Blue Whale

Scientific Name:
Balaenoptera musculus
21-27.5 m (70-90 ft)
90,000-136,000 kg (200,000-300,000 lbs)

Physical characteristics

Blue-gray coloration mottled with light gray. Long and streamlined bodies; small dorsal fins; long and thin pectoral flippers.

Behavioral characterization

Known to display a range of behaviors: breaching, blowing, pectoral flipper slapping, tail slapping, spy hopping, head slapping, "peduncle throw," and "peduncle arch." They fluke often because they have to dive so deep.


Found in every ocean across the world.

Population size



Humans and occasionally orcas

Migration/Dispersal patterns

The population off the California coast, migrates to Mexico and Costa Rica. Has summer/winter migration patterns in most areas of the world. In California, they spend the summers feeding in Monterey Bay, the Channel Islands, and the Farallon Islands,

Social system/Group size

Travel individually or in small groups.

Major threats

Vessel strikes and fisheries. Possibly noise pollution, resource competition, habitat degradation, and vessel disturbance. Whaling used to be a problem.

Research efforts

Aerial surveys in Australia are performed to show blue whale habitat and distribution. They are used to to investigate habitat choice for krill and photo-IDing of whales.

Fun fact

Largest animal in the world, has the heart the size of a small car.