What kind of animal is the capybara? The latest information on its characteristics, ecology, and habitat. An animal with a surprising side.

What kind of animal is a capybara? We will explain its characteristics, ecology, and habitat. Capybaras are so large and fat that they look like pigs, but they are actually different. It’s actually a member of the rat family. They are widely active on the continent of South America, so they are one of the animals that are familiar to South Americans.

What is a capybara? About basic status

Capybara is a rodent that belongs to the Capybara family. The largest rat in the world. The body length is 106 – 134 cm and the weight is 35 – 64 kg. The scientific name is Hydrochoerus hydrochaeris. The list of information is as follows. Capybara is very popular in South America and events are held there. If you enter the zoo in a group, the animals will show you their swimming skills inside the zoo. She is often exposed at hot springs, capybara cafes, X (twitter), YouTube, etc.

Japanese（和名）	カピバラ
English（英名）	Capybara
scientific name(学名)	Hydrochoerus hydrochaeris
classification（分類）	Mammalia、  Rodentia、 Hydrochoerinae、Hydrochoerus 哺乳綱、齧歯目、テンジクネズミ科、カピバラ属
IUCN Status(保全状況)	LEAST CONCERN
Length（体長）	106 – 134cm
Weight（体重）	35 – 64kg

What are the roots and origins of the capybara?

The capybara (scientific name: Hydrochoerus hydrochaeris) is the world’s largest rodent—a relative of mice and rats—that evolved in South America. While they currently inhabit riverbanks and wetlands in South America, their ancestry dates back tens of millions of years.

Ancestors from the “Giant Rodent Lineage” of Africa

The group to which capybaras belong—the Caviomorpha (caviomorph rodents)—did not originally exist in South America; their ancestors are believed to have drifted over from Africa during the Late Eocene epoch (approximately 40 million years ago). The prevailing theory is that small rodents crossed the ocean—likely on floating vegetation—and subsequently underwent unique evolution in South America.

The general evolutionary progression is as follows:

Small African rodents
↓
Arrival in South America (approx. 40 million years ago)
↓
Evolution into Caviomorpha
↓
Emergence of the Hydrochoeridae family (capybara family)
↓
Modern-day capybara

The Era When the Hydrochoeridae Family Emerged

The Hydrochoeridae family—the direct lineage of the capybara—flourished during the Miocene epoch (approximately 23 to 5 million years ago).

Among the oldest known fossils of this family is Cardiatherium chasicoense, discovered in Argentina. This represents a type of capybara-like animal from over 10 million years ago.

Even during this era, characteristics typical of modern capybaras were already beginning to take shape, such as:

Increased body size

Adaptation to life near water

Herd-based social behavior

Ancient Capybaras Were Even Larger Than Modern Ones

While modern capybaras measure about 1 to 1.3 meters in length and weigh between 35 and 70 kilograms, their ancestors included even more massive species. A prime example is:

Josephoartigasia monesi

Lived approximately 2 to 3 million years ago

Estimated weight of over 700 kg

Considered one of the largest rodents known to have existed.

In other words, the evolutionary history of the capybara lineage runs from

“giant rodents” to “the modern capybara adapted to a semi-aquatic lifestyle.”

Why did they adopt a semi-aquatic lifestyle?

Capybara ancestors originally lived in forests and grasslands, but amidst environmental changes in South America, they adapted to life near the water in order to:

escape predators (such as jaguars and crocodilians)

utilize aquatic plants and soft vegetation

regulate their body temperature

As a result, they evolved into semi-aquatic animals characterized by:

slight webbing between their toes

strong swimming ability

nostrils, eyes, and ears positioned high on the head

the ability to remain submerged for extended periods

About classification

There is a subspecies of capybara called the lesser capybara.

Hydrochoerus isthmius

Capybaras are found in eastern Panama, northwestern Colombia, and western Venezuela. Its name is lesser capybara or Hime capybara. The Japanese capybara looks a lot like a capybara, but the adult Japanese capybara usually weighs about 28 kg, so it is a little smaller.

Capybara Taxonomy

階級	分類
界	動物界 (Animalia)
門	脊索動物門 (Chordata)
綱	哺乳綱 (Mammalia)
目	銃歯目 / 齧歯目 (Rodentia)
科	ケナガネズミ科 (Caviidae)
属	カピバラ属 (Hydrochoerus)
種	カピバラ (Hydrochoerus hydrochaeris)

About habitat

Capybaras can be found in South America.

Capybara Habitat

Main Distribution Areas

Distributed throughout Central and South America

Tropical and subtropical regions, including Brazil, Venezuela, Colombia, Argentina, and Paraguay

Habitat

Prefers wetlands centered around water

Rivers, lakes, marshes, swamps, and mangrove forests

Grains grass near water and uses areas where it is easy to swim

Environmental Conditions

Adapted to warm, humid regions

Rarely found in areas without access to water

Swimming underwater protects them from predators

Relationship with Humans

Can sometimes be found around farmland and along rivers in South America

In some cases, they are kept as pets or kept in zoos

feature is? What kind of creature is it?

