Peafowl

• 1. Introduction

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  Peafowl are three species of large game birds, and the famous fan of the male is not a tail at all. It is a train of highly elongated upper tail coverts, each feather marked with an eyespot. Two of the species belong to the genus Pavo and one to the genus Afropavo, all within the pheasant family. Strictly speaking, a male is a peacock and a female is a peahen, although everyday speech uses peacock for both sexes. Scientists have argued for generations over why any bird would carry such a showy and conspicuous structure. Other questions follow. How can a feather make colour without any paint? And why did Hindu gods, Greek goddesses, Yazidi angels and Mughal rulers all claim this bird as a symbol?

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• 2. Plumage And Physics

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  The blue or Indian peafowl, Pavo cristatus, comes from the Indian subcontinent. Its male has iridescent plumage, mostly metal-like blue and green. The green peafowl, Pavo muticus, lives in Southeast Asia, and its male wears green with bronze or gold, plus black wings with a sheen of blue. The Congo peafowl, Afropavo congensis, is native only to the Congo Basin. All three species carry a crest on the head.

  The differences between the sexes vary by species. In both Asiatic species, females are a little smaller than males in weight and wingspan, while males are significantly longer. The Indian peahen is a mixture of dull grey, brown and green. She also fans her plumage, either to ward off female competition or to signal danger to her young. The green peahen looks much like her mate, with shorter upper tail coverts, a more coppery neck and less iridescence. Both sexes of the green species have spurs.

  The Congo male does something different from his Asian cousins. He does not display covert feathers at all and uses his actual tail feathers in courtship. Those feathers are much shorter, and their ocelli are far less pronounced. Females of the Indian and African species are dull grey or brown.

  Chicks of both sexes, in every species, are cryptically coloured. They range between yellow and tawny, usually with patches of darker brown or light tan and a dirty white ivory.

  Mature peahens can surprise observers. Some have been recorded suddenly growing typical male plumage and giving male calls. Research suggests the cause is a lack of estrogen from old or damaged ovaries, and that male plumage and calls are the default unless hormones suppress them.

  The brilliant colours of the male are not primarily pigments. As in many birds, the vibrant iridescence is structural coloration. Regular, periodic nanostructures in the barbules, the fiber-like components of each feather, produce optical interference known as Bragg reflections. Slight changes in the spacing of the barbules give different colours. Brown feathers are a mixture of red and blue. The periodic structure creates one of those colours, and a Fabry-Pérot interference peak from reflections off the outer and inner boundaries creates the other. Colour built from physical structure rather than pigment shifts with the viewing angle, and that shifting is what iridescence means. For a courting bird, the angle from which a feather is seen therefore decides the colour a peahen sees.

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• 3. Display And Daily Life

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  A courting peahen typically stops directly in front of the peacock, which lets her judge him at 90° to the surface of the feather. The male then turns and shows his train about 45° to the right of the sun's azimuth, so that sunlight accentuates the iridescence. If she chooses to interact, he turns to face her and shivers his train to begin the mating process.

  Different parts of the train do different jobs. The lower train is usually evaluated during close-up courtship, while the upper train works as a long-distance attraction signal. Train rattling and wing shaking also keep the peahen's attention. Voice matters too. Vocalisation is a primary way for peacocks to attract peahens, and some studies suggest the intricacy of the song impresses them. Singing usually comes just before, just after, or sometimes during copulation.

  During the breeding season, males gather for a communal display while peahens watch. They first defend their territory against intruders, then fight for places within the group so as to present a strong front. Older, dominant males usually take the central positions, which influences mating success. Train length helps in winning territory, while visual and vocal displays matter when peahens choose a mate. The redundant signal hypothesis tries to explain this layering. It holds that each signal is of about the same quality, yet adding signals makes the male a more reliable choice. Its success depends not only on repeating the signal but also on having multiple receivers.

  Away from the display ground, peafowl are forest birds that nest on the ground but roost in trees. All species are believed to be polygamous. Like other members of the Galliformes, males carry metatarsal spurs, also called thorns, on their legs. They use these spurs in territorial fights with their own kind.

