What kind of animal is a brown bear? An updated explanation of its characteristics, ecology, and habitat

What kind of animal is the brown bear that lives in America, Europe, Hokkaido, etc.? We will introduce and explain its characteristics, ecology, and habitat. Brown bears are widely distributed in the Northern Hemisphere and live in a variety of natural environments. However, because they are larger than humans, they may attack humans, so you need to be careful.

What is a brown bear? About basic status

Brown bears are mammals that belong to the bear family. I feel like it’s a brown fox, a scarlet bear, or a hikuma. In English, it is also called grizzly bear. The scientific name is Ursus arctos. They are 2-3 meters long and weigh 100-300 kg, making them larger carnivores than humans. The information is listed below.

Japanese（和名）	ヒグマ
English（英名）	Brown bear、Grizzly bear
scientific name(学名)	Ursus arctos
classification（分類）	Mammalia、 Carnivora、 Ursidae、Ursus 哺乳綱、食肉目、クマ科、クマ属
IUCN Status(保全状況)	LEAST CONCERN
Length（体長）	2-3m
Weight（体重）	100-300kg

What are the roots and origins of the brown bear?

Tracing the roots of the brown bear (Ursus arctos) leads back to ancient bears that inhabited the Eurasian continent millions of years ago.

Origins

Current research suggests that the ancestors of the brown bear emerged in Eurasia approximately 800,000 to 1.2 million years ago.

Their direct ancestor is considered to be

the Etruscan bear (Ursus etruscus).

The Etruscan bear lived across a range extending from Europe to Asia between approximately 5 million and 1 million years ago.

Groups that evolved from this species

branched out into modern bear species, such as

brown bears,

polar bears, and

American black bears.

Evolutionary Timeline

The general lineage is as follows:

Approximately 20 million years ago

Early ursids (bear family members)

⬇

Approximately 5 million years ago

Etruscan bear

⬇

Approximately 1 million years ago

Brown bear (Ursus arctos) emerges

⬇

Subsequently,

they spread widely across

Europe,

Siberia,

Northern China,

Japan, and

North America.

Roots of Brown Bears in Japan

The brown bears inhabiting Hokkaido did not, in fact, arrive in a single migration event.

During the Ice Age, sea levels were more than 100 meters lower than they are today, creating land bridges that connected Hokkaido to the continent and Sakhalin.

DNA analysis has revealed that, during this era,

brown bears of different lineages migrated to Hokkaido on multiple occasions—

approximately 160,000 years ago,

70,000 years ago, and

over 10,000 years ago.

Consequently, multiple genetic groups exist within the Hokkaido brown bear population.

Expansion into North America

Between approximately 70,000 and 100,000 years ago, brown bears crossed the Bering Land Bridge (the site of the modern-day Bering Strait) into North America.

They subsequently

expanded their range into

Alaska,

Canada, and

the western United States.

The massive Kodiak bear is also a population that evolved from this North American lineage.

About classification

There are several subspecies of the species, so check them out when you have time. They are also being studied in some areas. They are not found in some areas because they are extinct.

名前	Name	Scientific Name (学名)
ハイイログマ（灰色熊）	Grizzly bear	Ursus arctos horribilis
コディアックヒグマ	Kodiak bear	Ursus arctos middendorffi
エゾヒグマ（蝦夷羆）	Ezo brown bear	Ursus arctos yesoensis
ヒマラヤヒグマ	Himalayan brown bear	Ursus arctos isabellinus
メキシコハイイログマ	Mexican grizzly	Ursus arctos nelsoni
カリフォルニアハイイログマ	California golden bear	Ursus arctos californicus
カムチャッカオオヒグマ	Bergman’s Bear	Ursus arctos piscator
マルシカヒグマ	Marsican brown bear	Ursus arctos arctos

Ursus arctos horribilis

Grizzly bears are also known as American brown bears. The largest specimens are said to weigh more than 450 kilograms, and are so large that they can chase prey at speeds of 48 km/h, which is quite astonishing. The subspecies as a whole is classified as “endangered” in the United States and “of special concern” in Canada.