Capybara is the largest living rodent. It has four fingers on its front legs and three toes on its hind legs, and has small webs between its toes, which allow it to swim. Their body hair is hard and long, and has the ability to shed water just by shaking their body. Capybaras usually live in grasslands and riverside areas.

Characteristics of Capybaras

Body Size/Shape

Body Length: Approximately 100-130 cm

Weight: Approximately 35-66 kg (large individuals can exceed 70 kg)

Stout body with short limbs

Rounded snout and rodent-like front teeth

Fur/Color

Fur color is brown to reddish-brown

Coarse fur and not very water-repellent

Some individuals exhibit slight color changes between summer and winter

Head/Face

Round face, large nose and eyes

Nostrils can be closed They have small ears, allowing them to adjust their breathing while swimming underwater.

They have small ears, making them well-suited to aquatic life.

Diet

Completely herbivorous: Grasses, aquatic plants, fruits, bark, etc.

Prefers plants that can be gathered near water.

Behavior/Personality

They often live in groups and are highly social.

They are good at swimming underwater and will dive to escape.

They are gentle and easily tame.

Ecological Characteristics

Specialized for aquatic life: swimming, diving, finding resting places, etc.

They often actively feed at night and early in the morning.

What is your personality like?

Capybaras are very gentle and gentle animals. Basically, capybaras live in groups rather than alone, so they are very social creatures. They often fall asleep and are very laid-back animals. They also do not like getting wet in the rain and tend to huddle together to regulate their body temperature.

Capybara Personality and Behavior

Gentle and gentle

Low-aggression, relatively friendly with other animals and humans

When threatened, they do not attack but instead take evasive action, such as fleeing into the water

Highly sociable

They live in groups and communicate with each other

Maintain social relationships through grooming and physical contact

Curious but cautious

They may show interest in their surroundings

They can also be cautious, quickly hiding when they sense danger

Pack order

They have a sense of hierarchy and territoriality within the pack

Dominant individuals may prioritize eating and resting areas

Relationship with humans

In captivity, they easily tame people and can be petted and interact with others

Their gentle nature makes them popular at zoos and petting centers

What is the ecology like?

Capybaras are herbivores, so their preferred food (meals) are pellets, cabbage, apples, and other fruits, vegetables, and grass. They are particularly big eaters, so be careful as food costs can be high. Even though they are the same giant guinea pig, they can grow large and eat a lot from morning to midday and into the night. There are now many exhibits of this species in Japan, so if you like them, be sure to check them out first.

Capybara Ecology

Habitat

Waterside grasslands and wetlands, such as rivers, lakes, marshes, and swamps, in Central and South America

They live in groups in areas with access to water

Waterside areas serve as bases for rest, refuge, feeding, and social activities

Diet

Completely herbivorous

Eats mainly grasses, aquatic plants, fruit, and tree bark

They often actively feed at night or early in the morning

Sociality/Pack Life

Highly social animals that live in groups

Pack sizes are typically around 10-20 individuals, but can grow to over 50

Dominant individuals maintain order in the group They have priority for eating and resting.

Relationship with Water

They are excellent swimmers and will enter the water to escape or rest.

They can also dive, allowing them to protect themselves from predators in the water.

Reproduction

Breeding occurs year-round, regardless of the season.

Gestation period: Approximately 150 days.

They give birth to 1-8 (usually 3-4) young at a time.

The young can walk immediately after birth, but grow up under the care of their mother.

Activity Pattern

Behavior patterns intermediate between diurnal and nocturnal.

They rest during the day, often near water, and forage during cooler times and at night.

Are there any natural enemies?

Capybaras are attacked by jaguars, pumas, etc. However, capybaras have a way of escaping into the water, and since they can swim, they often look for rivers when they escape.

About Molting

Capybaras are animals that undergo “molting,” a process where their fur changes according to the season. However, unlike dogs or cats that shed large amounts of fur at once, capybaras replace their fur gradually to suit their environment.

Characteristics of Capybara Fur

Capybara fur is:

Coarse, short, and stiff

Not particularly dense

Structured to dry quickly

While it may look fluffy at first glance, it is actually “functional fur” adapted for a semi-aquatic lifestyle.

Molting Season

Although it varies by region, capybaras generally molt according to this cycle:

Spring to early summer: Transition from winter coat to summer coat

Autumn: Transition from summer coat to winter coat

For wild capybaras in particular, the timing of the molt shifts based on factors such as temperature, rainfall, and daylight hours.

Why Do They Molt?

