What are chipmunks? An updated explanation of their characteristics, ecology, and habitat

What kind of animal is a chipmunk? We will explain its characteristics, ecology, and habitat. Chipmunks, which are basically pets like dogs and cats, are small mammals, and many people start keeping them. I will explain the whole story, including what kind of personality a chipmunk has and what kind of ecology it is.

What is a chipmunk? About basic status

Chipmunks are mammals classified in the genus Chipmunk, in the order Mammalia, order Rodentia, family Squirrel. The scientific name is Tamias and the kanji is striped chestnut rat. The body length is 12-19cm and the weight is 70-120g. Tail length 8-11.5cm. A list of basic information is below.

Japanese（和名）	シマリス
English（英名）	Chipmunk
scientific name(学名)	Tamias
classification（分類）	Mammalia、Rodent、 Sciuridae、Tamias 哺乳綱、ネズミ目、リス科、シマリス属
IUCN Status(保全状況)	LEAST CONCERN
Length（体長）	12-19cm
Weight（体重）	70-120g

What are the roots and origins of the chipmunk?

Chipmunks are a group of small squirrels within the Sciuridae family that have adapted to life on the ground. The chipmunk most familiar in Japan is primarily the Siberian chipmunk (Tamias sibiricus), which is widely distributed across northern Eurasia.

The Origins of Squirrels

The ancestors of the squirrel family (Sciuridae) are believed to have appeared approximately 40 million years ago (during the late Eocene epoch).

Early squirrels were characterized by:

Small size

High climbing ability

A diet of nuts and insects

A primarily arboreal (tree-dwelling) lifestyle

These ancestral squirrels evolved from a common ancestor that also gave rise to modern flying squirrels and tree squirrels.

The Emergence of the Chipmunk Lineage

The chipmunk group (genus Tamias) is thought to have appeared around 8 to 10 million years ago (during the Miocene epoch).

During this period:

Forests gave way to expanding grasslands

Small, ground-dwelling mammals increased in number

Animals that utilized seeds and underground burrows flourished

Consequently, some squirrels adapted by shifting from:

Tree-dwelling to ground-dwelling lifestyles

Solitary behavior to the use of burrows

Leaping movement to running along the ground

The Evolution of the Chipmunk’s Defining Feature: Stripes on the Back

The stripes on the back—the chipmunk’s trademark—play an important evolutionary role.

Roles:

① Camouflage

Blending in with:

Dappled sunlight filtering through trees

Fallen leaves

Shadows cast by grass

② Protection from Predators

Making it harder for natural enemies—such as:

Foxes

Hawks

Snakes

Weasels

—to spot them.

③ Recognition of Conspecifics

Potentially aiding in identification among closely related species.

The Global Spread of Chipmunks

The ancestors of the chipmunk are believed to have developed in North America. Evolutionary Timeline:

Approx. 40 million years ago
Origin of primitive squirrels
↓
Approx. 10 million years ago
Divergence into ground-dwelling squirrels
↓
Approx. 8 million years ago
Appearance of the genus Tamias (chipmunks)
↓
Diversification in North America
↓
Expansion into Eurasia via the Bering Land Bridge
↓
Present day
Distribution across North America and Asia

About classification

There are several subspecies of chipmunks, including: The following is a quote from Wikipedia.

