(KTLA/KTXL) — You likely would not be surprised to see a ground squirrel with cheeks stuffed with nuts, seeds or grains. Researchers in one part of California, however, have found squirrels hunting, killing, and eating another mammal. The study, published in the Journal of Ethology, suggests that ground squirrels, previously viewed as granivorous, may be more flexible with their diet. According to the University of California, Davis — which collaborated on the study with the University of Wisconsin-Eau Claire — the unique observations were noted throughout the year in northern California's Contra Costa County. ‘Murder hornets’ eradicated from US, officials announce The project examined how California ground squirrels, native to the state’s grasslands, adapt their behavior in response to environmental changes — in this case, a higher number of voles than the average over the past decade. In June and July 2024, more than 70 squirrels were witnessed taking part in hunting, eating and competing over vole prey. Voles are relatives of hamsters and are sometimes known as field mice. The squirrels were not found to be eating any other kind of mammal during the June 10 to July 30 period. “We had never seen this behavior before. Squirrels are one of the most familiar animals to people. We see them right outside our windows; we interact with them regularly,” lead author Jennifer E. Smith, an associate professor of biology at UW-Eau Claire, said in a statement. “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.” The study, which can be viewed here, notes that California ground squirrels have been documented consuming nestlings of various birds, invertebrates, chicken eggs, and more. What stands out in the recent study is the act of hunting voles. According to Smith, squirrels are an essential part of California ecosystems. Understanding whether food discovery is a socially transmitted trait in these populations could provide key insights into how other species will adjust to shifting environments.