Pavo cristatusIndian peafowl

Geographic Range

Indian blue peafowl, Pavo cristatus, (also known as peacocks) are native to Sri Lanka and India, but can also be found naturally in Pakistan, Kashmir, Nepal, Assam, Nagaland, Burma, Java, Ceylon, Malaya, and the Congo. Peafowl are prized possessions and therefore can be found in any country in captivity through trade. The Arakan hills prevented this species from moving naturally to the east, while the mountains of the Himalayas and Karakoram further prevented their travel north. (Hopkins, 1997; Jackson, 2006)

Habitat

Indian blue peafowl do not migrate or travel widely. They are most common in deciduous, open forest habitats. In one study in Dak Lak, Vietnam, green peafowl preferred dry deciduous forest over mixed and evergreen forest. Areas that had sufficient water sources and were relatively distant from any human presence were also preferred if given the choice. Their basic requirements include a suitable roost tree, a small territory, and sufficient food. In their native range, peafowl are only found from 900 to 1200 m above sea level in areas with appropriate forest habitat to support them. Peafowl are able to adapt to much colder climates than their native range. In captivity, they can survive winters in southern Britain with only a simple shelter. However, in areas that are both damp and cold, peafowl do not fare as well. They are often kept in urban gardens and zoos. (Brickle, 2002; Jackson, 2006)

  • Range elevation
    900 to 1200 m
    2952.76 to 3937.01 ft

Physical Description

Indian blue peafowl are known best for their exquisite train and plumage. If the length of the tail and wing span is included, the peafowl is considered one of the largest flying birds. They weigh in between 2.7-6 kg and have a wingspan of 1.4-1.6 m. They vary widely in length from 0.86-2.12 m. This species has long, strong, grayish-brown legs equipped for running away into brush for safety. Both sexes are equipped with spurs that are around 2.5 cm long; males will use them during the breeding season to ward off other competing males. Females are brown, grey, and cream-colored. Chicks are usually a light yellow to brown color. The males have a long train, about 1.2 m in length on average, from June to December. The train is discarded in January, but is grown again at a rapid pace when breeding season approaches. Their necks and breasts are a bright blue, golden feathers line their sides and backs, and their trains are an iridescent arrangement of multiple colors featuring ocelli (eye-spots). When displayed, the male’s train spreads out in a wide fan, showing off gold, brown, green, and black feathers. Around 30 to 40 of the ocelli around the outer edges of the fan are not round but v-shaped. This complicated pattern is thought to be an advantage in mating, and even though it might seem like this bright pattern would make peafowl stand out, they can very easily disappear into foliage, making it extremely hard to spot.

There are three variations in the Indian blue peafowl. The white feathered peafowl has completely white feathers from the top of its head to the end of its train, with the ocelli barely visible. These are not albinos because they are true breeders (when bred with another white feathered peafowl, all their offspring will be white feathered peafowl as well) and have brown eyes. In another version known as pied, random white feathers appear in the plumage. This results from an incomplete dominant gene. Due to a different mutation, another variation results in dark feathers with blue and green tips, called the black-winged peafowl. In addition, Pavo cristatus can hybridize with the green peafowl, Pavo muticus. For the past two decades, a new mutation in the plumage has been discovered almost every year. (Jackson, 2006; Somes and Burger, 1993)

  • Sexual Dimorphism
  • male larger
  • sexes colored or patterned differently
  • male more colorful
  • ornamentation
  • Range mass
    2.7 to 6 kg
    5.95 to 13.22 lb
  • Average mass
    4 kg
    8.81 lb
  • Range length
    0.86 to 2.12 m
    2.82 to 6.96 ft
  • Average length
    1.50 m
    4.92 ft
  • Range wingspan
    1.4 to 1.6 m
    4.59 to 5.25 ft

Reproduction

There is a significant positive correlation between a peafowl’s train and its mating success. This correlation is due to female’s preference for more elaborate trains on their mates. Males spend a great deal of energy to produce and maintain good tail conditions, resulting in a trade-off between a longer train and avoiding predators or searching for food. Mating success is usually more successful for the males with the highest number of eyespots (also called ocelli) on their train. If eyespots were experimentally removed from a male’s train below the the range of other individuals eyespot numbers, mating success decreased significantly. There is also a positive correlation between the number of eyespots, the amount of time a male displays to a female during the breeding season, and the overall health of the individual. A peacock that displays less often and has less eyespots has more heterophils circulating in its body, indicating the peacock is spending more energy to fight off an infection than a male that displays more often with more eyespots. Peahens choose the peacocks with the most eyespots because her chicks will hopefully inherit the male’s superior immune system and have a greater chance at survival.

