BLUE WHALE

Blue whales are the largest animals on earth. These gorgeous mammals rule the oceans. They can be up to 100 feet long and 200 tons in weight. Their tongues alone can weigh as much as an elephant. Their hearts can weigh as much as a car.

Blue whales reach these sizes on a diet composed of little shrimp-like animals called krill. During certain times of the year, a single adult blue whale consumes about 4 tons of krill a day.

Blue whales are baleen whales. This means they have plates of fingernail-like material, called baleen, attached to their upper jaws. These giant animals feed by first gulping an enormous mouthful of water. Then their huge tongue forces the water out through the thin baleen plates. Thousands of krill are left behind and then get swallowed.

Blue whales look blue underwater, but on the surface, they are blue-grey. Their underbellies are yellowish because of the millions of microorganisms which live on their skin.

Blue whales live in all the oceans, occasionally swimming in small groups but usually alone or in pairs. They often spend summers feeding in polar waters and migrate a long way towards the Equator as winter arrives.

These graceful swimmers cruise the ocean at a speed of more than five miles an hour, but they can swim faster, up to 20 miles an hour. They are among the loudest animals on the planet. They make sounds like a series of pulses, groans and moans, and it’s thought that, in good conditions, blue whales can hear each other from up to 1,000 miles away.

Scientists think they use these sounds not only to communicate but also to navigate.

Blue whales are among the Earth’s longest-lived animals. The oldest blue whale found was around 110 years old. Their average lifespan is estimated at around 80 to 90 years.

Aggressive hunting in the 1900s by whalers looking for whale oil drove the whales to the edge of extinction. Between 1900 and the mid-1960s, nearly 360,000 blue whales were killed. They finally came under protection with the 1966 International Whaling Commission, but they’ve managed only a minor recovery since then.