The Vietnamese crested argus (''Rheinardia ocellata'') is a large and spectacular

peafowl Peafowl is a common name for two bird species of the genus '' Pavo'' and one species of the closely related genus '' Afropavo'' within the tribe Pavonini of the family Phasianidae (the pheasants and their allies). Male peafowl are referred t ...

-like species of bird in the

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's native range is restricted to Eura ...

family with dark-brown-spotted black and buff

plumage Plumage () is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, there can b ...

, a heavy pink bill, brown irises and blue skin around the eyes. The head has two crests; the hind crest, which extends down the occiput, is erected when alarmed and during intentional behaviors including pair bonding and courtship displays. The male has a broad and greatly elongated tail of twelve feathers. The tail covert (or "train") of the male is the longest of any bird and is believed to contain the longest (and widest) feathers to occur in a wild bird; the

Reeves's pheasant Reeves's pheasant (''Syrmaticus reevesii'') is a large pheasant within the genus ''Syrmaticus''. It is Endemism, endemic to China. It is named after the British people, British natural history, naturalist John Reeves (naturalist), John Reeves, wh ...

has tail feathers of similar length but which are considerably narrower. The tail coverts measure up to in length, giving the bird a total length of .

Description

Both sexes are similar in size, with females possessing a prominent marbled barring and more colourful dorsal plumage than the male. They possess white facial plumage marked with disruptive patterning. The female's crest is different morphologically, with more rigid plumes that take up more surface area along the occiput and upper hind neck. Their tails are elongated and laterally compressed, although females have considerably shorter tails. The average length of the female is . Despite being sexually dimorphic by length, the male only weighs about 20% more than the female. The average weight is around .Biddle, Tami Davis, ''Pheasants, Partridges, and Grouse : A Guide to the Pheasants, Partridges, Quails, Grouse, Guineafowl, Buttonquails, and Sandgrouse of the World (Princeton Field Guides)''. Princeton University Press (2002), The wings of the Vietnamese crested argus are of unusual size and length for its weight. They are wide and square like those of ''

Argusianus The great argus (''Argusianus argus''), or greater argus, is a large species of pheasant from Southeast Asia. It is known for its impressive plumage and courtship behavior. It is not to be confused with the two species of closely related crested ...

'' instead of rounded and abbreviated like those of 'true' pheasants. Additionally, there is no discernible trailing edge secondary wing notch amongst the flight feathers, indicating a capacity of sustained flight in species of this genus. Their wings are morphologically similar to the wings of certain semi-arboreal Craciformes, particularly the genus '' Pipile''. The feet and legs of crested argus are also notable in the presence of curiously developed leg scales in males which are widened in such a matter that they give each limb the appearance of the foreleg of a varanid lizard. The toes are long and gracile and like other peafowls, while the hind toe is less recumbent than those of more strictly terrestrial

Galliformes Galliformes is an order (biology), order of heavy-bodied ground-feeding birds that includes turkey (bird), turkeys, chickens, Old World quail, quail, and other landfowl. Gallinaceous birds, as they are called, are important in their ecosystems ...

Behaviour and ecology

Little is known about this species in the wild. A shy and elusive bird, the Vietnamese crested argus is found in submontane

primary forest An old-growth forest or primary forest is a forest that has developed over a long period of time without Disturbance (ecology), disturbance. Due to this, old-growth forests exhibit unique ecological features. The Food and Agriculture Organizati ...

s of

Vietnam Vietnam, officially the Socialist Republic of Vietnam (SRV), is a country at the eastern edge of mainland Southeast Asia, with an area of about and a population of over 100 million, making it the world's List of countries and depende ...

and

Laos Laos, officially the Lao People's Democratic Republic (LPDR), is the only landlocked country in Southeast Asia. It is bordered by Myanmar and China to the northwest, Vietnam to the east, Cambodia to the southeast, and Thailand to the west and ...

Southeast Asia Southeast Asia is the geographical United Nations geoscheme for Asia#South-eastern Asia, southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of the Mainland Au ...

. The diet consists mainly of

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

s, mollusks, amphibians, small reptiles, bamboo shoots, leaves,

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

s and fungi. Little is known about its reproductive strategy. While it is believed by some authorities to be

polygamous Polygamy (from Late Greek , "state of marriage to many spouses") is the practice of marrying multiple spouses. When a man is married to more than one wife at the same time, it is called polygyny. When a woman is married to more than one h ...

, there is no direct evidence to substantiate this theory. The male performs various displays utilizing serpentine erratic deportment behaviors, which include perceptible quill vibration. The lower extremities of the male's wings and tail are pushed vertically into the ground leaving trails in sand and leaf litter. These performances may culminate in the lateral compression of the body and plumage and spreading of his train. The head is held parallel to the ground throughout these display behaviors exhibiting upper throat bristles in one species and downy plumuelles in the second, which together with the forward positioning of the crests, obscure the shape of the head. The male also erects a nuchal hood and hisses audibly while stomping his feet. Like other peafowls, the crested argus employs these and more complex display behaviors in anti-predatory encounters, especially with reptiles.

Habitat and distribution

From limited anecdotal observations of local indigenous peoples, the species selects nest sites in elevated reaches, often amongst escarpments on steep slopes amongst leaf litter. They produce very small clutches of one or two large eggs which are incubated for 25 days. Like other peafowls, crested argus chicks hatch with developed wing feathers. They are bill-fed for the first few weeks. In captivity, males also invest in chick rearing, both bill feeding and brooding the chicks both on and off the ground. Like other peafowl, Vietnamese crested argus retire on emergent trees above the forest canopy for many hours a day. They will remain on these trees for days at a time during the wet season. Vietnamese crested argus are strong fliers and pairs have been reported flying together.

Status

Due to ongoing

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

loss as well as overhunting in some areas, the Vietnamese crested argus is evaluated as Critically Endangered on the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological ...

. It is listed on Appendix I of

CITES CITES (shorter acronym for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of inte ...

References

External links

* ARKive
images and movies of the Vietnamese crested Argus ''(Rheinardia ocellata)''

* ttps://web.archive.org/web/20060621010317/http://www.rdb.or.id/detailbird.php?id=5 Red Data Book {{Taxonbar, from=Q27603424

Vietnamese crested argus The Vietnamese crested argus (''Rheinardia ocellata'') is a large and spectacular peafowl-like species of bird in the pheasant family with dark-brown-spotted black and buff plumage, a heavy pink bill, brown irises and blue skin around the eyes. ...

Birds of Laos Birds of Vietnam