  Wild peafowl forage by scratching through leaf litter early in the morning or at dusk. They retreat to the shade and security of the woods for the hottest part of the day. They are omnivores that mostly eat plants, flower petals, seed heads, insects and other arthropods, reptiles and amphibians. They actively hunt ants, crickets, termites and millipedes, and will take small mammals. Indian peafowl also eat small snakes. They are not picky and will eat almost anything they can fit in the beak and digest.

  Domesticated peafowl accept bread, cracked grain such as oats and corn, cheese, cooked rice and sometimes cat food. Keepers have noticed that they enjoy protein-rich food, including larvae that infest granaries, different kinds of meat and fruit. They also like dark leafy greens, broccoli, carrots, beans, beets and peas. Whether the train that males carry is an advertisement, a warning or a burden is the question that Charles Darwin set out to answer.

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• 4. Darwin's Puzzle

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  In The Descent of Man and Selection in Relation to Sex, Charles Darwin proposed that peafowl plumage evolved through sexual selection. He reasoned that many female ancestors of the peacock appreciated the more splendid males over a long line of descent. Through a continued, unconscious preference for the most beautiful males, they had, in his words, "rendered the peacock the most splendid of living birds."

  Amotz Zahavi offered a harsher view in his handicap principle. The male's excessive tail plumes are likely to harm his survival, because their brilliance makes him more visible to predators and their length hinders escape. Zahavi argued that only the fittest males can survive such a handicap. A brilliant train is therefore an honest signal to females that its owner is good at surviving for other reasons. This contrasts with Ronald Fisher's hypothesis, in which male sexual traits come from an initially arbitrary aesthetic preference among females.

  Several hypotheses about female choice have been posited. In the good genes version, females choose males with more exaggerated traits, such as bigger and brighter trains, because those males tend to have better genes. Those genes directly benefit her offspring, and her own fitness and reproductive success.

  Runaway selection is a second hypothesis. Linked genes in males and females code for a male trait and for the female preference for it. Because the alleles for the train and for the preference sit close together on the chromosome, in what is called linkage disequilibrium, a positive feedback loop exaggerates both the male trait and the female preference.

  A third hypothesis is sensory bias, where females prefer a trait in a non-mating context and the preference is later transferred to mating. Merle Jacobs proposed such a food-courtship idea, in which peahens are drawn to peacocks because the eye spots resemble blue berries. The causes of female choice may also be multiple.

  A rival school sees the train through natural selection, with or without sexual selection as well. In this view the train, the loud call and the fearless behaviour work as an aposematic display that intimidates predators and rivals. It was designed to explain a puzzling field study, described in the next chapter. A feral flock in southern England had meanwhile become the setting for a direct experiment.

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• 5. Testing The Train

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  At Whipsnade Wildlife Park in southern England, Marion Petrie studied a feral population of peafowl to see whether displays signalled genetic quality. The number of eyespots in a male's train predicted his mating success. She then manipulated that success by cutting the eyespots off some males' tails. Females lost interest in the pruned males and kept their interest in untrimmed ones. Males with fewer eyespots, and therefore lower mating success, also suffered greater predation.

  Petrie next let females mate with males carrying differing numbers of eyespots. She reared the offspring in a communal incubator, which controlled for differences in maternal care. Chicks fathered by more ornamented males weighed more than those fathered by less ornamented males, a trait generally linked to better survival in birds. The chicks were released into the park and recaptured one year later. Those with heavily ornamented feathers had been better able to avoid predators and survive in natural conditions. Her work thus showed links between tail ornamentation, mating success and survival, in the males and in their offspring.

  A seven-year study of free-ranging peafowl in Japan reached a different conclusion. Mariko Takahashi found no evidence that peahens preferred peacocks with more eyespots, a more symmetrical arrangement or a greater length. She determined that the train was not the universal target of female mate choice. It showed little variance across male populations and did not correlate with the male's physiological condition.

  Other work points to colour and angle. A peacock's copulation success depends on the colours of his eyespots, or ocelli, and the angle at which he displays them. During courtship, that angle matters more to a peahen than train size or the number of ocelli.

