• 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. 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.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
A3cd	A3cd	A2cd+3cd+4cd

Red List history

Year	Category	Criteria
2020	Critically Endangered	A3cd
2018	Critically Endangered	A3cd
2016	Critically Endangered	A3cd
2015	Critically Endangered	A3cd
2012	Near Threatened	A2cd+3cd+4cd
2008	Near Threatened	A2c,d; A3c,d; A4c,d
2004	Near Threatened
2000	Lower Risk/Near Threatened
1994	Lower Risk/Near Threatened
1988	Threatened

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	3,570,000 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	unknown	-	-	-
Population trend	decreasing	poor	inferred	2019-2050
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)	80-100%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	30-49%	-	-	-
Generation length	10.4 years	-	-	-

Population justification: The population size of this species has not been quantified. In prime habitat, the density varies from 0.05 to 2.6 individuals per km² (as observed across protected areas and forest reserves; Medway and Wells 1971, Johns 2004, Lakim and Biun 2005, see also references in Jain et al. 2018).  However, populations subjected to even low hunting pressure have been demonstrated to have greatly suppressed densities,  e.g. 0.3 birds per km² (Johns 2004). Current hunting pressure is also far higher than reported in Jain et al. (2018).

Trend justification: The population is predicted to undergo an extremely rapid and severe decline over the next three generations (31.2 years) as a result of intense hunting pressure and habitat loss. On Sumatra, the species has almost disappeared from habitats where it was previously abundant (J. Eaton in litt. 2015). The number of Helmeted Hornbills in the illegal trade indicate that severe declines and local extinctions are likely to be the norm across the range.

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

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Forest	Subtropical/Tropical Moist Montane	marginal	resident
Altitude	0 - 1500 m	Occasional altitudinal limits

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		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Wood & pulp plantations - Agro-industry plantations	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		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%)		Very Rapid Declines		High Impact: 8
		Stresses Species mortality
Biological resource use	Logging & wood harvesting - Unintentional effects: (large 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 - Increase in fire frequency/intensity	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion
Transportation & service corridors	Roads & railroads	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion

Purpose	Scale
Other household goods	subsistence, national
Pets/display animals, horticulture	international

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Recommended citation
BirdLife International (2024) Species factsheet: Helmeted Hornbill Rhinoplax vigil. Downloaded from https://datazone.birdlife.org/species/factsheet/helmeted-hornbill-rhinoplax-vigil on 25/11/2024.
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 25/11/2024.