Northern Saw-whet Owl (Aegolius acadicus)

Northern Saw-whet Owl

[order] STRIGIFORMES | [family] Strigidae | [latin] Aegolius acadicus | [authority] Gmelin, 1788 | [UK] Northern Saw-whet Owl | [FR] Petite Nyctale | [DE] Sagekauz | [ES] Mochuelo Cabezon | [NL] Zaaguil


Monotypic species


Members of the genus Aegolius are small owls with a large, rounded head with no ear-tufts, and a well developed, rounded facial disc. The eyes are yellow or orange-yellow with black at the edges of the eyelids. They have long wings, are feathered down to and sometimes including the toes. The genus contains four species, all of which live in extensive forest (one in the Holarctic region, three in America).

Physical charateristics

A very tame little owl; smaller than a Screech-Owl, without ear tufts. Underparts have soft blotchy brown streaks. Young birds in summer are chocolate-brown, with conspicuous white eyebrows forming a broad V over the bill; belly is
tawny ochre.

Listen to the sound of Northern Saw-whet Owl

[audio: Saw-whet Owl.mp3]

Copyright remark: Most sounds derived from xeno-canto

wingspan min.: 46 cm wingspan max.: 56 cm
size min.: 17 cm size max.: 21 cm
incubation min.: 21 days incubation max.: 26 days
fledging min.: 20 days fledging max.: 34 days
broods: 0   eggs min.: 3  
      eggs max.: 7  


North America : widespread, also Central Mexico


Forests, conifers, groves. Breeds most commonly in coniferous forest of various kinds, including open pine forest, spruce-fir associations, white cedar swamps; also mixed woods such as pine-oak, spruce-poplar, and others.
In some places, breeds in oak woodland or in streamside groves in arid country. Winters in habitats with dense cover, especially groves of conifers.


Early in breeding season, male sings incessantly at night to defend territory and attract a mate.
Nest: Site is in cavity in tree, usually 15 -60′ above ground. Mostly use abandoned woodpecker holes. Will also use artificial nest boxes. No nest is built; eggs are laid on wood chips or other debris in bottom of n
est cavity.
Clutch 5 -6, sometimes 4 -7, rarely 3 -9. White. Incubation by female only, 27 -29 days; male brings food to her throughout this time.

Young: At first, adult male brings all food to nest, female feeds it to young. Female remains with chicks until youngest is about 18 days old; then she may hunt for them also, or may depart. Young leave nest at about 4 –
5 weeks, remain together near nest and are fed (mostly by male) for at least another 4 weeks. Female may sometimes find another mate and nest a second time.

Feeding habits

Mostly small rodents.
Feeds mostly on mice that live in forest, especially deer mice; also many voles. Also eats other mice, shrews, young squirrels, sometimes small birds and large insects. A resident race on Queen Charlotte Islands, British Columbia, may eat crustaceans and
insects in intertidal zone.
Behavior: Hunts almost entirely at night, mostly by waiting on low perches and then swooping down on prey. Finds its prey both by sound and by sight; as with many owls, ears are adapted for precisely locating the source of sounds.

Video Northern Saw-whet Owl


copyright: Leslie Lieurance


This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Northern Saw-whet Owl status Least Concern



Distribution map

Northern Saw-whet Owl distribution range map

Leave a Reply

Your email address will not be published. Required fields are marked *