzed permafrost-preserved ground squirrel coprolites, or ancient feces, and recovered DNA from woolly mammoths, steppe bison, horses, caribou, carnivores, birds, rodents, insects, fungi, microbes, and a large variety of plants.

So, did tiny Ice Age squirrels really nibble on mammoths, bison, horses, and big cats? The honest answer is: maybe some of them, but the DNA alone cannot prove it. That uncertainty is one of the most interesting parts of the study.

---

Frozen Squirrel Bathrooms Became 700,000-Year Time Capsules

The samples came from ancient ground squirrel burrows in the Klondike region of central Yukon. This part of eastern Beringia remained largely unglaciated during the Pleistocene, and frozen ground preserved burrows, food caches, plant remains, bones, insects, and piles of squirrel feces for tens of thousands of years.

Several coprolites date to the last Ice Age, including samples around 17,000 to 36,000 years old and others associated with deposits near 80,000 years old. One specimen, called SC-14, was found below the Gold Run volcanic ash layer. That ash has an age of about 688 +/- 44 thousand years, making the squirrel DNA in the sample extraordinarily old.

In other words, paleontologists did not just find an old squirrel bathroom. They found a frozen biological archive stretching across major glacial and interglacial changes.

---

What Was on the Ice Age Squirrel Menu?

The most obvious DNA in the Pleistocene coprolites came from ground squirrels themselves. That is reassuring when the sample you are calling squirrel poop actually contains lots of squirrel DNA.

The surprise was everything else. Across the 13 Pleistocene squirrel samples, the researchers detected ancient environmental DNA from large animals including Mammuthus primigenius, the woolly mammoth; Bison priscus, the steppe bison; horses; caribou; sheep; and canids. The samples also contained signals from mustelids, rodents, birds, and felids.

Plants were everywhere too. The team identified DNA from roughly 200 plant clades, along with fungi, insects, bacteria, archaea, and even parasitic worms. The coprolites were less like a simple record of one meal and more like tiny ecological grab bags.

---

So, Did They Actually Eat Mammoth Meat?

Here is the important caveat. Finding mammoth DNA in a ground squirrel coprolite does not automatically mean that mammoth passed through the squirrel's digestive system.

The researchers considered several possible sources. Some DNA may be dietary. Ground squirrels also cache food and other material in their burrows, so nearby tissues could contribute DNA. Some environmental DNA from surrounding sediment or midden material may also have moved into the pellets over time.

The study could not completely separate those possibilities. The safest conclusion is that the coprolites contain a mixture of information about the squirrels, their diet, and the ecosystem around their burrows.

Still, mammoth meat is not as silly as it first sounds. Modern Arctic ground squirrels are opportunistic omnivores. They eat plants, fungi, insects, and carrion. Researchers have documented Arctic ground squirrels scavenging whale and walrus meat, taking bird eggs and chicks, and even preying on other rodents.

A dead mammoth on the Pleistocene steppe would have been a massive pile of calories. A hungry squirrel taking advantage of that would fit what we know about living ground squirrels. The new study makes the idea plausible, but it does not catch one in the act.

---

And the Big Cats? Probably Do Not Picture a Squirrel Winning That Fight

The carnivore DNA needs even more caution. One sample around 31,000 years old contained low-level felid signals that could relate to Puma, Miracinonyx, or another Pleistocene cat. Ancient cat DNA is difficult to identify precisely because reference genomes for extinct felids are limited.

The authors suggest two very different possibilities. Squirrels could have scavenged carnivore remains. Or, perhaps more likely for that particular burrow, a carnivore may have entered the hibernaculum while trying to prey on the squirrels.

So the study does not show a heroic ground squirrel eating a large Ice Age cat. The cat may have been trying to eat the squirrel.

---

How Do You Read an Ice Age Ecosystem from a Piece of Poop?

The researchers used shotgun metagenomics, which sequences many DNA fragments in a sample rather than looking for one organism at a time. They also used targeted enrichment to pull out selected ancient DNA more efficiently.

