What kind of animal is a beluga whale? An updated explanation of its characteristics, ecology, and habitat. A dolphin you can see at the aquarium.

What kind of animal is a beluga? We will explain its characteristics, ecology, and habitat. This dolphin has white flesh and is found mainly in the Arctic Ocean. This species is the only one that makes up the genus Beluga. This dolphin is very familiar to humans, so we will introduce it to you.

What is a Beluga? Basic Status

Belugas are marine mammals classified as part of the Mammalia class, Artiodactyla order, Family Narwhalidae, Genus Beluga. They are very large dolphins, with a body length of 3-5m and a weight of 0.5-1.5t. Their scientific name is Delphinapterus leucas, and their English name is Beluga. The kanji for Beluga is “White Sea Pig”. The list of information is as follows.

Japanese（和名）	シロイルカ
English（英名）	Beluga White whale
scientific name(学名)	Delphinapterus leucas
classification（分類）	Mammalia、Artiodactyla/Cetartiodactyla、 Monodontidae、Delphinapterus 哺乳綱、偶蹄目、イッカク科科、シロイルカ属
IUCN Status(保全状況)	LEAST CONCERN
Length（体長）	3-5m
Weight（体重）	0.5-1.5t

What are the roots and origins of the beluga whale?

The roots of the beluga whale (scientific name: Delphinapterus leucas) trace back to cetaceans that evolved from primitive artiodactyls—land-dwelling mammals related to modern hippopotamuses—approximately 50 million years ago. The direct ancestors of the beluga itself belong to the Monodontidae family, a group of toothed whales (odontocetes) that adapted to the Arctic environment.

Origins leading to the whale

Approx. 50 million years ago: From land mammals to the sea

Their ancestors were small land mammals (of the artiodactyl lineage) that lived in the region of present-day India and Pakistan.

Evolutionary progression:

Land mammals
↓
Semi-aquatic primitive whales (e.g., Pakicetus)
↓
Fully aquatic cetaceans
↓
Toothed whales (e.g., dolphins, sperm whales)
↓
Monodontidae family (beluga whales, narwhals)
↓
Modern beluga whale

This is the evolutionary path they followed.

The beluga’s ancestors: The Monodontidae family

Although belugas resemble dolphins, their classification is somewhat unique.

Classification:

Order: Cetartiodactyla

Suborder: Odontoceti (toothed whales)

Family: Monodontidae

Genus: Delphinapterus

There are only two extant species in the Monodontidae family:

Beluga whale

Narwhal

These two species are very closely related and diverged from a common ancestor.

Reasons for evolving in the Arctic environment

From approximately 10 million years ago onwards, the ancestors of the beluga whale expanded into the waters of the Northern Hemisphere as the climate grew colder. Thus, they evolved adaptations for the Arctic environment, such as:

White body color

→ Camouflage in icy, snowy environments
→ Turning pure white upon reaching adulthood

Absence of a dorsal fin

→ To facilitate swimming beneath the ice

Thick fat (subcutaneous fat)

→ To maintain body temperature in freezing waters

Flexible neck

→ To search for food among the ice and in shallow waters

Ancient ancestors of the beluga whale

The fossil record identifies ancient members of the family Monodontidae—such as Denebola brachycephala (dating back approximately 9–10 million years to the Miocene epoch) and Bohaskaia monodontoides (dating back approximately 3–5 million years to the Pliocene epoch)—as ancestors leading to the modern beluga whale.

These species were smaller than modern belugas and were not yet as highly specialized for the Arctic environment.

Beluga whale taxonomy

• 界（Kingdom）: 動物界 (Animalia)
• 門（Phylum）: 脊索動物門 (Chordata)
• 綱（Class）: 哺乳綱 (Mammalia)
• 目（Order）: 鯨偶蹄目 / 鯨目 (Cetacea)
• 亜目（Suborder）: 歯鯨亜目 (Odontoceti)
• 科（Family）: ハクジラ科 (Monodontidae)
• 属（Genus）: シロイルカ属 (Delphinapterus)
• 種（Species）: シロイルカ (Delphinapterus leucas)

Habitat

Beluga whales can be seen widely in the Arctic Ocean. They are found in Hudson Bay, Greenland, the north coast of Iceland, and the north coast of Norway.

1. Main Habitat

Coastal waters around the Arctic Ocean

Northern Canada (Hudson Bay, Churchill River Estuary)

Northern Alaska (Bering Sea, Chukchi Sea)

Northern Russia (Laptev Sea, Chukotka Sea, around the mouth of the Ob River)

Greenland Coast

Estuarine, Bay, and Shallow Water

In summer, they gather in estuaries and bays to breed and raise their young.

In winter, they migrate along the edge of pack ice to search for food.

