Bald eagles in the farthest northern ranges begin moving to their wintering grounds in the fall. As lakes and streams freeze over, they must go south or head to the coast to find open fresh water.
Wintering grounds typically contain open water, ample food, limited human disturbance, and protective roosting sites.
Wintering eagles migrate alone but may gather by the hundreds at communal feeding and roosting sites. Preferred roosts are coniferous or deciduous super-canopy trees. The same roost trees are used for several years. The roost sites are usually in areas protected from the wind by vegetation or terrain. The use of these sheltering sites helps minimize the energy demands on the wintering birds.
Bald eagles leave their overwintering sites and return to their breeding territories in late winter, as soon as a food source is available.