• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Taxonomic note
Formerly regarded as a subspecies of R. ocellata but split following Davison et al. (2020). Monotypic.

Taxonomic source(s)
Handbook of the Birds of the World and BirdLife International. 2021. Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 6. Available at: https://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v6_Dec21.zip.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	D1

Red List history

Year	Category	Criteria
2021	Near Threatened	D1
2016	Not Recognised
2012	Not Recognised
2008	Not Recognised
2004	Not Recognised
2000	Not Recognised
1994	Not Recognised
1988	Not Recognised

Migratory status	not a migrant	Forest dependency	high
Land-mass type		Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	3,600 km2	good
Area of Occupancy (breeding/resident)	1,068 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	900-3000,1100-2000 mature individuals	poor	inferred	2021
Population trend	stable	poor	inferred	2008-2024
Generation length	5.6 years	-	-	-
Number of subpopulations	1-4,1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The population size has been reported as c. 200-2,000 individuals, with reported density of 8 birds/km² in 125-250 km² of habitat (McGowan & Kirwan 2020). Davison & Scriven (1987) reported densities of 1.9 males/km² on Gunung Rabong and 2.7-3.0 males per km² on Gunung Tahan, and that the total number of males on Gunung Rabong in May 1976 was only 15 (BirdLife International 2001). The confirmation of the species's occurrence in Terengganu (Liang et al. 2018) increases the total area within the suitable elevation (a maximum area of habitat) to 490 km². If all of this area were occupied at recorded densities of 3.8-6 mature individuals/km², i.e. using the above densities of calling males and assuming an equal sex ratio (a precautionary assumption), then the range of population size is 1,862-2,940 mature individuals. Should occupancy be lower, it is plausible that the lower bound of the population would fall below 1,000 mature individuals.
Given the uncertainty inherent in these calculations, the most precise estimate of population size for Malaysian Crested Argus is here considered to be 900-3,000 mature individuals, but it is most likely that the population is greater than 1,000 mature individuals.

Trend justification: There is no recent information about the population trend in Malaysia. The threats to the species are considered minimal given that almost the entire range lies within the well-protected Taman Negara National Park, however the population within the Dungun Timber Complex may be impacted by selective logging (Liang et al. 2018) and there is the possibility that illegally-set snares could capture the species, though it is not thought to be a target of hunters (Liang et al. 2018, Norsyamimi et al. 2020). In the absence of significant threats, the population is suspected to be stable.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Malaysia	extant	native	yes

Country/Territory	IBA Name
Malaysia	Taman Negara National Park

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Forest	Subtropical/Tropical Moist Montane	major	resident
Altitude	800 - 1150 m	Occasional altitudinal limits	680 - 1400 m

Threat (level 1)	Threat (level 2)	Impact and Stresses
Biological resource use	Hunting & trapping terrestrial animals - Unintentional effects (species is not the target)	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Species mortality
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		No decline		Low Impact: 4
		Stresses Ecosystem degradation, Ecosystem conversion

Purpose	Scale
Pets/display animals, horticulture	international

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Recommended citation
BirdLife International (2024) Species factsheet: Malaysian Crested Argus Rheinardia nigrescens. Downloaded from https://datazone.birdlife.org/species/factsheet/malaysian-crested-argus-rheinardia-nigrescens on 22/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 22/12/2024.