Aegolius acadicus
Saw-whets are opportunistic hunters, taking whatever they can, whenever they can. These small owls often catch more than they can eat, and they are known to store their food, usually in trees. The stored food freezes quickly in winter, and it has recently been discovered that the owls 'incubate' the frozen prey to thaw it out. This small owl delivers its slow, whistling notes through the nights from mid-winter through early spring. The common name 'saw-whet' comes from one of this owl's calls, which was thought to be similar to the sound of a large mill saw being sharpened. The scientific name acadicus is Latin for 'from Acadia' (New Brunswick, Nova Scotia and Maine), the region from which this bird was first collected. |
I.D.: Sexes similar. Adult: small body; large, rounded head; light, unbordered facial disk; dark bill; vertical, rusty streaks on the underparts; brown, white-spotted upperparts; lightly streaked forehead; short tail. Immature: white between the eyes; rich brown upperparts; buff-brown underparts. Size: L 7-9 in. (18-23 cm). Range: uncommon spring migrant and summer breeder in the Canadian Rockies; uncommon resident in the U.S. Rockies. Habitat: pure and mixed coniferous and deciduous forests in the foothills and the montane. Nesting: in abandoned woodpecker cavities and natural hollows in trees; female incubates 5-6 white eggs for 27-29 days. Feeding: swoops from a perch; eats mainly mice and voles, also larger insects, songbirds and shrews, and occasionally amphibians; caches food. Voice: single, evenly spaced (about 1 per second) whistled whew-whew-whew-whew; continuous and easily imitated. Similar Species: Boreal Owl: adult has a light-colored bill; heavy spotting on its forehead; a dark, vertical eyebrow and a dark border to the facial disk; immature has a brown breast. Northern Pygmy-Owl: light-colored bill; proportionately longer tail; patches on the nape; lacks the white streaking on the forehead. |
