07/26/2026
California squirrels have started turning carnivorous.
Scientists thought California ground squirrels mainly survived on seeds, grains and plants.
Then they watched them hunt, kill and eat other mammals.
Researchers studying squirrels at Briones Regional Park in California’s Bay Area documented widespread hunting of voles, small rodents that resemble mice. It was the first scientific evidence that California ground squirrels regularly engage in this kind of carnivorous behavior.
Between June 10 and July 30, 2024, the team recorded 74 interactions between squirrels and voles. About 42 percent involved active hunting.
The behavior was not limited to one unusual squirrel. Researchers saw males and females, as well as squirrels of different ages, chasing, killing, eating and competing over vole prey.
Once the team realized what was happening, they began seeing it almost every day.
The hunting peaked during the first two weeks of July, when vole numbers suddenly surged across the park. Scientists think the squirrels took advantage of an unusually abundant food source, revealing that they are opportunistic omnivores rather than animals that rely almost entirely on plants.
Researchers did not observe them hunting other mammals.
The discovery shows how even familiar animals can still surprise science. California ground squirrels are commonly seen stuffing their cheeks with nuts and seeds, but their ability to rapidly change their diet could help them survive in environments altered by people and shifting food supplies.
Important questions remain. Scientists do not yet know how widespread the behavior is, whether young squirrels learn it from adults or whether eating voles affects their survival and reproduction.
Learn more:
"Carnivorous Squirrels Documented in California." UC Davis
