Subspecies: The Bornean Peacock Pheasant is a lowland forest pheasant endemic to the island of Borneo and considered by some to be a full species; but when one is familiar with both Malay PP and this species, one cannot help to notice the peculiar similarities which make the Bornean PP seem more correctly considered to be a sub-species of P. malacense as in Smythies. These similarities include: very closely marked upperparts and tail (save for the shorter tail and black sub-terminal band), both with an orange facial and periophthalmic region and the diagnostic black (dark) ear coverts and the structures of both crest and ruff at the neck. Both the Malay and Bornean PP notably have a single-egg clutch, which is the norm for both species.
Range: Distributed historically and with museum specimens collected throughout various localities on the island of Borneo; in East, Central and Western Kalimantan, Indonesia and possibly existing in some locations in Sabah and Sarawak, North Borneo . Extremely rare and local in distribution.
Habitat: Lowland forests; where survival of the species probably depends upon the future of lowland primary forest below 300m.
Based on recent fieldwork and the extent of its remaining habitat, the population is estimated to be between 1000 and 2,499. The species is presumed always to have been difficult to detect, possibly reflecting very low densities.
Its ecological needs are poorly understood, research shows the species inhabits lowland plain and lowland dipterocarp forest on moderately fertile soils, probably avoiding wetter substrates in swamp-forest or near water bodies. Recent studies confirm the use of closed dry lowland dipterocarp forest habitats but a tolerance for regenerating habitats has yet to be properly established.
Description, Male: Crown short crested, barred pale grey and black, the centre glossed with green; ear-coverts black; a large ruff of disintegrated feathers barred black and pale grey, tips metallic violet-blue; upper parts as in P. m. malacense but much redder, the ocelli smaller and greener; tail shorter, the ocelli smaller, less closely connected on the coverts; there is a green ocellus on the outer web of the lateral rectrices and a dull black spot on the inner web; throat and upper breast pure white; sides of breast metallic blue-green; centre of the lower breast white, the rest of the upper parts black with whitish shafts and tiny vermiculations; under tail-coverts spotted brown and black patch near the tip. Iris – grey/white; facial skin orange-red; bill and feet dark grey. Like others of the genus, males can develop a number of spurs on each leg.
Description, Female: Similar to P. m. malacense but more reddish generally; tail shorter, the upper coverts are without blue ocelli, those of the rectrices is smaller and ill-defined; the rectrices are irregularly and coarsely barred with black. Iris light brown; facial skin orange, bill and feet grey. Hens do not develop spurs on their legs.
