Justification of Red List Category
This species qualifies as Vulnerable because it has undergone a rapid population decline and its small population is becoming increasingly fragmented with progressive erosion of its specialised lowland forest habitat.
The population is estimated to number 2,500-9,999 individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals.
This species is suspected to be declining rapidly, owing to on-going habitat loss and fragmentation and localised hunting pressure.
Polyplectron malacense is endemic to Peninsular Malaysia and possibly southern peninsular Thailand. Reports of its occurrence in Sumatra have been refuted, and evidence for its occurrence in Myanmar is flawed. It is possibly already extinct in Thailand, and its range in Malaysia has contracted dramatically - in 1997, it remained in just 54% of localities known before 1970. Remaining subpopulations are now restricted to a few forest blocks in which they are unevenly distributed, although it is apparently still common in several protected areas.
It is an extreme lowland specialist, resident in tall primary and secondary (including lightly logged) lowland dipterocarp forest, usually from just 15 to 80 m, and never above c.300 m, on level or gently sloping ground. Studies have found increased calling levels and numbers of display scrapes in mast fruiting years, when there are higher invertebrate densities, suggesting that distribution and reproductive output may be limited by food supply.
Lowland forest clearance and modification for cultivation remain the major threats. Only 25% of suitable habitat that was available for the species prior to 1970 remains today. Hunting for food, sport and the bird trade presumably contributed to its probable extinction in Thailand. Whilst it is susceptible to snaring targeted at all ground foraging animals, there is no evidence to indicate it is particularly sought after in Malaysia.
Conservation Actions Underway
CITES Appendix II. Important populations occur in at least two protected areas, Taman Negara and Krau Wildlife Reserve, and further populations have been reported at Sungai Dusun Wildlife Reserve (Selangor) and a number of Forest Reserves that do not qualify as protected areas under wildlife legislation, including Pasoh (Negeri Sembilan). PERHILITAN is embarking on a captive breeding and release programme with plans to release birds in parts of its historic range (Yeap Chin Aik in litt. 2007).
Male 50-53.5 cm, female 40-45 cm. Rusty-brown, crested peacock-pheasant. Similar spp. Warmer brown than extralimital Grey Peacock-pheasant P. bicalcaratum, with greener ocelli, long, dark green-glossed crest, blacker crown and hindneck, darker ear-coverts (contrast with pale surround), orange-pink facial skin and plainer underparts. Female, smaller and shorter tailed, with very short crest, blacker and more pointed ocelli, indistinct paler scaling above, more uniform underparts and yellower facial skin. Voice Male territorial call is loud, slow, melancholy puu pwoii (second note more drawn and rising). Also, sudden explosive cackle, running to throaty clucks: tchi-tchi-tchao-tchao wuk-wuk-wuk-wuk-wuk.
Text account compilers
Benstead, P., Bird, J., Davidson, P., Keane, A., Taylor, J.
Davison, G., Aik, Y.
BirdLife International (2020) Species factsheet: Polyplectron malacense. Downloaded from http://www.birdlife.org on 15/08/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 15/08/2020.