When a long-term study of squirrels in an area of Briones Regional Park in California this year rolled into its twelfth year, the researchers discovered something they had never seen before – the squirrels hunted and killed mice. And ate them.
"It was a shock. We have never seen this behavior before," says Jennifer E Smith, professor of biology and one of the researchers behind the study published in Journal of Ethology.
Her colleague Sonja Wild says she didn't believe her eyes at first.
The behavior has since been documented on film, in photos, and through direct observations. It turned out that the squirrels, regardless of gender and age, hunted and ate mice. The meat-eating reached its peak during the first weeks of July, at the same time as the number of mice was unusually high.
The researchers' theory is that the new diet emerged because there was simply an abundance of prey.
"The fact that squirrels are behaviorally flexible and can adapt depending on what food is available can help them survive in environments that are rapidly changing due to human presence," says Sonja Wild.
