Crested argus (Rheinardia ocellata)
|Synonyms:||Argus ocellatus, Rheinardia nigrescens, Rheinartia ocellata|
|Spanish:||Faisán de Rheinard|
|Size||Adult male length (including tail): up to 239 cm (2)|
Adult male tail feather length: up to 173 cm (3)
Adult male tail feather width: up to 20 cm (4)
Classified as Near Threatened (NT) on the IUCN Red List 2007 (1) and listed under Appendix I of CITES (5). Two subspecies are recognised: Rheinard's crested argus (R. o. ocellata) and the Malaysian crested argus (R. o. nigrescens) (6) .
This unmistakable bird is easily identified by its huge and magnificent tail feathers (2). Even the females of this species boast an impressive plumage, but the males are astonishing, having amongst the largest tail feathers in the world at 173 centimetres (3) (4). When spread, the tail feathers display a beautiful and intricate pattern of chestnut and almost-white, eye-shaped spots, set on a grey background (2). Males attain their adult plumage in their third year, but the tail may not reach full length until their sixth. The female is much smaller than the male, with a shorter tail and a darker plumage, which is more barred than spotted than the male’s. The head of the female argus also has a distinctive pattern and is crested (6). If out of sight, the bird can be identified by its two distinct calls: one a prolonged two-toned whistle, the other a soft clucking (2).
Endemic to Southeast Asia. The nominate subspecies, R. o. ocellata, occurs along the Annamite mountain chain in central and southern Vietnam and neighbouring eastern Laos, south to the Da Lat Plateau in southern Vietnam (7). R. o. nigrescens is found in central Peninsular Malaysia (6).
In Laos and Vietnam, this bird is found in primary and secondary evergreen forest from sea-level up to 1,500 metres, and from 1,700 to 1,900 metres on the Da Lat Plateau. Although frequently recorded in degraded, logged forest habitats, highest densities occur in moist primary forest in lowlands up to 900 metres. In Malaysia, the species inhabits montane forest, generally at an elevation between 800 and 1,100 metres (7).
Despite its size, the shy crested argus is not easy to observe, and little has been documented about its biology. Its distinctive loud calls indicate that the bird is usually solitary and territorial, coming together only to breed (2). This species is polygamous in the wild (9) (10), with males performing elaborate courtship rituals, calls and dances during the mating season to attract mates. Head feathers are ruffled and the crest is spread whilst the male dances in an area of the forest floor cleared of leaves (2). Assuming peaks in calling frequency occur during the breeding season. The breeding season is March to May in Laos, although breeding in captivity (northern hemisphere) falls between March and June. Females nest on the ground, in the shelter of a bush or clump of low vegetation. The female lays two eggs, which are incubated for 25 days, and chicks are fed directly by their mother for the first few days of life (9) (10). As soon as they hatch, they instinctively hide under their mother’s tail feathers, which she spreads like an umbrella to provide protection from rain and the eyes of predators (10). Once able to forage for itself, the bird’s diet consists of berries, grubs, insects, tree leaves, fruits and sometimes amphibians (9) (10).
The crested argus is threatened by habitat degradation, fragmentation and loss, both within and outside protected areas. Although the bird can survive in small pockets of forest, habitat fragmentation isolates populations, which results in reduced fitness through inbreeding. The greatest damage is caused by commercial logging, illegal timber extraction, clearance for agricultural plantations, encroachment by shifting cultivators and road-building (7). Indeed, the tendency for paths and logging roads to be constructed along the crests of spurs and ridges concentrates disturbance and hunting in precisely the areas favoured by crested argus for their calling and display arenas (9). Hunting pressure compounds these threats (2), with snaring at display arenas being a common practice in many regions of Laos and Vietnam (9), and posing a more significant danger than deforestation in some areas (7). Very little is known about the Malaysian population, which is found at a higher altitude than the Vietnamese birds in just one or two locations in the mountains near the border of the Taman Negara National Park (4). This subspecies is much rarer than the Vietnamese race and has only once been seen in captivity (4).
The crested argus is protected by its listing on Appendix II of the Convention on International Trade in Endangered Species (CITES) (5). The bird occurs in numerous protected areas, including Bach Ma National Park and at least ten nature reserves in Vietnam, at least two designated and two proposed National Biodiversity Conservation Areas in Laos, and Taman Negara National Park in Malaysia (7). In the Gunung Rabong and Gunung Gagau areas of the Taman Negara National Park in Malaysia, the Department of Wildlife and National Parks has provided protection since 1972 for the very small remaining population of this species (8). The World Wildlife Fund (WWF) is working in areas in Vietnam through the MOSAIC project (Management of Strategic Areas for Integrated Conservation), which involves working with both local villagers and forest officials to design and implement sustainable management practices (2). Several captive breeding initiatives are in progress, but none have resulted in any re-introductions into the wild. Posters highlighting the plight of the species and an appeal to stop hunting it have been distributed within the bird’s range in Laos by the Wildlife Conservation Society’s Lao programme (9). However, further locally targeted conservation-awareness initiatives are desperately needed across Vietnam, combined with the strict enforcement of hunting regulations in protected areas (7), if this astonishing and spectacular, long-tailed bird is to survive.
For further information on the crested argus see:
- BirdLife International:
- BirdLife International. (2001) Threatened Birds of Asia: the BirdLife International Red Data Book. BirdLife International, Cambridge, UK.
- The World Pheasant Association:
Authenticated (02/05/2006) by John Corder, Vice President of the World Pheasant Association, and Chairman of the European Conservation Breeding Group of the World Pheasant Association.
- Dipterocarpaceae: a family of resinous trees that are found in the old world tropics.
- Endemic: a species or taxonomic group that is only found in one particular country or geographic area.
- Inbreeding: the breeding of closely related individuals. An inbred population usually has less genetic variability and this is generally disadvantageous for its long-term survival and success.
- Polygamous: mating with more than one partner in the same season.
- Primary forest: forest that has remained undisturbed for a long time and has reached a mature condition.
- Subspecies: a population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.
- Territorial: an animal, a pair of animals or a colony that occupies and defends an area.
IUCN Red List (November, 2011)