Plumage

Plumage (Latin: plūma 'feather') refers both to the layer of feathers that cover 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 emerge in organized, overlapping rows and groups, and these feather tracts are known by standardized names. Plumage (Latin: plūma 'feather') refers both to the layer of feathers that cover 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 emerge in organized, overlapping rows and groups, and these feather tracts are known by standardized names. Most birds moult twice a year, resulting in a breeding or nuptial plumage and a basic plumage. Many ducks and some other species such as the red junglefowl have males wearing a bright nuptial plumage while breeding and a drab eclipse plumage for some months afterward. The painted bunting's juveniles have two inserted moults in their first autumn, each yielding plumage like an adult female. The first starts a few days after fledging replacing the juvenile plumage with an auxiliary formative plumage; the second a month or so later giving the formative plumage. Abnormal plumages include a variety of conditions. Albinism, total loss of colour, is rare, but partial loss of colours is more common. Some species are colour polymorphic, having two or more colour variants. A few species have special types of polymorphism, as in the male ruff which has an assortment of different colours around the head and neck in the breeding season only. Hen feathering is an inherited plumage character in domestic fowl controlled by a single gene. Plumology (or plumage science) is the name for the science that is associated with the study of feathers. Almost all species of birds moult at least annually, usually after the breeding season, known as the pre-basic moult. This resulting covering of feathers, which will last either until the next breeding season or until the next annual moult, is known as the basic plumage. Many species undertake another moult prior to the breeding season known as the pre-alternate moult, the resulting breeding plumage being known as the alternate plumage or nuptial plumage. The alternate plumage is often brighter than the basic plumage, for the purposes of sexual display, but may also be cryptic to hide incubating birds that might be vulnerable on the nest. The Humphrey-Parkes terminology requires some attention to detail to name moults and plumages correctly. Many male ducks have bright, colourful plumage, exhibiting strong sexual dimorphism. However, they moult into a dull plumage after breeding in mid-summer. This drab, female-like appearance is called eclipse plumage. When they shed feathers to go into eclipse, the ducks become flightless for a short period of time. Some duck species remain in eclipse for one to three months in the late summer and early fall, while others retain the cryptic plumage until the next spring when they undergo another moult to return to their breeding plumage. Although mainly found in the Anatidae, a few other species, including related red junglefowl, most fairywrens and some sunbirds also have an eclipse plumage. In the superb and splendid fairywrens, very old males (over about four years) may moult from one nuptial plumage to another whereas in the red-backed and white-winged fairywrens, males do not acquire nuptial plumage until four years of age – well after they become sexually mature and indeed longer than the vast majority of individuals live. In contrast to the ducks, males of hummingbirds and most lek-mating passerines – like the Guianan cock-of-the-rock or birds of paradise – retain their exuberant plumage and sexual dimorphism at all times, moulting as ordinary birds do once annually.