Researchers Shocked To Discover Carnivorous Squirrels: 'I Could Barely Believe My Eyes'

A group of California squirrels—long thought to be nut-hoarding vegetarians—have evolved into carnivorous predators, according to a groundbreaking study.

Scientists documented California ground squirrels hunting and consuming live voles in the first-ever recorded instance of the species displaying carnivorous behavior. The research, published Wednesday in the Journal of Ethology, was conducted as part of the Long-Term Behavioral Ecology of California Ground Squirrels Project in Briones Regional Park, Northern California.

Dr. Jennifer Smith of the University of Wisconsin-Eau Claire led the study where researchers observed squirrels adapting their diets in response to a surge in the local vole population. Over a period of six weeks, researchers recorded 74 interactions between the squirrels and voles, with 42% involving predatory behavior.

"I could barely believe my eyes," coauthor Sonja Wild, a postdoctoral researcher at UC Davis, told CNN. "Once we started looking, we saw it everywhere."

The findings challenge long-held perceptions of squirrels as herbivores or granivores.

"This research radically changes our perception of squirrels," Smith said. "What is most striking and incredible is the speed at which they shifted their behavior to this local surge in vole abundance."

This dietary shift is an example of dietary plasticity, John Koprowski, dean of the Haub School of Environment and Natural Resources at the University of Wyoming explained. Voles, considered pests due to frequent surges in population, presented a more accessible protein source to their opportunistic new predators.

"In the face of human insults such as climate change and drought, these animals are resilient and have the potential to adapt to live in a changing world," Smith emphasized. "By studying these processes we can offer meaningful insights for conservation."