What makes flight possible?
Flight is achieved by air pressure. Air passing over the top of the curved wing must travel faster than air taking the shorter route beneath it; air pressure decreases above the wing generating lift. You can demonstrate this with a piece of paper. Hold the paper by the corners with the edge just below your bottom lip and blow over the top surface. The paper rises.
There are many adaptations for flight:
- hollow bones
- air sacs
- massive flight muscles
- high metabolic rate
- rapid digestive system
- fused pelvic and shoulder girdles, vertebrae
- egg laying
- toothless; hollow light weight bill