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

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	A3c+4c

Red List history

Year	Category	Criteria
2022	Vulnerable	A3c+4c
2016	Near Threatened	A2c+3c+4c
2012	Near Threatened	A2c+3c+4c
2008	Near Threatened	A2c; A3c; A4c
2004	Near Threatened
2000	Lower Risk/Near Threatened
1994	Lower Risk/Near Threatened
1988	Near Threatened

Migratory status	nomadic	Forest dependency	medium
Land-mass type	shelf island	Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	926,000 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	unknown	-	-	-
Population trend	decreasing	medium	suspected	2015-2027
Rate of change over the past 10 years/3 generations (longer of the two periods)	20-29%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	26-35,30-35%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	26-35,30-35%	-	-	-
Generation length	4.4 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: Attempts to assess the population size of this species are confounded by its nomadic behaviour. Although it is described as uncommon (e.g. Smythies and Davison 1999, Eaton et al. 2016) it is widespread across Borneo's lowlands (Witt and Sheldon 1994, Mann 2008) and is not considered likely to approach population size thresholds (<10,000 mature individuals) for listing as threatened.

Trend justification: Pityriasis gymnocephala is tied to lowland forests, which are being lost rapidly on Borneo. Global Forest Watch (2021, using data from Hansen et al. [2013] and methods disclosed therein) indicate forest cover loss within the range of the species was at a rate of 1.95% per year (13.2 years; Bird et al. 2020) in the period 2007-2020, equivalent to c.25% over three generations. Between 2015-2020, the rate increased to 2.3-2.5% per annum, equivalent when projected forward to a rate of 30-33% over three generations. Although it can be found in mature secondary and selectively logged forests, it is most abundant in tall, primary forests, and almost never in plantations (Witt & Sheldon 1994, Mann 2008). Given most forest loss on Borneo has amounted to total clearance or conversion to plantations, it is suspected that this species will decline at a rate near-equal to that of forest loss. There is no reason to suspect that these rates of forest loss will slow or cease in the near-future.

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

Country/Territory	IBA Name
Brunei	Belait Swamp Forest
Indonesia	Hutan Samarinda-Balikpapan
Malaysia	Danum Valley Conservation Area
Malaysia	Gunung Pueh
Malaysia	Kabili-Sepilok
Malaysia	Kelabit Highlands
Malaysia	Kinabatangan floodplain
Malaysia	Lambir Hills National Park
Malaysia	Lanjak Entimau Wildlife Sanctuary
Malaysia	Maliau Basin Conservation Area
Malaysia	Mulu - Buda Protected Area
Malaysia	Niah National Park
Malaysia	Sadong-Saribas coast
Malaysia	Similajau National Park
Malaysia	Tabin Wildlife Reserve
Malaysia	Tanjung Datu-Samunsam Protected Area
Malaysia	Tawau Hills Park

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Terrestrial	Subtropical/Tropical Heavily Degraded Former Forest	suitable	resident
Forest	Subtropical/Tropical Mangrove Vegetation Above High Tide Level	suitable	resident
Forest	Subtropical/Tropical Moist Lowland	major	resident
Forest	Subtropical/Tropical Swamp	major	resident
Altitude	0 - 600 m	Occasional altitudinal limits	(max) 1200 m

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Agro-industry farming	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Annual & perennial non-timber crops - Small-holder farming	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Wood & pulp plantations - Agro-industry plantations	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Rapid Declines		Medium Impact: 7
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (large scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Rapid Declines		Medium Impact: 7
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion
Natural system modifications	Fire & fire suppression - Trend Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation

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Recommended citation
BirdLife International (2024) Species factsheet: Bornean Bristlehead Pityriasis gymnocephala. Downloaded from https://datazone.birdlife.org/species/factsheet/bornean-bristlehead-pityriasis-gymnocephala 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.