Squirrels Documented Consuming Meat for the First Occasion
When you picture squirrels, you might envision adorable, furry creatures with bushy tails, constantly munching on nuts. However, a group of researchers from the University of Wisconsin-Eau Claire (UW-Eau Claire) and the University of California (UC), Davis, captured on camera Californian ground squirrels engaging in a brutal act of predation – devouring small rodents known as voles. This is the first instance where scientists have observed the animal consistently consuming meat.
The scientists' findings, published in a study on December 18 in the Journal of Ethology, serve as a reminder that our knowledge of even the most common animals is incomplete.
Jennifer E. Smith from UW-Eau Claire made this observation in a statement issued by UC Davis. She stated, "We had never seen this behavior before. Squirrels are among 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."
Smith leads the Long-term Behavioral Ecology of California Ground Squirrels Project along with Sonja Wild from UC Davis, who also contributed to the study. Last summer, during the project's 12th year, researchers observed ground squirrels actively hunting voles in 42% of their interactions with the smaller rodents.
"I could hardly believe my eyes," said Wild. "From then, we saw that behavior almost every day. Once we started looking, we saw it everywhere."
The team, including undergraduate students, documented Californian ground squirrels hunting, consuming, and competing over voles at Briones Regional Park in Contra Costa County in June and July of 2024. The carnivorous behavior peaked during the first two weeks of July, coinciding with a sudden increase in the vole population.
It is suggested in the study that the squirrels may have started hunting voles due to the increase in their population. Scientists previously believed that California ground squirrels were granivorous (grain eaters), but now the researchers suggest that they may actually be opportunistic omnivores.
"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 explained.
"Through this collaboration and the data coming in, we’re able to document this widespread behavior that we had no idea was going on," Smith added. "Digital technology can inform the science, but there’s no replacement for going out there and witnessing the behavior because what animals are doing always surprises us."
While the team still has many unanswered questions, including how widespread the behavior is, how it is passed on to new generations, and how it impacts ecological processes, the study has significantly altered scientists' understanding of this commonly observed animal living in close proximity to humans.
The discovery of squirrels hunting and consuming voles challenges the previously held belief that California ground squirrels are solely granivorous, suggesting they might be opportunistic omnivores. In the future, further studies could uncover more details about the prevalence, transmission, and ecological implications of this carnivorous behavior in these animals.
Moving forward, advanced technologies and field observations could offer insights into the natural history of these animals, possibly leading to a more comprehensive understanding of their dietary habits and adaptability in various environments.
