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Plumage ( "feather") is a layer of
feather
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 ...
s that covers a
bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...
and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
and subspecies and may vary with age classes. Within species, there can be different colour
morph
Morph may refer to:
Biology
* Morph (zoology), a visual or behavioral difference between organisms of distinct populations in a species
* Muller's morphs, a classification scheme for genetic mutations
* "-morph", a suffix commonly used in tax ...
s. The placement of feathers on a bird is not haphazard, but rather emerge in organized, overlapping rows and groups, and these are known by standardized names.
Most birds
moult
In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is the manner in which an animal routinely casts off a part of its body (often, but not always, an outer ...
twice a year, resulting in a breeding or ''nuptial plumage'' and a ''basic plumage''. Many
duck
Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a form ...
s and some other species such as the
red junglefowl
The red junglefowl (''Gallus gallus'') is a tropical bird in the family Phasianidae. It ranges across much of Southeast Asia and parts of South Asia. It was formerly known as the Bankiva or Bankiva Fowl. It is the species that gave rise to the ...
have males wearing a bright nuptial plumage while breeding and a drab ''eclipse plumage'' for some months afterward. The
painted bunting
The painted bunting (''Passerina ciris'') is a species of bird in the cardinal family, Cardinalidae. It is native to North America. The bright plumage of the male only comes in the second year of life; in the first year they can only be distingu ...
'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
Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and pink or blue eyes. Individuals with the condition are referred to as albino.
Varied use and interpretation of the term ...
, 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
Ruff may refer to:
Places
*Ruff, Virginia, United States, an unincorporated community
*Ruff, Washington, United States, an unincorporated community
Other uses
*Ruff (bird) (''Calidris pugnax'' or ''Philomachus pugnax''), a bird in the wader fami ...
which has an assortment of different colours around the head and neck in the breeding season only.
Hen feathering
Hen feathering in cocks is the occurrence of a genetically conditioned character in domestic fowl (''Gallus gallus domesticus''). Males with this condition develop a female-type plumage, although otherwise look and respond as virile males.
Hen-fe ...
is an inherited plumage character in
domestic fowl
The chicken (''Gallus gallus domesticus'') is a domesticated junglefowl species, with attributes of wild species such as the grey and the Ceylon junglefowl that are originally from Southeastern Asia. Rooster or cock is a term for an adult ...
controlled by a single gene. ''
Plumology'' (or ''plumage science'') is the name for the science that is associated with the study of feathers.
Humphrey–Parkes (H–P) moult and plumage terminology
Almost all species of birds
moult
In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is the manner in which an animal routinely casts off a part of its body (often, but not always, an outer ...
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
Humphrey–Parkes terminology is a system of nomenclature for the plumage of birds. Before the Humphrey–Parkes system, plumage was named after the belief that a certain plumage was breeding plumage and others were not. However, as this system di ...
requires some attention to detail to name moults and plumages correctly.[
]
Eclipse plumage
Many male ducks have bright, colourful plumage, exhibiting strong sexual dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...
. 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
The Anatidae are the biological family of water birds that includes ducks, geese, and swans. The family has a cosmopolitan distribution, occurring on all the world's continents except Antarctica. These birds are adapted for swimming, floating ...
, a few other species, including related red junglefowl
The red junglefowl (''Gallus gallus'') is a tropical bird in the family Phasianidae. It ranges across much of Southeast Asia and parts of South Asia. It was formerly known as the Bankiva or Bankiva Fowl. It is the species that gave rise to the ...
, most fairywrens and some sunbird
Sunbirds and spiderhunters make up the family Nectariniidae of passerine birds. They are small, slender passerines from the Old World, usually with downward-curved bills. Many are brightly coloured, often with iridescent feathers, particularly ...
s also have an eclipse plumage. In the superb
Superb may refer to:
*Škoda Superb car
*, nine Royal Navy ships
*The Superb
The ''Superb'' was used as U.S. President Warren G. Harding's personal Pullman railroad car in a cross-country tour in 1923. After Harding's death, the car returned hi ...
and splendid fairywren
The splendid fairywren (''Malurus splendens'') is a passerine bird in the Australasian wren family, Maluridae. It is also known simply as the splendid wren or more colloquially in Western Australia as the blue wren. The splendid fairywren is fou ...
s, very old males (over about four years) may moult from one nuptial plumage to another whereas in the red-backed and white-winged fairywren
The white-winged fairywren (''Malurus leucopterus'') is a species of passerine bird in the Australasian wren family, Maluridae. It lives in the drier parts of Central Australia; from central Queensland and South Australia across to Western Aus ...
s, 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
The Guianan cock-of-the-rock (''Rupicola rupicola'') is a species of cotinga, a passerine bird from South America. It is about in length and weighs about . It is found in tropical rainforests, near its preferred habitat of rocky outcrops. The ...
or birds of paradise
The birds-of-paradise are members of the family Paradisaeidae of the order Passeriformes. The majority of species are found in eastern Indonesia, Papua New Guinea and eastern Australia. The family has 44 species in 17 genera. The members of ...
