The Western Gray Squirrel is the largest native tree squirrel in Washington. It is silver gray with dark flanks and creamy white underparts. Western Gray Squirrel (Sciurus griseus) has been accorded a "threatened" status by the Washington Department of Wildlife. The western gray squirrel is vulnerable because of the small size and isolation of remnant populations. Major threats to the western gray squirrel in Washington include habitat loss and degradation, road-kill mortality, and disease.
The Western Gray Squirrel produces one litter of 2-5 young a year. May is the earliest that young have been observed to leave the nest. Individual Western Gray Squirrels can live 8-10 years in the wild. Potential predators of this squirrel include raptors, great-horned owls, goshawks, golden eagles, bobcats, coyotes, cougars, martens, domestic dogs and cats and humans. The The Western Gray Squirrel appears to be particularly vulnerable to being killed by automobiles.
Although the squirrels require mast-producing trees and forests of larger trees, in Washington the Western Gray Squirrel inhabits three different vegetation types: white-oak-Douglas fir woodlands in the Puget Sound area, white oak-ponderosa pine forests in the Columbia River Gorge, and the grand fir-Douglas fir zone in north-central Washington. In California, the squirrel's habitat ranges from the valley oaks low in the Sacramento Valley to red-fir forest in Fresno county.
Western Gray Squirrel
Photo by Dr. Lloyd Glenn Ingles ©California Academy of Sciences