Northern Prairie Wildlife Research Center
STATUS: Rare and endangered; catastrophic decline primarily due to organochlorine pesticides.
HABITAT: Usually inhabits open country from tundra and seacoasts, to high mountains and more open forested regions, preferably where there are rocky cliffs with ledges overlooking rivers, lakes, or other water and an abundance of birds. Sometimes breeds in cities.
SPECIAL HABITAT REQUIREMENTS: Cliffs or other nesting habitat near water, and an abundance of prey.
NEST:Prefers to nest in a shallow depression scraped in gravel and debris on a high cliff ledge, pothole, or small cave that provides sanctuary from disturbance. Bluffs, slopes, pinnacles, cutbanks, and seastacks are also used as nest sites in the far north. Other nest sites include old stick nests of ravens and hawks, ledges of tall buildings, and historically, holes and stubs of large trees. Tends to return to the same nesting cliff.
FOOD: Pursues prey, primarily birds, after sighting from perch or while soaring. Small- to medium-sized birds are usually captured in flight; birds too large to be carried are knocked to the ground. Feeds on a wide variety of birds; occasionally takes mammals, some insects, and fishes.
REFERENCES: Cade 1960, DeGraff et al. 1980, Evans 1982, Heintzelman 1979, Hickey 1942, Hickey and Anderson 1969, Terres 1980, White and Cade 1971.