Identification
The Crested Argus (Rheinardia ocellata) is one of the largest pheasant species. Adult males have a crest of feathers on the head, up to 60mm long, dark brown with dark brownish-black and white spots. They have a broad, elongated white eyebrow. The back and tail are dark brown, with some reddish-brown highlights. The belly is similar to the back but with more reddish-brown hues. The tail is long, with the two central tail feathers developing to a length of up to 1500mm. Females are similar to males but smaller. The crest is sparse and shorter in females. The tail is also shorter and lacks the long central tail feathers found in males. The beak is pink, the eyes are brown, and the legs are dark brown with a reddish-pink hue, with spurs. The spur of the male is more developed than in the female.
Biology and Ecology
Reproductive data for the Crested Argus in the wild is limited. The breeding season of the Crested Argus begins from March to July. Crested Argus raised in the Hanoi Zoo lay 2-3 eggs per clutch, which are oval-shaped, with one end larger than the other. The eggshells are light brown with many brown spots on the larger end. The average dimensions are (6.53 x 5.48mm), and the average weight of 3 eggs is 75.17g. The incubation period is 24 days (Dang Gia Tung, 1997).
The Crested Argus feeds on fruits, tree seeds, and grass seeds. They prefer small, soft fruits of the Ficus genus. They also eat insects and earthworms.
Crested Argus lives and forages in primary and secondary evergreen forests on hills and slopes of varying steepness at altitudes from 100-1000m, commonly below 700m. The calls of the Crested Argus can be heard from a great distance, both day and night, especially when there is a sudden loud noise. At the beginning of the breeding season, males display and perform courtship rituals, forming “display grounds” in the forest, which facilitates observation.
In the same habitats, one may also find species like the Bronze-winged Peacock-Pheasant, Red Junglefowl, Silver Pheasant, and Grey Peacock-Pheasant. The Crested Argus exhibits similar behaviors as other pheasant species, foraging on the ground during the day and roosting in trees at night. They usually sleep in the highest branches compared to other pheasant species.
Distribution
Within Vietnam: Only one subspecies, R. o. ocellata, is distributed in Nghe An (Con Cuong, Quy Chau…), Ha Tinh, Quang Binh, Quang Tri, Thua Thien – Hue, Quang Nam, Quang Ngai, Binh Dinh, Phu Yen, Khanh Hoa, Kontum, Gia Lai, Dak Lak, and Lam Dong (Bi Dup Mountain).
Worldwide: This subspecies is also found in central Laos. A second subspecies is found in Malaysia.
Value
A rare and valuable endemic subspecies of Vietnam, with scientific and aesthetic value.
Status
The Crested Argus is currently found in many forest regions from north-central to south-central Vietnam. They are frequently observed in the forests of Nghe An (Pù Mát National Park), Ha Tinh (forest areas around Ke Go Lake, Cat Bin in Cam Xuyen district), extending to the northern part of Quang Binh province, Thua Thien – Hue. Bach Ma National Park, the forest area along the 41 pass in A Luoi district, Gia Lai (Kon Ha Nung, Kon Cha Rang, Kon Ka Kinh), Lam Dong (Bi Dup Mountain, Lac Duong district), Phong Dien Nature Reserve, Dak Rong, and at altitudes of 500-700m in Ba Na-Nui Chua Nature Reserve. However, due to deforestation and hunting, the population of the Crested Argus in Vietnam has significantly decreased.
Classification
VU A1b,c,d.
Conservation Measures
It has been included in the Vietnam Red Data Book (1992-2000), the IUCN Red List (1996, 2000), the Red List of Asian Birds (2001) as Vulnerable (VU). Included in Decree 18/HDBT (1992), 48/ND-CP (2002), and Appendix I of the CITES Convention. Especially, Bach Ma National Park has the largest density of Crested Argus in Vietnam and is best protected, so the population will increase rapidly in the future. However, there is a need for increased education and awareness to improve effective conservation efforts among the public.