California Ground Squirrels Show Unexpected Carnivorous Behavior, Study Reveals
A new study published in the Journal of Ethology reveals a surprising dietary shift in California ground squirrels, long considered herbivores, CNN reports.
Researchers have documented the squirrels actively hunting, killing, and consuming voles, a behavior previously unrecorded for this species. This discovery challenges established understandings of squirrel diets and highlights their adaptability in the face of environmental change.
The research, conducted as part of the Long-Term Behavioral Ecology of California Ground Squirrels Project at Briones Regional Park, focused on a region experiencing a significant increase in vole populations over the past decade. Lead author Jennifer Smith, associate professor of biology at the University of Wisconsin-Eau Claire, emphasizes the groundbreaking nature of the findings.
The study, conducted between June 10 and July 30, involved trapping, marking, and releasing squirrels. Researchers observed 74 interactions between squirrels and voles, with 42% involving squirrels – both male and female, juveniles and adults – actively hunting and consuming the voles. The team meticulously documented squirrel characteristics, including sex, reproductive status, and body mass, ensuring accurate tracking throughout the study period.
The findings show not only predation but also a range of social interactions between the two species, including positive interactions like foraging and playing, alongside competitive behaviors such as chasing and biting.
This opportunistic carnivory, the researchers suggest, is a display of dietary plasticity, a common adaptation in animals to capitalize on available resources. The abundance of voles provides a readily accessible protein source, crucial for squirrel survival and potentially easier to obtain than seeds. Koprowski explains that such dietary shifts are normal, and the increase in predation could help control vole populations, which are often considered pests.
