Birds live on every habitat on the surface of the earth. Among ten thousand or so species of birds worldwide, a few stand out in the crowd. From tiny hummingbirds to huge ostriches, the oddest birds provide the best lessons about the nature of birds. Birds have many things in common -- wings, scaly legs, song, and beaks. The one feature unique to all birds, and what makes a bird a bird, is the feather. But, why do some have bushy headgear, while others have no head feathers? How cam some eat wax, while others dine exclusively on snails? Why do some have different types of beaks, and why do some build huge nests, and others none? With a lively text and eye-catching color photographs, this book explores the unique habits of birds from your backyard and around the world.