However, females rely on more than one trait when picking a male. Feather ornaments, such as length and number of eyespots during breeding season, is a fixed characteristic based on genetics and can reflect their past condition such as attacks or illnesses. Behavioral displays are flexible characteristics that can change day to day, mate to mate, and improve with experience. For example, peacocks use the sun at different angles when performing visual displays such as “train-rattling” or “wing-shaking”. Visual genetic traits and behavior of the male allow the peahen to determine the health of a mate and the benefits it would confer to their offspring.

Peahens are also very aggressive when it comes to finding a suitable partner. The bigger and stronger females will fight away other females and try to monopolize the male by repeatedly mating with him. Favored males tend to mate with more females and the same female more than once, increasing their fitness significantly. On average, males usually mate with up to six different peahens every breeding season. Because the male only contributes its sperm, females must pick the best possible choice and try to limit the access of other females to increase their own offspring’s survival rates. (Dakin, 2008; Loyau, et al., 2005; Petrie and Halliday, 1994; Petrie, et al., 1992; Walther and Clayton, 2005)

This species becomes sexually mature at three years, though some males can breed at age 2. Females will lay 3-5 brownish oval eggs, but in some cases have laid up to 12. The eggs are laid one at a time every other day. Their glossy shells have deep, small pores that let in water to keep it moist. The incubation period lasts up to 28 days.

The nest is made up of dry sticks and leaves, and is located on the ground, under shrubs. Naturally, a peahen will only lay one clutch per breeding season. If raised in captivity and a clutch is taken away from the female, she will mate again and can lay up to three clutches in a breeding season. The clutches removed from the mother can be given to a foster parent such as a turkey hen.

Chicks are mobile and fully feathered at hatching, can fly in about one week, and rely on their mother for only an additional few weeks. Although the chicks are fairly resilient, they do need relatively warm temperatures to survive and can die in colder climates. Some aviculturists have avoided this problem by raising eggs in incubators. Peachicks must be taught to eat and drink through imitation. Males and females look alike until the males develop their train and bright feathers. It takes up to three years for males to develop a full train. It is almost impossible to tell the difference until a couple of months after hatching in which the males have longer legs. Also, the males will have light gray outer primary feathers and their female counterparts will be brown. (Jackson, 2006)

  • Breeding interval
    Indian blue peafowl breed once per year, and more often if clutch is lost.
  • Breeding season
    Indian blue peafowl breed from April to September.
  • Range eggs per season
    3 to 12
  • Average eggs per season
    5
  • Range time to hatching
    27 to 29 days
  • Range fledging age
    1 to 2 weeks
  • Average fledging age
    1 weeks
  • Range time to independence
    7 to 10 weeks
  • Average time to independence
    8 weeks
  • Range age at sexual or reproductive maturity (female)
    1 to 3 years
  • Average age at sexual or reproductive maturity (female)
    3 years
  • Range age at sexual or reproductive maturity (male)
    2 to 3 years
  • Average age at sexual or reproductive maturity (male)
    3 years

Only the females are involved in the incubating of the eggs and the rearing of the chicks. Chicks are mobile and fully feathered at hatching, can fly in about one week, and rely on their mother for only an additional few weeks. If the female mates with a favored male, they usually have larger eggs with a higher amount of testosterone deposited in the yolk. Chicks of males who have the largest or most eye-spots tend to grow faster and have a better survival rate. (Loyau, et al., 2007; Petrie and Williams, 1993)

  • Parental Investment
  • precocial
  • female parental care
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

Pavo cristatus can live up to 25 years in the wild, but the average is around 20 years due to predation, diseases, electrocution from flying into power lines, pesticide poisoning, and destruction of their natural habitat. In captivity, the maximum life span is 23.2 years, with an average around 16 years. These differences in lifespan between captivity and the wild can be due to the diet. In the wild, peafowl have an entirely different lifestyle because they are always searching for food and must eat whatever they can find. In captivity, peafowl eat the feed that is given to them and do not have to search constantly for food. Because they are not burning off excessive protein and calcium, gout and kidney failure can shorten the lifespan of these captive birds. Those who decide to have Pavo cristatus as pets need to worm the peafowl twice a year to get rid of any parasites and prevent disease. (Hopkins, 1997; Norris, 1999; de Magalhaes and Costa, 2002)

