FLICKR, GRENDELKHAN
Fox squirrels appear to use complex food assessment strategies, according to a study published last month (March 26) in PLOS One. A team led by the University of California, Berkeley’s Mikel Delgado studied squirrels on the campus. Although their behaviors seemed scattered, the squirrels evaluated the values of food resources differently based on nut type and season. The animals flicked their heads or pawed the nut to assess its value.
For one set of experiments, the researchers gave 23 campus squirrels a series of hazelnuts and peanuts. Hazelnuts are larger and store better, but peanuts have more calories and protein per nut. During lean summers, the squirrels ate most of the peanuts and cached more of the hazelnuts. In the bountiful fall season, however the ...