The northern saw-whet owl, Aegolius acadicus, breeds across much of Canada, in the United States (with the exception of the southeastern United States), and in Mexico. Most wintering activity occurs within the breeding range, although some individuals in northern areas do migrate south for winter. This species is moderately abundant year-round in Utah, where it prefers dense forests, marshes, and brushy areas. Utah populations may migrate from the mountains to lower elevations for winter.
The northern saw-whet owl is a cavity nester that nests in woodpecker holes, hollow trees, and nest boxes. Females lay one clutch of five or six eggs; incubation is by the female alone and lasts for about one month. The young are able to fly at about five weeks of age.
This owl is primarily nocturnal, although it is also active at dusk and dawn. Individuals often hunt from a perched position, pouncing on prey when it is detected. Small mammals are the major component of the diet, although birds and invertebrates are also consumed.