Chipmunks & Ground Squirrels

Two of a Kind

People commonly mistake eastern chipmunks and 13-lined ground squirrels for the same animal, but both species have distinguishing marks and habits.

Eastern Chipmunk Tamias striatus

An eastern chipmunk has five dark brown stripes that run from its head to its rump. The two outer stripes on both sides sandwich lighter ones. Two light and three dark stripes run above and below each eye. It has rounded, erect ears and pouches in each cheek, which allow it to stash and carry food and soil.

Chipmunks are active during the day year-round, scurrying with their tails up in the air. They prefer the edges of woodlands and occasionally climb trees to find food but have adapted to urban areas, where they tunnel under trees, shrubs, rocks, woodpiles, driveways, sidewalks and porches. Burrows have interconnected galleries up to 30 feet long with several entrances, although a chipmunk normally uses only one. After working on a burrow, a chipmunk carries the dirt away so piles by the entrance don’t attract predators.

Chipmunks eat berries, nuts and seeds and may eat worms, slugs, insects, small mice, birds, frogs and snakes.

They have two breeding seasons — one in spring and one late summer — and have five or six young per litter.


Thirteen-Lined Ground Squirrel Spermophilus tridecemlineatus

As its name suggests, a 13-lined ground squirrel has 13 lines on its back, some spotted, which run from its head to its rump. It has large eyes and short ears.

Thirteen-lined ground squirrels are active during the day. They prefer open grasslands, where they often stand on their hind legs to survey their surroundings, but have adapted to lawns, golf courses and cemeteries. They hibernate in winter in burrows that can have multiple entrances.

They eat equal amounts of plants and animals, including seeds, fruits, nuts, roots, foliage, grasshoppers, moths and butterflies, earthworms, and young birds and mice.

Females have one litter of six or seven young usually around the end of May.