  Adeline Loyau and her colleagues answered Takahashi's results by saying that alternative and possibly central explanations had been overlooked. They concluded that female choice might indeed vary in different ecological conditions.

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• 6. Gods And Emperors

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  In Hinduism, the Indian peacock serves as the mount of Kartikeya, the god of war, and of the warrior goddess Kaumari. It is also depicted around the goddess Santoshi. One story says that Kartikeya split the demon king Surapadman in half during a war with the Asuras. Out of respect for his adversary's prowess in battle, the god made both halves part of himself. One became the peacock that carries him, and the other a rooster on his flag. When a peacock spreads its plumes into a full circle, it is said to show the divine shape of Omkara. In Tantric traditions, the goddess Tvarita is depicted with peacock feathers, and a peacock feather adorns the crest of the god Krishna.

  Chandragupta Maurya, founder of the Mauryan Empire, was born an orphan and raised by a family that farmed peacocks. Buddhist tradition says his ancestors settled in a region where peacocks were abundant. The Pali word for peacock is mora, so they became known as Moriyas, meaning belonging to the place of peacocks. Another Buddhist account says they built a city called Moriya-nagara, using bricks coloured like peacocks' necks. After conquering the Nanda Empire and defeating the Seleucid Empire, the dynasty reigned uncontested. Its royal emblem remained the peacock until Emperor Ashoka changed it to a lion, as seen in the Lion Capital of Ashoka and in his edicts. The bird still stood for elegance and royalty in medieval India, and the Mughal seat of power was called the Peacock Throne.

  Buddhist art gives the bird further roles. The deity Mahamayuri is depicted seated on a peacock. Peacocks also support the throne of Amitabha, the ruby red, sunset-coloured archetypal Buddha of Infinite Light. The peacock appears in the Burmese and Sinhalese zodiacs, and to the Sinhalese people of Sri Lanka it is the third animal of the zodiac. A popular belief held that peacocks deliberately eat poisonous substances, to become immune and to make their plumage more vibrant. That idea seems to have some merit, since so many poisonous plants and animals are colourful through aposematism. India adopted the peacock as its national bird in 1963.

  In Yazidism, Tawûsî Melek is one of the central figures and is symbolized by a peacock. Yazidi creation stories say that God created seven Divine Beings before this world and appointed Tawûsî Melek as their leader. They are also called the Seven Angels, or heft sirr, the Seven Mysteries. The peacock represents the diversity of the world, and its colourful feathers stand for all the colours of nature. The feathers also symbolize sun rays, which bring light and brightness, and a tail opened in a circle symbolizes the sunrise. Because of this holiness, Yazidis may not hunt or eat the peacock, ill-treat it or speak badly of it. Images of the peacock are drawn around the sanctuary of Lalish and on other shrines, homes, and religious, social, cultural and academic centres.

  In Mandaeism, the text known as The Baptism of Hibil Ziwa describes the uthra and emanation Yushamin as a peacock.

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• 7. Myth, Faith, And Logo

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  Ancient Greeks believed that peafowl flesh did not decay after death, so the bird became a symbol of immortality. In Hellenistic imagery, the goddess Hera's chariot was pulled by peacocks, even though Greeks had not known the birds before the conquests of Alexander. Aristotle, who had been Alexander's tutor, called it "the Persian bird." When Alexander saw peacocks in India, he was so amazed at their beauty that he threatened the severest penalties for any man who killed one. Claudius Aelianus wrote that India had peacocks larger than anywhere else.

  One myth explains the eyes in the tail. Hera's servant, the hundred-eyed Argus Panoptes, was told to guard Io, a woman Hera had turned into a cow after learning of Zeus's interest in her. Zeus had Hermes, the messenger of the gods, kill Argus and free Io. According to Ovid, Hera honoured her faithful watchman by preserving his hundred eyes forever in the peacock's tail.

