Habitat: This northern owl is normally found in the mixed conifer-hardwood forests of Canada (Peterson 1961). One juvenile reported in Colorado during August suggests that this owl may nest in the southern Rocky Mountains (Bailey and Niedrach 1965). Boreal owls are confined to evergreen woods and dense alder, white pine, and spruce forests.
Nest: Old flicker and pileated woodpecker holes are preferred, usually at a height of 10 to 25 feet (Fisher 1893, Preble 1908, Tufts 1925, Lawrence 1932). Conifer snags seems to be preferred for nest trees, although hardwoods have been used (Bent 1938).
Food: The main portion of the boreal owl’s diet consists of small rodents. Mendall (1944) examined the contents of 20 stomachs in Maine and found 73 percent mice (chiefly meadow voles) and 20 percent short-tailed shrews. Pigeons and grasshoppers made up the remaining 7 percent. In Ontario, Catling (1972) found 86.2 percent meadow voles, 5.6 percent deer mice, 4.2 percent star-nosed moles, 2.7 percent masked shrews, and 1.4 percent short-tailed shrews. Small birds, bats, insects, amphibians, and reptiles are also occasionally eaten (Karalus and Eckert 1974).
Saw-whet owl
Aegolius acadicus
L 7″ W 17″
Habitat: Saw-whet owls are small, nocturnal hunters of the deep north woods. They nest in the Rocky Mountains up to about 11,000 feet (Bailey and Niedrach 1965). This widely distributed owl nests in most of the forest types throughout the northern half of the United States, but only rarely do they nest as far south as central Missouri.
Nest: These small owls prefer to nest in old flicker or other woodpecker holes (Bent 1938). Nesting habitat may be improving in areas where Dutch Elm disease has infested many elms, and woodpeckers have drilled nest holes (Hamerstrom 1972). Saw-whets will use nesting boxes if sawdust or straw is provided. Nest boxes should be 6 × 6 × 9 inches with a 2.5-inch entrance hole (Hamerstrom 1972).
Food: Saw-whet owls consume mostly small mammals and insects. Specific food items include mice, shrews, young squirrels, chipmunks, bats, beetles, grasshoppers, and occasionally small birds (Scott and Patton 1975, Burton 1973, Hamerstrom 1972, Bent 1938).