what are adaotions in aves that enables them to fly
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Adaptations for Flight The evolution of flight has endowed birds with many physical features in addition to wings and feathers. One of the requirements of heavier-than-air flying machines, birds included, is a structure that combines strength and light weight. One way this is accomplished in birds is by the fusion and elimination of some bones and the "pneumatization" (hollowing) of the remaining ones. Some of the vertebrae and some bones of the pelvic girdle of birds are fused into a single structure, as are some finger and leg bones -- all of which are separate in most vertebrates. And many tail, finger, and leg bones are missing altogether. Not only are some bones of birds, unlike ours, hollow, but many of the hollows are connected to the respiratory system. To keep the cylindrical walls of a bird's major wing bones from buckling, the bones have internal strut-like reinforcements.
The evolution of flight has endowed birds with many physical features in addition to wings and feathers. One of the requirements of heavier-than-air flying machines, birds included, is a structure that combines strength and light weight. One way this is accomplished in birds is by the fusion and elimination of some bones and the "pneumatization" (hollowing) of the remaining ones. Some of the vertebrae and some bones of the pelvic girdle of birds are fused into a single structure, as are some finger and leg bones -- all of which are separate in most vertebrates. And many tail, finger, and leg bones are missing altogether. Not only are some bones of birds, unlike ours, hollow, but many of the hollows are connected to the respiratory system. To keep the cylindrical walls of a bird's major wing bones from buckling, the bones have internal strut-like reinforcements.
