Northern Saw-whet Owl
(Aegolius acadicus)


Picture of bird
© Chuck Kling
For additional photos and vocalizations, visit Dendroica. (Link opens in a new window.)

The Northern Saw-whet Owl is the most common owl found across most of southern Canada. Like other owls, it is a difficult species to monitor because of its nocturnal habits. Results from the Christmas Bird Count suggest a large increase in the Canadian population relative to 1970, though the reliability of this assessment is considered low. The Northern Saw-whet Owl brooksi subspecies is found only on the Haida Gwaii archipelago in British Columbia (COSEWIC 2017c), where its distribution is strongly correlated with the presence of old-growth forests (Gill and Cannings 1997). Rates of habitat loss through forest harvest led the Committee on the Status of Endangered Wildlife in Canada to assess the subspecies as Threatened in 2006 and again in 2017 (COSEWIC 2017c). These rates suggest that there has also been a decrease in the subspecies population since 1970. With such a large percentage of the global breeding population, Canada's responsibility for the Northern Saw-whet Owl brooksi subspecies is very high. This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.


Main designations for the species
DesignationStatusDateSubspecies, population
COSEWIC (Canada)Threatened2017Northern Saw-whet Owl brooksi subspecies
SARA (Canada)Threatened2007Northern Saw-whet Owl brooksi subspecies
IUCN (Global)Least concern2018 
Wild Species (Canada)Secure2015 
Bird Conservation Region StrategyPriority Species2013 

Population status

Geographic area or populationPopulation change relative to ~1970ReliabilityStatus in relation to goal
CanadaLarge IncreaseLowAt an Acceptable Level
Northern Saw-whet Owl brooksi subspeciesModerate DecreaseLowBelow Acceptable Level

Population estimate

Geographic area or populationPopulation estimate
Canada500,000 - 1,000,000 adults

Distribution maps


Migration strategy, occurrence

Short-distance migrant

Responsibility for conservation

Geographic areaResponsibility based on % of global population

General nesting period in Canada

Nesting period starts between early March and late April and ends between early July and late July, depending on the region. Before or after this period, the probability of an active nest is lower.

Conservation and management

Northern Saw-whet Owls nest in cavities excavated by large woodpeckers (e.g., Northern Flickers and Pileated Woodpeckers), but will also readily use appropriate nest boxes (Rasmussen et al. 2008). Local population densities can vary widely from year to year, presumably fluctuating with the density of their prey (Marks and Doremus 2000, Confer et al. 2014). The species prefers older forest and woodlot habitats (Rasmussen et al. 2008), which provide nest-sites and openings for foraging. The brooksi subspecies is endemic to the Haida Gwaii archipelago and is different genetically, morphologically, and behaviourally from continental populations of Saw-whet Owls (Withrow et al. 2014). The subspecies is non-migratory and is thought to be threatened by on-going logging (particularly of its preferred old forest nesting habitat), nest predation by introduced species such as red squirrels, raccoons, and rats, and by over-browsing by introduced deer, which may reduce prey availability. Approximately one third of the Archipelago is now protected within the Gwaii Haanas National Park Reserve and Haida Heritage Site (Parks Canada Agency 2016a). For information on the legal status of this subspecies under the Species at Risk Act (SARA) see the SARA Registry.


Bird conservation region strategies

Environment and Climate Change Canada and partners have developed Bird Conservation Region Strategies in each of Canada’s Bird Conservation Regions (BCRs). In these strategies, selected species are identified as priorities for one or more of the following reasons:

  • conservation concerns (i.e., species vulnerable due to population size, distribution, population trend, abundance, or threats)
  • stewardship responsibilities (i.e., species that typify the regional avifauna or have a large proportion of their range or population in the sub-region)
  • management concerns (i.e., species that require ongoing management because of their socio-economic importance as game species, or because of their impacts on other species or habitats)
  • other concerns (i.e., species deemed a priority by regional experts for other reasons than those listed above or because they are listed as species at risk or concern at the provincial level)

Select any of the sub-regions below to view the BCR strategy for additional details.

BCRs, marine biogeographic units, and sub-regions in which the species is listed as a priority
RegionSub-region and priority type
Atlantic Northern ForestsAtlantic Northern Forests, sub-region and priority type: Quebec -- Stewardship
Boreal Hardwood TransitionBoreal Hardwood Transition, sub-region and priority type: Quebec -- Other
Boreal Softwood ShieldBoreal Softwood Shield, sub-region and priority type: Quebec -- Other
Great BasinGreat Basin, sub-region and priority type: Pacific and Yukon -- Conservation
Lower Great Lakes/St. Lawrence PlainLower Great Lakes/St. Lawrence Plain, sub-region and priority type: Quebec -- Other
Northern Pacific RainforestNorthern Pacific Rainforest, sub-region and priority type: Pacific and Yukon -- Stewardship
Northern RockiesNorthern Rockies, sub-region and priority type: Pacific and Yukon -- Stewardship