VU
Plain-pouched Hornbill Rhyticeros subruficollis



Taxonomy

Taxonomic note
Rhyticeros subruficollis (del Hoyo and Collar 2014) was previously placed in the genus Aceros.

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.

IUCN Red List criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - A2cd+3cd+4cd

Red List history
Year Category Criteria
2016 Vulnerable A2cd+3cd+4cd
2012 Vulnerable A2cd+3cd+4cd
2008 Vulnerable A2c,d; A3c,d; A4c,d
2004 Vulnerable
2000 Vulnerable
1996 Vulnerable
1994 Vulnerable
1988 Threatened
Species attributes

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

Estimate Data quality
Extent of Occurrence (breeding/resident) 360,000 km2 medium
Number of locations 11-100 -
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size 1500-7000 mature individuals medium estimated 2000
Population trend decreasing poor suspected 1998-2045
Rate of change over the past 10 years/3 generations (longer of the two periods) 30-49% - - -
Rate of change over the future 10 years/3 generations (longer of the two periods) 30-49% - - -
Rate of change over the past & future 10 years/3 generations (longer of the two periods) 30-49% - - -
Generation length 19 years - - -
Number of subpopulations 2-100 - - -
Percentage of mature individuals in largest subpopulation 1-89% - - -

Population justification: A population estimate of 2,500-9,999 individuals has been derived from analyses of records and surveys by BirdLife International (2001). This equates to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals. At least 1,000 are known from Thailand as well as strong population centres in northern Peninsula Malaysia and southern Myanmar. Regular monitoring has been conducted at Pos Chiong/Kg Tebang in Temengor Forest Reserve, Peninsular Malaysia since 2004. Numbers fluctuate greatly from year to year, with the highest count on a single occasion of 3,261 on 14 September 2008 (Yeap and Ong 2011). Subsequent counts have been much lower (less than 1,000 individuals) (C. A Yeap in litt. 2012). Despite counts in previous years of between 2,500-3,000 individuals, less than 100 birds were counted in Perak, Malaysia in 2009 (F. Lambert in litt. 2009). A roosting flock of between 700-900 individuals has been recorded at Bang Lang National Park in Yala Province, Thailand (P. Poonswad in litt. 2012).

Trend justification: Hunting, trapping and deforestation are suspected to be causing rapid population declines.


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

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Malaysia Belum-Temenggor
Myanmar Pachan
Myanmar Lampi Island
Thailand Thung Yai - Naresuan
Thailand Huai Kha Khaeng
Thailand Khao Laem
Thailand Kaeng Krachan
Thailand Khao Nor Chuchi
Thailand Bala Sector, Hala-Bala Wildlife Sanctuary
Myanmar Ngawun (Lenya extension)
Myanmar Chaungmon-Wachaung
Myanmar Karathuri
Thailand Hala Sector, Hala-Bala Wildlife Sanctuary and Bang Lang National Park
Malaysia Ulu Muda

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Lowland major resident
Altitude 0 - 1000 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Agro-industry farming Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Annual & perennial non-timber crops - Small-holder farming Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Species mortality
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
Species disturbance, Ecosystem degradation, Ecosystem conversion
Biological resource use Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation

Utilisation
Purpose Primary form used Life stage used Source Scale Level Timing
Food - human - - non-trivial recent
Pets/display animals, horticulture - - international non-trivial recent

Recommended citation
BirdLife International (2024) Species factsheet: Rhyticeros subruficollis. Downloaded from https://datazone.birdlife.org/species/factsheet/plain-pouched-hornbill-rhyticeros-subruficollis on 05/03/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org on 05/03/2024.