A caruncle is defined as 'a small, fleshy excrescence that is a normal part of an animal's anatomy'. Within this definition, caruncles in birds include wattles (or dewlaps),

comb A comb is a tool consisting of a shaft that holds a row of teeth for pulling through the hair to clean, untangle, or style it. Combs have been used since prehistoric times, having been discovered in very refined forms from settlements dating ba ...

s, snoods, and earlobes. The term ''caruncle'' is derived from Latin ''caruncula'', the diminutive of ''carō'', "flesh".

Taxonomy

Caruncles are carnosities, often of bright colors such as red, blue, yellow or white. They can be present on the head, neck, throat, cheeks or around the eyes of some birds. They may be present as combs or crests and other structures near the beak, or, hanging from the throat or neck. Caruncles may be featherless, or, have small scattered feathers. In some species, they may form pendulous structures of erectile tissue, such as the snood of the

domestic turkey The domestic turkey (Meleagris gallopavo domesticus) is a large fowl, one of the two species in the genus '' Meleagris'' and the same species as the wild turkey. Although turkey domestication was thought to have occurred in central Mesoamerica ...

. Caruncles are sometimes

secondary sexual characteristics Secondary sex characteristics are features that appear during puberty in humans, and at sexual maturity in other animals. These characteristics are particularly evident in the sexually dimorphic phenotypic traits that distinguish the sexes of a ...

, having a more intense color or even a different color, developing as the male reaches sexual maturity.

Function

Caruncles are also ornamental elements used by males to attract females to breeding. Having large caruncles or colorful bright ones indicates high levels of testosterone, that they are well-fed birds able to elude other predators thus showing the good quality of their genes. It has been proposed that these organs are also associated with genes which encode resistance to disease. It is believed that for birds living in tropical regions, the caruncles also play a role in thermoregulation, making the blood cool faster when flowing through them.

Turkeys

In turkeys, the term usually refers to small, bulbous, fleshy protuberances found on the head, neck and throat, with larger structures particularly at the bottom of the throat. The wattle is a flap of skin hanging under the chin connecting the throat and head and the snood is a highly erectile appendage emanating from the forehead. Both sexes of turkey possess caruncles, although they are more pronounced in the male. Usually they are pale, but when the male becomes excited or during courtship, the caruncles, wattle and snood all engorge with blood, become bright red or blue, and enlarge. The ''beard'' (a tuft of modified brush-like feathers) also becomes erect.

Muscovy ducks

In the context of Muscovy ducks, caruncles refer to the red fleshy mask that surrounds the head of adult birds, particularly prominent in adult drakes (males).

Birds with caruncles

Many species from a variety of families have caruncles, including: *

Phasianidae The Phasianidae are a family of heavy, ground-living birds, which includes pheasants, partridges, junglefowl, chickens, turkeys, Old World quail, and peafowl. The family includes many of the most popular gamebirds. The family is a large one ...

(

pheasant Pheasants ( ) are birds of several genera within the family Phasianidae in the order Galliformes. Although they can be found all over the world in introduced (and captive) populations, the pheasant genera native range is restricted to Eurasia ...

rooster 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 m ...

s and

turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a transcontinental country located mainly on the Anatolian Peninsula in Western Asia, with a small portion on the Balkan Peninsula ...

s) *

Cathartidae The New World vulture or condor family, Cathartidae, contains seven extant species in five genera. It includes five extant vultures and two extant condors found in warm and temperate areas of the Americas. The "New World" vultures were widespr ...

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condor Condor is the common name for two species of New World vultures, each in a monotypic genus. The name derives from the Quechua ''kuntur''. They are the largest flying land birds in the Western Hemisphere. They are: * The Andean condor (''Vu ...

s and

vulture A vulture is a bird of prey that scavenges on carrion. There are 23 extant species of vulture (including Condors). Old World vultures include 16 living species native to Europe, Africa, and Asia; New World vultures are restricted to North and ...

s) *

Falconidae The falcons and caracaras are around 60 species of diurnal birds of prey that make up the family Falconidae (representing all extant species in the order Falconiformes). The family is divided into three subfamilies, Herpetotherinae, which inclu ...

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falcon Falcons () are birds of prey in the genus ''Falco'', which includes about 40 species. Falcons are widely distributed on all continents of the world except Antarctica, though closely related raptors did occur there in the Eocene. Adult falcons ...

s) *

Accipitridae The Accipitridae is one of the three families within the order Accipitriformes, and is a family of small to large birds with strongly hooked bills and variable morphology based on diet. They feed on a range of prey items from insects to medium-s ...

