What is Bird flight?
[[File:Colca-condor-c06.jpg|thumb|right|An [[Andean Condor]] soaring. This is one of the largest birds able to fly.]] [[File:Lift-force-en.svg|thumb|right|Forces acting on a wing. The lift force has both a forward and a vertical component.]] [[File:Domestic_Pigeon_Flock.jpg|thumb|Pigeons flapping their wings]] [[Flight]] is a method of moving through the air. To do this, birds use wings with light, hollow [[bone]]s and feathers on them. Birds have a [[wikt:streamlining|streamlined]] body shape, so that they slip through [[air]] more easily. Birds can move by flapping their wings, or they can stay in the same place. This is called [[wikt:hover|hovering]], with rapid wing beats, as with the [[kestrel]]. Birds that [[wikt:soar|soar]] use very little [[energy]] for it: they use columns of rising hot air to lift them. They [[wikt:glide|glide]] from the top of a warm air current, and then move on to another warm air current. That way birds like buzzards can fly all day while using little energy.<ref>Videler J.J. 2005. ''Avian flight''. Oxford University Press. {{ISBN|0-19-856603-4}}</ref> Birds like [[hawk]]s and [[gannet]]s dive on their [[prey]]. They get to a height, them fold their wings and dive head-first. == Lift == The fundamentals of bird flight are similar to those of [[aircraft]]. [[Lift (force)|Lift force]] is produced by the action of air flow on the [[wing]], which is an [[airfoil]]. The lift force occurs because the air has a lower [[air pressure|pressure]] just above the wing and higher pressure below. == References == {{reflist}} [[File:FlightSilhouettes.svg|thumb|left|300px|Wing shapes determine flight style]] [[Category:Birds|Flight]] [[Category:Fluid mechanics]] [[Category:Animal locomotion]]