The eastern gray squirrel has been introduced from eastern U.S. to cities, campuses, and large private estates in the vicinity of San Francisco Bay and in Sacramento, San Joaquin, Calaveras, and Stanislaus cos. Populations of eastern gray squirrels are found in orchard-vineyard, urban, and possibly valley foothill riparian habitats. Caches mast in scatterhoards in the fall for winter and spring use.
Food intake is lowest in winter.
About half of daily water needs are met through food. Prefers dense stands of large trees and snags with abundant cavities, mast, preferably near water. Size of home range varies with available food, habitat quality, and sex. Mating occurs from December through March, and again in June elsewhere. Gestation requires about 44 days.