“We had never seen this behavior before. Squirrels are one of the most familiar animals to people,” said one scientist
Squirrels in California aren’t as vegan as people may assume.
A new study from U.C. Davis and UW-Eau Claire found that California ground squirrels not only eat nuts and fruit — but also hunt and eat voles, which are small mouse-like rodents.
The study was conducted in 2024 at Briones Regional Park in Contra Costa County, Calif., and found that the park’s ground squirrels exhibited carnivorous behaviors — particularly in the peak summer months — and hunted voles.
“This was shocking,” said study lead author Jennifer E. Smith, an associate professor of biology at UW-Eau Claire who leads the long-term ground squirrels project with Sonja Wild of UC Davis, in a press release.
“We had never seen this behavior before,” she added. “Squirrels are one of the most familiar animals to people. We see them right outside our windows; we interact with them regularly. Yet here’s this never-before-encountered-in-science behavior that sheds light on the fact that there’s so much more to learn about the natural history of the world around us.”
Data from the study shows that 74 ground squirrels interacted with voles between June and July, and nearly half (42%) of those squirrels hunted the smaller rodents down. This activity was captured on video in the park.
Never miss a story — sign up for PEOPLE‘s free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.
In the footage, squirrels are “hunting, eating and competing over vole prey.” According to a UC Davis press release, this carnivore behavior in the squirrels peaked in the first two weeks of July, when the vole population was at its highest at the park. The study said the squirrels’ “hunting behavior emerged” as the creatures became more available at the park.
“The fact that California ground squirrels are behaviorally flexible and can respond to changes in food availability might help them persist in environments rapidly changing due to the presence of humans,” Wild said.
According to the study, although some ground squirrels showed a carnivorous side, they did not appear to eat any creatures other than voles. Smith called them “incredible opportunists” because they were flexible with their eating habits.
While the study’s scientists have observed this new behavior, they said they still have many questions to answer, including how the squirrels began to hunt voles, whether it was “passed down” behavior from parent squirrels, and how this hunting behavior affects “ecological processes.”
According to Los Angeles County, California, ground squirrels eat green grasses and herbaceous plants after hibernating and seeds, grains, fruits, and nuts in the other months. They are often dormant during the winter and summer months. In the wild, ground squirrels usually live up to five years and can grow up to 18-20 inches.
People
