• 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+4cd

Red List history

Year	Category	Criteria
2020	Vulnerable	A3cd+4cd
2018	Vulnerable	A3cd+4cd
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/Least Concern
1988	Lower Risk/Least Concern

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	3,370,000 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	unknown	-	-	-
Population trend	decreasing	poor	inferred	2004-2044
Rate of change over the future 10 years/3 generations (longer of the two periods)	35-40%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	35-40%	-	-	-
Generation length	14 years	-	-	-

Population justification: The population size of this species has not been quantified. The species is widespread throughout its range, but occurs at low densities, even in suitable habitat (Poonswad et al. 2013).
In Peninsular Malaysia, Sungai Tekam Forestry Concession (Pahang State) population density was found to be 1.6 groups/km² in primary forest and 2.3, 1.8, 1.2, 0.4 groups/km² in 0-6 month, 1-2 year, 3-4, 5-6-year-old logged forest respectively (Johns 1987). In Kuala Lompat (Krau Wildlife Reserve) the population density was 2 individuals/km² (Medway & Wells 1971). In Sarawak, Upper Baram and Batang Ai National Park had population densities of 0.27 individuals/km² (Chin & Jantan 2001) and 0.96 individuals/km² (Meredith 1995) respectively. In Sabah, Crocker Range Park and Tawau Hills Park had population densities of 0.94 individuals/km² and 5.67 individuals/km² respectively (Lakim & Biun 2005).

Trend justification: An analysis of deforestation between 2000 and 2012 estimated forest loss within the species's range at a rate equivalent to 35% over three generation lengths (42 years) (Tracewski et al. 2016). Being largely restricted to primary forests and intolerant of habitat conversion, the species is additionally threatened by hunting. Thus, its actual rate of population decline is likely greater than the estimate decline based on forest loss alone, possibly exceeding 35% over three generations. The rate of decline is therefore placed in the band 35-40% over three generations. Since this species has a long generation length, with three generations stretching over 42 years, there is insufficient evidence to calculate the magnitude of reduction over the past three generations. Assuming the recent rate of decline remains constant, the species is projected to decline by 35-40% over the next three generations.

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

Country/Territory	IBA Name
Malaysia	Bako-Buntal Bay
Malaysia	Belum-Temenggor
Malaysia	Bintang Range
Malaysia	Central Titiwangsa Range
Malaysia	Danum Valley Conservation Area
Malaysia	Danum-Linau
Malaysia	Endau-Rompin
Malaysia	Gunung Pueh
Malaysia	Hose-Laga mountains
Malaysia	Kabili-Sepilok
Malaysia	Kelabit Highlands
Malaysia	Kinabatangan floodplain
Malaysia	Kledang Range
Malaysia	Krau Wildlife Reserve
Malaysia	Kulamba Wildlife Reserve
Malaysia	Lambir Hills National Park
Malaysia	Lanjak Entimau Wildlife Sanctuary
Malaysia	Maliau Basin Conservation Area
Malaysia	Mount Kinabalu
Malaysia	Mulu - Buda Protected Area
Malaysia	Nakawan Range
Malaysia	Niah National Park
Malaysia	Panti forest
Malaysia	Pondok Tanjung Forest Reserve
Malaysia	Sadong-Saribas coast
Malaysia	Selangor Heritage Park
Malaysia	Similajau National Park
Malaysia	South-east Pahang peat swamp forest
Malaysia	Tabin Wildlife Reserve
Malaysia	Taman Negara National Park
Malaysia	Tanjung Datu-Samunsam Protected Area
Malaysia	Tawau Hills Park
Malaysia	Ulu Muda
Malaysia	Usun Apau plateau
Thailand	Bu Do - Sungai Padi
Thailand	Hala Sector, Hala-Bala Wildlife Sanctuary and Bang Lang National Park
Thailand	Khao Banthad
Thailand	Thaleban

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Forest	Subtropical/Tropical Moist Montane	marginal	resident
Altitude	0 - 1750 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		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Species mortality
Biological resource use	Hunting & trapping terrestrial animals - Unintentional effects (species is not 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%)		Slow, Significant Declines		Medium Impact: 6
		Stresses 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, Ecosystem conversion

Purpose	Scale
Food - human	subsistence, national
Handicrafts, jewellery, etc.	subsistence, national
Pets/display animals, horticulture	national, international

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Recommended citation
BirdLife International (2024) Species factsheet: Rhinoceros Hornbill Buceros rhinoceros. Downloaded from https://datazone.birdlife.org/species/factsheet/rhinoceros-hornbill-buceros-rhinoceros 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.