Ursus arctos middendorffi

The Kodiak brown bear is also known as the Alaskan brown bear. Females weigh between 180 and 315 kg, and males between 270 and 635 kg. It is an extremely large bear, reaching a height of 3 meters when the male stands on his hind legs. The population in 2005 was 3,526, and the estimated population is increasing.

Ursus arctos yesoensis

Ezo brown bears are distributed in the forests and fields of Hokkaido. It is large, reaching 2-3 meters in length. They are good at being independent and are active day and night. Ezo brown bears are being exterminated and are now designated as an endangered species.

Ursus arctos isabellinus

The Himalayan brown bear, also known as the Himalayan red bear or Isabeline bear, is a subspecies of brown bear that lives in the western Himalayas. It is the largest mammal in this region. Males are 1.5 to 2.2 meters long and brown in color. It is also listed in the Washington Convention.

Ursus arctos nelsoni

The Mexican grizzly bear is a subspecies that lived from Mexico to the United States, but is now confirmed to be extinct. The Mexican grizzly bear was thoroughly exterminated as a pest.

Ursus arctos californicus

The California grizzly bear is a bear that lived in California. The body color was brown, the body length ranged from 1.8m to 3m, and the weight ranged from 130kg to 680kg. However, it became extinct due to hunting for its fur.

Ursus arctos piscator 

The Kamchatka brown bear lived on the Kamchatka Peninsula in Russia. However, in 1920, complete extinction was confirmed.

Ursus arctos arctos

The Marsican brown bear is also known as the Apennine brown bear, or in Italian, Orso Bruno Marsicano. It is a European brown bear and is protected in Italy’s Abruzzo National Park, Lazio Emolise. This bear is designated as an endangered species.

Where is its habitat?

Brown bears are found mainly in the Americas, but are also distributed in Japan (Honshu) and Europe.

Brown Bear Habitats in Japan

In Japan, brown bears are found in Hokkaido and parts of Honshu.

Hokkaido Brown Bear (Ursus arctos)

Mainly in the mountainous and forested areas of Hokkaido.

Living mainly in forests and along rivers.

Scattered throughout Hokkaido, but particularly common in the mountainous areas of northern and eastern Hokkaido.

Honshu Brown Bear (Different from Asiatic Black Bear)

Mountainous areas north of central Honshu (Iwate, Akita, Nagano, etc.).

Honshu brown bears are extremely rare and are sometimes designated as endangered.

Although it is easy to confuse the two, Honshu is primarily home to Asiatic black bears, while Honshu brown bears are found in very limited areas.

Brown Bear Habitats Around the World

Brown bears are distributed widely around the world.

North America

Alaska, British Columbia, Canada, and the Rocky Mountains, among other areas.

Europe

Scandinavian Peninsula and forested areas of western Russia.

Asia

Siberia, Mongolia, northern China, etc.

Environmental Requirements:

Prefers forested and mountainous areas.

Gathers along rivers and in areas with abundant berries, where food sources are abundant.

Needs a safe place, such as a hole or cave, to hibernate during the winter.

feature is? What kind of creature is it?

Brown bears have a sturdy and sturdy physique, and are characterized by being larger than humans. There are differences in the color of the body hair depending on the population. They also tend to be solitary, preferring to live in forest areas.

1. Physical Characteristics

Size:

Male: Approximately 1.8-2.8m in length, weighing 100-400kg (some Hokkaido brown bears can weigh over 500kg)

Female: Smaller than males, weighing approximately 50-200kg

Fur Color:

Brown to dark brown (varies slightly by region and season)

Hokkaido brown bears have thick fur, and are covered in thick fur in winter

Face:

Sturdy, round face with a pointed nose

Small eyes and small ears

Limbs:

Thick, powerful limbs

Long, sharp claws on front paws (used for climbing trees and digging)

2. Ecology and Behavior

Diet: Omnivorous

Spring to Summer: Grasses, wild vegetables, berries, insects, fish

Autumn: Eat acorns and nuts to store fat for winter

Prey on small animals and deer as needed

Activity: Generally active day and night (tends to be nocturnal in areas with human activity)

