Eastern Gray Squirrels (Sciurus carolinensis) eat about two pounds of food per week. Nuts and other seeds are at the top of the list, but fungi, berries, bird eggs and nestlings, tree buds and sap are also consumed. Because they stay active in winter, Eastern Gray Squirrels must store food in the fall in order to survive the colder months, and this food must be viable for the duration of the winter. They are what are called “scatter-hoarders” – they bury each nut separately, not all in one spot. After digging a hole 1-2 inches deep with its front paws, the squirrel places a nut in the hole and forcibly puts it in place by pounding it into the ground with its front incisors. It then fills the hole with soil and covers it with leaves. A combination of memory (experiments found that this works for about 20 minutes) and after that, scent, allows squirrels to relocate a portion of their cached nuts.
Hickory nuts are the food of choice for Eastern Gray Squirrels, in part because they have twice the calories of an average acorn. They also store well over winter, as they don’t germinate until spring. As the accompanying photograph shows, Eastern Gray Squirrels, before burying the nuts (in this case, Shagbark Hickory, Carya ovata), methodically remove the fragrant husks, leaving a pile of small pieces of husk on the ground. It’s likely this practice developed in order to prevent competitors from smelling, digging up and consuming the squirrel’s winter food supply.