Builds an open platform of sticks in a tree, usually a conifer. Usually nests close to water. Favors coastlines, lakeshores, wetlands. Yearlong, diurnal activity. May. Wanders in search of abundant prey.
Some individuals migrate as far as South America in winter.
No data found on winter territory. Not rigidly territorial in nonbreeding season, but is intraspecifically aggresslve. Because feeds mostly on birds, numbers probably have been reduced by pesticides. Birds of Lincoln County, Oregon. Oregon State Univ., Exten.