Chipmunk

Quick Take

• Chipmunks appear to hibernate all winter, though what they actually do underground is nothing like what most people assume. Hibernation habits explained →
• The name 'chipmunk' has a surprisingly literal origin rooted in a sound you've probably heard but never connected. Origin of the name →
• A ground squirrel and a chipmunk look nearly identical, though one simple trick instantly tells them apart. Spot the difference →
• Chipmunk tunnels are far more engineering marvels than they look from the outside. See the tunnel facts →

Chipmunks are small mammals that live in burrows, fallen logs, or holes under houses. This rodent is the tiniest member of the squirrel family.

They are omnivores, eating a variety of plants and small animals. Chipmunks have a collection of chirps and other sounds they use to communicate with one another. They have a lifespan of two to three years.

5 Incredible Chipmunk Facts

• There are 25 species or types.
• While foraging during the day, this rodent stuffs food into pouches in its cheeks.
• This animal remains in its burrow over the winter.
• A chipmunk baby is the size of a jellybean.
• They live in tunnel systems measuring up to 30 feet in length.

Evolution and Origins

Chipmunks are part of the squirrel family and actually split off from rats and mice close to 70 million years ago. Scientists think chipmunks probably evolved their stripes independently of rats and mice. The only species of chipmunk that isn’t native to North America is the Siberian chipmunk, as indicated by its name.

The name ‘chipmunk’ is derived from their behavior of waking up during winter to eat stored food. Others suggest they get their name from the “chip chip” sound they make while eating.

Classification and Scientific Name

Chipmunks are sometimes called striped squirrels or timber tigers. They belong to the Sciuridae family and the Mammalia class. Chipmunks can also be classed into three different genera: the eastern chipmunk, the Siberian chipmunk, and the Neotamias. This last genus contains around 23 different species that live in the western US. Because all chipmunks are so similar, there is disagreement about whether they should be classified as different genera or just referred to all of them as belonging to the same genus.

There are around 25 species. Some of these include:

• Eastern chipmunk (Tamias striatus). Native to North America.
• Siberian chipmunk (Eutamias sibiricus). Native to Russia.
• Townsend’s chipmunk (Neotamias townsendii). Native to North America.
• Uinta chipmunk (Neotamias umbrinus). Native to North America.
• Red-tailed chipmunk (Tamias ruficaudus). Native to North America.
• Colorado chipmunk (Tamias quadrivittatus). Native to the American Southwest.

Appearance and Behavior

One of the most recognized species is the Eastern chipmunk. It has two tiny black eyes and a coat of reddish-brown fur featuring five black stripes on its back, with one stripe down the center and two on each side bordered by light tan stripes. Also, this species has a light brown stripe near each ear and a dark tail. This animal’s fur can be brown, reddish-brown, or gray depending on what type it is.

This rodent uses its delicate claws to dig holes and climb trees. In addition, these animals have pouches in their cheeks that they fill up with nuts, fruit, seeds, and more. These pouches allow them to take a large supply of food back to their home after spending time foraging in the open.

Understandably, the less time the animal spends out in the open, the less vulnerable they are to predators. These animals can sometimes become quite a pest in the home and need to be removed.

A grown chipmunk measures from four to seven inches in length with a tail that adds another three to five inches. They weigh anywhere from one to five ounces. A five-ounce chipmunk weighs about the same as a major league baseball.

An average four-inch chipmunk is about as long as two golf tees placed end to end. The biggest species is the Eastern chipmunk. An adult Eastern chipmunk measures about 12 inches long, from the tip of its nose to the tip of its bristly tail.

As for defensive features, the dark coat of these animals helps them blend in with their woodland habitat. Their speed can also help them outrun some predators and find a hole to hide in.

Though chipmunks may not live right next to one another, they communicate with others in the same territory. These animals have a variety of calls or sounds that mean different things. Some chirping sounds let other chipmunks know a predator is in the area.

Other chirping sounds are made by males as they compete with each other for a female. In other words, they have their own rodent language.

These rodents are solitary animals. They are only together during the breeding season. They are shy rodents that want to stay out of sight most of the time. When chipmunks do form a group, it is called a scurry.

Habitat

Most of these animals live somewhere in North America. One species, the Siberian chipmunk, lives in the northern region of Asia. Specifically, wherever you find trees in North America, you’re likely to find these animals. They can also live in fallen logs and in holes under houses. Many species live in tunnels located three feet beneath the ground.

These animals are found in a temperate climate. If they live in an area with very cold winters, they will go into hibernation. However, these rodents don’t go to sleep in the wintertime as bears do. Instead, they sleep on and off while surviving on the nuts and seeds they collected throughout the warm weather months. Seeing the animal out of its shelter in the wintertime is a rare occurrence. They hibernate in late October and come out in March or April.

These animals sometimes migrate when they need to find a place with better access to water.

Diet

These animals are omnivores. They eat whatever is most plentiful in their habitat.

What do chipmunks eat?

They eat fruit, nuts, seeds, insects, snails, birds’ eggs, and frogs. It’s not uncommon to see an Eastern chipmunk and other types of chipmunks in North America feeding at a backyard bird feeder.

Food not immediately eaten is stuffed into its cheek pouches and taken back to the nest to store for winter.

Predators and Threats

Many predators of chipmunks are fast and share the same habitat. For example, a coyote may stalk a chipmunk and sneak up on it while it’s foraging in the open.

A hawk can easily see the animal foraging for food on the ground and swoop down to grab it. A snake can pursue the rodent by following it into its tunnel as the rodent tries to escape.

It’s not uncommon to see these animals dead on the road. They live in the same areas as many humans, so they are vulnerable to passing cars.

Some humans think of them as pests. A pest control technician may be called in to set a trap to catch one or more chipmunks that are living in a hole beneath a home or beneath a home’s roof. The presence of chipmunk poop in the area is a sure sign that a chipmunk is occupying the space.

A pest control professional may use a trap that kills the rodent. Alternatively, some pest professionals use humane methods and trap them alive so they can be moved to another location away from the residential area.

The conservation status of the Eastern chipmunk is Least Concern. Its population is stable.

What eats chipmunks?

These animals are an important food source for many animals. So, they have a long list of predators. Some examples include hawks, snakes, raccoons, rats, weasels, coyotes, and owls. Of course, they also fall prey to housecats from time to time.

Reproduction, Babies, and Lifespan

The breeding season of an Eastern chipmunk takes place twice a year. They breed from February to April and from June to August. Females release a scent when they are ready to mate.

Sometimes males fight over females during this active season. One male may mate with several females. The gestation period is approximately 31 days. As a comparison, the gestation period of the Eastern gray squirrel is a little longer at 44 days.

Most of these animals give birth to two to six live babies, also called pups. However, it’s possible for them to have up to nine pups in a litter.

A baby chipmunk or pup weighs less than an ounce. The size of a newborn animal is about the same as one jellybean. They are born blind and without any hair. The pups stay out of sight in the burrow for the first six weeks of life. They nurse on their mother during that time. The father doesn’t play a part in the care of the pups.

At about six weeks old, the pups venture out of the burrow with their mother to learn how to forage for food. The pups have a full coat of fur and can live independently at around eight weeks old.

Chipmunks can carry fleas and ticks. These rodents can also carry diseases such as leptospirosis, salmonella, and even rabies. Chipmunks have a lifespan of two to three years.

Population

The IUCN Red List of Threatened Species describes the population of Eastern chipmunks as “abundant.” Also, it’s estimated that there are from one to 15 chipmunks per acre depending on the area.

The conservation status of the Eastern chipmunk is Least Concern with a stable population.