- Bald eagles use a specific territory for their nesting site, winter feeding grounds, or year-round residence.
- Northern, non-coastal bald eagle populations including those in Alaska, generally migrate south for the winter between August and January.
- Bald eagles in the Great Lakes region and adjacent areas in Canada may migrate eastward to winter along the Atlantic Coast from Maine and New Brunswick to Chesapeake Bay.
- The search for food forces bald eagles, which nest in the northern United States and Canada, to migrate south in late autumn and early winter, when lakes and rivers in their nesting grounds freeze over.
- Bald eagles generally choose to roost in large trees in protected places within eight miles of their feeding grounds.
- Bald eagles will winter as far north as ice free water permits.
- During winter months, bald eagles are widely scattered throughout much of the continental United States. Substantial numbers may be found along the Upper Mississippi River and its larger tributaries. Smaller concentrations may be found in other areas, including the deserts of the West and Southwest.
- Bald eagle wintering grounds typically contain open water, ample food, limited human disturbance, and protective roosting sites.
- Preferred roosts are coniferous or deciduous super-canopy trees.
- Stopover habitat is similar to wintering habitat, with food supply being the most important factor.
- Bald eagles migrate alone but may gather by the hundreds at communal feeding sites and roosts.
- Bald eagles return to their breeding territories in late winter, as soon as a food source is available.
- The majority of wintering eagles are found near open water where they feed on fish and waterfowl, often taking the dead, crippled, or otherwise vulnerable animals. Mammalian carrion is also an important alternate source of food.
- At night, wintering eagles often congregate at communal roost trees, in some cases traveling 32 miles (20 km) or more from feeding areas to a roost site.
- The same roost trees are used for several years, many in locations that are protected from the wind by vegetation or terrain, providing favorable thermal environment.
- Northern birds return to breeding grounds as soon as weather and food availability permit, generally January to March.