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LET'S EXPLORE The animal kingdom

How do whales and dolphins live?

A humpback whale spyhoppingA humpback whale spyhoppingWhales, dolphins and porpoises make up a group of mammals called cetaceans. These animals live in the waters of the oceans all the time. They have no hair or fur on their bodies. Instead of four legs, they have a tail, called a fluke, and two flippers. Under their skins they have a thick layer of fat called blubber to keep them warm in cold waters. As air-breathing mammals, whales have to come to the surface of the water to breathe air. They breathe through the holes on top of their heads called blowholes. They have excellent hearing, but a poor sense of smell.

 

Whales

Blue whaleBlue whale

A grey whale and calfA grey whale and calf

Whales are the largest animals in the world. In fact, the enormous blue whale, which can measure over 30 metres (100 feet) long, is probably the biggest animal that has ever lived. Whales are able to grow so large because their huge weight is supported by the water. If a land animal grew to this size, its legs would collapse under the weight of its own body. There are two types of whale: baleen whales and toothed whales.

Stranding or beaching is when a whale, or groups of whales, are washed ashore while still alive and healthy. Only some kinds do this and they are all toothed whales. No one knows why this happens. It may be that changes in the Earth's magnetic field confuse the whales' sense of direction.

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