There are three main reasons:

① Body Temperature Regulation

Since capybaras live in hot regions, switching from a dense winter coat to a summer coat helps to:

Prevent heat from becoming trapped

Regulate body temperature while in the water

Conversely, during colder seasons, the fur becomes thicker to prevent a drop in body temperature.

② Adaptation to Aquatic Life

Capybaras are skilled swimmers that enter:

Rivers

Swamps

Wetlands

Molting allows them to shed old or damaged fur, thereby maintaining their ability to retain heat and dry off efficiently while in the water.

③ Maintaining Skin Health

Molting helps keep the skin clean by replacing:

Old fur

Fur coated in sebum (natural oils)

Soiled fur

Do Capybaras Groom Themselves?

Yes. Capybaras engage in behaviors such as:

Grooming the area around their faces with their front paws

Rubbing their bodies against objects

Grooming one another

Because they live in herds, mutual grooming serves several purposes:

Checking the condition of the fur

Removing insects or parasites

Facilitating social communication

About Diving

Although capybaras appear laid-back, they are actually semi-aquatic animals with exceptional adaptations for life in the water. When they sense danger or wish to escape the heat, they submerge themselves to hide.

How long can they stay underwater?

Generally, capybaras are known to:

Stay submerged for several minutes (around 5 minutes)

Remain hidden underwater for extended periods if necessary

They may submerge and wait quietly, particularly when evading natural predators.

Why are they able to stay submerged for so long?

① Nostrils, eyes, and ears are located on top of the head

This is the capybara’s most significant aquatic adaptation.

The parts that remain above the water’s surface—

eyes

nostrils

ears

—are positioned on the upper part of the head.

This structure allows them to:

Observe their surroundings while keeping the majority of their body submerged

This is an “ambush-style” aquatic adaptation similar to that of hippos and crocodiles.

② Ability to close their nostrils

They can close their nostrils when diving, preventing water from entering.

Underwater, they move safely by:

Holding their breath

Closing their nostrils

Submerging their bodies

③ Feet suited for swimming

Capybara feet feature:

Small webs between the toes on both front and hind feet

Powerful hind legs

These features enable them to:

Swim

Make sharp turns

Escape quickly from the water

About Capybara Vocalizations

While capybaras often give the impression of being very calm animals, they actually use a wide range of vocalizations to communicate with one another. Because they live in herds, communicating through sound is just as important as visual communication.

① High-pitched “pi-pi” sounds (Young capybara vocalizations)

These sounds are frequently made by young capybaras.

Functions:

Calling their mother

Checking the location of herd mates

Expressing anxiety

These sounds serve a purpose similar to a human saying, “I’m right here.”

② Low-pitched “purr-purr” or “kuk-kuk” sounds

These are typical communication sounds made by adult capybaras.

Situations where they are used:

Signaling herd mates

When feeling at ease

Interacting at close range

Even when close together, capybaras exchange information using these subtle vocalizations.

③ “Kyu” or “pi” alarm calls

These sounds are made when a capybara senses danger.

For example, they are used:

Upon spotting a predator

When an unfamiliar animal approaches

To alert the herd to danger

Hearing this sound puts the entire herd on alert.

④ Teeth grinding or clicking sounds

Capybaras communicate their intentions not only through vocalizations but also by making sounds with their teeth.

These sounds are particularly observed during:

Nervousness

Excitement

Establishing dominance hierarchies

Seasonal Activities

Since capybaras inhabit the warm wetlands, grasslands, and riverbanks of South America, their lifestyle rhythms are governed primarily by the shift between the rainy and dry seasons, rather than the four distinct seasons found in Japan.

Spring (End of the rainy season – a time of abundant vegetation)

Activity Level: ★★★★★

Spring is a season of plant growth, providing an abundance of food for capybaras.

Key Behaviors:

Actively grazing on grass

Moving across wide areas in herds

Intensified rearing of young

Frequent movement between waterside areas and grasslands

Diet:

They prefer nutrient-rich plants such as:

Tender grasses

Aquatic plants

Young leaves

Additionally, in areas where water levels stabilize after the rainy season, they spend more time swimming and bathing.

Summer (High-temperature period)

Activity Level: Low during the day; concentrated in the morning and evening

In the hot regions of South America, daytime temperatures soar during the summer.

Consequently, capybaras adopt the following lifestyle:

Active early in the morning

Active from evening through the night

Resting in water or shade during the day

Key Behaviors:

Increased bathing and diving

To cope with the heat, they engage in behaviors such as:

Entering rivers

Resting in swamps

Submerging their bodies in water

While in the water, they:

Regulate body temperature

Prevent skin from drying out

Evade predators

Autumn (Transition to the dry season)

Activity Level: ★★★★☆

As rainfall decreases, they adapt to the changing environment.

