Western gray squirrel

The western gray squirrel (Sciurus griseus) is a large tree squirrel of the western coast of North America, found in the United States and Mexico. Three geographic subspecies are recognised, running from central Washington through California to northern Baja California. It is the largest tree squirrel in the Sierra Nevada and central California, weighing roughly 0.35 to 1 kilogram and measuring 43 to 61 centimetres including the tail, with solid gray fur on its back and sides. Shy compared with the eastern gray and fox squirrels, it forages mainly on the ground but stays close to trees, is primarily active by day, and nests in stick nests or tree cavities. Its diet centres on oak and conifer seeds and on fungi, especially truffles. By burying acorns and spreading fungal spores in its droppings it helps maintain and renew oak woodlands, though in some landscapes it has lost habitat or disappeared locally through competition with other squirrels and other pressures.