Hibernation:

Hibernates in winter in Hokkaido and other cold regions

Sleep in dens, caves, and tree bases

Reproduction:

Give birth once every 2-3 years

Mother bears give birth to 1-4 cubs and raise them for 1-2 years

3. Personality and Behavior

Generally timid but highly aggressive

Often solitary and territorial

Very dangerous when guarding food or cubs

4. Appearance

Huge and sturdy, giving a powerful and imposing impression

Their fluffy fur makes them appear especially large in winter

They support their body with all four limbs and walk leisurely

What is your personality like?

Brown bears usually avoid people. Most of them are very cautious and tend to avoid people, but if they happen to encounter a human and provoke them, they become excited and often attack. They don’t like winter, so they tend to rest there.

1. Basic Personality

Timidity

Generally avoid humans.

Even if they encounter a human in the forest, they tend to flee first.

Highly Vigilance

Sensitive to smells and noises.

Very wary of anything approaching their territory or food source.

2. Aggression

Usually gentle, but can become aggressive under certain conditions.

Mother bears protecting their cubs are extremely dangerous.

Individuals weakened by injury or illness can also become aggressive.

They can also become aggressive in fights over food.

3. Sociality

Solitary behavior is the norm.

Males are particularly solitary.

Females tend to stay with their cubs.

Territorial.

Mark their territory with scent and claw marks.

4. Learning Ability/Intelligence

Intelligent Animals

Learns the location of food and danger.

Individuals that venture into human habitats may memorize the location of garbage and fish.

What is the ecology like?

Brown bears are omnivorous. In the wild, they eat a wide variety of foods, including fruits, nuts, acorns, plants, and even insects and fish. Depending on the time of year and location, they may cause damage to large agricultural crops in order to obtain nutrients. In winter, they hibernate in their dens. Brown bears reach sexual maturity at around 3 to 5 years of age and become able to breed. The breeding season is from May to July. Their lifespan is around 20 to 30 years.

1. Habitat

Living mainly in forested areas, mountainous regions, and along rivers

Living in vast forests and mountainous areas in Hokkaido, and limited mountainous areas in Honshu

Living mostly away from human habitations

2. Diet

Brown bears are omnivorous, and their diet changes depending on the season and region.

Spring: New shoots, wild vegetables, insects, and animal carcasses

Summer: Fruits, berries, and fish (such as salmon)

Fall: Eat nutritious plants like acorns and nuts to store fat in preparation for hibernation.

If necessary, they also prey on small animals and deer meat.

3. Behavior Patterns

Activity: Active day and night (tends to be nocturnal in areas with many people)

Hibernation: Hibernates in cold regions

Hibernates for approximately 3-5 months without food.

Sleep in dens, caves, and tree bases.

Migration: May travel extensively in search of food.

4. Breeding and Rearing

Breeding Season: Spring (April-May)

Birth: During hibernation (give birth to 1-4 cubs)

Rearing: Mother bear raises cubs for 1-2 years

Learns hunting and foraging skills alongside their mother

Cubs travel with their mother and depend on her until they become independent

5. Social Structure

Primarily solitary

Males sometimes fight over territory.

The strongest bond exists between mother bears and their cubs.

6. Intelligence and Learning

They have a high ability to remember the location of food sources and dangers.

Some individuals use garbage and fields in human habitations.

They behave flexibly according to the situation, employing unique strategies to find food.

Are there any natural enemies?

Brown bears are the largest bears on land and have no rivals. If I had to guess, it would be human. In the past, there was a history of people shooting at brown bears.

Brown Bear Vocalizations

Brown bears (Ursus arctos) rarely let out loud roars like lions; instead, they employ a variety of vocalizations and sounds depending on the situation. In fact, sounds other than vocalizations—such as snorting or teeth-clacking—serve as important means of communication.

Key Vocalizations

“Wooo!” / “Gaooo!” (Roar)

The most powerful vocalization, emitted during displays of aggression or actual attacks.

