“Aerospace and materials engineers can (now) start rethinking how they can design, manufacture and control materials and wings that morph as deftly as birds do,” said David Lentink, an assistant professor of mechanical engineering at Stanford and the senior author of two papers describing the results in the journals Science and Science Robotics.
All four-limbed animals, including dinosaurs, evolved from an ancestor that had five digits at the end of its limbs, which became hands, paws, flippers, or wings over time.
Modern birds retained three digits, or fingers. By studying the pigeon wings in a wind tunnel, the researchers found that wrist and finger action provided fine control over feather placement, wing span, and area.
In flight tests, manipulation of the wrist and fingers initiated stable turn maneuvers at tight angles, which the researchers said provided some of the first evidence that birds primarily use these digits to steer in flight.
Jesus: Hey, Dad? God: Yes, Son? Jesus: Western civilization followed me home. Can I keep it? God: Certainly not! And put it down this minute--you don't know where it's been! Tom Robbins in Another Roadside Attraction