  Early Christianity adopted the symbolism, so many early Christian paintings and mosaics show the peacock. It is still used in the Easter season, especially in the east. The eyes of the tail feathers can symbolise the all-seeing Christian God, the Church or angelic wisdom. A pair of peacocks drinking from a vase stands for the eucharist and the resurrection, since it shows the believer drinking the waters of eternal life. Read as a whole, the many-eyed tail can symbolise the cosmos, a vault of heaven dotted with sun, moon and stars. Augustine adopted the ancient idea that the flesh did not decay, so the bird was again linked with immortality. In Christian iconography, two peacocks are often shown on either side of the Tree of Life. Peacock feathers were also associated with angels' wings, which led to a belief that waving liturgical fans made of such feathers automatically sent up prayers. Artists painted angels with peacock-feather wings.

  Among Ashkenazi Jews, the golden peacock is a symbol of joy and creativity, and quills from its feathers are a metaphor for a writer's inspiration. The Renaissance revived the motif through an iconography that unified Hera and Juno, and European painters focused on it.

  In 1956, John J. Graham created an abstraction of an 11-feathered peacock as a logo for the American broadcaster NBC. The brightly hued bird was chosen because of the increase in colour programming, and the first colour broadcasts showed only a still frame of it. The emblem first appeared on air on the 22nd of May 1956. The current six-feathered logo debuted on the 12th of May 1986.

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• 8. Breeders And Banquets

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  Hybrids between Indian and green peafowl are called Spaldings, after Keith Spalding, the first person to hybridise them successfully. A Spalding with a high-green phenotype does much better in cold temperatures than the cold-intolerant green peafowl, while still looking like its green parent. Plumage varies between individuals. Some look far more like green peafowl, some far more like blue, and most carry traits of both.

  Among breeders, several hundred colour and pattern variations of the Indian blue are recognised as separate morphs. Patterns include solid-wing or black shoulder, pied, white-eye and silver pied. Colours include white, purple, Buford bronze, opal, midnight, charcoal, jade and taupe, as well as the sex-linked colours purple, cameo, peach and Sonja's Violeta. The United Peafowl Association must first approve a new variation before it becomes an official morph. Each colour is recognisable at hatching, though a peachick's plumage does not necessarily match its adult plumage.

  White peafowl are occasionally seen, but almost all are not albinos. True albinos exist but are quite rare. Most white birds have leucism, a genetic condition in which pigment cells fail to migrate from the neural crest during development. A leucistic bird can produce pigment but cannot deposit it in the feathers, leaving blue-grey eyes and plumage with no colour at all. Pied peafowl have partial leucism, so they carry colour along with patches that have none, and they also have blue-grey eyes. A true albino would lack melanin completely, giving irises that look red or pink. Leucistic peachicks are born yellow and turn fully white as they mature.

  The black-shouldered or Japanned mutation, P. c. nigripennis, was once treated as a subspecies of the Indian peafowl, or even as a separate species. It drew interest in the time of Charles Darwin (1809-1882). Darwin presented firm evidence that it was a variety under domestication, a view now well established. Proving this mattered to him, because a wild species would have undermined his theory of slow modification by natural selection in the wild. The adult male of this mutation is melanistic with black wings.

  In ancient Rome, peafowl were served as a delicacy, and the dish was introduced there in approximately 35 B.C. Peafowl eggs were also valued. The poet Horace ridiculed the habit by saying the birds tasted like chicken. Gaius Petronius, in his Satyricon, mocked the ostentation and snobbery of eating peafowl and their eggs.

  In the medieval period, poorer people such as serfs ate common birds like chicken. The wealthy gentry were privileged to eat rarer foods such as swan, and even peafowl. On a king's table, a peacock was there for ostentatious display as much as for eating.

  The English and Australian Cookery Book of 1864 describes how to prepare one. The cook skins the bird with great care rather than plucking it, so that the feathers are not detached or broken. The bird is stuffed with items such as truffles, mushrooms, fowl livers, bacon, thyme, bread crumbs and a bay leaf. The head and claws are wrapped in cloth and basted during cooking to preserve them. A bird to be served cold is set upright on a wooden trencher with a skewer through the body, and the tail is arranged like a fan on wire. The book adds that no ordinary cook can present a peacock properly. In the age of chivalry, the honour of carrying it in, amid inspiring music, went to the lady most distinguished for her beauty. At a wedding feast, the maid of honour served the peacock and placed it before the bride.

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