• 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.
Olsen, J.; Wink, M.; Sauer-Gürth; Trost, S. 2002. A new Ninox owl from Sumba, Indonesia. Emu 102: 223-231.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	B2ab(i,ii,iii,v)	B1ab(i,ii,iii,v)+2ab(i,ii,iii,v)

Red List history

Year	Category	Criteria
2017	Endangered	B2ab(i,ii,iii,v)
2016	Near Threatened	C1+2a(ii)
2012	Near Threatened	C1+2a(ii)
2008	Near Threatened	C1; C2a(ii)
2004	Near Threatened
2000	Not Recognised
1994	Not Recognised
1988	Not Recognised

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	6,100 km2	medium
Area of Occupancy (breeding/resident)	160 km2
Number of locations	3	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	10000-19999 mature individuals	poor	estimated	2008
Population trend	decreasing	-	inferred	-
Generation length	4.1 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: This species is very poorly known but it is thought to be uncommon given that it escaped detection for many years and there are few records available. It is placed in the band 10,000-19,999 mature individuals, equating to 15,000-29,999 individuals in total, rounded here to 15,000-30,000 individuals. This preliminary population estimate requires clarification.

Trend justification: The population is inferred to be in decline owing to on-going habitat destruction.

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

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Terrestrial	Subtropical/Tropical Heavily Degraded Former Forest	suitable	unknown
Forest	Subtropical/Tropical Moist Lowland	major	resident
Forest	Subtropical/Tropical Moist Montane	possible	resident
Altitude	600 - 950 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		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	Logging & wood harvesting - Unintentional effects: (large scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Natural system modifications	Fire & fire suppression - Increase in fire frequency/intensity	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation

---

Recommended citation
BirdLife International (2024) Species factsheet: Least Boobook Ninox sumbaensis. Downloaded from https://datazone.birdlife.org/species/factsheet/least-boobook-ninox-sumbaensis 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.