Northern Prairie Wildlife Research Center
STATUS: Endangered and threatened in parts of the lower 48 states.
HABITAT: Closely associated with lakes and large rivers in open areas, forests and mountains, and along seacoasts. In Alaska and Canada, where human disturbance is slight, habitat is composed of a narrow strip of land along lakeshores and rivers that provides trees for nesting, fishing, and loafing. Needs large trees adjacent to water, preferably snags, but also live trees or boulders that provide good visibility, for perching. Winters in coastal habitats and inland where ice-free waters allow access to fish.
SPECIAL HABITAT REQUIREMENTS: Large bodies of water containing abundant fish resources, large trees for nesting, perching, and roosting, and freedom from human disturbance.
NEST: Prefers to build a large, heavy nest 10 to 150 feet above ground in very tall living trees, usually close to water. If suitable trees are not available, nests are built on rocky cliffs or on the ground. Shows strong attachment to the nest site, and characteristically adds new material to the nest each year.
FOOD: Feeds primarily on fish it catches or takes from an osprey. Will feed on waterfowl and other birds, carrion, small- to medium-sized mammals, and turtles. Inland, subsists mainly on dead waterfowl during winter.
REFERENCES: DeGraff et al. 1980, Evans 1982, Fielder 1982, Grubb and Kennedy 1982, Heintzelman 1979, Mackenzie 1977, Sprunt 1955.