2. Habitat Characteristics

Water Temperature: Adapted to cold regions (approximately -2°C to 10°C)

Relationship with Sea Ice: Their rounded body shape, lacking a dorsal fin, allows them to swim easily under ice.

Estuarine and Shallow Water: Young animals often grow up safely in shallow water.

Migration: Seasonal coastal migration (estuaries and bays in summer, the edge of sea ice in winter).

3. Highlights

Beluga whales sometimes enter freshwater.

Populations have been observed temporarily entering rivers in Alaska and Canada.

Plants live in relatively small to medium sizes (10-50 individuals).

They migrate flexibly depending on feeding grounds and ice conditions.

What are its characteristics? What kind of creature is it?

Beluga whales are large dolphins that come from the Arctic Ocean. They are pure white and have no dorsal fin. They have a fatty tissue called melon in the front of their heads. They use the melon to communicate with each other and for echolocation, generating sound waves by vibrating the back of their nasal cavity. Unlike other toothed whales, melons can change their shape at will. Their heads are small and their pectoral fins curl upward as they age. They are called the “canaries of the sea” because their cries sound like small birds.

1. Physical Characteristics

Body Color: Adults are pure white. Juveniles are gray or bluish-gray, turning white as they mature.

Body Shape: Rounded, streamlined, and lacks a dorsal fin.

The lack of a dorsal fin allows them to swim easily under drifting ice.

Body Length and Weight:

Males: Approximately 4-5 m, Females: Approximately 3-4 m

Weight: Approximately 1,000-1,600 kg

Head: A round, soft “melon” emits sound waves (echolocation).

Mouth: Because it appears to be smiling, it is sometimes called the “sea canary.”

2. Behavior and Personality

Highly Social

Live in small to medium-sized groups (approximately 10-50 individuals)

Communicate with each other using calls and clicking sounds.

Curious

May approach boats and humans.

Playful

Jumps on the water surface and splashes with their tail fin.

3. Biological Characteristics

Diet: Fish (cod, salmon, etc.), squid, and crustaceans

Reproduction: Gives birth to one baby at a time

Gestation Period: Approximately 14-15 months

Raising is dominated by the mother, but they sometimes cooperate in groups

Adaptability

Body shape allows them to swim under drifting ice

They can safely raise their young in estuaries and shallow waters

What is their personality like?

Beluga whales are very social animals that value discipline. They are usually seen in groups. However, they often act alone. They are curious but also fearful, so they behave favorably towards humans.

1. Sociable

Live in small to medium-sized groups (approximately 10-50 individuals)

Communicate with each other using vocalizations and clicking sounds

Mothers and their young form strong bonds, and the entire group sometimes helps raise their young.

2. Inquisitive

Interested in boats, people, and objects

They often play on the water or sea ice, and may approach observers.

They are nicknamed “sea canaries” because of their vocalizations and playful nature.

3. Playful

Jumping on the water, splashing with their tails, and chasing each other.

Young individuals learn hunting and social skills, especially through play.

4. Gentle but cautious

Generally not aggressive

Quickly avoids perceived danger, such as boats or predators.

What is their ecology like?

Beluga whales live by eating fish, crustaceans, invertebrates, etc. Mating occurs from February to May and the gestation period is about 14 months. They can give birth to one baby at a time and can live for 30-40 years in the wild. Males reach sexual maturity at 8 years old and females at 5 years old. There is a 2-year gap between births.

1. Habitat

Coastal areas, estuaries, and bays around the Arctic Ocean

Northern Canada (Hudson Bay, Churchill River Estuary)

Northern Alaska (Bering Sea, Chukchi Sea)

Northern Russia (Laptev Sea, Chukotka Sea, Ob River Estuary)

Relationship with Pack Ice

Without a dorsal fin, their rounded body shape allows them to swim easily under the ice.

In winter, they search for food by moving along the edge of the sea ice.

Estuarine and shallow waters

Suitable for rearing and breeding young.

2. Diet

Mainly fish (cod, salmon, haddock, etc.)

Also eats squid and crustaceans.

Predation Method: They sometimes herd and hunt fish in schools.

3. Social and Behavioral Characteristics

Public Life: Small to medium-sized groups of 10-50 individuals

Communication: Communicate using clicks and whistling calls

Swimming Behavior: Jumping on the water surface and splashing with their tail fins

Migration: Move between coastal areas and the sea ice edge depending on the season

4. Reproduction and Rearing

Gestation Period: Approximately 14-15 months

Birth: One calf at a time

Rearing: The mother takes the lead, but the entire pack protects the young

Growth: Within a few years, the young reach adult size and learn to hunt and live in groups.

Do they have any natural enemies?

The biggest threat to beluga whales is the killer whale. When they are in danger, they use their melons to warn their companions of the danger.

About Diving

Beluga whales possess a highly advanced diving system that evolved to enable survival in the icy waters of the Arctic. Among the dolphin family, they are a species specifically adapted to shallow-water and under-ice environments.

