Plumage is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, there can be different colour morphs. The placement of feathers on a bird is not haphazard but rather emerges in organized, overlapping rows and groups, and these feather tracts are known by standardized names.
Close-up view of the plumage on a house sparrow
The differences in plumage of a blue grosbeak, from top to bottom, between a breeding male (alternate plumage), a non-breeding male (basic plumage), a female, and the related indigo bunting
Mandarin duck (male) in eclipse plumage
Axanthic budgerigar
Feathers are epidermal growths that form a distinctive outer covering, or plumage, on both avian (bird) and some non-avian dinosaurs and other archosaurs. They are the most complex integumentary structures found in vertebrates and a premier example of a complex evolutionary novelty. They are among the characteristics that distinguish the extant birds from other living groups.
Feather variations
Parts of a feather: Vane Shaft, rachis Barb Aftershaft, afterfeather Quill, calamus
Feather structure of a blue-and-yellow macaw
A contour feather from a Guinea fowl