Bird

irds are warm-blooded vertebrates with wings instead of forelimbs or arms. Birds are the only animals with feathers. These strong but delicate structures keep a bird warm and help it to fly.

The Study of Flight

The first people to dream of flying undoubtedly gazed at birds. Birds are truly masters of the air, although other animals, such as insects and bats, also fly. Scientists of old must have watched a bird or a bee and puzzled over how these creatures flew. Today’s scientists have analyzed the aerodynamics of the bumblebee and are amazed that this insect can even get off the ground!

People in ancient times thought they could imitate bird flight. It looked so easy-if a swan or a goose could fly simply by flapping its wings, why not a human? So inventors tried to fly by strapping feathery wings to their arms and leaping from high towers, waving their arms. Sadly, like Icarus in the ancient Greek myth, they crashed to the ground. A machine called an ornithopter can fly by flapping its wings, but a person cannot.