Maximum Diving Depth

Recorded dives exceeding approximately 700 meters exist.

Typical dives range from a few tens to a few hundred meters.

However, belugas are not deep-sea hunters; they primarily forage along continental shelves and in coastal areas, so they do not usually dive to extreme depths.

Dive Duration

Typical: Around 5–10 minutes

Long dives: Over 15 minutes

They lack the ability to stay submerged for nearly an hour, unlike deep-diving whales such as sperm whales.

This is because belugas employ a different hunting strategy.

Belugas…

…repeatedly perform short dives while searching for prey such as:

Cod

Herring

Squid

Shrimp and crabs

Small crustaceans

① Muscles that store large amounts of oxygen

Beluga muscles contain high levels of a protein called…

…myoglobin,

…which stores oxygen.

The concentration is far higher than in human muscles,

…enabling muscle activity during dives

…and efficient oxygen use when the heart rate slows down.

② Diving reflex

Upon entering the water, the body automatically triggers a response that:

Lowers the heart rate

Concentrates blood flow to vital organs

Reduces oxygen consumption

Oxygen is preferentially supplied to the…

…brain

…and heart.

③ Flexible ribcage

When diving deep, belugas can…

…strongly compress their lungs.

This serves to:

Prevent excessive nitrogen from dissolving into the blood

Reduce the risk of decompression sickness

About Their Vocalizations

Beluga whales produce an exceptionally diverse range of sounds—so much so that they are known as the “Canaries of the Sea.”

Types of Beluga Vocalizations

Belugas are believed to use dozens of different types of sounds.

Common examples:

“Pip-pip” clicking sounds

(Click sounds)

Purpose:

Echolocation

Checking surrounding terrain

Locating fish

They emit ultra-fast sound waves and use the returning echoes to determine:

Distance

Size

Shape

Movement

“Q-q” or “Gyu-gyu” sounds

(Whistle sounds)

Purpose:

Communicating with others

Calling out

Maintaining the pod

These serve a function similar to humans calling each other by name.

High-pitched, bird-like sounds

These are characteristic sounds of the beluga whale.

In settings like aquariums,

Bird chirps

Children’s laughter

Electronic sounds

…are some of the things they can sound like.

This is why they earned the nickname

“Canaries of the Sea.”

How do they produce sound?

They do not have vocal cords like humans do.

Belugas use

A sound-producing organ (phonic lips)

Located deep within their nasal passages.

The process:

Air moves from the nasal passages

The phonic lips vibrate

Sound is focused by the “melon” (the rounded organ on the forehead)

Sound is projected into the water

…this is the mechanism involved.

Do they “converse”?

Yes, they do.

Belugas are highly social animals,

Engaging in complex vocal exchanges with

Mothers and calves

Pod members

Mating partners

Calves, in particular, may possess

A unique vocalization (signature whistle)

To identify their mothers.

This functions much like a “name” among dolphins.

Seasonal Activities

Beluga whales are animals that significantly alter their habitats, behaviors, diets, and herd structures depending on the season. In the Arctic region particularly, changes in sea ice dictate their annual life rhythm.

Spring (March–May): Ice begins to melt; the season for moving north

Key activities:

Begin migrating from wintering grounds

Travel north using leads (cracks in the sea ice)

Herds grow larger

During winter, belugas avoid areas where the sea is completely frozen,

Bering Sea

Chukchi Sea

Waters around Norway

…spending the season in areas with relatively little ice.

As the sun returns and the ice begins to break up in spring,

a massive migration involving hundreds to thousands of whales

begins.

Summer (June–August): The most active season

Summer is the most important time of year for belugas.

① Gathering in estuaries and shallow waters

Well-known gathering spots include:

Estuaries in northern Canada

Cook Inlet, Alaska

Coasts of the Russian Arctic

Purposes:

Molting (shedding skin)

In summer, belugas rub their bodies against shallow sandy or pebbly seabeds.

This serves to:

Shed old skin

Condition new skin

② Birthing season

Summer is the season for raising calves.

Gestation period:

Approximately 14–15 months

Birth:

Mainly June–August

Newborn calves are characterized by:

Gray to blue-gray coloration

Turning white over the course of several years

Mothers nurse their calves for about two years.

③ Feeding heavily

Food is abundant in summer.

Diet:

Cod

Salmon

Herring

Squid

Shrimp

They build up fat reserves in preparation for winter.

Autumn (September–November): Moving south and preparing for winter

As temperatures drop and sea ice expands again,

they migrate south from the Arctic. Activities:

Moving between feeding grounds

Traveling long distances in pods

Storing fat

Beluga whales feed particularly actively in the autumn.

Since food sources dwindle in winter,

a thick layer of fat (ranging from several centimeters to over ten centimeters)

becomes crucial.

