• 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. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	B1ab(ii,iii,v); C2a(i); D	B1ab(ii,iii,v); C2a(i); D1

Red List history

Year	Category	Criteria
2016	Endangered	B1ab(ii,iii,v); C2a(i); D
2012	Endangered	B1ab(ii,iii,v);C2a(i)
2008	Endangered	B1a+b(ii,iii); C2a(i)
2006	Endangered
2004	Not Recognised
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)	1,500 km2	medium
Number of locations	5	-
Severely fragmented?	yes	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	150-700 mature individuals	poor	estimated	2007
Population trend	decreasing	poor	suspected	-
Generation length	3.7 years	-	-	-
Number of subpopulations	2-100	-	-	-
Percentage of mature individuals in largest subpopulation	1-89%	-	-	-

Population justification: Extensive surveys have located 100 individuals and led to a global population estimate of 200-250 individuals. However, given the species's elusive nature and its ability to remain undiscovered for so long the true population size is likely to be somewhat higher. Therefore, it is probably best placed in the band 250-999 individuals. This equates to 167-666 mature individuals, rounded to 150-700 mature individuals here.

Trend justification: The species appears to be intolerant of habitat loss and severe fragmentation, and so is suspected to be declining as the very few remaining unprotected areas of forest are slowly lost. The likely rate of population decline has not been estimated.

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

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Altitude	30 - 530 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Scale Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Rapid 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%)		Rapid Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion
Energy production & mining	Mining & quarrying	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Residential & commercial development	Housing & urban areas	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2024) Species factsheet: Serendib Scops-owl Otus thilohoffmanni. Downloaded from https://datazone.birdlife.org/species/factsheet/serendib-scops-owl-otus-thilohoffmanni on 23/11/2024.
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 23/11/2024.