This title is intended for ages 6-12. Whales are the only mammals that spend their entire life in the water. From playful dolphins to enormous blue whales, the behaviour, habitats, and physiology of these amazing marine mammals are explored in this book. Spectacular full-colour photos help show: flukes, flippers, and fins; the whale family tree; baleen and toothed whales; how whales communicate through echolocation; watery homes and what they eat; baby whales; whale-watching and why whales are in danger.