Have you seen goose down feathers from a jacket or comforter? Like you, birds wear these soft, fluffy feathers close to their skin to stay warm. They weigh less than hair or fur, so they’re better for flying.
A smooth, streamlined body helps a bird slide through the air.
Instead of a heavy jawbone and teeth, a bird has a lightweight beak.
Birds have big, strong chest muscles. They need them to flap their wings hard and fast, so they can make the air around them move quickly enough to lift the bird.
A bird’s outer feathers are strong but lightweight. Like shingles on a roof, they overlap and lie flat, so rain runs off and the bird stays dry.
To stay lightweight for flying, most birds have short, skinny…