Changes:

Shifting their range of movement to center around water sources

Moving in search of edible plants

Strengthening herd bonds

In some regions, breeding activity is also observed during this period.

Males engage in behaviors such as:

Signaling via scent

Establishing dominance

Approaching females

Winter (Dry season – period of dropping temperatures)

Activity Level: ★★★☆☆

As capybaras are tropical and subtropical animals, they are not well-suited to extreme cold. Winter behavior:

They spend more time resting in sunny spots.

Activity levels decrease during the morning and evening.

They enter the water less frequently.

However, since their South American habitats do not get as cold as Japan, they do not hibernate.

About Walking Speed

While capybaras are often perceived as slow-moving animals, they are actually quite agile relative to their size. Although they usually walk at a leisurely pace, they are capable of running quickly and escaping into the water when they sense danger.

Normal Walking Speed

A capybara’s normal movement speed is estimated to be:

Approximately 2–4 km/h

This is comparable to the speed of a human taking a slow stroll (about 3–4 km/h).

In their daily lives, capybaras lead an energy-efficient lifestyle characterized by:

Walking while grazing

Moving alongside their companions

Traveling back and forth between the water’s edge and resting areas

Speed ​​When Hurrying

When sensing danger or fleeing, they can run at speeds of:

Around 30 km/h

This represents remarkable athletic ability for a large rodent weighing between 40 and 70 kg.

Escape behavior:

Detect danger
↓

Emit a short alarm call
↓

Move as a group
↓

Run toward the water
↓

Dive and submerge to hide

Characteristics of Their Gait

Unusual for a rodent, the capybara’s gait resembles that of a large mammal.

Characteristics:

Walks stably on four legs

Places the soles of the feet flat on the ground

Sways the body from side to side while moving

Capable of rapid acceleration over short distances

Due to their large size, their way of walking is closer to that of a small wild boar or a hippopotamus than a typical mouse or rat.

More Capable in Water Than on Land

Although capybaras can run on land, they have evolved primarily for a semi-aquatic lifestyle.

In the water:

Buoyancy reduces the burden of their body weight

They can generate propulsion with their hind legs

They can make sharp turns

Consequently, the water offers a greater advantage than land when escaping from natural predators.

About Baby Capybaras

Baby capybaras have unique characteristics in appearance, behavior, and growth.

Characteristics of Baby Capybaras (Juvenile Capybaras)

Size at Birth

Body Length: Approximately 30-40cm

Weight: Approximately 1-2kg

Covered in soft, brown downy fur

Behavior

Able to walk immediately after birth (to escape predators)

Live protected by their mother or herd

While drinking breast milk, they gradually begin to eat grass and aquatic plants

Growth Process

At one month of age, they begin to adapt to a herbivorous diet

At three to four months, they are almost completely weaned from their mother’s milk

By six months, their physique is quite close to that of an adult, and they have learned social behavior within the group

Sociality

Juveniles play with each other and observe the behavior of their parents and other adults

Learning rules and hierarchical relationships within the group

Defensive Behaviors

When sensing danger, they hide near their mother or herd

Fleeing into the water is also observed from an early age

Are capybaras an endangered species?

Capybaras as a whole are not an endangered species. However, the lesser capybara, which is a subspecies, is in a pinch. The possibility of extinction has been pointed out due to the destruction of mining forests, the drainage of swamps, and the extremely small habitat.

Conservation Status Details

International Assessment (IUCN)

Classification: Least Concern (LC)

Reason: Widespread distribution, stable population

Distribution and Population

Found throughout South America (Brazil, Venezuela, Argentina, Paraguay, etc.)

They form schools near rivers and lakes, where relatively large numbers have been observed.

Threats

Habitat development, wetland destruction, and hunting have had localized impacts.

However, there has been no significant impact on the overall population, and the species is not currently at risk of extinction.

Can capybaras be kept as pets?

Can you keep a capybara as a pet? There is a big hurdle: money. To buy a capybara, you will need to spend 700,000 to 1 million yen. Since capybaras are rare animals to keep as pets, the price is high, so it is not easy. Another key is whether you can find a veterinarian who will treat capybaras. They can display unexpected behaviors, so humans need to take good care of them.

What should I feed?

Capybaras are herbivores, so they like pellets, fruits, vegetables, and grass. They are especially big eaters, so be careful as food costs can be high. Even though they are the same giant guinea pig, they can grow large and eat a lot from morning to midday and into the night. There are many exhibits of this species in Japan now, so if you like them, be sure to check them out first.

Breeding space

Capybaras are the largest rodents in the world. They require a fairly large space to be kept. A bathing area is essential. If they are not exposed to water for a long time, their skin will dry out. They also need a toilet, a place to sleep, and a heater. Their fur continues to grow to keep them warm in the winter, so this care is also necessary.