Justification of Red List Category
The continuing rapid reduction in the extent and quality of its habitats across much of this partridge's range is suspected to be causing a rapid population decline, qualifying it as Vulnerable.
The population size has been previously suggested to fall into the band 10,000-19,999 mature individuals, based on a relatively high population density from related species (10 individuals per square kilometer) and an estimated low occupied proportion of the mapped range. However, there is much uncertainty in this population size. Given that there are so few recent records of the species it appears that the density used may be unrealistically high. There is no direct density estimate, primarily because encounters are so rare, despite considerable ornithological effort in multiple areas of expected occurrence. While it is a very unobtrusive species, whose vocalisations are confusing and have been poorly-known until recently (van Balen & Fischer 2016), this evidence points to occurrence at a very low density or very patchily in the available forest habitat. Noting that it is classified in a monotypic genus, inference from other species may be unwise. In addition, remapping the species's range indicates that the potential area of suitable habitat is smaller than previously judged, and occupancy is still likely to be very low in this newly estimated extent. There remains a relatively large area of potentially occupied habitat on Borneo, but that in Peninsular Malaysia and Sumatra now appears to be small. As such, it is suspected that the current population size could be smaller than that previously estimated, potentially much smaller. As such a new global population estimate is a high research priority for the species.
None have been observed in Peninsular Malaysia for more than a decade (eBird 2021, D. L. Yong in litt. 2021, GBIF.org 2021), despite searches, and here the population is likely to be small or very small. The area of intact forest remaining in 2020 contiguous with forest containing records of the species since 1980 is c. 2,300 km2, based on the remnant intact forest after the application of the plantation layer (Peterson et al. 2016, Harris et al. 2019) and forest cover loss since the production of this layer (data from Global Forest Watch 2021).
There are recent records in the few larger remnants of dense peat-swamp forest on Sumatra (eBird 2021, GBIF.org 2021), but the extent of forest cover loss here has been very rapid. Current apparently suitable forest here has an extent of 11,087 km2, (estimated as above). On the island of Borneo, a similar forest extent assessment results in potentially over 240,000 km2 remaining potentially suitable habitat. However, it is unclear what proportion is actually suitable for the species as it has only been recorded at a handful of widely spaced sites on Borneo, and much of this area may actually be degraded logged forest.
Rates of forest loss in the Sundaic lowlands have been extremely rapid, with total forest cover loss within suitable elevations in the range of the species estimated at 32.9% over the 14 years between 2006-2020 (data from Global Forest Watch 2021). This rate of deforestation is suspected to have driven a rapid population decline in this species, which is expected to continue and may slightly accelerate: average annual rates of forest loss have increased such that projecting the average annual rate for the past five years results in a 34.3% forest cover loss over the next three generations.
Melanoperdix niger is known from Peninsular and East Malaysia (including both Sabah and Sarawak), and Kalimantan and south Sumatra, Indonesia. It is described as local and sparse to uncommon in Peninsular Malaysia, and there are recent records from at least three sites in Kalimantan and one in Sumatra. It seems scarce and patchy in distribution, although it is easily overlooked owing to a previous lack of information on vocalisations and its elusive behaviour (B. van Balen in litt. 2012). As a result, its distribution and population status are generally very poorly known across its entire range. It is presumably declining because of rapid on-going reductions in its habitat.
In Peninsular Malaysia, it is judged to be a lowland specialist, where it has a proclivity for primary or mature, regenerated, closed-canopy evergreen forest on alluvial soils. In Indonesia, it has been recorded in peatswamp forest, and historically was described as inhabiting brushwood and high bamboo-jungle. Recent evidence from Borneo suggests that it probably extends up to at least 900 m, perhaps occasionally up to 1,200 m, but the specific habitat requirement at these elevations is unknown.
The overriding threats are habitat loss, degradation and fragmentation as a result of large-scale clearance for plantations of oil-palm and to a lesser extent rubber and timber. The conversion of habitat is typically preceded by commercial logging, which targets all remaining stands of valuable timber, even within protected areas. Rates of forest loss in the Sundaic lowlands have been extremely rapid and have been around 30% over the past three generations (14 years). Associated impacts of forest loss such as degradation and increased access for hunting may be having additive impacts on the rate of reduction, but this is uncertain for this very poorly known species. Drought fires appear to be increasing in frequency and severity on Sumatra and Borneo and a more general drying of lowland forest would be suspected to have further negative impacts on the species. Hunting for food may pose an additional, more localised, threat.
Conservation Actions Underway
It is known to occur in at least six protected areas: Taman Negara and Krau Wildlife Reserve (Peninsular Malaysia), Kinabalu National Park (Sabah), Gunung Mulu National Park (Sarawak), Tanjung Puting National Park and Gunung Palung Nature Reserve (Kalimantan), and Berbak Game Reserve (Sumatra). It also occurs in Pasoh Reserve Forest in Peninsular Malaysia.
c.24-27 cm. Black (male) or chestnut-brown (female) partridge with distinctive short, stout bill. Male wholly black, female rich chestnut-brown with variably paler (creamy) throat and belly/vent, and blackish bars across inner secondaries. Both have grey legs and feet. Similar spp. Male Roulroul Rollulus rouloul has white crown-band, red crest and red legs. Ferruginous Wood Partridge (Caloperdix oculea) has brighter rufous plumage than female with bold black-and-white markings on upperparts and flanks. Arborophila partridges are duller with less uniform body plumage. Voice Poorly known, but reportedly utters double whistle similar to R. rouloul, and low creaking sound. Hints Shy, typically sits tight until approaching human within few metres, then runs away.
Text account compilers
Wells, D.R., van Balen, B.S., Eaton, J., Keane, A., Bird, J., Taylor, J., Benstead, P., Davidson, P. & Yong, D.
BirdLife International (2022) Species factsheet: Melanoperdix niger. Downloaded from http://www.birdlife.org on 27/06/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 27/06/2022.