Northern Saw-whet Owl

Northern Saw-whet Owl

Other Names

• Mochuelo Cabezón (Spanish)
• Petite Nyctale (French)

Basic Description

A tiny owl with a catlike face, oversized head, and bright yellow eyes, the Northern Saw-whet Owl is practically bursting with attitude. Where mice and other small mammals are concerned this fierce, silent owl is anything but cute. One of the most common owls in forests across northern North America (and across the U.S. in winter), saw-whets are highly nocturnal and seldom seen. Their high-pitched too-too-too call is a common evening sound in evergreen mountain forests from January through May.

 

• Cool Facts
  • The Northern Saw-whet Owl may have been named for giving a call that sounds like a saw being sharpened on a whetting stone, but there is no consensus as to which of its several calls gave rise to the name.
  • The main prey items of the Northern Saw-whet Owl are mice, and especially deer mice of the genus Peromyscus. Saw-whets usually eat adult mice in pieces, over the course of two meals.
  • The female Northern Saw-whet Owl does all of the incubation and brooding, while the male does the hunting. When the youngest nestling is about 18 days old, the female leaves the nest to roost elsewhere. The male continues bringing food, which the older nestlings may help feed to their younger siblings.
  • The female saw-whet keeps the nest very clean, but a mess starts to accumulate when she leaves. By the time the young owls leave the nest, 10 days to 2 weeks later, the nest cavity has a thick layer of feces, pellets, and rotting prey parts.
  • Migration in saw-whets has historically been poorly understood, because of their nocturnal, reclusive behavior. In the 1990s researchers began Project Owlnet, a collaboration that now consists of more than 100 owl migration banding sites. Researchers use the too-too-too call to lure owls in to mist nets, and band thousands of saw-whets every fall.
  • Migrating Northern Saw-whet Owls can cross the Great Lakes or other large bodies of water. In October of 1999, one landed on a fishing vessel 70 miles from shore in the Atlantic Ocean near Montauk, New York.
  • The oldest Northern Saw-whet Owl on record was at least 9 years, 5 months old when it was captured and released by a Minnesota bird bander in 2007. It was originally banded in Ontario in 1999.

  Habitat:

  Northern Saw-whet Owls breed in forests across southern Canada and the northern and western United States, extending through central Mexico. They seem to prefer mature forest with an open understory for foraging, deciduous trees for nesting, dense conifers for roosting, and riverside habitat nearby. But they nest in a wide range of wooded habitats, including coniferous swamps, disturbed deciduous woods, savannahs, riverside forest, and shrub-steppe habitat. They also nest in boxes placed in coastal scrub, sand dune meadows, and poplar plantations. Saw-whets winter in dense forest throughout the breeding range and across most of the United States, excluding the southernmost edges.

  Food:

  Northern Saw-whet Owls eat mostly small mammals, hunting them at night from a low perch along the forest edge. The most common prey are deer mice and white-footed mice, but may include shrews, house mice, harvest mice, pocket mice, jumping mice, montane voles, red-backed voles, meadow voles, heather voles, red tree voles, shrew-moles, bats, and juveniles of larger mammals like pocket gophers, chipmunks, and squirrels. During migration they supplement their diet with birds, such as titmice, chickadees, kinglets, juncos, waxwings, sparrows, thrushes, wrens, warblers, robins, and even other small owl species. They may eat beetles, grasshoppers, moths, and bugs. Saw-whets that live along the coasts may eat intertidal invertebrates such as amphipods and isopods. Males provide nearly all of the food while females are incubating and brooding the young.

   

  Behavior:

  Although saw-whets are usually monogamous, when prey is abundant each male may have more than one mate. Males start giving their too-too-too call as early as late January, before females arrive, and continue until May. When a female hears a male calling she responds with a high-pitched tssst call or a series of whistles. The male circles her about 20 times in flight before landing beside her and presenting a prey item. Some year-round resident males or pairs probably maintain territories throughout the year, but each year they pair up with new mates. Saw-whets are preyed on by larger raptors, including Eastern Screech-Owls, Spotted Owls, Great Horned Owls, Cooper’s Hawks, Broad-winged Hawks, and Peregrine Falcons. They roost during the day in thick conifers at an average of 11 feet above the ground, often hidden by foliage near the outer edge of a branch. They are occasionally discovered by mixed-species flocks of songbirds, which mob the predator in an effort to drive it away. Tuning in to all that commotion is one of the best ways for bird watchers to find these well-hidden owls.

   

  Data Source: allaboutbirds