The Indian peafowl ( Pavo cristatus), also known as the common peafowl, or blue peafowl, is a species of peafowl native to the Indian subcontinent. While it originated in the Indian subcontinent, it has since been introduced to many other parts of the world. Male peafowl are referred to as peacocks, and female peafowl are referred to as peahens, although both sexes are often referred to colloquialism as a "peacock".
The Indian peafowl displays a marked form of sexual dimorphism. The brightly coloured male has a blue coloured head with a fan-shaped crest and is best known for his long train. The train is made up of elongated upper-tail covert feathers with colourful eyespots. These stiff feathers are raised into a fan and quivered in a display during courtship. The peahen is predominantly brown in colour, with a white face and iridescent green lower neck, and lacks the elaborate train. There are several colour mutations of the Indian peafowl including the leucistic white peafowl.
Despite the length and size of the covert feathers, the peacock is still capable of flight. The peafowl lives mainly on the ground in open forests or on cultivable lands where it forages for berries and grains, and also preys on snakes, lizards and small rodents. It makes loud calls, which makes it easier to detect, and are often used to indicate the presence of a predator in the forest areas. It forages on the ground in small groups and usually escapes on foot through undergrowth and avoids flying, though it flies into tall trees to roost.
The function of the Indian peacock's elaborate train has been debated for more than a century. In the 19th century, Charles Darwin found it a puzzle, hard to explain through ordinary natural selection. His later explanation, sexual selection, is widely but not universally accepted. In the 20th century, Amotz Zahavi argued that the train was a handicap, and that males were honestly signalling their fitness in proportion to the splendour of their trains. Despite extensive study, opinions remain divided on the mechanisms involved.
The Indian peafowl is listed as Least Concern on the IUCN Red List. It is the national bird of India and venerated in Hindu mythology and Greek mythology.
The earliest usage of the word peacock in written English was from the 14th century where Geoffrey Chaucer used the word in a simile " proud a pekok" in his poem Troilus and Criseyde. Various spelling variants included peacock, pacok, pecok, pekok, pokok, and pocok among others.
The male is best known for his elongated train, which extend from the rump. The train is made up of elongated upper tail coverts, which are bronze-green train with the outermost and longer feathers ending up with an elaborate eye-spot. The eye-spots consist of a purplish-black, heart-shaped nucleus, enclosed by blue and an outer copper rim, which is surrounded by alternating green and bronze. A few of the outer feathers lack the spot and end in a crescent shaped black tip. The feathers of the train does not have colored pigments and the colorization is a result of the micro-structure of the feathers and the optical phenomena involved. The male has a spur on the leg above the hind toe. The train feathers and the tarsal spur of the male starts developing only in the second year of its life. The trains are not fully developed until the age of four. The train feathers of the male Indian peafowl are also moulted every year, usually starting at the end of the monsoon in August or September and are fully developed by February to March. The moult of the flight feathers may be spread out across the year.
The females or peahens, are smaller at around in length and weigh . The peahen has a rufous-brown head with a crest, whose tips are chestnut colored and edged with green. The upper body is brownish with pale mottling and the primaries, secondaries and tail are dark brown. The lower neck is metallic green with dark brown breast feathers glossed with green and whitish underparts. Both the sexes have dark brown eyes, brown colored beak and legs. Young males also resemble the females with chestnut colored primaries.
Crosses between a male green peafowl ( Pavo muticus) and a female Indian peafowl ( P. cristatus) produce a stable hybrid called a "Spalding", named after Keith Spalding, a bird fancier from California. There can be problems if birds of unknown pedigree are released into the wild, as the viability of such hybrids and their offspring is often reduced as per Haldane's rule.
The first whole-genome sequencing of the Indian peafowl identified 15,970 Coding region and was found to have less repetitive DNA (8.62%) than that of the chicken genome (9.45%). Studies have suggested that the population suffered at least two bottlenecks (four mya and 450,000 years ago), which resulted in a severe reduction in its effective population size.
A peacock use its ornate train in a courtship display, wherein it raises the tail feathers into an arched fan and quivers them. The wings are held half open and drooped and it periodically vibrates the long feathers, producing a ruffling sound. It faces the peahen initially and might turn around to display the tail. The peacock may also freeze over food to invite a peahen in a form of courtship feeding. While peacocks may also display even in the absence of peahens, it is usually done close to the females. When a peacock is displaying, peahens appear not to show any interest and usually continue their foraging.
The nests are usually shallow hollow scrapes on the ground lined with leaves, sticks and other debris. The peafowl might also nest on crevices in the buildings, and disused nests of vultures. The female lays a clutch of three to eight oval shaped eggs. The eggs measure about in length and in width. They appear polished and have thick shells with pits and pores. The color varies from pale white to buff or reddish-brown. The males take no part in hatching or rearing the young. However, isolated unusual instance of a male incubating a clutch of eggs has been reported. The eggs are incubated by the females for about 28 days. The chicks are nidifugous and follow the mother around after hatching. Downy young may sometimes climb on their mothers' back and the female may carry them in flight to a safe tree branch.