– retain their exuberant plumage and sexual dimorphism at all times, moulting as ordinary birds do once annually.
Abnormal plumages
There are hereditary as well as non-hereditary variations in plumage that are rare and termed as abnormal or aberrant plumages. Melanism refers to an excess of black or dark colours. Erythromelanism or erythrism
Erythrism or erythrochroism refers to an unusual reddish pigmentation of an animal's hair, skin, feathers, or eggshells.
Causes of erythrism include:
* Genetic mutations which cause an absence of a normal pigment and/or excessive production o ...
is the result of excessive reddish brown erythromelanin deposition in feathers that normally lack melanin. Melanin of different forms combine with xanthophylls to produce colour mixtures and when this combination is imbalanced it produces colour shifts that are termed as schizochroisms (including xanthochromism
Xanthochromism (also called xanthochroism or xanthism) is an unusually yellow pigmentation in an animal. It is often associated with the lack of usual red pigmentation and its replacement with yellow. The cause is usually genetic but may also be ...
– overabundance of yellow – and axanthism – lack of yellow – which are commonly bred in cagebird
Aviculture is the practice of keeping and breeding birds, especially of wild birds in captivity.
Types
There are various reasons that people get involved in aviculture. Some people breed birds to preserve a species. Some people breed parrots a ...
s such as budgerigars
The budgerigar ( ; ''Melopsittacus undulatus''), also known as the common parakeet or shell parakeet, is a small, long-tailed, seed-eating parrot usually nicknamed the budgie ( ), or in American English, the parakeet. Budgies are the only spe ...
). A reduction in eumelanin leads to non-eumelanin schizochroism with an overall fawn plumage while a lack of phaeomelanin results in grey coloured non-phaeomelanin schizochroism. Carotenism refers to abnormal distribution of carotenoid pigments.
The term "dilution" is used for situations where the colour is of a lower intensity overall; it is caused by decreased deposition of pigment in the developing feather, and can thus not occur in structural coloration
Structural coloration in animals, and a few plants, is the production of colour by microscopically structured surfaces fine enough to interfere with visible light instead of pigments, although some structural coloration occurs in combination wi ...
(i.e., "dilute blue" does not exist); pale structural colors are instead achieved by shifting the peak wavelength at which light is refracted. Dilution regularly occurs in normal plumage (grey, buff, pink and cream colours are usually produced by this process), but may in addition occur as an aberration (e.g., all normally black plumage becoming grey).
In some birds – many true owl
The true owls or typical owls (family Strigidae) are one of the two generally accepted families of owls, the other being the barn owls (Tytonidae). This large family comprises 230 living or recently extinct species in 24 genera. The typical owl ...
s (Strigidae), some nightjar
Nightjars are medium-sized nocturnal or crepuscular birds in the family Caprimulgidae and order Caprimulgiformes, characterised by long wings, short legs, and very short bills. They are sometimes called goatsuckers, due to the ancient folk tal ...
s (Caprimulgidae) and a few cuckoo
Cuckoos are birds in the Cuculidae family, the sole taxon in the order Cuculiformes . The cuckoo family includes the common or European cuckoo, roadrunners, koels, malkohas, couas, coucals and anis. The coucals and anis are sometimes separ ...
s (''Cuculus
''Cuculus'' is a genus of cuckoos which has representatives in most of the Old World, although the greatest diversity is in tropical southern and southeastern Asia.
Taxonomy
The genus ''Cuculus'' was introduced in 1758 by the Swedish naturalist ...
'' and relatives) being widely known examples – there is colour polymorphism. This means that two or more colour variants are numerous within their population
Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction using a ...
s during all or at least most seasons and plumages; in the above-mentioned examples a brown (phaeomelanin) and grey (eumelanin) morph exist, termed "hepatic form" particularly in the cuckoos. Other cases of natural polymorphism are of various kinds; many are melanic/nonmelanic (some paradise-flycatchers, ''Terpsiphone'', for example), but more unusual types of polymorphism exist – the face colour of the Gouldian finch (''Erythrura' gouldiae'') or the courtship types of male ruff
Ruff may refer to:
Places
*Ruff, Virginia, United States, an unincorporated community
*Ruff, Washington, United States, an unincorporated community
Other uses
*Ruff (bird) (''Calidris pugnax'' or ''Philomachus pugnax''), a bird in the wader fami ...
s (''Philomachus pugnax'').
