Carol, With a few exceptions, all birds have feathers on their heads that have bases forward and shafts pointing backward. The feathers do not normally stick straight up, but instead lie mostly flat, with the base of the rear feathers underneath the feathers in front. Crown feathers do not move like hair (more or less rotating around a base and sticking straight up), but instead they rise up-and-forward and down-and-backward as groups. Long feathers that stick out farther to the rear are higher above the head when raised, and those feathers create what we think of as a crest (see an example at http://picasaweb.google.com/KevinJ.McGowan/BasinSpecies2009#5390313795604835538).
All birds can raise their crown feathers more or less at will, and how distinct a "crest" is depends on the respective length of the feathers in that feather tract. The longer in front and shorter in back (especially, short directly behind the long feathers), the more obvious the crest. But, even birds with no crest to speak of can raise those feathers noticeably (see example at http://picasaweb.google.com/KevinJ.McGowan/BasinSpecies2009#5390314741659575122). Lots of birds that you wouldn't think of as having crests use erected crown feathers as a signal expressing their displeasure with another bird nearby, as shown in your lovely photo of the American Tree Sparrow. Best, Kevin -----Original Message----- From: bounce-7659687-3493...@list.cornell.edu [mailto:bounce-7659687-3493...@list.cornell.edu] On Behalf Of Carol Keeler Sent: Thursday, January 13, 2011 7:02 PM To: cayugabirds Subject: [cayugabirds-l] Crests I have a question. Are all birds able to raise a crest even though they normally do not have one? Is it something that they do when they are agitated, angry, or upset? I took a picture of an American Tree Sparrow with a "crest". I have never seen this before with a bird which doesn't have a crest. Maybe it's not called a crest on birds without them. http://www.pbase.com/carol_keeler_photo/image/131804983 This made me wonder if it is something all birds can do when so motivated. Carol Keeler Auburn -- Cayugabirds-L List Info: http://www.NortheastBirding.com/CayugabirdsWELCOME http://www.NortheastBirding.com/CayugabirdsRULES ARCHIVES: 1) http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html 2) http://birdingonthe.net/mailinglists/CAYU.html 3) http://www.surfbirds.com/birdingmail/Group/Cayugabirds Please submit your observations to eBird: http://ebird.org/content/ebird/ -- -- Cayugabirds-L List Info: http://www.NortheastBirding.com/CayugabirdsWELCOME http://www.NortheastBirding.com/CayugabirdsRULES ARCHIVES: 1) http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html 2) http://birdingonthe.net/mailinglists/CAYU.html 3) http://www.surfbirds.com/birdingmail/Group/Cayugabirds Please submit your observations to eBird: http://ebird.org/content/ebird/ --