In the 1970s, Israeli people biologist Amotz Zahavi proposed a possible resolution to the apparent contradiction between natural selection and sexual selection. He argued that the peacock honestly signalled the handicap of having a large and costly train. However, the mechanism may be less straightforward than it seems and the cost could be that the that enhance feather development also results in the depression of the immune system.
A study on the feral population of Indian peafowl at Whipsnade Wildlife Park in southern England, showed that the number of eyespots in the train predicted a male's mating success, and this success could be manipulated by cutting the eyespots off some of the male's ornate feathers. Furthermore, the study also found that the chicks fathered by more ornamented males weighed more than those fathered by less ornamented males, which indicated an increased survival ability. However, recent studies have failed to find a relation between the number of displayed eyespots and mating success.
A seven-year study of free-ranging peafowl came to the conclusion that female peafowl do not select mates solely on the basis of their trains and it is an obsolete signal for which female preference has already been "lost or weakened". It found no evidence that peahens expressed any preference for peacocks with more elaborate trains, trains having more ocelli, a more symmetrical arrangement, or greater length. It determined that the peacock's train was not the universal target of female mate choice, and do not correlate to male physical conditions. It argued that the removal of eyespots substantially changed the appearance of male peafowls, and it was likely that the females mistook these males for sub-adults, or perceived that the males were physically damaged. Moreover, in a feral peafowl population, there is little variation in the number of eyespots in adult males as it is rare for adult males to lose a significant number of eyespots and hence, it might not form the basis for sexual selection. The British research team argued that alternative explanations for these results had been overlooked, and concluded that female choice might indeed vary in different ecological conditions.
A 2010 study on a natural population of Indian peafowls in northern India proposed a "high maintenance handicap" theory. It stated that only the fittest males can afford the time and energy to maintain a long tail and the long train is an indicator of good body condition, which results in greater mating success. While train length seems to correlate positively with major histocompatibility complex diversity in males, females do not appear to use train length to choose males. Another study in France brought up two possible explanations with the first explanation stating that there might be a genetic variation of the trait of interest under different geographical areas due to a founder effect and/or a genetic drift. The second explanation suggested that "the cost of trait expression may vary with environmental conditions," so that a trait that is indicative of a particular quality may not work in another environment. A 2013 study that tracked the eye movements of peahens responding to male displays found that the peahens looked in the direction of the upper train of feathers only when at long distances and that they looked only at the lower feathers when males displayed close to them. The rattling of the tail and the shaking of the wings helped in keeping the attention of females.
The Indian peafowl is protected both culturally and by law in India and Sri lanka. Methods to identify if feathers have been plucked or have been shed naturally have been developed, as Indian law allows only the collection of feathers that have been shed. Various methods have been employed to restrict access to the farmlands such as usage of jute fencing and application of non-poisonous pesticides to reduce fatality of the birds. Cities have been introduced peafowl management programmes, which include education on how to prevent the birds from causing damage while treating the birds humanely. Various wildlife sanctuaries have been established in India such as Adichunchanagiri, Choolannur, and Viralimalai for the protection of the species. The Indian peafowl also breed readily in captivity and various zoos, parks, and bird-fanciers maintain breeding populations across the world.
Numerous uses of the bird's parts as an antidote to snake venom in Ayurveda and other folk remedies have been documented. It is part of folklore with beliefs such as the impregnation of peahens orally by means of the tears of the peacocks. In Greek mythology, the origin of the Indian peacock's plumage is explained in the tale of Hera and Argus Panoptes. The main figure of , Melek Taus, is commonly depicted as a peacock.
A golden peacock is considered as a symbol of Yiddishkeit, and is the subject of several folktales and songs in Yiddish.
In the Middle Ages, knights in Europe took a "vow of the peacock" and decorated their helmets with its plumes. In Robin Hood stories, the titular archer uses arrows fletched with peacock feathers. Peacock feathers were buried with Viking warriors.
The birds were often kept in menageries and as ornaments in large gardens and estates in the middle ages. In 1526, the legal issue as to whether peacocks were wild or domestic fowl was thought sufficiently important for Cardinal Wolsey to summon all the English judges to give their opinion, which was that they are domestic fowl. Indian peacocks were frequently used in European heraldry with the peacocks most often depicted as facing the viewer and with the tails displayed. In this pose, the peacock is referred to as being "in his pride". Peacock tails, in isolation from the rest of the bird, are rare in British heraldry, but are used frequently in German people systems. The Indian peacock feathers are used in many rituals and ornamentation and its motifs are widespread in architecture, coinage, textiles and modern items of art and utility. Indian peacock motifs are widely used even today such as in the logos of the NBC logo television network and the Sri Lankan Airlines.
The term "peacocking" is often used as a means of depicting pride in English language and is used to describe someone who is very proud or gives a lot of attention to clothing. In Australia, it referred to the practice of buying up the best pieces of land so as to render the surrounding lands valueless.
Description
Mutations and hybrids
Distribution and habitat
Behaviour and ecology
Feeding
Communication
Breeding
Sexual selection
Lifespan and mortality
Threats and conservation
In culture
Further reading
External links
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