Blue whale Facts

About the blue whale

A blue whale can measure 29.9 to 30.5 m (98 to 100 ft) and weigh up to 190 to 200 metric tons. Its long, slim body is grayish-blue on top and somewhat paler below. Four subspecies are recognized across the North Atlantic, North Pacific, Southern Ocean, Indian Ocean and South Pacific, and a population off Chile may be a fifth. Most populations travel between summer feeding grounds near the poles and winter breeding areas near the tropics.

Krill is almost the whole diet, strained from the water by filter feeding. Blue whales usually travel alone or in small groups, and the only firm social tie is between a mother and her calf. Their calls sit at a fundamental frequency of 8 to 25 Hz and can shift by region and season, and by behavior or time of day. Whalers hunted them almost to extinction before the International Whaling Commission banned blue whale hunting in 1966.

Did you know?

• Blue whales were plentiful in nearly all of Earth's oceans before the 19th century ended.
• The pygmy blue whale, B. m. brevicauda, lives in the South Pacific and Indian Ocean.
• The blue whale belongs to the rorqual family, Balaenopteridae.