Photo: Kameron Perensovich/Flickr Creative Commons

Northern Saw-whet Owl

Aegolius acadicus

Birders who prowl through conifer groves in winter sometimes find this round-headed little gnome perched there, sitting still as if to avoid notice. Avoiding notice is a task at which this owl often succeeds; it is overlooked in many places where it occurs. Late at night in the breeding season, males give a rhythmic tooting song that may go on for hours with scarcely a break. The bird was named for this song, which reminded settlers of the sound of a whetstone sharpening a saw.
Conservation status Probably some declines in numbers with loss of habitat, but still widespread and fairly common.
Family Owls
Habitat 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.
Birders who prowl through conifer groves in winter sometimes find this round-headed little gnome perched there, sitting still as if to avoid notice. Avoiding notice is a task at which this owl often succeeds; it is overlooked in many places where it occurs. Late at night in the breeding season, males give a rhythmic tooting song that may go on for hours with scarcely a break. The bird was named for this song, which reminded settlers of the sound of a whetstone sharpening a saw.
Photo Gallery
  • adult
  • fledglings
  • adult
Feeding 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.


Eggs

5-6, sometimes 4-7, rarely 3-9. White. Incubation is by female only, 27-29 days. Female remains in nest almost constantly from time first egg is laid; 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 begin to 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 in one year.


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 begin to 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 in one year.

Diet

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. Resident race on Queen Charlotte Islands, British Columbia, may eat crustaceans and insects in intertidal zone.


Nesting

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 woodpeckers holes, especially those of flickers and Pileated Woodpeckers. Will also use artificial nest boxes. Apparently will not use same site two years in a row.

Illustration © David Allen Sibley.
Learn more about these drawings.

Text © Kenn Kaufman, adapted from
Lives of North American Birds

Migration

Some remain all year on breeding range, others move south in autumn. Some western mountain birds may move downhill for winter. Migration is relatively early in spring, late in fall. Migrates at night.

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Migration

Some remain all year on breeding range, others move south in autumn. Some western mountain birds may move downhill for winter. Migration is relatively early in spring, late in fall. Migrates at night.

  • All Seasons - Common
  • All Seasons - Uncommon
  • Breeding - Common
  • Breeding - Uncommon
  • Winter - Common
  • Winter - Uncommon
  • Migration - Common
  • Migration - Uncommon
Songs and Calls
Usually silent; in late winter and spring utters monotonous series of tooting whistles.
Audio © Lang Elliott, Bob McGuire, Kevin Colver, Martyn Stewart and others.
Learn more about this sound collection.

How climate change could affect this bird's range

In the broadest and most detailed study of its kind, Audubon scientists have used hundreds of thousands of citizen-science observations and sophisticated climate models to predict how birds in the U.S. and Canada will react to climate change.

Learn more

Read more: climate.audubon.org
Owls

Northern Saw-whet Owl

The darker the color, the more favorable the climate conditions are for survival. The outlined areas represent approximate current range for each season.

More on reading these maps.

Each map is a visual guide to where a particular bird species may find the climate conditions it needs to survive in the future. We call this the bird’s “climatic range.”

The colors indicate the season in which the bird may find suitable conditions— blue for winter, yellow for summer (breeding), and green for where they overlap (indicating their presence year-round).

The darker the shaded area, the more likely it is the bird species will find suitable climate conditions to survive there.

The outline of the approximate current range for each season remains fixed in each frame, allowing you to compare how the range will expand, contract, or shift in the future.

The first frame of the animation shows where the bird can find a suitable climate today (based on data from 2000). The next three frames predict where this bird’s suitable climate may shift in the future—one frame each for 2020, 2050, and 2080.

You can play or pause the animation with the orange button in the lower left, or select an individual frame to study by clicking on its year.

The darker the color, the more favorable the climate conditions are for survival. The outlined areas represent approximate current range for each season. More on reading these maps.
Winter
Summer

Winter Range
Summer Range
Both Seasons
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