What is Crest (feathers)?
[[File:Nymphicus hollandicus -aviary -upper body-8a-1c.jpg|right|thumb|The [[Cockatiel]] - an example of a crested bird species]] The '''crest''', in some cases called a '''crown''', of a bird, is a group of [[feather]]s that some [[species]] of [[bird]]s have on top of the head. The feathers of these crests can move up and down or be permanently up, depending of the species. For example, the crests of [[cockatoo]]s and the [[hoopoe]] could be up or down but the feathers in the crest of the [[grey crowned crane]] are always up. Crests on birds are generally used for [[display (zoology)|display]] purposes. Birds with crests often use them to communicate with others and as a part of their [[wikt:courtship|courtship]]. They also tend to display their crests when they are frightened or ready to fight because the birds may appear larger than they really are. [[Cockatoo]]s and their smaller cousins, [[cockatiel]]s, are part of the Cacatuidae family of parrots found in Australia, the Bismarck Archipelago and the Philippines, and are probably the most recognizable birds to feature crests.<ref>{{cite web|last=Roberson|first=Don|title=COCKATOOS Cacatuidae|url=http://creagrus.home.montereybay.com/cockatoos.html|publisher=Bird Families of the World|access-date=17 June 2013}}</ref> [[Cockatoo]]s and [[cockatiel]]s possess crests which may be raised or lowered at will. Their crests are used to communicate with fellow members of their species, or as a form of defense to frighten away other species that approach too closely, making the bird appear larger when the crest is suddenly and unexpectedly raised.<ref>{{cite web|last=Highfill|first=Carol|title=Those Magnificent Cockatoo Crests|url=http://www.birdsnways.com/cockatoo/crests.htm|publisher=Cockatoo Heaven|access-date=17 June 2013|archive-date=1 March 2017|archive-url=https://web.archive.org/web/20170301234333/http://www.birdsnways.com/cockatoo/crests.htm|url-status=dead}}</ref> {{Clear}} ==Gallery of birds with crest== <center> <gallery> File:Citron crest feathers.JPG|[