How do birds fly?

Bird

Most birds are well suited for flying.  First of all, a bird has feathers and wings, and powerful muscles in its breast with which to flat them.  A bird’s body is streamlined to other little air resistance. Its bones are light in weight. Many of them are hollow and filled with air. 

When a bird beats its wings downward, it produces a lifting force that holds the bird in the air.  As the wings flap downward to flight, the long wingtip feathers twist and push against the air, moving the bird forward.  The bird uses its tail feathers as a brake and as a rudder for steering. – Dick Rogers