(noun) A prominent tuft of feathers on the crown of a bird's head. Crests vary greatly, from just a few longer feathers on the head, such as the very small and subtle crest of the ruby-crowned kinglet, to the longer, more prominent crest of birds such as the northern cardinal or blue jay. In some species, such as the double-crested cormorant, a pair of crests are located on the sides of the head rather than directly on the crown. The crest may also be a temporary feature as part of the bird's breeding plumage, and it will disappear after the breeding season.
Some birds of all families will display crests, and the shape, size, color and length of the crest can vary. If the crest is fleshy, as with the red junglefowl, it is referred to as a comb rather than a crest. When a crest is prominent, it is a distinguished field mark and may be part of the bird's name, such as the sulfur-crested cockatoo or crested tit. Birds are often able to control a crest and can raise or lower it for a courtship display or to show aggression, dominance or submission.
When using a crest for bird identification, note the color, shape and length of the crest, as well as its thickness and whether it appears to be just a few feathers or the full crown. Also note how the bird uses the crest and what positions the crest has in a bird's relaxed posture versus more aggressive or prominent displays.
Photo – Crested Pigeon © Richard Taylor