Heard during territorial disputes or when the bear is highly wary of humans or other animals.

Not frequently produced.

“Hoo!” / “Buf!” (Snort)

One of the most commonly heard sounds.

Indicates wariness, dissatisfaction, or a mild threat.

Can also be heard during encounters with humans.

“Grrrrr…”

A low growl.

Serves as a warning: “Do not come any closer.”

“Sniff-sniff”

A snuffling sound.

Often heard when the bear is exploring its surroundings while investigating scents.

“Kyu” / “Pee-pee”

Sounds made by cubs to call their mother.

Frequently heard when they are hungry or anxious.

“Moo” / “Uun”

A low, soft sound sometimes made by a mother bear to call her cubs.

Heard in calm situations.

Seasonal Activities

The activity patterns of brown bears (Ursus arctos) vary significantly by season. In Hokkaido, in particular, their behavior shifts distinctly in accordance with hibernation, breeding, and changes in food availability.

Season	Activity Details	Activity Level
Spring (Mar–May)	Waking from hibernation; foraging	★★★☆☆
Summer (Jun–Aug)	Wide-ranging movement; foraging & breeding	★★★★☆
Autumn (Sep–Nov)	Heavy feeding before hibernation	★★★★★
Winter (Dec–Mar)	Hibernation	★☆☆☆☆

🌸 Spring (March–May)

Waking from hibernation

They emerge from hibernation around March or April (timing varies by region and climate).

Males wake up first, while females and those with cubs wake up slightly later.

They may lose 20–40% of their body weight during the winter.

Diet

Butterbur (fuki)

Asian skunk cabbage (mizubasho)

Young grass

Tree buds

Deer/Ezo deer carcasses

Insects

As food is still scarce, they travel over wide areas to forage.

☀️ Summer (June–August)

The most active season

They may travel 10–30 km in a single day.

They roam widely across rivers, forests, and grasslands.

Diet

Berries

Ants

Bee larvae

Insects

Herbaceous plants

Young deer (fawns)

Fish (depending on the region)

Breeding season

The breeding season is from May to July.

Males may fight with one another.

Females may mate with multiple males.

🍂 Autumn (September–November)

The period of heaviest feeding

Known as the “hyperphagia” phase; they store vast amounts of energy in preparation for hibernation.

Diet

Acorns

Walnuts

Grapes

Wild grapes

Salmon (in areas with rivers)

Nuts/Tree fruits

They may consume over 20,000 kcal per day.

During this period, they may appear near human settlements, and the risk of encounters tends to increase.

❄️ Winter (December–March)

Hibernation

They hibernate in places such as:

Rock crevices

Beneath fallen trees

Burrows dug into the ground

Characteristics during hibernation

Body temperature drops by only a few degrees Celsius.

Heart rate decreases significantly.

They rarely excrete waste.

They are able to relatively maintain muscle and bone mass.

Birth

Pregnant females give birth to 1–3 cubs (rarely 4) around January or February while hibernating.

Newborn cubs are tiny, characterized by:

Weight: Approximately 300–500g

Eyes: Closed

Diet: Exclusively mother’s milk

Walking Speed

The walking speed of the brown bear (Ursus arctos) varies significantly depending on the situation.

Movement Speeds: Slow walk (approx. 3–5 km/h); Normal walk (approx. 5–8 km/h); Brisk walk (approx. 8–12 km/h); Running/Sprinting (short distance) (approx. 40–50 km/h; sometimes cited as up to 56 km/h).

Normal Walking

When foraging for food, they walk slowly at about 3–5 km/h.

When traveling long distances, they move at about 5–8 km/h and may cover tens of kilometers.

Running Speed

They accelerate rapidly when sensing danger or pursuing prey.

Top speed: Around 50 km/h.

There are reports of speeds reaching approximately 56 km/h under certain conditions.

They can generally maintain this speed only over short distances (around a few hundred meters).

This is faster than a human sprinter; it is virtually impossible for an average person to outrun them.

Capabilities by Terrain

Brown bears are not only fast but can also navigate various terrains with ease.

