Friday, October 17, 2008

Green Peafowl

The Green Peafowl, ''Pavo muticus'' is a large member of the Galliformes order that is found in the tropical forests of Southeast Asia. During the Pliocene, the earliest fossil species Pavo bravardi had a large range that evidentially included much of Eastern Africa and Southern Europe. The familiar Indian Peafowl diverged from the Green Peafowl Superspecies ~ 70,000 years ago. The genetic divergence between Annametic and Arakan populations is ~1.8 million years~~ twice this old. In other words, some of the Ecological Species that make up the Green Peafowl Superspecies are less related to one another than they are to the Indian Peafowl which seems illogical to some minds on the grounds of phenotypey. The appearances of peafowl that live in habitats that have not changed for many millions of years have not diverged from that of the common ancestor of all Pavo peafowl, which probably closely resembled Pavo bravardi. The Indian Peafowl is endemic to the Indian Subcontinent and Sri Lanka which were dramatically affected about 80,000 years ago when 90% of its tropical forests were destroyed by an elecological catastrophe called the Mount Toba Eruption. India would become seasonally arid and as a consequence, the Indian Peafowl is adapted for life in dry monsoon forest and desert scrub. It probably endured genetic bottlenecks that 'fixed' its phenotype within a much more arid environment than what we see in most of India today. The Green Peafowl of tropical conifer forest habitat, for example the enigmatic Deqen Dragonbird of mountain forests of Nothern Western Yunnan and Southern Sichuan, and the Broadleafe Evergreen Habitat adapted Annamensis Dragonbird of the montane regions of South East Asia, exhibit the least sexual dichromaticism. That is the sexes closely resemble one another. Their habitats are remarkeable for the absence or abbreviation of a marked decidious season. This contrasts with the habitat of the Indian Peafowl which lives in a markedly deciduous habitat.



Description




The sexes of Green Peafowl, or Dragonbirds as they are known in their native haunts, are quite similar in appearance, especially in the field. During most of the year, when the males have no visible trains, it is quite difficult to distinguish the sexes. Bot sexes carry tall pointed crests and are long legged and heavy winged and long tailed in silhouette. Seen in the distance, they are generally dark coloured birds with pale vermillion or buff coloured primaries which are quite visible in in their peculiar flight which has been described as a true flapping flight with little gliding that one associates with Gallinates. Some ecological species of Green Peafowl are distinctly bluer in appearance whilst others are decidedly bronze and purple , or dull gold and emerald , bright citrus green and cerulean blue or blackish grey and violet blue with purple trains The wings of each respective geographic form are quite distinctive and like Turacoas,and Lophura Pheasants their reticulate phylogenetic pathways are complex and best understood as ecological. COnsequently, the phenotypey of different populations that are only distantly related to one another on a genetic level may converge, much as we have seen in the mirror phenotypes of certain dark kalijs and their altitudinal equivalents amongst the black silver pheasants. For example, Dragonbirds from Southern Vietnam are dull and greyish green and share a very similar habitat with phenotypically similar birds endemic to Southern Western Myanmar and Northern Malaysia.


The males of the mainland races are bluish-green, ''imperator'' has a metallic-green neck. The breast, wing-coverts are blue and the outer webs of secondaries are blue-green in ''imperator''. Race ''spicifer'' has a duller and bluer neck and breast with more extensively black wing-coverts and outer web of secondaries; Nominate ''muticus'' is more golden-green with less blue on the neck and breast. Considerable variation exists in plumage of neck and breast which may be linked with age and sex.

The male of some forms of Green Peafowl has a loud call of ''ki-wao'' which is often repeated. The female has a loud ''aow-aa'' call with an emphasis on the first syllable. The males call from their roost sites at dawn and dusk.
Some forms of Green Peafowl have divergent trachea morphology and this has an impact on their voices.

The Indian Peafowl has a much louder voice than all but the imperator because of the special apparatus that accentuate volume. The Arakan spicifer has no such apparatus and as such is much quieter. Green Peafowl are noted ventriloquists however and make many low vibrational vocalizations and even piercing whistle-like shrieks in some forms.

