Bald Eagle Home Range and Habitat Use in the Columbia River Estuary

Abstract

Little information is available on how areas heavily impacted by humans affect habitat use and home range size of bald eagles (Haliaeetus leucocephalus). Thus, we studied home range and seasonal habitat use of bald eagles in the Columbia River estuary (CRE), Oregon and Washington, 1984-86. Aerial and boat surveys of the entire population and intensive observations of 9 breeding pairs were conducted. Most resident pairs were present near their nests year-round. Home range size of resident pairs averaged approximately 22 km 2 for both breeding and nonbreeding periods, and ranged from 6 to 47 km 2 among pairs