Codex on the Flight of Birds of a kite as seeking a wind current. When the winds are high, one will see the bird very high in the sky, but when the winds are low, the bird stays closer to the ground. Leonardo describes how a bird rests in the air, after flapping its wings to gain altitude, by gliding downward to the ground. Folio 6 contains multiple diagrams of birds flying and their bone structure, and all of the commentary is on flight and how birds fly the way that they do. Leonardo starts off by describing how a bird ascends or descends in different
Preening (bird) bathing, dusting, sunning, oiling or anting, and can either precede or follow these other behaviours.Preening typically involves an action between its beak and claws on its foot. Because fully-grown feathers are essentially dead structures, it is vital that birds have some way to protect and lubricate them. To facilitate this, many species have a preen or uropygial gland, which opens above the base of the tail feathers and secretes a substance containing fatty acids, water, and waxes. The bird gathers this substance on its bill, and applies it to its feathers. The gland is generally larger (in relation to body