Albinism
Albinism
Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and pink or blue eyes. Individuals with the condition are referred to as albino.
Varied use and interpretation of the term ...
in birds is rare, occurring to any extent in perhaps one in 1800 individuals. It involves loss of colour in all parts including the iris of the eyes, bills, skin, legs, and feet. It is usually the result of a genetic mutation causing the absence of tyrosinase
Tyrosinase is an oxidase that is the rate-limiting enzyme for controlling the production of melanin. The enzyme is mainly involved in two distinct reactions of melanin synthesis otherwise known as the Raper Mason pathway. Firstly, the hydroxy ...
, an enzyme essential for melanin synthesis. Leucism
Leucism () is a wide variety of conditions that result in the partial loss of pigmentation in an animal—causing white, pale, or patchy coloration of the skin, hair, feathers, scales, or cuticles, but not the eyes. It is occasionally spelled ...
(which includes what used to be termed as "partial albinism") refers to loss of pigments in some or all parts of feathers. A bird that is albino
Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and pink or blue eyes. Individuals with the condition are referred to as albino.
Varied use and interpretation of the term ...
(from the Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
''albus'', "white") has white feather
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 ...
s in place of coloured ones on some portion of its body. A bird that is naturally white, such as a swan, goose
A goose ( : geese) is a bird of any of several waterfowl species in the family Anatidae. This group comprises the genera ''Anser'' (the grey geese and white geese) and '' Branta'' (the black geese). Some other birds, mostly related to the ...
, or egret
Egrets ( ) are herons, generally long-legged wading birds, that have white or buff plumage, developing fine plumes (usually milky white) during the breeding season. Egrets are not a biologically distinct group from herons and have the same build ...
, is not an albino, nor is a bird that has seasonally alternating white plumage.["Albinism". Terres, John. K. ''The Audubon Society Encyclopedia of North American Birds'', New York: Alfred A. Knopf, 1980. .]
Four degrees of albinism have been described. The most common form is termed ''partial albinism'', in which local areas of the bird's body, such as certain feathers, are lacking the pigment melanin
Melanin (; from el, μέλας, melas, black, dark) is a broad term for a group of natural pigments found in most organisms. Eumelanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino ...
. The white areas may be symmetrical, with both sides of the bird showing a similar pattern. In ''imperfect albinism'', the pigment is partially inhibited in the skin
Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation.
Other cuticle, animal coverings, such as the arthropod exoskeleton, have diffe ...
, eyes, or feathers, but is not absent from any of them. ''Incomplete albinism'' is the complete absence of pigment from the skin, eyes, or feathers, but not all three.
A completely albino bird is the most rare. The eyes in this case are pink or red, because blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the c ...
shows through in the absence of pigment in the iris
Iris most often refers to:
*Iris (anatomy), part of the eye
*Iris (mythology), a Greek goddess
* ''Iris'' (plant), a genus of flowering plants
* Iris (color), an ambiguous color term
Iris or IRIS may also refer to:
Arts and media
Fictional ent ...
es. The beak
The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for food ...
, legs, and feet are very pale or white. Albino adults are rare in the wild because their eyesight is poor resulting in greater risk of predation. They are likely easier targets for predator
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...
s because their colour distinguishes them from their environment. Falconers have observed that their trained birds are likely to attack a white pigeon
Columbidae () is a bird family consisting of doves and pigeons. It is the only family in the order Columbiformes. These are stout-bodied birds with short necks and short slender bills that in some species feature fleshy ceres. They primarily ...
in a flock because it is conspicuous. A complete albino often has weak eyesight and brittle wing and tail feathers, which may reduce its ability to fly. In flocks, albinos are often harassed by their own species. Such observations have been made among red-winged blackbird
The red-winged blackbird (''Agelaius phoeniceus'') is a passerine bird of the family Icteridae found in most of North America and much of Central America. It breeds from Alaska and Newfoundland south to Florida, the Gulf of Mexico, Mexico, and G ...
s, barn swallow
The barn swallow (''Hirundo rustica'') is the most widespread species of swallow in the world. In fact, it appears to have the largest natural distribution of any of the world's passerines, ranging over 251 million square kilometres globally. ...
s, and African penguins. In a nesting colony of the latter, three unusual juveniles—one black-headed, one white-headed, and one full albino—were shunned and abused by companions.
Albinism has been reported in all orders and in 54 families
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Ideal ...
of North American birds. The American robin and house sparrow led bird species in the incidence of albinism. Albinistic white appears to replace brown pigments more often than red or yellow ones; records suggest a greater incidence in crow
A crow is a bird of the genus '' Corvus'', or more broadly a synonym for all of ''Corvus''. Crows are generally black in colour. The word "crow" is used as part of the common name of many species. The related term "raven" is not pinned scientifica ...
s, ravens, and hawks than in goldfinches or orioles.
