California squirrels show signs of hunting for first time in new study
Credit: Journal of Ethology. Jennifer E. Smith, Joey E. Ingbretson, Mackenzie M. Miner, Ella C. Oestreicher, Mari L. Podas, Tia A. Ravara, Lupin M. L. Teles, Jada C. Wahl, Lucy M. Todd, Sonja Wild
LOS ANGELES - Move over acorns, a new study has shown evidence of a species of California squirrel hunting other animals and exhibiting carnivorous behaviors for the first time.
The findings, published this week in the Journal of Ethology, are part of a larger study on how squirrels adapt to changes in their environment, and focused on an area in Briones Regional Park in Contra Costa County.
While squirrels are mostly known for eating things like acorns, seeds and fruit, the study notes on rare occasions, the animal had killed and ate other small animals. Specifically, California ground squirrels, which this study looked at, have been known to eat bird eggs and even some smaller fish and rodents on occasion. But, according to the authors, in many of those cases, it's "challenging to distinguish between scavenging" and hunting. Their data, they claim, shows the first evidence of squirrels "repeatedly hunting, killing and consuming adult vertebrate prey in nature."
Credit: Journal of Ethology. Jennifer E. Smith, Joey E. Ingbretson, Mackenzie M. Miner, Ella C. Oestreicher, Mari L. Podas, Tia A. Ravara, Lupin M. L. Teles, Jada C. Wahl, Lucy M. Todd, Sonja Wild
The authors looked at a 20-day period in July 2024 and analyzed the number of interactions between the squirrels and voles. Over that time, they observed more than 70 interactions. Nearly half of those interactions showed the squirrels actively hunting their prey. In some cases, the squirrels stalked their prey before pouncing; in others, they chased the voles down. Once they got their prey, the researchers found the squirrels would rip off the voles' heads and eat them.
So why do these squirrels hunt, instead of stuffing acorns in their cheeks like most of us have come to expect?
The researchers believe the behavior is linked to a spike in the vole population. In Northern California in 2024, there were vole "infestations," according to the study, with the population seven times greater than the 10-year average. Those numbers were even higher at Briones Regional Park. Voles provide more energy than the squirrels' typical acorns and seeds.
The authors suggest that their study "fundamentally changes our understanding of this primarily granivorous species, suggesting that they are considerably more flexible in their diet than previously assumed."
The full findings can be found by tapping or clicking here.