Green Peafowl are large birds, one of the largest living galliformes in terms of overall length and wingspan, though rather lighter-bodied than the Wild Turkey. The male grows up to 3 meters long, including the "train" and weighs up to 5 kg . The female is 1.1 meter long and weighs about 1.1 kg . It has large wingspan of~ four feet. Green Peafowl are unusual amongst Galliform birds in their capacity for sustained flight. They are documented flying over the ocean to roost on islets off the coast of Java and on islands in large lakes in Yunnan. Some of the islets and islands are more than fifteen miles from shore. All known genera of peafowl, Rheinartia, Afropavo, Pavo and Argusianus are known to perch on emergent trees which tower over the canopy of the rain forest or tropical savannah. Pheasants and Junglefowl do not perch above the canopy. Peafowls are obliged to fly to and from their emergent trees which form territorial anchors for adult males and their social units. They will also move by wing to forage in areas some distance from their favorite roosts. Subsequently, the morphology of the Peafowl wing is quite different from Pheasants.

Distribution and habitat


The Green Peafowl was widely distributed in Southeast Asia in the past from northern Myanmar and southern China, extending through Laos, Thailand into Vietnam, Cambodia, Malaysia and the islands of Java. The ranges have reduced with habitat destruction and hunting.

Green Peafowls are found in a wide range of habitats including primary and secondary forest, both tropical and subtropical, as well as evergreen and deciduous. They may also be found amongst bamboo, on grasslands, savannas, scrub and farmland edge. In Vietnam, the preferred habitat was found to be dry deciduous forest close to water and away from human disturbance. Proximity to water appears to be an important factor.

Classification



It is well established,that Peafowl are a genetically isolated group with no close relatives.
Peafowl will eventually be formally placed in their own monophyletic family.
The Green Peafowls are an ancient tribe with many divergent populations that have been isolated from one another for many tens of thousands and even hundreds of thousands of years. Though the birds appear superficially very similar to one another, they are genetically surprisingly divergent. In the following years, when more data has been compiled, Green Peafowls, will probably be reclassified, forming six distinct species, each with its own local races.

Following the advice of his Hong Kong bird dealer, World Pheasant Association founder and bird importer, Jean Delacour described three races of green peafowl.
: ''P. m. muticus'' , ''P. m. imperator'' and ''P. m. spicifer''. Some authors suggest that the race found in Yunnan may be distinct.

Race ''muticus'' was known from Malay peninsula from the northern part extending south to Kedah. Race ''imperator'' is known from the lowland forests of northern and eastern Thaliand. Race ''spicifer'' is distributed in northwestern Burma.
While peafowl are often considered members of the pheasant family, recent molecular work has shown that the Phasianidae is paraphyletic, and that peafowl are not closely related to pheasants, grouse or . They are distantly related to junglefowl and francolins however, and share a common ancestor with ''Coturnix'' quail and ''Alectoris'' Rock Partridges. While this has yet to be published, the World Pheasant Association of Germany already lists peafowl as a distinct family .

Since Delacour's profitable discovery, other forms of Green Peafowl that do not fit into any of the three described races have been described. An ongoing genetic analysis is underway. Preliminary analysis suggests that some of the more isolated Ecological Species of the Green Peafowl may in fact warrant species status. Foremost of these are the Elephant Mountain Range Pavo annamensis bokorensis and aforementioned Deqen Dragonbird of North Western Yunnan Pavo antiquus.

Like other members of the genus ''Pavo'', Green Peafowl is a colourful bird. Iridescent plumage may be a highly specialized form of crypsis that is useful in open forests and near water. Most predatory species like leopards and tigers, wild dogs, civets, owls and hawk-eagles that have been documented hunting peafowl do not have colour vision.

Green Peafowls are found today in Southeast Asia in mainland Burma, Yunnan, Thailand, Laos, Vietnam, Cambodia and on the island of Java in Indonesia. They are curiously absent from both Sumatra and Borneo. Records from northeastern India have been questioned and old records are possibly of feral birds.

Behaviour


The Green Peafowl is a forest bird which nests on the ground laying 3 to 6 eggs.

It has been widely believed without quantification that the Green Peafowl is polygynous, the male having no parental responsibilities whatsoever. It has been reported that some males are very solitary, trying to mate with every female that enters his territory, while females gather in harems.

