New technique captures birds’ flight patterns

If birds left visible evidence in the sky, it would look like Spanish photographer Xavi Bous’ photos. He records birds with a high-speed video camera, combining single images, which are united into one picture of a bird’s flight patterns. This is a yellow-legged gull captured in flight. Each wing stroke consists of two stages: the downward motion ensures propulsion, whereas the upward wing stroke motion and the bird’s speed contribute to the lift.