Winter (December–March): A season of survival in icy waters

Winter presents the harshest conditions.

They utilize:

the edge of the sea ice

cracks in the ice

open water areas (polynyas)

Because beluga whales lack a dorsal fin,

they can easily swim beneath the ice

and surface to breathe through cracks in the ice.

Swimming Speed

Beluga whales are not high-speed hunters; rather, they are “low-speed, high-maneuverability” whales that move freely through icy waters.

Normal Speed

Approx. 2–6 km/h

They swim at this leisurely pace during routine movement or when swimming in a pod.

Purposes:

Maintaining distance from other pod members

Foraging for food

Exploring beneath the ice

Cruising Speed ​​(Long-distance travel)

Approx. 5–10 km/h

During seasonal migrations, they travel hundreds to thousands of kilometers, swimming at a pace that conserves energy.

During northward migration in spring/summer

and southward migration in autumn,

they travel over the course of days to weeks,

moving as a pod.

Top Speed

Approx. 20–25 km/h

They can reach high speeds temporarily to avoid danger or pursue targets.

Examples include:

Escaping from orcas

Chasing prey

Rapidly approaching other pod members

About Baby Beluga Whales

To take a closer look at baby beluga whales (Delphinapterus leucas), their appearance, behavior, and lifestyle differ slightly from those of adult whales.

1. Physical Characteristics

Body Length: Approximately 1.2 m at birth

Weight: Approximately 80-100 kg

Body Color: Gray to blue-gray, turning white as they grow

Head and Dorsal Fin: Their rounded head and lack of a dorsal fin are the same as those of adults

2. Behavior and Personality

Dependent on Their Mother

For about a year after birth, they swim alongside their mother, protecting them from food and danger.

Playful

Jumping on the surface of the water and splashing with their tail fin and body

Playing games with their packmates

Learning Behavior

They learn how to catch food and the rules of the pack by observing the behavior of their mother and the pack.

3. Biological Features

Diet: Breastfed for the first few months

Weaning: Begins eating fish at around 6-12 months

Growth Rate: Reaches near adult size in 1-2 years and is able to participate in pack activities

Dangers: Young animals are sensitive to drifting ice, shallow waters, ships, and predators, making them at high risk

Are beluga whales an endangered species?

Beluga whales are not endangered when viewed as a whole. However, the population in Cook Inlet has drastically decreased due to whaling. More than 2,000 whales are hunted annually throughout the Arctic, which is a very critical situation. There are also concerns about a decrease in the population due to changes in water temperature. In 1979, they were listed as an endangered species in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Environmental destruction caused by the installation of pipelines and the construction of dams for hydroelectric power generation has become a problem.

1. International Union for Conservation of Nature (IUCN) Assessment

Beluga whales as a whole

Rated “Least Concern” on the IUCN Red List

The population is considered relatively stable throughout the Arctic.

Regional Populations

Some populations in Alaska and Canada are locally vulnerable due to impacts from fishing, shipping, and pollution.

Some populations in the Russian Arctic have been reported to be declining due to mining development and pollution.

2. Reasons why they are not endangered

Distributed along the wide Arctic coast.

Living in groups, with a relatively stable reproductive rate.

Their only natural predators are killer whales and large sharks, and they are stable in areas without human impact.

3. Caution

Reduction of sea ice due to global warming may affect beluga whale habitats and prey resources.

Populations that gather in estuaries and bays are vulnerable to shipping and water pollution.

Can beluga whales be kept as pets?

Beluga whales are an endangered species and cannot be kept by the general public. If you are looking for them, we recommend visiting an aquarium or other place to view them and getting guided or guided at events. The performances of beluga dolphin shows and play are popular. You can also purchase illustrations, photos, and goods such as stuffed animals at the store. They are noteworthy for their diverse expressions and large size. You can also observe bubble rings, where beluga whales blow ring-shaped bubbles.

1. Legal and Conservation Issues

Beluga whales are Arctic wildlife, internationally listed under Appendix II of the CITES, and international trade is strictly restricted.

Even in Japan, capturing and keeping wild beluga whales is prohibited by law.

Only individuals with special permission can be kept in aquariums or research facilities.

2. Ecological and Breeding Environment Issues

Large water area required: They live in vast environments along the coasts and estuaries of the Arctic, making them impossible to recreate at home.

Water temperature control is difficult: They are adapted to cold water temperatures (-2°C to 10°C), and maintaining them in an artificial environment requires highly advanced equipment.

Highly social: They live in groups, so keeping them alone is stressful.

Diet: They require large amounts of fish and crustaceans, and their feeding behavior requires training.

3. Aquarium Breeding

Only kept in specialized facilities worldwide.

Only a few aquariums in Japan can observe them.

Breeding requires large pools, low water temperature control, veterinarians, and specialized staff.