Welcome, Squirrel Friends & Foes!
We find ourselves in an odd situation here on the West Coast of the United States. Many of us humans love seeing squirrels — so much so that when our native West Coast species began to disappear from view, well-meaning people tried to replace them with squirrels from east of the Mississippi.
Today, most squirrels seen in California’s cities, suburbs, campuses, and parks are not native. But whether you love them or, well... would prefer that they stay out of your yard ... we hope you'll find something on this site to brighten your day.
What You’ll Find Here
Meet the Species
Photos and facts about each California tree squirrel, native and non-native.
Species →Featured
The Bigger Story
How Squirrels Came West
Why are these squirrels here? The surprising answer is a story about how we built nature into our cities.
Read the story →Start Here
Which squirrel is this?
Use location, size, tail, belly, and behavior to tell California’s four tree squirrels apart.
Identify a squirrel →Meet the Four Tree Squirrels
What’s Native ... and What’s Not?
Pacific Coast Native Tree Squirrels
- Western Gray Squirrel (Sciurus griseus)
- Douglas Squirrel (Tamiasciurus douglasii)
Western Gray Squirrel and Douglas Squirrel (click images for more info)
Non-native Squirrels - Introduced from Eastern US - early 1900's
- Eastern Gray Squirrel (Sciurus carolinensis)
- Fox Squirrel (Sciurus niger)
Eastern Gray Squirrel and Fox Squirrel (click images for more info)
Why Identify My Tree Squirrel?
Non-native squirrels typically cause more problems than natives!
It’s important to know what kind of squirrel you’re looking at. Some species can be managed with humane deterrents, but others are protected by law.
Knowing the difference matters.
What is a Tree Squirrel?
Tree Squirrels Nest in Trees
Tree squirrels typically build their nests in trees, rather than underground. They are agile climbers, have long bushy tails for balance, and rely on a tree canopy to stay safe from predators.
Close Cousins – NOT Tree Squirrels
Ground Squirrels and Chipmunks nest underground, have stripes or spots, and sport cheek pouches for food collecting.
Tree squirrels do not.
- If it nests in a tree, it’s likely a tree squirrel.
- If it lives underground or in rock piles, it’s probably a ground squirrel or a chipmunk.