Native and Non-native Squirrels

At first glance, all squirrels might look alike. But there are actually three different species you might see in this area! Fox squirrels (Sciurus niger), with their brownish-gray fur and fluffy tail, are the most common, though they are not a native species. It’s likely that, in the early 1900s, Civil War veterans from the South brought them to California. California made squirrel importation illegal in 1933, but it was probably too late. Fox squirrels quickly established dominance over native species because they use human infrastructure for food and nesting sites. They will feast on food scraps, garden vegetables, seeds, berries, and nut and fruit orchards.

If you’re lucky, you might spot a Western gray squirrel (Sciurus griseus) with silver-gray fur, pure white underside, and bushy tail. These are the largest native tree squirrels in their range and help seed dispersion by hiding food in different places within their territory. They are true arboreal species, choosing to live in dense forests, eating only acorns, pine nuts and fungi that grow on trees. As their habitat has shrunk over time, they prefer to keep their distance from humans.

If you see a squirrel with a mottled or dappled coat and brown tail, you’ve met the native California “Beechey” ground squirrel (Otospermophilus beecheyi). Unlike fox or Western gray squirrels that prefer living in trees, this keystone species is famous for its burrowing behavior. This also disperses seeds and aerates the soil, promoting plant growth. Ground squirrel burrows can be up to six feet deep and 35 feet long, with multiple rooms, such as nurseries, food storage or sleeping quarters.