• シマリス（シベリアシマリス）Tamias sibiricus
• チョウセンシマリス Tamias sibiricus barberi
• エゾシマリス Tamias sibiricus lineatus
• トウブシマリス Tamias striatus
• タカネシマリス Tamias alpinus
• キマツシマリス Tamias amoenus
• ブラーシマリス Tamias bulleri
• ハイアシシマリス Tamias canipes
• クビワシマリス Tamias cinereicollis
• デュランゴシマリス Tamias durangae
• ガケシマリス Tamias dorsalis
• メリアムシマリス Tamias merriami
• チビシマリス Tamias minimus
• ススイロシマリス Tamias obscures
• レッドウッドシマリス Tamias ochrogenys
• パルマーシマリス Tamias palmeri
• パナミントシマリス Tamias panamintinus
• ミミナガシマリス Tamias quadrimaculatus
• コロラドシマリス Tamias quadrivittatus
• アカオシマリス Tamias ruficaudus
• アカシマリス Tamias rufus
• シエラネバダシマリス Tamias senex
• クレーターレークシマリス Tamias siskiyou
• ソノマシマリス Tamias sonomae
• サンバーナディーノシマリス Tamias speciosus
• タウンゼンドシマリス Tamias townsendii
• ユインタシマリス Tamias umbrinus

About habitat

Most chipmunks live in North America, but many also live in Eurasia.

① Asian Chipmunk (Representative)

Habitat:
Japan (Hokkaido)
Russia (Siberia)
Northern China
Korean Peninsula

Environment:
Deciduous broadleaf forests and coniferous forests

Wild chipmunks found in Japan are only found in Hokkaido

② North American chipmunks

*Strictly speaking, this is a closely related species called a “chipmunk”

Habitat:
United States, Canada

Environment:
Forests, grasslands, mountains, suburban parks

A very large number of species

Habitat characteristics

Chipmunks prefer the following types of habitats:

Forests with many trees

Ground with a thick layer of fallen leaves

Environments with many hiding places

Soil that allows for burrowing

A highly terrestrial squirrel, it is more likely to be active on the ground than in the trees.

Nest Location

Dig complex burrows in the ground

Build sleeping areas

Food storage

Hibernate (or semi-hibernate)

feature is? What kind of creature is it?

The chipmunk is a small squirrel with stripes on the back of its body and face, and has cheek pouches. They have cheek pouches on the inside of their cheeks, and are known to pack a lot of food, such as nuts, and carry them to their burrows. This squirrel is diurnal and prefers to live alone. They often build nests in tree cavities or underground, where they live. It is said that people sleep an average of 15 hours a day.

① Appearance

Body Length: Approximately 15cm

Tail: Approximately the same length as the body

Five distinct vertical stripes on the back

Large eyes and cheek pouches

The stripes are their most distinctive trademark.

② Movement/Behavior

Extremely agile

Jumping around on the ground

Often seen standing up and alert

Restless and always on guard.

③ Personality

Timid and cautious

Generally solitary

Territorial

Once accustomed to them, they will take food from a human’s hand,
but they “get used” to them rather than becoming tame.

More wild-like than hamsters.

④ Diet (Omnivorous)

Nuts, seeds, acorns

Fruit, mushrooms

Eats insects and earthworms

Surprisingly carnivorous despite their appearance.

⑤ Cheek Pouches and Food Storage

They stuff large amounts of food into their cheek pouches.

They carry it to their burrows and store it.

They have a strong instinct to prepare for winter.

They’re good at hoarding.

⑥ Lifestyle

Diurnal

Predominantly terrestrial, but also climbs trees.

In winter, they hibernate.

They semi-hibernate (depending on the species and region).

⑦ Distance from Humans

They avoid people in the wild.

Even pets often dislike being held.

They may bite if handled forcefully.

What is your personality like?

Chipmunks are very curious. Therefore, I try my hand at things that interest me. However, on the other hand, it is an animal with many external enemies, so it has a rough temper. They may bite, so be careful when handling them.

① They are very cautious.

They react quickly to noises and movements.

They don’t like unfamiliar people or environments.

They’re always standing and watching their surroundings.

They always seem to be thinking of an escape route.

② They generally act alone.

They don’t form groups.

They have a strong sense of territory.

They may fight with other chipmunks.

They prefer to be alone.

③ They are very curious.

They are curious about new things.

They sniff and nibble to check things out.

They often have a tendency to explore.

They’re timid, but they’re also curious.

④ Relationships with people.

They get used to people more than they do to become attached.