However, these are only presuppositions based upon the behaviors of captive or semi-captive Indian Peafowl which are facultatively polygynous and from observations of highly territorial male Green Peafowl guarding nest sites. The notion that the male is polygynous also conflicts with observations in the field and captivity; pairs left alone with no human interaction have been observed to be strongly monogamous. The close similarity between both sexes also suggests a different breeding system in contrast to that of the Indian Peafowl. Thus, some authors have suggested that the harems seen in the field are juvenile birds and that males are not promiscuous. Indeed, it may be that the males are more higly invested in the long-term care of their progeny than the female. Green Peafowl have been observed in Java in multiple generation helper systems where sexually immature bird help their parents look after their younger siblings. This has also been documented in captive Afropavo, and Argusianus peafowls and even in the facultatively polygamous Indian peafowl.

They usually spend time on or near the ground in tall grasses and sedges. Like other peafowl, the Dragonbirds love to wade and forage for food in the shallows for a good portion of each day. Family units roost in trees at a height of 10-15m. The diet consists mainly of invertebrates, insects, reptiles, fruits and small animals. As with other members of its genus, the Green Peafowl can even hunt venomous snakes, making them useful for pest control. Ticks and termites, flower petals, buds leaves and berries are favorite foods of adult peafowl. Frogs and other aquatic small animals probably make up the bulk of the diet of growing birds.


Their natural predators include large cats, the clouded leopard, Asiatic leopard, tiger, jungle cat and fishing cat prey on adult birds. As Dragonbirds are so large with both sexes armed with powerful kicking thorns or metatarsal spurs, many predators ignore peafowl. for example birds of prey which specialize on junglefowl and pheasants routinely ignore peafowl. During the long weeks of incubation and chick rearing close to the ground, mortality is at its height. This one reason field biologists familiar with peafowl believe that their nest defense strategies have evolved. The most serious enemies of the nest are probably reptilian, monitor lizards and snakes for example, but civets and non obligatory birds like crows are probably also important nest predators. Adult and subadult progeny help defend the nest site and foraging territories against intruders.
The Dragonbird earned its name for its proclivity to attack monitor lizards and large snakes like pythons. Green peafowl have also been documented attacking young leopards and an adult fishing cat.

Green Peafowl occupy a very similar ecological niche as the unrelated Secretary Bird, Seriama, and Bustard. That is to say, Green Peafowl hunt for small animals on the ground in tropical savannah. Like these other predatory bird species, Green Peafowl are monogamous and enjoy prolonged relationships with their offspring. All these cursorial hunters display delayed maturity, are long legged, heavily winged, with prominent crests and long, broad tails.


Status


Due to hunting and a reduction in extent and quality of habitat, the Green Peafowl is evaluated as on the IUCN Red List of Threatened Species. It is listed on Appendix II of CITES. The world population has declined rapidly and the species no longer occurs in many areas of its past distribution. The population in the wild was estimated to be about 5,000 to 10,000 individuals around 1995.

Hybridisation with the Indian Peafowl may also be a cause for the decline of the Green Peafowl, damaging the gene stock of captive birds. Certain birds both in the wild and captivity which are thought to be pure Green Peafowl are really hybrids, known by some as "spauldings" or "spaldings". Additionally, the subspecies of Green Peafowl have also been heavily mixed in captivity.

Although all subspecies are declining, ''P. m. spicifer'' and ''P. m. imperator'' are not declining as much as ''P. m. muticus''. Some breeders mistakingly say that the race ''spicifer'' is extinct, although this is not true. Nonetheless, this subspecies is also declining rapidly. The race/group ''imperator'' may still be common in isolated parts of its range.

The nominate race supposedly lived in Malaysia, as well as the Isthmus of Kra, but had became extinct in the 1960s.

In 2005, reported that successful reintroductions were being made in Malaysia by the World Pheasant Association .

However, the reintroductions have not been without controversy. The publication stated that the Javan and Malay form were genetically identical, which has been widely accepted by the scientific community. However, some do not believe the forms are identical; more recent genetic work confirms this. Because of the notion that the two forms were not identical there are concerns that the wrong form of Green Peafowl was introduced. Another statement by certain publications is that the birds introduced were the nominate ''muticus''. Photos and video footage of some of the reintroduced birds in Malaysia have been identified as ''spicifer''. However, the DNA of the introduced stock of spicifer matched that of old museum skins in Malaysia, confirming the birds introduced were native to the area.

Media

No comments: