Northern Prairie Wildlife Research Center
STATUS: Locally common to rare.
HABITAT: Inhabits dense coniferous forests in Canada, and montane coniferous forests of the western States. Usually prefers pine and fir forests, rarely straying far out onto tundra barrens and muskeg marshes. Nests in mature poplar woodlands, preferably near muskeg areas, well secluded from human activities, and in spruce stands with islands of tamarack. In winter, may inhabit forests, sparse woodland edges bordering open fields, weedy fields with posts or scattered low trees or bushes, or brackish tidal meadows.
SPECIAL HABITAT REQUIREMENTS: Old hawk or crow nests high in trees.
NEST: Does not build its own nest but uses old nests of goshawks, red-tailed hawks, other large hawks, crows, ravens, or artificial nests. Locates nests 10 to 100 feet high in tamarack, balsam poplar, aspen, and spruce trees.
FOOD: Preys primarily on small mammals but also takes some birds up to the size of a grouse.
REFERENCES: Godfrey 1967, Heintzelman 1979, Johnsgard 1979, Karalus and Eckert 1974, Nero 1980.