Food storability and the foraging behavior of fox squirrels (Sciurus niger)

Food storage in animals allows foragers to reap when food is plentiful and costs are low and eat when food is scarce and costs are high, thus shifting resources from periods of low value or high availability to periods of high value or low availability. To a caching animal, a food item has two components: its present value for immediate consumption and its future value if stored. We explored some properties of caching in the context of a food's future value using free-living fox squirrels (Sciurus niger) and manipulations of cacheability of supplemental food. We assessed squirrel behavior using giving-up densities (GUDS) of noncacheable food in artificial food patches. Squirrels had higher GUDs in assessment trays when given noncacheable supplemental food than when food was not augmented; when given supplemental food in a highly storable form, squirrels had intermediate GUDs. Thus, future value of food affects the foraging behavior of squirrels through the balancing of present and future needs.