Because a coprolite can contain DNA from the animal that produced it, food, microbes, parasites, and the surrounding environment, the researchers refer to much of the mixed genetic signal as ancient environmental DNA, or aeDNA.

Ancient DNA is fragmented and chemically damaged, so the team used damage patterns, negative controls, several taxonomic classification approaches, computer simulations, and comparisons with nearby sediments to test whether the signals were genuine.

The microbial communities inside the intact coprolites were distinct from nearby sediment communities. That argues against the idea that the pellets simply soaked up all of their DNA from the surrounding ground after burial. The researchers still caution that some external DNA may have entered the coprolites, but widespread post-burial leaching does not appear to explain the entire signal.

---

The 700,000-Year-Old Squirrel May Be the Bigger Scientific Story

The mammoth-eating angle is fun, but the oldest squirrel coprolite produced another remarkable result. It preserved enough mitochondrial DNA to reconstruct much of the squirrel's mitochondrial genome.

A mitochondrial genome, or mitogenome, is the small set of DNA found in mitochondria, the energy-producing structures inside cells. Because cells contain many copies of mitochondrial DNA, it can sometimes be recovered from ancient material when nuclear DNA is too damaged or scarce.

The roughly 700,000-year-old squirrel did not fall neatly within modern Yukon Arctic ground squirrels. Its genetic position suggests an ancient, previously undescribed population or lineage of Urocitellus. According to the study, this is the oldest mitochondrial genome yet assembled from ancient feces and is tied for the third-oldest mitogenome recovered from a discrete biological specimen.

The study also reconstructed 18 mitochondrial genomes from ground squirrels, a snowshoe hare, steppe bison, and horses. Six additional mammoth mitogenomes recovered from the coprolites are being analyzed separately.

---

A Mammoth-Steppe Ecosystem Preserved in Squirrel Poop

During much of the Late Pleistocene, central Yukon was part of the mammoth-steppe, a cold and dry grass- and herb-dominated ecosystem that spread across huge portions of the Northern Hemisphere.

It supported woolly mammoths, steppe bison, horses, caribou, saiga, muskoxen, wolves, large cats, bears, small mammals, birds, and a rich community of insects and plants. The squirrel coprolites recovered many of the same organisms known from bones, plant macrofossils, sediments, and other ancient-DNA studies from the region.

That agreement matters. It shows that a tiny pellet from a squirrel burrow can preserve a surprisingly broad snapshot of the surrounding ecosystem. Instead of relying only on bones from large animals, researchers can use coprolites to recover genetic information from organisms that rarely fossilize well, including plants, fungi, insects, parasites, and microbes.

---

Why This Study Matters

The real breakthrough is not that Pleistocene squirrels were secretly miniature carnivores. It is that their permafrost-preserved feces can act as unusually rich archives of ancient DNA.

A single burrow can contain information about the animal that lived there, the food it ate, the microbes in its gut, the plants around it, nearby insects, large mammals moving through the landscape, and the evolutionary history of the squirrel itself.

The authors argue that ground squirrel middens could become valuable archives for studying population change, climate shifts, extinction, and ecosystem turnover across the Quaternary. Many such frozen burrows remain preserved across Yukon and Alaska.

So yes, "squirrels ate woolly mammoths" is a wonderfully strange headline. The science is even better: ancient squirrel poop preserved a genetic record of Ice Age life for hundreds of thousands of years.

---

Journal Article:

Murchie, T. J., Cocker, S. L., Baleka, S., et al. (2026). Ground squirrel coprolites preserve complex archives of ancient environmental DNA over 700,000 years. Nature Communications, 17, 4868. Published June 9, 2026. https://doi.org/10.1038/s41467-026-72977-6.

Publication license: The Nature Communications article is published under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. The publication figures are not reproduced on this Fossilguy page. The hero photograph is a public-domain U.S. Fish and Wildlife Service image.

---

Recommended Prehistoric Mammal Books:

---