Tree Squirrels of California

Welcome, Squirrel Friends & Foes!

This site began with the squirrels outside my door in a Sonoma County redwood forest, and it keeps growing as I learn.

Two Western Gray Squirrels climbing the trunk of a redwood

Western Gray Squirrel · Sciurus griseus

The Native Gray Squirrel Is Different

Western Gray Squirrels are naturally cautious around people. They typically do not initiate contact, can be quick to startle, and won't join a picnic to beg for food like those that appear in viral videos.

“secretive and wary by nature”

Washington State Dept. of Fish and Wildlife, 2023 status review

A Western Gray Squirrel in side view on a redwood log, tail raised over its back

Frames of a Western Gray Squirrel wrestling a strip of redwood bark on a deck rail — Native Western Gray Squirrel wrestling a strip of redwood bark 3

An Eastern Gray Squirrel crouched on a branch, looking toward the camera

Wait. That Squirrel Isn’t From Here?

In many West Coast cities and suburbs, the tree squirrels people see every day came from east of the Mississippi. People deliberately introduced Eastern Gray and Fox Squirrels to western cities more than a century ago.

How Squirrels Came West

A redwood glen: Douglas Squirrels on the trunk and log above, a Western Gray Squirrel on the deck below

Why I Started Looking Closer

I live in a small patch of second-growth redwood forest in western Sonoma County, where Western Gray and Douglas squirrels visit the same feeding area at the edge of my deck.

Over time, the Douglas Squirrels have become more tolerant of my presence. If I move slowly and keep my distance, they may stay and carry on eating, chirping and chattering. If I get too close, they might dart to a tree trunk, but they typically watch me and stealthily move back to their foraging near the deck.

The Western Grays are different. After years of seeing me almost every day, the turn of a doorknob can still send them racing up a tree. Occasionally, they stop on the first high redwood branch and watch from there, but more often, they withdraw much farther or disappear from view altogether.

I kept wondering why. I expected that eventually they would become comfortable around me, like the squirrels in parks and videos that approach people or even eat from their hands.

They never did.

So I started looking for an explanation.

Meet the Four Daytime Tree Squirrels

A Douglas Squirrel eating seeds beside a redwood

Native Douglas Squirrel Bold, loud, forest dweller

A Western Gray Squirrel on a log in front of a redwood trunk

Native Western Gray Squirrel Shy and wary

An Eastern Gray Squirrel sitting in the fork of a tree

Introduced Eastern Gray Squirrel Habituates readily to people

An Eastern Fox Squirrel in the fork of a tree, looking at the camera

Introduced Fox Squirrel Bold and adaptable to built environments

Native vs Introduced Squirrel Photo Library

Beyond the Four

This site focuses on four daytime tree squirrels found in California. But they are not the whole story.

A flying squirrel gliding with its legs spread

The Night Shift

Native

Humboldt’s Flying Squirrel

Humboldt’s Flying Squirrel is also a native California tree squirrel. It is nocturnal, glides between trees, and is rarely seen.

More about flying squirrels

A California Ground Squirrel resting on bare, rocky ground

Ground Squirrels

Ground squirrels are not tree squirrels. The California Ground Squirrel, pictured here, lives in burrow systems, where it sleeps, stores food, and rears its young.

More about ground squirrels

A Sonoma Chipmunk crouched on a weathered log

Chipmunks

California has numerous native chipmunk species, often tied to particular regions, elevations, or habitats; this one is a Sonoma Chipmunk. Chipmunks belong to the squirrel family but are not tree squirrels. They can climb, and depending on the species they nest in burrows, logs, rock crevices, or tree cavities.

More about chipmunks

What makes a tree squirrel a tree squirrel? →

Cute Complicates Everything

An Eastern Fox Squirrel on a mossy branch, looking at the camera

In many California cities and suburbs where the two introduced squirrels have become established, Eastern Gray and Fox Squirrels live close to people. Some might say they: steal from feeders, terrorize gardens, and gnaw on our trees and houses. However, we can objectively say that they: visit feeders, explore gardens, and customize the human built environment for their own use. And, they tend to interact with the humans who offer them food.

That closeness is part of their appeal. For many people, squirrels are among the few wild mammals they can watch regularly and at close range.

An Eastern Gray Squirrel peeking out of a bird feeder

An Eastern Gray Squirrel climbing a person’s pant leg

But close neighbors can also come into conflict. Squirrels may dig up plants in the garden, strip bark, take fruit or nuts, gnaw wood or wiring, or enter attics and other buildings. An encounter that is charming in one setting can become a serious problem in another.

A Fox Squirrel gnawing the wooden edge of a box in a yard

An Eastern Gray Squirrel between wooden framing members inside a roof space, looking toward the camera

Living with squirrels →

Field observation

Western Sonoma County

A Douglas Squirrel on a feeder platform and a Western Gray Squirrel on the deck rail below, in a redwood grove

Western Gray and Douglas squirrels regularly use the same small patch of redwood forest where I live. I often see them feeding within a few feet of one another, as you can see in some of my photos. Both species will vocalize strongly at the other, and they seem to be trying to make a claim to the territory, but I see them chasing the other species about as much as they chase their own: round and round the big redwood trunks, spiraling up and down.

That does not tell us how the two species interact everywhere, or what happens when food is scarce. But here, at least, I have repeatedly observed both species using the same patch of forest.

Why Identify My Tree Squirrel?

Identification matters because California’s rules and the appropriate response differ by species and situation.

Identify your squirrel →

Tree Squirrels of California

The Native Gray Squirrel Is Different

Wait. That Squirrel Isn’t From Here?

Why I Started Looking Closer

Meet the Four Daytime Tree Squirrels