Identification
Species:
This species comprises two subspecies:
- Polyplectron bicalcarratum bicalcaratum (Linnaeus, 1758)
- Polyplectron bicalcarratum ghigii Delacour and Jabouille, 1924
Adult Male: Overall plumage is greyish-brown. The skin around the face is pinkish-yellow. The crown has a raised, ruffled appearance, forming a low crest, and is yellowish-white. The flanks and the front of the neck are pale brownish-white. The nape and chest exhibit distinct white spots. The back, rump, and tail coverts also feature white spots arranged in neat rows, though these are less prominent than those on the chest. The wings display iridescent blue-green ocelli (eye-like spots). The tail feathers also possess oval-shaped, bluish-green ocelli. Each pair of ocelli is aligned horizontally.
Adult Female: Similar to the male, but smaller in size and with duller plumage. Facial skin is flesh-pink. The white coloration of the crest, nape, and throat is less distinct. The ocelli on the wings are smaller and darker, with less iridescence compared to those of the male. The shortest tail feathers lack ocelli.
Bill: Black at the tip and edges, the rest is flesh-pink.
Legs: Greyish-brown. Possess two spurs (one on each leg), with the possibility of up to four spurs (two on each leg) that are blackish-grey. The female’s spurs are less developed.
Biology and Ecology
Reproduction:
Limited data is available. Recent studies indicate that the breeding season for the species extends from February to July. Each clutch consists of 2-3 eggs, which are ivory-white. The incubation period is 20-21 days. Similar numbers of eggs laid and incubation times were also observed in captivity.
Diet:
The species consumes fruits and seeds from forest trees. They also supplement their diet with insects, earthworms, and small snails found in limestone areas.
Habitat and Behavior:
They live in pairs or small flocks of three in secondary and primary evergreen forests, mixed forests (with a mix of woody trees, bamboo, and reeds), at elevations of 50-1500m. They inhabit areas along streams, rivers, valleys, and limestone mountain slopes. The species forages on the ground during the day and roosts in trees at night. They can be found in the same habitat as other pheasant species, such as White-crested Pheasant, Siamese Fireback, Red Junglefowl, and various species of Spurfowl.
Distribution
In Vietnam:
- Subspecies 1 – Polyplectron bicalcarratum bicalcarratum (Linnaeus, 1758) is distributed in Northwestern Vietnam.
- Subspecies 2 – Polyplectron bicalcarratum ghigii Delacour and Jabouille, 1924 is distributed in Northeastern Vietnam, extending to Quảng Nam and Đà Nẵng (Bà Nà Nature Reserve, Núi Chúa), and is endemic to Vietnam.
Worldwide:
- Subspecies 1 – Polyplectron bicalcarratum bicalcarratum (Linnaeus, 1758) is distributed in Northeastern Thailand, Upper Laos, China (Yunnan), and Northwestern Vietnam.
Value
The species is a valuable bird, and one of its two subspecies is endemic to Vietnam. It holds scientific, aesthetic, and commercial value.
Status
The population is rapidly declining and becoming increasingly rare due to habitat loss (deforestation), which results in the loss of their habitats and food resources. The distribution area is rapidly shrinking, along with the continued threat of indiscriminate hunting, leading to their rarity in many areas.
Classification
VU A1a,c C2a
Conservation Measures
The species is included in Decree 18/HDBT (1992), Decree 48/NĐ-CP (2002), and Appendix II of the CITES Convention. Active conservation efforts are needed in the areas where the species is found, both within and outside of National Parks and Nature Reserves.