Even squirrels have their secrets. And what has just been revealed by research published in the Journal of Ethology is destined to forever change the image we have of these animals, normally considered docile, shy and harmless. A team of scientists from the University of California at Davis and the University of Wisconsin-Eau Claire has in fact observed and photographed specimens of the California citle (Otospermophilus beecheyi), a ground squirrel widespread in the western United States, intent on hunting, killing and devouring field mice. It is the first time that such behavior has been described on a large scale in a squirrel species, and the discovery could lead to reclassification of the diet and attitudes of these animals.
The observations were made this year as part of a 10-year project studying the behavior of California sandpipers in Briones Regional Park, located in California’s Contra Costa County. And as we mentioned, they reveal an extremely widespread propensity for hunting and meat consumption, at least among the specimens in the area: 42% of the 74 interactions studied between ground squirrels and voles (field mice) ended with squirrels who chased the small rodents.
“For us it was a shock – commented Jennifer Smith, biology professor at the University of Wisconsin-Eau Claire who leads the project – we had never seen similar behavior in the past. Squirrels are extremely familiar animals to humans. We see them outside our windows, we interact with them on a regular basis. Yet we are faced with behavior never before observed by science, which reveals how much we still have to learn about the natural history of the world around us.”
The discovery – say the researchers – came by chance, studying the videos captured by one of the cameras used to monitor the behavior of the squirrels. But once they figured out what to look for, scientists began to continually notice California stone voles of all sizes and ages hunting the little voles. The peak of these aggressive behaviors arrived in the summer, in the second half of July, corresponding to the weeks in which the maximum number of field mice was present in the area.
In all likelihood – therefore – the predatory instincts of squirrels are influenced by the availability of food. And specifically, they were driven by the temporary abundance of prey, and the lesser availability of seeds and acorns they normally feed on. There are currently many questions that remain unanswered. For example how common hunting is in other squirrel species. Whether it is learned behavior or innate instinct. And whether what was observed in the American natural park is something that repeats itself from year to year, and not rather a more unique than rare event.
To find out, researchers look forward to resuming observations next spring. In the meantime, the research will give experts something to discuss: squirrels have always been classified as docile granivores (animals that feed on seeds), but now they could have what it takes to officially become omnivores, just like our species.