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

Taxonomic note
Aegolius gradyi (del Hoyo and Collar 2014) was newly described from fossil remains by Olson (2012).

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
-	-	-

Red List history

Year	Category	Criteria
2022	Extinct
2016	Extinct
2014	Extinct
2012	Not Recognised
2008	Not Recognised
2004	Not Recognised
2000	Not Recognised
1994	Not Recognised
1988	Not Recognised

Migratory status	not a migrant	Forest dependency	does not normally occur in forest
Land-mass type		Average mass	-

	Estimate	Data quality
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	unknown	-	-	-
Population trend		-	-	-
Generation length	3.8 years	-	-	-

Population justification: No extant population remains.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Bermuda (to UK)	extinct	native	yes

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Temperate	major	resident
Altitude		Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Unspecified species	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Unknown		Unknown		Past Impact
		Stresses Ecosystem degradation, Reduced reproductive success, Species mortality
Residential & commercial development	Housing & urban areas	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Unknown		Unknown		Past Impact
		Stresses Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2025) Species factsheet: Bermuda Saw-whet Owl Aegolius gradyi. Downloaded from https://datazone.birdlife.org/species/factsheet/bermuda-saw-whet-owl-aegolius-gradyi on 02/01/2025.
Recommended citation for factsheets for more than one species: BirdLife International (2025) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 02/01/2025.