• Brainly User
Air cavities in bones make them less denser . So the bird wont be facing any problem with the mass of the bones. It will enable them to fly high. Feathers will make their flight through air easy by providing less friction . The flight through air is really challenging one. The shape of the body of bird enables them to pierce through the air easily with less friction. Feathers along with it will decrease friction. It will allow the flow of air without providing any sort of hindrance