Flying birds

Flying birds have several characteristics that allow them to fly, including:
Feathers: Lightweight and smooth feathers reduce drag and weight.
Beak: A beak instead of heavy jaws and teeth reduces weight.
Sternum: An enlarged breastbone called a sternum helps with thrust.
Bones: Hollow bones with air sacs and thin cross-sections reduce gravity.
Skeleton: A rigid skeleton forms strong attachments for powerful flying.
Body: A streamlined body covered with feathers reduces air resistance.
Wings: The bony parts of the forelimbs help birds fly.
Wing shape: The shape of a bird's wings is ideal for catching air.
Lungs: Efficient lungs that can get a lot of oxygen allow birds to fly long distances without tiring.