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 A dewlap is a longitudinal flap of skin or similar flesh that hangs beneath the lower jaw or neck of many vertebrates. More loosely, it can be various similar structures in the neck area, such as those caused by a double chin or the submandibula ...

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 Erectile tissue is tissue in the body with numerous vascular spaces, or cavernous tissue, that may become engorged with blood. However, tissue that is devoid of or otherwise lacking erectile tissue (such as the labia minora, the vestibule/vagina and ...

, 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, 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

turkeys The turkey is a large bird in the genus ''Meleagris'', native to North America. There are two extant turkey species: the wild turkey (''Meleagris gallopavo'') of eastern and central North America and the ocellated turkey (''Meleagris ocellat ...

, 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 duck The Muscovy duck (''Cairina moschata'') is a large duck native to the Americas, from the Rio Grande Valley of Texas and Mexico south to Argentina and Uruguay. Small wild and feral breeding populations have established themselves in the United St ...

s, 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 (

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 in ...

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 widespre ...

(

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 (

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 ( cassowaries) * Ciconiidae ( storks) *

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 ...

(

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 spoonbills) *

Charadriidae The bird family Charadriidae includes the plovers, dotterels, and lapwings, about 64 to 68 species in all. Taxonomy The family Charadriidae was introduced (as Charadriadæ) by the English zoologist William Elford Leach in a guide to the con ...

(

lapwings Lapwings (subfamily Vanellinae) are any of various ground-nesting birds (family Charadriidae) akin to plovers and dotterels. They range from in length, and are noted for their slow, irregular wingbeats in flight and a shrill, wailing cry. A gro ...

) *

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 ...

( swans,

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 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 she ...

) *

Cuculidae 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 separa ...

(

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 The turacos make up the bird family Musophagidae ( "banana-eaters"), which includes plantain-eaters and go-away-birds. In southern Africa both turacos and go-away-birds are commonly known as loeries. They are semi-zygodactylous: the fourth ( ...

(

turaco The turacos make up the bird family Musophagidae ( "banana-eaters"), which includes plantain-eaters and go-away-birds. In southern Africa both turacos and go-away-birds are commonly known as loeries. They are semi-zygodactylous: the fourth ( ...

s) *

Cacatuidae A cockatoo is any of the 21 parrot species belonging to the family Cacatuidae, the only family in the superfamily Cacatuoidea. Along with the Psittacoidea (true parrots) and the Strigopoidea (large New Zealand parrots), they make up the orde ...

(

cockatoos A cockatoo is any of the 21 parrot species belonging to the family Cacatuidae, the only family in the superfamily Cacatuoidea. Along with the Psittacoidea (true parrots) and the Strigopoidea (large New Zealand parrots), they make up the ord ...

) *

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 macaws) *

Coliidae The mousebirds are birds in the order Coliiformes. They are the sister group to the clade Eucavitaves, which includes the Leptosomiformes (the cuckoo roller), Trogoniformes ( trogons), Bucerotiformes (hornbills and hoopoes), Piciformes (woo ...

(

mousebird The mousebirds are birds in the order Coliiformes. They are the sister group to the clade Eucavitaves, which includes the Leptosomiformes (the cuckoo roller), Trogoniformes (trogons), Bucerotiformes (hornbills and hoopoes), Piciformes (wood ...

) * Callaeidae ( 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) *

Meliphagidae The honeyeaters are a large and diverse family, Meliphagidae, of small to medium-sized birds. The family includes the Australian chats, myzomelas, friarbirds, wattlebirds, miners and melidectes. They are most common in Australia and New Gu ...

(

honeyeaters The honeyeaters are a large and diverse family, Meliphagidae, of small to medium-sized birds. The family includes the Australian chats, myzomelas, friarbirds, wattlebirds, miners and melidectes. They are most common in Australia and New Gui ...

) *

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 inverteb ...

(

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 higher ...

) *

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. These ...

( 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 The Indian silverbill or white-throated munia (''Euodice malabarica'') is a small passerine bird found in the Indian Subcontinent and adjoining regions that was formerly considered to include the closely related African silverbill (''Euodice cant ...

)

Gallery

References

{{reflist Bird anatomy Anatomy