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

Taxonomic note
Rhyticeros everetti (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.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	A2cd+3cd+4cd; C2a(ii)	A2cd+3cd+4cd; C2a(i,ii)

Red List history

Year	Category	Criteria
2020	Endangered	A2cd+3cd+4cd; C2a(ii)
2016	Vulnerable	A2cd+3cd+4cd;B1ab(ii,iii,iv,v);C1+2a(ii)
2012	Vulnerable	A2cd+3cd+4cd;B1ab(ii,iii,iv,v);C1+2a(ii)
2010	Vulnerable	A2c,d; A3c,d; A4c,d; B1a+b(ii,iii,iv,v); C1; C2a(ii)
2008	Vulnerable	A2c,d; A3c,d; A4c,d; B1a+b(ii,iii,iv,v); C1; C2a(ii)
2004	Vulnerable
2000	Vulnerable
1996	Vulnerable
1994	Vulnerable
1988	Threatened

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	13,100 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	1000-2000 mature individuals	medium	estimated	2020
Population trend	decreasing	poor	inferred	2000-2025
Rate of change over the past 10 years/3 generations (longer of the two periods)	50-76%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	50-79%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	50-79%	-	-	-
Generation length	8.4 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: Recent population estimates indicate that there has been a rapid decline in the population over the past three generations, and it appears that extrapolations from high densities from a short survey of Manupeu-Tandaru National Park were inappropriate, and the estimate of 6,400 (D. Mulyawati in litt. 2010) is considered an overestimate (T. O'Brien in litt. 2020). The most recent population estimate is of 1,650 mature individuals, based on the reduction in extent and number of large forest patches. With a rapid suspected population reduction underway and an inferred continuing decline in mature individuals the current population size is estimated to be between 1,000-2,000 mature individuals.

Trend justification: Despite the adequate protection of an area of lowland forest in the Manupeu-Tanadaru National Park (D. Mulyawati in litt. 2010), an overall population decline of 30-49% is estimated owing to the extensive and on-going loss and fragmentation of forest habitats outside of the reserve.

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

Country/Territory	IBA Name
Indonesia	Laiwanggi Wanggameti
Indonesia	Luku Melolo
Indonesia	Manupeu Tanadaru
Indonesia	Poronumbu
Indonesia	Tanjung Ngunju
Indonesia	Yawila

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Savanna	Dry	suitable	resident
Altitude	0 - 950 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
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	Livestock farming & ranching - Small-holder grazing, ranching or 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		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Species mortality
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Rapid Declines		Medium Impact: 6
		Stresses Ecosystem degradation
Natural system modifications	Fire & fire suppression - Increase in fire frequency/intensity	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Rapid Declines		Medium Impact: 7
		Stresses Species disturbance, Ecosystem degradation, Ecosystem conversion, Reduced reproductive success, Species mortality

Purpose	Scale
Food - human
Pets/display animals, horticulture

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Recommended citation
BirdLife International (2024) Species factsheet: Sumba Hornbill Rhyticeros everetti. Downloaded from https://datazone.birdlife.org/species/factsheet/sumba-hornbill-rhyticeros-everetti on 23/12/2024.
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 23/12/2024.