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
Choiseul pigeon pigeon may be a link between that species and the crowned pigeons. The adult pigeon was largely blue-grey, with a buffy orange belly and a distinctive slaty-blue crest. It is unknown how this crest was held by the bird in life. The bird's head sported a blue frontal shield surrounded by black feathers and a bicoloured beak. The wings were brown and the short tail was a blackish purple. It was described as having a beautiful rising and falling whistling call. As the bird became extinct before significant field observations could be made, not much is known about its behaviour.