Species: Aegolius acadicus

Northern Saw-whet Owl

Species

Birds

Encyclopedia of Puget Sound

Classification

Kingdom

Animalia

Phylum

Craniata

Class

Aves

Order

Strigiformes

Family

Strigidae

Genus

Aegolius

NatureServe

Source:
ELEMENT_GLOBAL.2.106412

Classification

Other Global Common Names

Tecolote Afilador - petite nyctale

Informal Taxonomy

Animals, Vertebrates - Birds - Other Birds

Formal Taxonomy

Animalia - Craniata - Aves - Strigiformes - Strigidae - Aegolius - Constitutes a superspecies with and may be conspecific with Middle American A. RIDGWAYI (AOU 1998).

Ecology and Life History

Migration

true - true - false - Probably makes local elevational migrations in the mountains of the western U.S. and possibly the Appalachians; fairly extensive north-south movement in east and north. Apparently two main migration corridors exist in the east: Ohio River valley and Atlantic coastal lowlands (Johnsgard 1988). At Cape May Point, New Jersey, 90% of fall migration was completed between mid-October and mid-November (Duffy and Kerlinger 1992). See also Russell et al. (1991) for an account of fall migration at Cape May Point, New Jersey. At Whitefish Point, Michigan, begins arriving in early April; migration peaks in mid- to late April, with a secondary peak in late May (Wilson Bull. 105:356-359).

Non-migrant

true

Locally Migrant

true

Food Comments

Eats mainly small mammals (e.g., PEROMYSCUS, MICROTUS, shrews) (e.g., see Swengel and Swengel 1992b); sometimes birds and insects. In the Queen Charlotte Islands, British Columbia, nonbreeding owls may include marine intertidal invertebrates (amphipods) in the diet. Apparently obtains prey mainly by pouncing on it from above, after short flight from elevated perch. May hunt in areas with thick shrub cover.

Reproduction Comments

Nesting March-July (mainly April-May) in northeastern U.S. and southeastern Canada. Clutch size usually is about 5-6. Incubation, by female, lasts 26-28 days. Young first fly at 4-5 weeks (Johnsgard 1988).

Ecology Comments

Studies of a few birds yielded seasonal home range estimates of about 75-150 ha. Two breeding males had home ranges of 142 and 159 hectares (Cannings 1987). Limited data on breeding density suggests maximum of a few pairs per sq km (Johnsgard 1988); singing males can be as close as about 250 meters apart (Swengel 1990). However, most breeding habitat probably supports a maximum of about 1 pair/square kilometer, often much less (Cannings 1993).

Length

Weight

Conservation Status

NatureServe Global Status Rank

Global Status Last Reviewed

1996-11-27

Global Status Last Changed

1996-11-27

Distribution

Conservation Status Map

Global Range

BREEDS: southern Alaska to central Saskatchewan and northern New Brunswick, south to southern California, southern Arizona, southern Mexico, western Texas, Missouri, southern Michigan, Maryland; also in Great Smoky Mountains. WINTERS: generally throughout breeding range (some southward withdrawal), irregularly or casually south to southern U.S.

ELEMENT_GLOBAL.2.106412