  • Range lifespan
    Status: wild
    10 to 25 years
  • Average lifespan
    Status: wild
    18 years
  • Range lifespan
    Status: captivity
    10 to 23.2 years
  • Average lifespan
    Status: captivity
    15 years
  • Typical lifespan
    Status: wild
    10 to 20 years
  • Typical lifespan
    Status: captivity
    10 to 18 years
  • Average lifespan
    Status: captivity
    15 years

Behavior

Indian blue peafowl prefer a mostly solitary and isolated lifestyle. During the breeding season, a male will defend its territory and females will seek them out as mates. A single male can have a harem of six females. Outside of the breeding season, females live alone or with other females in groups of 2 or 3. Males also can live in small groups with other males or alone. This species is very cautious and always alert to spot any potential danger. Its head is always moving about, searching its surroundings for any predators. Unlike Congo peacocks (Afropavo congensis), or green peacocks (Pavo muticus), Pavo cristatus is less affected by the presence of humans, making it much easier for aviculturists to raise this species. Indian blue peafowl are diurnal, seeking protection high up in trees when it sleeps. Pavo cristatus only flies to the lowest branch, and then works its way up branch by branch until it has reached a safe height. This can sometimes be a very obvious roosting place, but it is very effective for avoiding its natural predators.

Indian blue peafowl require a lot of water to drink, but will not bathe in water because it weighs down their feathers. If their feathers do get wet, they wait in a safe location until they are dry. Instead of water baths, they take dust baths which help to get rid of any parasites or bugs. Peafowl spend a lot of time preening their feathers, especially the males whose mating success is very reliant on their displays.

Males will tend not to display when high winds make it too difficult to maintain their balance. However, their trains can be used for other purposes. Males will display as an intimidating factor against other males or other aggressive species. When fighting another male, the bird will leap up in the air and slash down at the defending male with their spurs. If they are attacked, they run away into dense undergrowth. Their coloring makes it almost impossible to spot once hidden away in shrubbery. Even a group of fifteen peafowl can vanish in seconds into shady foliage. If cover is not available and they are forced to take flight, they do not fly very fast or very far. (Jackson, 2006)

Home Range

Males defend their territory during the breeding season, attacking competing males with their spurs. During the non-breeding months, the males are less agressive towards other males, but will attack other animals (such as humans) if they feel threatened. Owners of these exotic birds put Indian blue peafowl in pens with their chickens or turkeys because they intimidate potential predators that roam onto their territory. (Jackson, 2006)

Communication and Perception

The calls of Indian blue peafowl are extremely loud and are often described as unpleasant, harsh shrieking. These calls are extremely varied, with up to six alarm calls issued by both sexes and seven additional calls that males emit during territorial disputes. Three of the calls the males produce are only associated with reproduction, and are typically only used during breeding season. These calls are only created by sexually-mature males, and can affect mating success. The calls mostly differ in pitch and the number of notes. These calls could be more important than the actual visual display of the males trains in which even the most elaborate can have varying rates of mating success. Vocal calls with more than five notes are generally more successful and it is believed that these types of calls are sexually selected by the females. Also, when predators, humans, or any other type of disturbance agitates a peafowl, they can issue an alarm call. The type of alarm call emitted depends on the threat. However, no matter how great the level of alarm, peafowls of any age and gender call back to increase awareness among the group. If the call indicates great danger, the peafowls will relocate to a safer position.

The elaborate ornamentation of male plumage is an important visual cue that communicates fitness to potential mates. Indian blue peafowl perceive their environment through visual, auditory, tactile, and chemical stimuli. (Takahashi and Hasegawa, 2008)

Food Habits

Indian blue peafowl are omnivorous. They consume insects, worms, lizards, frogs, and snakes. Termites are their food of choice. This species name in Sanskirt means “killer of snakes” because they eat young cobras (Ophiophagus Hannah), making them invaluable and often revered. They also feed on tree and flower buds, petals, grain, and grass and bamboo shoots. In order to help with the breakdown of their food, peafowl will ingest pebbles which are stored in their gizzard and help grind up grains. It is also reliant on an abundance of water for survival. (Jackson, 2006)

  • Animal Foods
  • amphibians
  • reptiles
  • insects
  • terrestrial worms
  • Plant Foods
  • leaves
  • roots and tubers
  • seeds, grains, and nuts
  • flowers

Predation

The natural enemies of Indian blue peafowl are large cats like civets (Civettictis civetta), tigers (Panthera tigris), and leopards (Panthera pardus). Wild dogs like dholes (Cuon alpines) and jackals (Canis aureus) are also considered to be main predators. Because peafowl are so effective at running away and disappearing into shrubbery, predators usually take the birds down in a surprise attack.

