• 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
-	-	-

Red List history

Year	Category	Criteria
2024	Least Concern
2016	Least Concern
2012	Least Concern
2009	Least Concern
2008	Least Concern
2004	Least Concern
2000	Lower Risk/Least Concern
1994	Lower Risk/Least Concern
1988	Lower Risk/Least Concern

Migratory status	full migrant	Forest dependency	medium
Land-mass type		Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	18,700,000 km2	medium
Extent of Occurrence (non-breeding)	18,600,000 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	0-0 mature individuals	poor	estimated	2020
Population trend	increasing	-	estimated	-
Generation length	4.04 years	-	-	-

Population justification: The global population has been estimated at 2,000,000 mature individuals (Partners in Flight 2020). In North America (USA and Canada), the total population size is estimated at 2,000,000 mature individuals (Partners in Flight 2020). This species is considered to have a medium dependency on forest habitat, and tree cover is estimated to have declined by 11.3% within its mapped range over the past three generations (12.12 years) (Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein). However, the species' population in North America (USA and Canada) is estimated to have a slightly positive annual trend, which equates to a rapid increase in population size over three generations (Partners in Flight 2024). As North America holds the vast majority of the species' global range, the global population size is considered to be increasing at a rapid rate over three generations.

Trend justification: This species has undergone a small or statistically insignificant decrease over the last 40 years in North America (data from Breeding Bird Survey and/or Christmas Bird Count: Butcher and Niven 2007).

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Bermuda (to UK)	extant	vagrant
Canada	extant	native				yes
Costa Rica	extant	native		yes
Guatemala	extant	native		yes
Mexico	extant	native
St Pierre and Miquelon (to France)	extant	vagrant			yes	yes
USA	extant	native		yes

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Terrestrial	Urban Areas	suitable	non-breeding
Desert	Temperate	suitable	non-breeding
Desert	Temperate	suitable	breeding
Forest	Boreal	suitable	non-breeding
Forest	Boreal	suitable	breeding
Forest	Subtropical/Tropical Moist Montane	suitable	non-breeding
Forest	Subtropical/Tropical Moist Montane	suitable	breeding
Forest	Subtropical/Tropical Swamp	suitable	non-breeding
Forest	Subtropical/Tropical Swamp	suitable	breeding
Altitude	1350 - 3100 m	Occasional altitudinal limits

Purpose	Scale
Pets/display animals, horticulture	international

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Recommended citation
BirdLife International (2024) Species factsheet: Northern Saw-whet Owl Aegolius acadicus. Downloaded from https://datazone.birdlife.org/species/factsheet/northern-saw-whet-owl-aegolius-acadicus 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.