Birds.

Birds. Pretend you are on a TV quiz show. The question is, "What is a bird?" Think carefully before you answer. Is a bird an animal that can fly? Bees and butterflies are animals that fly, but they're not birds. Penguins, emus, and ostriches are birds, but they can't fly. You answer, "A bird is an animal with feathers and wings." "Correct!" says the quiz show host. FEATHERS, WINGS, AND BEAKS Feathers cover almost every part of a bird's body. The feathers are strong and light to help birds fly. The feathers also keep a bird warm. Most birds lose their feathers and grow new ones every year. The feathers of some birds are red, green, yellow, blue, and other beautiful colors. A bird's wings are also covered with feathers. Some birds have long wings for soaring and gliding. Others have short wings that they flap quickly when they fly. A bird's tail is made of short and long feathers. Some birds have forked tails. Other birds have tails that are rounded, pointed, or square. Birds have beaks or bills instead of jaws with teeth. There are many shapes and sizes of beaks. The shape of the beak depends on what the bird eats. Toucans are tropical birds with huge, curved beaks. They use their beaks to crack open nuts. Sparrows and finches have thick beaks that are perfect for crushing seeds. HOW BIG ARE BIRDS? The tiniest bird is the bee hummingbird. It is only a little more than 2 inches (5 centimeters) long. It weighs less than a dime! The biggest bird is the ostrich. It is about 9 feet (2.7 meters) tall and weighs up to 345 pounds (156 kilograms). The ostrich cannot fly. One of the heaviest flying birds is the great bustard. It can weigh as much as 40 pounds (18 kilograms). WHERE DO BIRDS LIVE? Birds live almost everywhere on Earth. Some kinds of birds can live only in certain places. Penguins live only in cold places. Parrots live only in the warm tropics. Many birds have summer and winter homes. Some birds live in the northern United States and Canada during the summer. They migrate (fly) south to spend the winter in Central or South America. Birds that live in Europe during the summer migrate south to Africa for the winter. WHAT KINDS OF BIRDS ARE THERE? There are about 10,000 kinds of birds. Scientists have different ways of grouping birds. One way to group them is by how and where they live. Some birds live in water or get most of their food from water. The albatross and shearwater are birds that live over the ocean far away from land. They can even drink salt water. Loons, ducks, geese, gulls, pelicans, puffins, and penguins are also birds that live on or near water. Some birds live on beaches or shores. They are called wading birds because they have long legs for wading into water to catch fish or other animals. Herons, storks, ibises, spoonbills, and flamingos are large wading birds. Hawks, eagles, and falcons swoop down and grab other animals with their claws. They are called birds of prey. Owls are birds of prey that hunt at night. Running birds run on the ground instead of flying. Ostriches, rheas, emus, cassowaries, and kiwis are running birds that cannot fly. Most birds are perching birds. Perching birds are small birds with special toes that let them hang on to small twigs. Most perching birds are songbirds. Sparrows, robins, finches, warblers, and blackbirds are songbirds. Other kinds of birds include parrots, doves and pigeons, cuckoos, hummingbirds, and woodpeckers. DO BIRDS SLEEP? Birds need much less sleep than people do. One seabird, called the sooty tern, can fly for years by taking "naps" that last only a few seconds. Most birds that live on land are active during the day and sleep at night. Owls are just the opposite. They sleep during the day and hunt at night. Birds usually sleep in shrubs, on tree branches, in holes in trees, or on the ground. Most ducks sleep on the water. Many birds sleep while they are standing. MATING AND BREEDING Many kinds of birds have only one mate. First, a male bird has to get the attention of a female bird. Some males show off their beautiful feathers. Male songbirds sing to attract females. Most female birds lay their eggs in nests to protect them and keep them warm. Some kinds of birds build big, fancy nests. Eagles build huge nests of sticks. Many birds use holes in trees for nests. Some birds warm their eggs without any type of nest at all. The male emperor penguin keeps a single egg on top of its feet under a fold of skin. HOW ARE BIRDS BORN? Birds hatch out of eggs. They break the shell and hop out. Baby songbirds and pelicans do not have any feathers when they are born. They cannot see at first. Their parents must feed them and keep them warm. Ducks and other baby birds are born covered with soft down. They can feed themselves soon after hatching. Some kinds of young birds stay in the nest less than a day. Some baby birds stay around the nest for months. HOW LONG DO BIRDS LIVE? Most birds do not survive longer than one year. Many birds get sick and die. Some cannot find enough food. Some get eaten by other animals. About one bird in ten lives longer than a year. Scientists are not sure how long birds can live in the wild. They think that many small songbirds live 3 to 5 years. But some albatrosses can live to be more than 60 years old. Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.