The male train can contribute to a higher predation rate on this species. When they are drinking or displaying, the train obstructs their view of potential predators stalking them from behind. Predators can also snatch a male's train if they are roosting too low. For example, tigers can stretch up to three meters and male peacocks can have trains over a meter long therefore it’s crucial for the peacock to be up at least five meters from the ground in order to be secure. Peafowl can use the spurs on their legs to defend themselves, but do not easily deter predators. However, humans have done the most damage to peacock populations and are considered to be the greatest enemy. Humans have been destroying their natural range, reducing their habitat, hunting them for sport, and eating them and their eggs. (Jackson, 2006)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Indian blue peafowl help regulate the numbers of venomous snakes, abundant lizards, and insects to maintain a stable ecosystem. Peafowl are a carrier of lice and microorganisms. In one study, Pavo cristatus was found to be a host for two louse species, Goniodes pavonis and Amyrisdea minuta. Because males and females only come together to mate and there is no parental care by the father, louse distribution is largely continued from the mother to the offspring. The father can still pass on the lice secondarily by infecting the mother, who then passes the lice to the peachicks. Females avoid this situation by picking the favored males because those mates most likely have the best parasite resistance and are less likely to pass on any parasites during copulation. In another study of captive peafowl at three different zoos, scientists tested the birds for the presence of harmful microorganisms. All three zoos had peafowl that carried Bordetella avium, Mycoplasma synoviae, Clostridium perfringens, and Escherichia coli. Bordetella avium and Mycoplasma synoviae are contagious and can be passed on to other species, but do not result in high mortality rates. Clostridium perfringens is a helpful bacteria for the digestive system of birds and is opportunistic, only becoming harmful under certain circumstances (like if the immune system is compromised by some other illness). (Hollamby, et al., 2003; Jackson, 2006; Moller, et al., 1999; Stewart, et al., 1996)

Mutualist Species
  • Intestinal bacteria Clostridium perfringens
Commensal/Parasitic Species
  • Intestinal bacteria Clostridium perfringens
  • Intestinal bacteria Escherichia coli
  • Louse Amyrisdea minuta
  • Louse Goniodes pavonis
  • Respiratory bacteria Bordetella avium
  • Respiratory bacteria Mycoplasma synoviae

Economic Importance for Humans: Positive

Pavo cristatus feather extract in the form of water or ash can be used to treat the poisonous bites of Russell vipers Vipera russelii, common cobras Naja naja, and Malabar pit vipers Trimeresurus malabaricus. The extract is high in iron, protein, and steroids, and acts as an inhibitor to harmful enzymes in the venom that cause tissue damage. This is a traditional treatment in India for those who live far away from hospitals and doctors.

Not only can the feathers be used for medical purposes, but can be used for decoration. Feathers were used to embellish helmets and hats during the Middle Ages, and more recently are used in flower arrangements. The feathers were used to fletch arrows and were woven into clothes. Over one hundred feathers can be collected from a single peacock when it molts, a collection method that does not harm the birds.

Their eggs are a profitable source of income in areas where they are not revered and protected through religion. Because of their extravagant trains, peacocks have been depicted in art and literature throughout the ages. In Hindu and Buddhist religions, Pavo cristatus is considered a vehicle for the gods. Religion is not the only reason Indian blue peafowl are respected and loved. They also kill deadly snakes such as cobras, and consumes a large number of insects reducing the amount of pesticides used on crops. (Jackson, 2006; Murari, et al., 2005)

Economic Importance for Humans: Negative

In areas where Indian blue peafowl have been introduced and allowed to roam free, it has the potential to disrupt the ecosystem if it feeds on endangered lizards, for example. This could result in irreversible and expensive damage. A high density of peafowl can easily cause destruction to farmers’ crops or flowerbeds. In some residential communities, this species can be a nuisance because of its frequent screeching. (Jackson, 2006)

  • Negative Impacts
  • crop pest

Conservation Status

Because this species is so thoroughly woven into many cultures, they face little threat of becoming endangered. However, because the human population is growing so quickly, peafowl face the loss of natural habitat and access to water sources. National parks are working to protect the habitats in India and nearby countries considered native to peafowl. Because Indian blue peafowl are so adaptable, it has been introduced to different countries to extend its range. There are also a large number of aviculturalists who raise and breed this species as pets. (Brickle, 2002; Jackson, 2006)

Contributors

Erin Fowler (author), Radford University, Karen Powers (editor), Radford University, Tanya Dewey (editor), University of Michigan-Ann Arbor, Rachelle Sterling (editor), Special Projects.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

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Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

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Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

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Neotropical

living in the southern part of the New World. In other words, Central and South America.

