WHALES & DOLPHINS

Although they live in the water -- whales, dolphins and porpoises are mammals. Since whales and dolphins are mammals, they cannot breathe under water. They must come to the surface to breathe air. They breathe through a blowhole, or nostrils, on the top of their head. Babies are born under water and must be pushed to the surface, by the mother, so that they can take a breath. Whales and dolphins also look different from many other mammals because they don't have fur. Although, they do have a sparse covering of hair.

The circulatory and respiratory systems have adapted to living in water. Whales and dolphins can dive deep in the water on a single breath. Whales and dolphins also have a highly developed brain. They are consider to be very intelligent. Dolphins, and some whales, can use echolocation to find food and identify objects around them. They make loud clicking and squeaking sounds that bounce off objects and echo back to the dolphin. This echo tells the dolphin about the nearby object