Feeding Behavior

Hunts by flying low over the ground, often hovering before dropping on prey. Reportedly finds prey mostly by sound but also by sight. May hunt by day, especially in far north, but mostly active at dawn and dusk.

Eggs

3-11, usually 6-8. White, becoming stained in nest. Incubation is apparently by female only, 24-37 days. Male brings food to female during incubation period. Young: Male brings food for young, gives it to female, who actually feeds the young (and broods them in cold weather). If nest is threatened, adults may fly at intruder and make loud wing-clap, or sit on ground with feathers ruffed up, wings spread and tilted forward, to look as large as possible. Young may leave nest on foot after 12-18 days, can fly at 27-36 days.

Young

Male brings food for young, gives it to female, who actually feeds the young (and broods them in cold weather). If nest is threatened, adults may fly at intruder and make loud wing-clap, or sit on ground with feathers ruffed up, wings spread and tilted forward, to look as large as possible. Young may leave nest on foot after 12-18 days, can fly at 27-36 days.

Diet

Mostly rodents. Feeds mainly on voles, also other rodents such as lemmings, deer mice, pocket mice. Also eats shrews, rabbits, gophers; rarely bats, muskrats. Eats birds, especially in coastal regions.

Nesting

In courtship, male spirals up into the air, hovers while giving series of short rapid hoots, then dives, clapping the wings together loudly under its body. Nest site is on dry ground, often on a raised hummock or ridge, especially in marshy country. Usually among tall grass or under a shrub. Very rarely above ground. Nest (built by female) is a depression in soil, lined with grass and feathers.