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Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

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acoustic

uses sound to communicate

arboreal

Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

diurnal
  1. active during the day, 2. lasting for one day.
drug

a substance used for the diagnosis, cure, mitigation, treatment, or prevention of disease

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

food

A substance that provides both nutrients and energy to a living thing.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.

omnivore

an animal that mainly eats all kinds of things, including plants and animals

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

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oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

pet trade

the business of buying and selling animals for people to keep in their homes as pets.

polygynous

having more than one female as a mate at one time

polymorphic

"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

sexual ornamentation

one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.

solitary

lives alone

suburban

living in residential areas on the outskirts of large cities or towns.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5? N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

urban

living in cities and large towns, landscapes dominated by human structures and activity.

visual

uses sight to communicate

young precocial

young are relatively well-developed when born

References

Brickle, N. 2002. Habitat use, predicted distribution and conservation of green peafowl (Pavo muticus) in Dak Lak Province, Vietnam. Biological Conservation, 105: 189-197.

Dakin, R. 2008. The role of the visual train ornament in the courtship of peafowl, Pavo cristatus. Masters Abstracts International, 47/03: 97.

Hollamby, S., J. Sikarskie, J. Stuht. 2003. Survey of peafowl (Pavo cristatus) for potential pathogens at three Michigan zoos. Journal of Zoo and Wildlife Medicine, 34/4: 375-379.

Hopkins, C. 1997. "Peafowl: Family Phasianidae" (On-line). Accessed April 20, 2010 at http://www.peafowl.org/ARTICLES/14/.

Jackson, C. 2006. Peacock. London: Reaktion Books LTD.

Loyau, A., M. Saint Jalme, C. Cagniant, G. Sorci. 2005. Multiple sexual advertisements honestly reflect health status in peacocks (Pavo cristatus). Behavioral Ecology and Sociobiology, 58/6: 552-557.

Loyau, A., M. Saint Jalme, R. Mauget, G. Sorci. 2007. Male sexual attractiveness affects the investment of maternal resources into the eggs in peafowl (Pavo cristatus). Behavioral Ecology and Sociobiology, 61/7: 1043-1052.

Moller, A., P. Christe, E. Lux. 1999. Parsitism, host immune function, and sexual selection. The Quarterly Review of Biology, 74/1: 3-20.

Murari, S., F. Frey, B. Frey, T. Gowda, B. Vishwanath. 2005. Use of Pavo cristatus feather extract for the better management of snakebites: Neutralization of inflammatory reactions. Journal of Ethnopharmacology, 99/2: 229-237.

Norris, T. 1999. "Captive bird diets vs. wild bird diets" (On-line). Accessed April 20, 2010 at http://www.peafowl.org/ARTICLES/19/.

Petrie, M., M. Hall, T. Halliday, H. Budgey, C. Pierpoint. 1992. Multiple mating in a lekking bird - Why do peahens mate with more than one male and with the same male more than once. Behavioral Ecology and Sociobiology, 31/5: 349-358.

Petrie, M., T. Halliday. 1994. Experimental and natural changes in the peacock's (Pavo cristatus) train can affect mating success. Behavioral Ecology and Sociobiology, 35/3: 213-217.

Petrie, M., A. Williams. 1993. Peahens lay more eggs for peacocks with larger trains. Proceedings: Biological Sciences, 251/1331: 127-131.

Somes, R., R. Burger. 1993. Inheritance of the white and pied plumage color patterns in the Indian Peafowl (Pavo cristatus). Journal of Heredity, 84/1: 57.

Stewart, I., F. Clark, M. Petrie. 1996. Distribution of chewing lice upon the polygynous peacock Pavo cristatus. The Journal of Parasitology, 82/2: 370-372.

Takahashi, M., T. Hasegawa. 2008. Seasonal and dinural use of eight different call types by Indian peafowl (Pavo cristatus). Journal of Ethology, 26/3: 375-381.

Walther, B., D. Clayton. 2005. Elaborate ornaments are costly to maintain: evidence for high maintenance handicaps. Behavioral Ecology, 16/1: 89-95.

de Magalhaes, J., J. Costa. 2002. "AnAge entry for Pavo cristatus" (On-line). A database of vertebrate longevity records and their relation to other life-history traits. Accessed April 20, 2010 at http://genomics.senescence.info/species/entry.php?species=Pavo_cristatus.