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 related to the animal's diet. A
Cornell University
Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to tea ...
survey of unusual-looking birds visiting
feeders reported that 4% of such birds were described as xanthochromistic (compared with 76%
albinistic
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 opposite of xanthochromism, a deficiency in or complete absence of yellow pigment, is known as ''axanthism''.
Birds exhibiting genetic xanthochromism, especially deliberately bred mutations of several species of
parrot
Parrots, also known as psittacines (), are birds of the roughly 398 species in 92 genera comprising the order Psittaciformes (), found mostly in tropical and subtropical regions. The order is subdivided into three superfamilies: the Psittacoide ...
in
aviculture
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 ...
, are termed "lutinos". Wild birds in which xanthochromism has been recorded include
yellow wagtail,
wood warbler
The wood warbler (''Phylloscopus sibilatrix'') is a common and widespread leaf warbler which breeds throughout northern and temperate Europe, and just into the extreme west of Asian Russia in the southern Ural Mountains.
This warbler is stro ...
,
Cape May warbler
The Cape May warbler (''Setophaga tigrina'') is a species of New World warbler. It breeds in northern North America. Its breeding range spans all but the westernmost parts of southern Canada, the Great Lakes region, and New England. It is migrat ...
,
rose-breasted grosbeak
The rose-breasted grosbeak (''Pheucticus ludovicianus''), colloquially called "cut-throat" due to its coloration, is a large, seed-eating grosbeak in the cardinal family ( Cardinalidae). It is primarily a foliage gleaner. Males have black heads, ...
,
evening grosbeak
The evening grosbeak (''Hesperiphona vespertina'') is a passerine bird in the finch family Fringillidae found in North America.
Taxonomy
The IOC checklist and the '' Handbook of the Birds of the World'' place the evening grosbeak and the clos ...
,
red-bellied woodpecker
The red-bellied woodpecker (''Melanerpes carolinus'') is a medium-sized woodpecker of the family Picidae. It breeds mainly in the eastern United States, ranging as far south as Florida and as far north as Canada. Though it has a vivid orange-red ...
,
scarlet tanager
The scarlet tanager (''Piranga olivacea'') is a medium-sized American songbird. Until recently, it was placed in the tanager family (Thraupidae), but it and other members of its genus are now classified as belonging to the cardinal family (Cardin ...
,
northern cardinal,
great spotted woodpecker,
common tailorbird,
crimson-breasted shrike
The crimson-breasted shrike (''Laniarius atrococcineus'') or the crimson-breasted gonolek, ('gonolek' - supposedly imitative of its call), or the crimson-breasted boubou, is a southern African bird. It has black upper parts with a white flash on ...
,
kakariki and
kea
The kea (; ; ''Nestor notabilis'') is a species of large parrot in the family Nestoridae found in the forested and alpine regions of the South Island of New Zealand. About long, it is mostly olive-green with a brilliant orange under its wing ...
.
See also
*
Albinism in biology
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 ...
*
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 ...
*
Albino and white squirrels
*
Amelanism
Amelanism (also known as amelanosis) is a pigmentation abnormality characterized by the lack of pigments called melanins, commonly associated with a genetic loss of tyrosinase function. Amelanism can affect fish, amphibians, reptiles, birds, an ...
*
Dyschromia
Dyschromia refers to an alteration of the color of the skin or nails.
"Hyperchromia" can refer to hyperpigmentation, and "hypochromia" can refer to hypopigmentation.
"Dyschromatoses" involve both hyperpigmented and hypopigmented macules.
__TOC__ ...
*
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 ...
*
Heterochromia iridum
Heterochromia is a variation in coloration. The term is most often used to describe color differences of the iris, but can also be applied to color variation of hair or skin. Heterochromia is determined by the production, delivery, and concentr ...
*
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 ...
*
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 ...
*
Piebaldism
Piebaldism refers to the absence of mature melanin-forming cells (melanocytes) in certain areas of the skin and hair. It is a rare autosomal dominant disorder of melanocyte development.James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews ...
*
Carotenosis
Carotenosis is a benign and reversible medical condition where an excess of dietary carotenoids results in orange discoloration of the outermost skin layer. The discoloration is most easily observed in light-skinned people and may be mistaken for ...
References
Cornell University Project Feeder Watch 2002-2003Accessed 19 March 2007.
*
*
*
*
External links
Birders’ World Magazine, August 2003Strange birds at your feederYellow-breasted Crimson-breasted Shrike
Genetic disorders with no OMIM
Disturbances of pigmentation
Bird health
{{Veterinary-med-stub