1. Division of Migratory Bird Management U.S. Fish and Wildlife Service 11510 American Holly Drive Laurel Maryland 20708 USA
2. College of the Environment University of Washington Seattle Washington 98195 USA
3. Division of Migratory Bird Management U.S. Fish and Wildlife Service 3020 State University Drive East, Modoc Hall, Suite 2007 Sacramento California 95819 USA
4. U.S. Geological Survey Patuxent Wildlife Research Center 12100 Beech Forest Road Laurel Maryland 20708 USA