Migration Patterns of Double-crested Cormorants Wintering in the Southeastern United States

Migration patterns of Double-crested Cormorants (Phalacrocorax auritus) wintering in the southeastern U.S. are poorly understood. Movement data were analyzed from 28 cormorants captured in Alabama, Arkansas, Louisiana and Mississippi and equipped with satellite transmitters. Four (three immature, one adult) cormorants did not migrate and stayed in the southeastern U.S. throughout the year. During spring, cormorants captured in Alabama migrated east of the Mississippi River and primarily west of the Appalachian Mountains. Cormorants from Arkansas, Louisiana and Mississippi migrated north along the Mississippi River Valley, the Missouri River Valley and/or the Ohio River Valley. The earliest departure for spring migration was 26 March, whereas the latest departure was 12 May. Adult cormorants departed for spring migration earlier than immature cormorants. The average departure date for fall migration was 1 October. Mean duration of spring migration was twelve days, and cormorants traveled an average of 70 km per day. Received 16 September 2007, accepted 7 November 2009.