They often only manage to take food from your hand.

They don’t like being held or petted.

They tend to be more distant than hamsters.

⑤ Moody

Approach when in a good mood

Hide and bite when displeased

May become aggressive during the breeding season

⑥ Individual differences are significant

Gentle type

Nervous type

Fully curious type

Even chipmunks can be quite different.

What is the ecology like?

Chipmunks are omnivorous, eating mostly seeds, nuts, fruits, and buds. They often climb trees to get the nuts, and they also eat plants in farmlands and gardens, making them easy to become pests. Chipmunks breed twice a year, in early spring and early summer. They can give birth to one baby at a time. Lifespan is 5 to 10 years.

① Habitat/Range

Live primarily on the forest floor

They can climb trees, but their main activity is on the ground

Live within a small range centered around their burrow

“Ground squirrels.”

② Burrow Life

Dig complex burrows underground

The burrow contains separate sleeping areas, food storage areas, and toilets

Multiple entrances and exits

Very meticulous.

③ Daily Rhythm

Diurnal

Especially active in the morning and evening

Forage and watch during the day

Rest in their burrows at night

④ Food and Food Storage

Omnivorous

Nuts, seeds, acorns

Fruit, mushrooms

Insects, small animals

Stuff food in their cheek pouches and carry it to their burrow

They have a strong habit of storing large amounts of food

Preparing for winter is crucial.

⑤ Seasonal Changes

Autumn:
Focus on food storage

Winter:
Hibernation or semi-hibernation
(Not completely asleep)

Spring-Summer:
Active activity and breeding

⑥ Breeding

Breeding season: Spring (twice a year in some areas)

Birthing: 4-6 pups per litter

Only the mother raises them

They become independent at about 2 months

Are there any natural enemies?

Natural enemies include birds of prey, mustelids, foxes, and snakes.

About Molting

Chipmunks molt (shed and regrow their fur) about twice a year in response to seasonal changes. Siberian chipmunks, in particular—which inhabit cold regions—undergo significant changes in their coat to survive the winter.

🌸 Spring Molt (Winter Coat → Summer Coat)

Timing:
Around March to May

This coincides with the time they wake up from hibernation.

Changes:

Thick, dense winter fur is shed

Replaced by short, lightweight summer fur

Facilitates heat dissipation

As activity levels increase in the spring, the animal needs to be able to cope with the heat.

🍂 Autumn Molt (Summer Coat → Winter Coat)

Timing:
Around September to November

This occurs before hibernation.

Changes:

Fur grows longer

Undercoat increases

Heat retention improves

Winter coat density becomes particularly high in individuals living in cold regions like Hokkaido and Siberia.

Differences Between Summer and Winter Coats

Feature	Summer Coat	Winter Coat
Fur Volume	Low	High
Length	Shorter	Longer
Density	Low	High
Role	Heat dissipation	Heat retention
Color	Somewhat vivid	Grayish / Paler tones

About Vocalizations

Chipmunks communicate with one another using a surprisingly wide variety of vocalizations, considering their small size.

However, like many other members of the squirrel family, they do not vocalize as frequently as dogs or birds. They primarily use their voices in situations such as:

Alerting others to danger

Signaling to companions

Interacting with potential mates

Communicating with their young

Common Vocalizations

“Chit-chit” or “Chit-chit-chit” (Alarm call)

This is the most frequently heard vocalization.

Characteristics:

High-pitched, short sounds

Rapid repetition

Vocalizing while remaining alert to the surroundings

Meaning:

“Danger is near”

“Something looks suspicious”

“I’ve spotted a predator”

It serves as a warning.

Alarm Calls for Predators

As small animals, chipmunks have many natural predators.

Main predators:

Birds of prey (hawks, eagles, etc.)

Foxes

Weasels

Snakes

Felines (cats)

When they sense danger, they:

Stand up

Scan their surroundings

Flick their tails

Emit high-pitched calls

“Chat” or “Kaka-kaka” Sounds

These sounds are made when the animal is excited or highly alert.

Uses:

Alerting nearby companions

Warning predators

Asserting territorial claims

These sounds are frequently heard around their burrows.

Courtship Vocalizations

They vocalize more frequently during the breeding season.

Males:

Use soft chirps

Call out while chasing

Make specific sounds when approaching

…to approach females.

These vocalizations tend to increase after they become active in the spring.

Vocalizations of Young Chipmunks

Young chipmunks produce:

High-pitched sounds

Soft chirps

Quivering or trembling sounds

Seasonal Activities

Chipmunks are animals whose lifestyles change significantly with the seasons. Their seasonal cycle centers primarily on hibernation, food hoarding, molting, and breeding.

🌸 Spring (Season of Activity Onset and Breeding)

Timing

Around March to May

This is the time when they wake up from hibernation.

Key Activities

① Waking from Hibernation

Emerging from underground burrows

Body temperature and metabolism returning to normal levels

Basking in the sun

Since their physical strength is depleted immediately after hibernation, they search for easily digestible foods such as:

Tree buds

New shoots

Seeds

Insects

② Breeding Activities

Spring is the breeding season.

Males:

Search for females

Vocalize (call out)

Pursue females

…engage in increased activity.

Females raise their young in the burrow.

③ Start of Molting

Transitioning from winter coat to summer coat.

Shedding fur

Body becomes lighter

Activity levels increase

☀️ Summer (Season of Peak Activity)

Timing

Around June to August

This is the most active period for chipmunks.

Key Activities

① Foraging

Food sources:

Nuts

Seeds

Fruits

Insects

Mushrooms

…and more.

They are most active in the morning and evening.

② Raising Young

The young born in spring grow up.

Young chipmunks:

Emerge from the burrow

Learn to forage

Begin living independently

③ Territorial Behavior

Chipmunks are essentially solitary animals.

Therefore, they:

Secure feeding grounds

Defend the area around their burrow

Maintain distance from other individuals

🍂 Autumn (Season of Preparation for Hibernation)

Timing

Around September to November

This is the most critical season for chipmunks.

① Food Hoarding

Their primary task is preparing for hibernation.

Items collected:

Acorns

Nuts

Seeds

Grains

…and more.

They stuff these into their cheek pouches and carry them to their burrows.

A single chipmunk hoards a large amount of food.

② Autumn Molting

Transitioning from summer coat to winter coat. Changes:

Increased fur density

Improved heat retention

Tail becomes bushy

③ Preparing the hibernation burrow

Inside the burrow:

Lining the floor with dead leaves

Arranging food supplies

Creating a sleeping area

…and so on.

❄️ Winter (Hibernation season)

Timing

From November to around March of the following year

Activity ceases for an extended period in cold regions.

State during hibernation

Changes:

Drop in body temperature

Lower heart rate

Reduced breathing

Decreased energy consumption

However, unlike the “light” hibernation seen in bears, chipmunks undergo true hibernation (deep dormancy).

Behavior during hibernation

They do not remain asleep continuously.

Occasionally:

They wake up

Eat stored food

Defecate

Walking Speed

Although chipmunks are small mammals, they are capable of moving quickly across the ground and possess excellent explosive speed over short distances.

However, unlike cheetahs or large mammals that can maintain high speeds for extended periods, chipmunks are built for short-distance movement—such as avoiding danger, foraging for food, or moving between their burrows.

🚶 Normal Walking

Approximately 1–3 km/h

During routine movement, they:

Walk along the ground

Check their surroundings

Forage for nuts and seeds

Move around the area near their burrow

…and generally move at a leisurely pace.

Because chipmunks are naturally wary, they frequently stop while walking to scan their surroundings.

🐾 Active Movement

Approximately 4–8 km/h

This speed is observed when they are foraging or traveling back and forth between their burrow and feeding grounds.

