The blue whale is the largest animal ever known to have existed on Earth. Found in all oceans except the Arctic, its elongated body and broad, U-shaped head give it a streamlined, majestic presence. Its mottled skin, a blend of light and dark grey patches, appears slate blue on overcast days and shimmers silvery turquoise under bright sunlight. The dorsal fin, located far back on the body, is small and varies in shape, while their long, blunt flippers are slate grey with white undersides. These features, combined with their immense size, make blue whales unmistakable in the wild.
Credit: Igor Francetic
Quick Blue Whale Facts
| Scientific name | Balaenoptera musculus |
| Length | Up to 30m (up to 100 ft) |
| Weight | Up to 145 tonnes (160 tons) |
| Population | 10,000 – 25,000 individuals |
| Species Conservation Status | Endangered |
Diet and Behaviour
Blue whales are filter feeders, consuming vast quantities of krill, tiny shrimp-like creatures that form the foundation of their diet. Occasionally, they may also ingest small fish and copepods. Using baleen plates in their mouths, they trap prey and expel seawater in a single, powerful motion.
These whales are typically solitary or travel in pairs, though small groups are sometimes observed. During summer, they feed in polar waters, undertaking long migrations to equatorial regions as winter approaches. Their spouts, tall, dense columns reaching up to 12 metres, are a breathtaking sight for observers at sea.
Breeding and Conservation
Despite their size, much about the blue whale’s life cycle remains a mystery, although it’s believed that gestation lasts around 10 to 12 months, with calves born in warmer waters. Blue whales can live up to 80 or 90 years, though their populations were severely reduced by industrial whaling.
Since gaining international protection in 1966, blue whales have shown signs of recovery, particularly in the Southern Ocean. However, they remain endangered, and sightings in Antarctic waters are a rare and humbling experience.
Blue Whale FAQs
Where can blue whales be found?
Blue whales are found in all major oceans except the Arctic. They typically feed in polar waters during summer and migrate to warmer, equatorial regions in winter to breed and give birth.
How big is a blue whale?
Blue whales are the largest animals ever known to have lived on Earth. They can reach lengths of up to 30 metres and weigh as much as 180 tonnes, roughly the size of a Boeing 737.
Are blue whales endangered?
Yes. Blue whales were hunted to near extinction during the 20th century. Although protected since 1966, they remain endangered, though some populations, particularly in the Southern Ocean, are showing signs of recovery.
How do blue whales communicate?
Blue whales produce low-frequency vocalisations that can travel hundreds of kilometres underwater. These calls are believed to help them navigate, locate prey, and communicate with other whales.