(

eagle Eagle is the common name for many large birds of prey of the family Accipitridae. Eagles belong to several groups of genera, some of which are closely related. Most of the 68 species of eagle are from Eurasia and Africa. Outside this area, j ...

s and

s) *

Casuariidae The bird family Casuariidae has four surviving members: the three species of cassowary and the emu. All living members of the family are very large flightless birds native to Australia-New Guinea.Clements, J (2007) Species *† ''Emuarius'' B ...

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cassowaries Cassowaries ( tpi, muruk, id, kasuari) are flightless birds of the genus ''Casuarius'' in the order Casuariiformes. They are classified as ratites (flightless birds without a keel on their sternum bones) and are native to the tropical fo ...

) * Ciconiidae (

stork Storks are large, long-legged, long-necked wading birds with long, stout bills. They belong to the family called Ciconiidae, and make up the order Ciconiiformes . Ciconiiformes previously included a number of other families, such as herons an ...

s) *

Threskiornithidae The family Threskiornithidae includes 36 species of large wading birds. The family has been traditionally classified into two subfamilies, the ibises and the spoonbills; however recent genetic studies have cast doubt on this arrangement, and ha ...

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ibis The ibises () (collective plural ibis; classical plurals ibides and ibes) are a group of long-legged wading birds in the family Threskiornithidae, that inhabit wetlands, forests and plains. "Ibis" derives from the Latin and Ancient Greek word ...

es and

spoonbill Spoonbills are a genus, ''Platalea'', of large, long-legged wading birds. The spoonbills have a global distribution, being found on every continent except Antarctica. The genus name ''Platalea'' derives from Ancient Greek and means "broad", refe ...

s) * Charadriidae ( lapwings) *

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, flo ...

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swan Swans are birds of the family Anatidae within the genus ''Cygnus''. The swans' closest relatives include the geese and ducks. Swans are grouped with the closely related geese in the subfamily Anserinae where they form the tribe Cygnini. Som ...

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 geese) * Cuculidae (

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 and relatives) * Musophagidae ( turacos) * Cacatuidae ( cockatoos) *

Psittacidae The family Psittacidae or holotropical parrots is one of three families of true parrots. It comprises the roughly 10 species of subfamily Psittacinae (the Old World or Afrotropical parrots) and 157 of subfamily Arinae (the New World or Neotropi ...

(

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 ...

s and

macaw Macaws are a group of New World parrots that are long-tailed and often colorful. They are popular in aviculture or as companion parrots, although there are conservation concerns about several species in the wild. Biology Of the many differ ...

s) * Coliidae ( mousebird) *

Callaeidae Callaeidae (sometimes Callaeatidae) is a family of passerine birds endemic to New Zealand. It contains three genera, with five species in the family. One species, the huia, became extinct early in the 20th century, while the South Island kokak ...

( kokako, saddleback and

huia The huia ( ; ; ''Heteralocha acutirostris'') is an extinct species of New Zealand wattlebird, endemic to the North Island of New Zealand. The last confirmed sighting of a huia was in 1907, although there was a credible sighting in 1924. It ...

) * Campephagidae (

lobotos ''Lobotos'' is a genus of bird in the cuckooshrike family Campephagidae. It is sometimes included in the genus Campephaga. It contains the following two species: * Western wattled cuckooshrike The western wattled cuckooshrike or Ghana cuc ...

) * Meliphagidae ( honeyeaters) *

Picathartes The picathartes, rockfowl, or bald crows are a small genus of two passerine bird species forming the family Picathartidae found in the rain-forests of tropical west and central Africa. They have unfeathered heads, and feed on insects and inverte ...

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white-necked rockfowl The white-necked rockfowl (''Picathartes gymnocephalus'') is a medium-sized bird in the family Picathartidae, with a long neck and tail. Also known as the white-necked picathartes, this passerine is mainly found in rocky forested areas at high ...

) *

Platysteiridae Platysteiridae is a family of small, stout passerine birds of the African tropics. The family contains the wattle-eyes, batises and shrike-flycatchers. They were previously classed as a subfamily of the Old World flycatchers, Muscicapidae. Thes ...

( black-throated wattle-eye) *

Tyrannidae The tyrant flycatchers (Tyrannidae) are a family of passerine birds which occur throughout North and South America. They are considered the largest family of birds known to exist in the world, with more than 400 species. They are the most dive ...

( indian silverbill)

Gallery

References

{{reflist Bird anatomy Anatomy