Several kinds of albinism in chickens has been described: A complete albinism controlled by an autosomal recessive gene and two different kinds of partial albinism. One of the partial albinisms is sex-linked and the other is autosomal recessive. A fourth kind of albinism severely reduce pigmentation in the eyes, but only dilutes the pigment in the plumage.
Abnormally white feathers are not always due to albinism. Injury or disease may change their color, including dietary deficiencies or circulatory problems during feather development. Aging may also turn a bird's feathers white.
Hen feathering in cocks
Hen feathering in cocks is a genetically conditioned character in domestic fowl (Gallus gallus domesticus
The chicken (''Gallus gallus domesticus'') is a domesticated junglefowl species, with attributes of wild species such as the grey and the Ceylon junglefowl that are originally from Southeastern Asia. Rooster or cock is a term for an adult ...
). Males with this condition develop a female-type plumage, although otherwise look and respond like virile males. In some breeds, one can see males that have a plumage completely similar in all aspects to that of females. The trait is controlled by a simple autosomic dominant gene
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...
, whose expression is limited to the male sex. The condition is due to an enhanced activity of the aromatase complex of enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...
s responsible for estrogen
Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal acti ...
synthesis. So estrogen formation in the skin is as much as several hundred-fold higher than that of normal chickens.[
]
Pigmentation conditions
* Albinism
Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and pink or blue eyes. Individuals with the condition are referred to as albino.
Varied use and interpretation of the term ...
, the lack of melanin pigmentation
* Leucism
Leucism () is a wide variety of conditions that result in the partial loss of pigmentation in an animal—causing white, pale, or patchy coloration of the skin, hair, feathers, scales, or cuticles, but not the eyes. It is occasionally spelled ...
, a condition similar to albinism in animals, characterized by reduced pigmentation in general
* Melanism
The term melanism refers to black pigment and is derived from the gr, μελανός. Melanism is the increased development of the dark-colored pigment melanin in the skin or hair.
Pseudomelanism, also called abundism, is another variant of ...
(or melanosis), unusually dark melanin pigmentation
* Xanthochromism
Xanthochromism (also called xanthochroism or xanthism) is an unusually yellow pigmentation in an animal. It is often associated with the lack of usual red pigmentation and its replacement with yellow. The cause is usually genetic but may also be ...
, unusually yellow pigmentation
* Ino budgerigar mutation, the occurrence of this mutation in captive-bred budgerigar
The budgerigar ( ; ''Melopsittacus undulatus''), also known as the common parakeet or shell parakeet, is a small, long-tailed, seed-eating parrot usually nicknamed the budgie ( ), or in American English, the parakeet. Budgies are the only spe ...
s
See also
* Animal coloration
* Hen feathering
Hen feathering in cocks is the occurrence of a genetically conditioned character in domestic fowl (''Gallus gallus domesticus''). Males with this condition develop a female-type plumage, although otherwise look and respond as virile males.
Hen-fe ...
* Imping
Imping is the practice of replacing a broken feather of a bird with another one, referred to as a donor feather, from a previous Moulting, molt of the same animal or from another animal of the same or of a different species. Imping is mostly done ...
* Pluma porgy
* Plume hunting
Plume hunting is the hunting of wild birds to harvest their feathers, especially the more decorative plumes which were sold for use as ornamentation, such as aigrettes in millinery. The movement against the plume trade in the United Kingdom w ...
* Sea pen
Sea pens are colonial marine cnidarians belonging to the order Pennatulacea. There are 14 families within the order; 35 extant genera, and it is estimated that of 450 described species, around 200 are valid. Sea pens have a co ...
* Vermiculation
Vermiculation is a surface pattern of dense but irregular lines, so called from the Latin ''vermiculus'' meaning "little worm" because the shapes resemble worms, worm-casts, or worm tracks in mud or wet sand. The word may be used in a number of ...
Notes
Males of the white-shouldered and emperor fairywren
The emperor fairywren (''Malurus cyanocephalus'') is a species of bird in the Australasian wren family, Maluridae. It is found in New Guinea in its natural habitat of subtropical or tropical moist lowland forests. It is the largest species of fa ...
s of New Guinea
New Guinea (; Hiri Motu
Hiri Motu, also known as Police Motu, Pidgin Motu, or just Hiri, is a language of Papua New Guinea, which is spoken in surrounding areas of Port Moresby (Capital of Papua New Guinea).
It is a simplified version of ...
do not enter an eclipse plumage.
References
{{Birds
Bird anatomy
Feathers