Characteristics:

Scampering with quick, short steps

Making rapid changes in direction

Coming to a sudden stop

…displaying the typical movements of a small animal.

🏃 Maximum Short-Distance Speed

Approximately 15–25 km/h

*Note: Exact top speeds vary depending on the species and measurement conditions.

Chipmunks are able to move very quickly over short distances thanks to:

Long legs

A flexible spine

Strong hind legs

Jumping Ability

In addition to running, chipmunks are adept at jumping.

Capabilities:

Jumping distances ranging from several tens of centimeters to over a meter

Quickly navigating over rocks and fallen logs

Instantly climbing trees

When sensing danger, they:

Move rapidly across the ground

Flee into trees or burrows

Freeze in the cover of shadows or objects

About Baby Chipmunks

Baby chipmunks are very small, immature, and wild babies that grow rapidly in a short space of time.

Contrary to their cute appearance, they grow very quickly.

① Immediately after birth

Body length: Approximately 5 cm

Weight: A few grams

Hairless, eyes closed

Ears not yet open

Completely dependent on their mother

They are born very fragile.

② 2-3 weeks after birth

Hair begins to grow

Eyes and ears open

Movement gradually becomes more active

This is when they start to lose their “baby” look.

③ Around 1 month after birth

Stripes appear on their backs

Walking around in their burrow

Beginning to nibble on solid foods

They begin to look like chipmunks.

④ 5-6 weeks old

Begins to leave the burrow

Increased activity through running and climbing

Still under mother’s supervision

⑤ 7-8 weeks old (approximately 2 months old)

Almost independent

Leaves mother and begins to act independently

Searches for and digs burrows

Very early independence.

⑥ Relationship with mother

Mother alone cares for the young

Father not involved

Once independent, mother and young keep their distance

Wild and reserved.

⑦ Risk and survival rate

High mortality rate during the juvenile stage

Risks include predators, cold, and food shortages

This is why they grow so quickly

Are chipmunks an endangered species?

Are chipmunks an endangered species? That being said, that is not currently the case. The population is stable and distributed all over the world.

① Chipmunks Well Known in Japan and Asia

(Siberian Chipmunk, etc.)

IUCN Classification:
LC (Least Concern)

Currently, there is little risk of extinction.

Relatively stable in Hokkaido and the continent.

This is the “chipmunk” that most people associate with.

② North American Chipmunks

Many species are LC (Least Concern).

However, some species with limited habitats, including island and mountain species, have reported population declines.

③ Examples of High Risk of Extinction (Few).

Some locally distributed species are strongly affected by deforestation, urbanization, and climate change.

Some species are listed as Vulnerable (VU) and Endangered (EN).

Chipmunks do not necessarily mean safe.

Why are most not extinct?

Relatively high reproductive rate

Wide range of diet (omnivorous)

Highly adaptable to the environment

Many species can live near human settlements

Can chipmunks be kept as pets?

Can chipmunks be kept as pets? Chipmunks are available through common pet stores.

What is the selling price?

The market price is 7,000 yen to 10,000 yen. If the item is rare, the price can be several times higher. Some shops have different prices for males and females.

cage required

Chipmunks are semi-arboreal and require a lot of exercise, so they need a spacious cage. They will also escape from the house if there is no cage. Please also prepare flooring materials. We recommend using natural materials such as wood chips and grass.

Toilet/Toilet sand

Toilets and litter are also required. Deodorant sand made specifically for small animals is preferable.

birdhouse

A hive is a must. Chipmunks tend to live in nests. I need a safe haven. Chipmunks hibernate when it gets cold, so make sure you have warm gear as well.

pet food

Feed your squirrel or hamster food specifically for squirrels and hamsters. You will also need a water bottle. It is easy to use one that can be fixed to the cage.

perch

You will also need a perch. Chipmunks have a habit of chewing on wood to sharpen their ever-growing teeth. Commercially available gnawing wood is recommended.