Bald eagles, Haliaeetus leucocephalus, are highly mobile consumers that are found across much of the North American continent, from coastal areas in the Pacific Northwest through interior Canada and the United States, southward to parts of northern Mexico, northward into the southern part of the Arctic Circle, and eastward through the eastern seaboard of the US and Canada.
Bald eagles are generalist predators that feed predominately on fish, particularly in coastal regions. Habitat loss, human hunting, and DDT contamination contributed to severe population declines in eagle populations, and bald eagles were listed as an endangered species under the Endangered Species Act in the interior United States until 1995. The species was classified as “threatened” until 2007, when populations had recovered sufficiently to merit de-listing. Populations in Canada and Alaska remained strong during this time period. Bald eagles are still protected in the United States under the Bald and Golden Eagle Protection Act.
Bald eagles in many regions display migratory or nomadic trends, traveling anywhere from hundreds to several thousands of kilometers in search of food. Many eagles travel to salmon spawning grounds in late summer and autumn, and return to breeding territories the following spring. Variation in eagle movement patterns and limitations in equipment used to monitor eagle movements has restricted our understanding of the fine-scale details surrounding the influence of salmon availability on eagle migrations. Our research hopes to better define and understand the importance of these interactions.
Our work is based out of Haines, Alaska, home to one of the largest annual congregations of bald eagles in the world. Each October through December, several thousands of eagles gather on the Chilkat River near Haines to feed on a late run of chum salmon. In November of 2012, our research team captured 5 bald eagles from this area and fitted them with GPS/satellite tracking devices to follow their movement pathways. You can find out where these eagles are now by checking out our Eagle Tracker.
If you’d like to learn more about bald eagles, our eagle research in southeastern Alaska, or the process involved in capturing and handling these wild birds, check out the following blog posts: