Eastern Chipmunk (Tamias striatus): Facts, Diet and Burrows

What does an eastern chipmunk look like?

The eastern chipmunk is a compact, reddish-brown rodent with a pattern that is easy to recognize. Five dark brown stripes run along its back, separated by pale buff or gray bands, and the stripes stop before a rusty orange patch on the rump. The face is striped too, with pale lines above and below each eye. The belly is white.

The tail is furry but fairly flat and not bushy, unlike a tree squirrel’s. Each front foot has four toes and each hind foot five. Large cheek pouches inside the mouth can expand dramatically, making the head look twice as wide when they are full. Males and females look alike.

The eastern chipmunk is larger than the least chipmunk and other western chipmunks. A good field mark is the back stripes: in the least chipmunk they continue all the way to the base of the tail, while in the eastern chipmunk they end at the reddish rump.

How big is an eastern chipmunk?

The eastern chipmunk is the largest chipmunk species, but it is still small enough to fit in a cupped hand.

Weight changes through the year. Chipmunks are heaviest in autumn, when they are busy collecting food, and lighter by spring. Fur color and pattern also vary across the range, from grayer, duller chipmunks in some areas to brighter reddish ones elsewhere, and several subspecies have been described on that basis.

Habitat and range

Eastern chipmunks live across the eastern United States and southeastern Canada. The range runs from Nova Scotia and southern Quebec west to southern Manitoba and Saskatchewan, and south to eastern Oklahoma, Louisiana, Mississippi, Alabama and the Florida Panhandle. They are missing from peninsular Florida and much of the coastal plain of the Southeast. A population was introduced to Newfoundland.

Their favorite habitat is open deciduous woodland, especially mature beech and maple forest, with plenty of cover such as logs, stumps, stone walls and rocky outcrops. They also live along forest edges, in brushy fields, river valleys, suburban gardens, cemeteries and city parks. Wet, swampy ground is generally avoided because it is poor for digging.

What do eastern chipmunks eat?

Eastern chipmunks are omnivores, though most of their diet is plant food. Seeds and nuts are the staples: acorns, beechnuts, hickory nuts, maple seeds and many weed and grass seeds. They also eat berries and other fruit, buds, bulbs and mushrooms. Animal food includes insects and their larvae, earthworms, slugs, snails and occasionally bird eggs, nestlings and small frogs.

Chipmunks forage mostly on the ground, but they climb readily to reach ripening nuts and fruit. They stuff food into their cheek pouches and carry it back to the burrow, where much of it is stored in a large larder for winter. For details on the menu and the hoarding habit, see what chipmunks eat.

Behavior: burrows, territory and calls

Daily life and burrows

Eastern chipmunks are diurnal, active by day, with peaks in mid-morning and mid-afternoon. Each animal lives alone in its own burrow system and defends the area around the entrance.

A burrow usually lies less than 1 m (3.3 ft) below the surface. The tunnel system is often several meters long and can reach about 10 m (33 ft), with side chambers for food storage, a nest chamber lined with dry leaves and escape routes. The entrance is a neat hole about 5 cm (2 in) across with no pile of soil beside it, because the chipmunk scatters the dirt or uses it to plug old tunnels. This makes burrows very hard to spot.

Home ranges are small, usually between about 800 and 6,000 m² (0.2 to 1.5 acres), and chipmunks can be fairly common, with roughly 10–22 animals per hectare in good habitat.

Communication and calls

Eastern chipmunks are noisy for their size. The best-known sound is the sharp, repeated “chip” that gives the animal its name, and a lower “chuck.” Both can go on for many minutes and are mostly alarm calls: chips are often given for predators on the ground, and chucks for hawks overhead. A fast trill is usually given when a chipmunk is being chased.

Chipmunks also use scent and body posture to settle disputes. Males chase one another in high-speed pursuits during the breeding season, which helps decide who gets access to females.

Winter: hibernation and torpor

Eastern chipmunks spend winter underground, from about late October or November until March or April in much of their range. They are not deep hibernators like the groundhog. Instead, they enter periods of torpor, when body temperature and heart rate fall sharply for several days at a time, then wake to eat from their stored food. On mild winter days some chipmunks even come above ground.

This strategy depends on the food stored in autumn. Unlike a groundhog, which lives on body fat, a chipmunk does not put on a thick fat layer, so its larder is its lifeline. Studies of wild chipmunks have found that animals with bigger food stores spend less time in deep torpor, while those with little food rely on it more. In years with a poor nut crop, more chipmunks die over winter, and fewer young are born the next spring.

Males usually leave their burrows first at the end of winter, sometimes while snow is still on the ground, to look for females. Learn more in do chipmunks hibernate?

Reproduction and life cycle

Eastern chipmunks breed twice a year in much of their range: once in early spring, from about February to April, and again in early summer, from about June to August. Females are receptive for only a short time and mate with several males.

Pregnancy lasts about 31 days. A litter usually has two to five young, born blind and hairless in the underground nest and weighing about 3 g (0.1 oz). The mother raises them alone. The young are weaned at around 40 days, first come above ground at about six weeks and become independent at about two months. Most breed for the first time the following spring.

Lifespan, predators and conservation

Life is short for a chipmunk. Most live only two to three years in the wild, and many die before their first winter. In captivity they can reach about eight years.

Almost every daytime predator in eastern North America takes chipmunks. Known predators include hawks such as the red-tailed hawk, owls, red foxes, coyotes, bobcats, lynx, weasels, fishers, raccoons, snakes and domestic cats and dogs. Their main defenses are alertness, alarm calls and a quick dash to the burrow.

The species faces no serious threats. Habitat loss and roads affect some local populations, but chipmunks adapt well to parks and suburbs.

The IUCN Red List classes the eastern chipmunk as Least Concern. It has a large range, is common in many areas and has no major threats. Numbers in any one woodland can still rise and fall sharply from year to year, mainly following the size of the nut and seed crop.

Ecological role

Chipmunks are important seed handlers in eastern forests. Most seeds stored in their underground larders are eaten, but seeds buried in small surface caches and later forgotten can sprout into new trees. Chipmunks also eat many kinds of fungi and spread their spores in their droppings, including fungi that help tree roots take up nutrients.

Their digging also matters. Tunnels and chambers mix and loosen the soil, carry leaf litter underground and create small spaces that other animals, from salamanders to insects, may use. A chipmunk that dies or moves away leaves behind a ready-made burrow system.

As abundant small mammals, chipmunks are a key food for predators. They are also nest predators of some ground-nesting and shrub-nesting songbirds.

Myths and facts

Myth: chipmunks carry away soil in their cheek pouches. The naturalist John Burroughs once wrote this, then later corrected himself. Chipmunks use their pouches to carry food and nest material, not dirt.

Myth: all chipmunks are the same species. There are about 25 chipmunk species. The eastern chipmunk is the only living member of the genus Tamias; most others are western North American species in the genus Neotamias, and one, the Siberian chipmunk, lives in Asia.

Fact: the name probably comes from an Indigenous language. The word chipmunk is thought to come from an Ojibwe or Odawa word, later anglicized as “chitmunk” and “chipmonk.”

Relationship with people

Eastern chipmunks are among the most watched wild mammals in North America, thanks to their bold stripes, busy habits and willingness to live near houses. Cartoon characters such as Chip ’n’ Dale and Alvin and the Chipmunks made them famous worldwide.

They are wild animals, though, and are best enjoyed from a distance. Like other rodents, a handled chipmunk can bite. Watching them collect seeds along a woodland trail in autumn is one of the easiest ways to see wildlife in eastern North America.