🏔️ Steep slopes: Capable of powerful climbing.

🌲 Forests: Move quickly while maneuvering around obstacles.

🏞️ Rivers: Strong swimmers; capable of swimming several kilometers.

❄️ Snow: Large paws prevent them from sinking too deeply.

About Brown Bear Cubs

This article summarizes the characteristics of brown bear cubs. They vary from birth to independence.

1. Birth

Time: Hibernation (January-February)

Location: A safe place such as the mother bear’s den, a cave, or the base of a tree

Weight and Size: Newborns are very small, weighing approximately 300-500g, with short, soft fur.

2. Growth

They feed on their mother’s milk (mother’s milk is highly nutritious).

They open their eyes within a few weeks of birth and become increasingly active.

Within a few months, their fur grows thick and their bodies grow rapidly.

3. Behavior

They rarely leave their den for about a month after birth.

While protected by their mother, they gradually become accustomed to the outside environment.

They learn how to forage and survive in the forest with their mother.

4. Until Independence

Rearing Period: They stay with their mother for 1-2 years.

They become independent around 1.5-2 years of age.

During this time, they learn how to hunt, find food, and avoid danger.

Are brown bears an endangered species?

Statistics show that the European brown bear, which is a subspecies of the brown bear, has decreased dramatically and is now an endangered species. Among them, the Marsica brown bear that we introduced is on the verge of extinction and can only be seen in a few areas of Italy. They also cause damage to areas where people live, so they have been exterminated as wild animals in the past. There are also fewer industries and volunteers to support.

1. Japan

Hokkaido Brown Bears

The population is considered stable (estimated at approximately 3,000-5,000 in Hokkaido).

Currently, they are not endangered.

However, there is a risk of habitat fragmentation due to habitat development and road construction, as well as traffic accidents.

Honshu Brown Bears (Rarely found outside of Hokkaido)

There are very few brown bears in Honshu, and they are at high risk of extinction.

The Ministry of the Environment may assess each regional population separately.

2. Global Situation

The brown bear (Ursus arctos) as a whole is classified as “Least Concern” on the International Union for Conservation of Nature (IUCN) Red List.

Global populations are relatively stable.

However, some regions have small populations and are at risk of extinction.

Examples: Brown bear populations in southern Europe and parts of Central Asia.

3. Conservation Status

In Japan, they are protected under the Wildlife Protection Act.

Because their feeding grounds and territories are sometimes threatened by human development, they are managed and public warnings are issued.

In Hokkaido, electric fences and warning signs have been installed to prevent damage from brown bears.

Can brown bears be bred?

Unless you are an experienced zookeeper, you cannot keep them as pets. They can attack and eat people, so it is very dangerous. If you come across one in the wild, the best thing to do is not to provoke it. If you want to see one, we recommend going to a zoo or other tourist spot and viewing the facility, where there will be guided tours. In recent years, due to changes in the environment, the Ministry of the Environment and organizations in Japan are also working to protect them.

1. Legal Status

In Japan, brown bears are designated as designated animals (Regulations on the Keeping of Designated Animals).

Designated animals are those deemed dangerous or rare and therefore cannot be kept without permission.

Keeping one requires permission from the prefectural governor, and the following conditions must be met:

Professional knowledge and facilities are required.

Safe enclosures, cages, and escape prevention devices are required.

Measures to prevent harm to the surrounding area must be in place.

2. Difficulties in Keeping Brown Bears

Because they are very large and powerful, inadequate cages and facilities pose a danger to humans and the surrounding area.

Securing food is difficult.

A balanced diet of large amounts of meat, fish, fruits, and vegetables is required.

Providing living space.

They live in mountainous areas and require a high level of exercise.

Small enclosures can easily cause stress.

3. In what circumstances are brown bears kept as pets?

Zoos and wildlife sanctuaries

Mainly kept for research, education, and conservation purposes

Managed by specialized animal care staff

Private ownership is nearly impossible

While there have been cases of private ownership in the past, it is extremely dangerous and almost always illegal