1. USGS Patuxent Wildlife Research Center, 11510 American Holly Drive, Laurel, Maryland 20708-4019, USA
2. Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506, USA
3. US Fish and Wildlife Service, Migratory Birds and State Programs, P.O. Box 25486, Denver, Colorado 80225, USA
4. US Fish and Wildlife Service, Nevada Fish and Wildlife Office, 1340 Financial Boulevard, Suite 234, Reno, Nevada 89502, USA
5. US Fish and Wildlife Service, Migratory Bird Management, 11510 American Holly Drive, Laurel, Maryland 20708-4019, USA
6. USGS National Wildlife Health Research Center, 6006 Schroeder Road, Madison, Wisconsin 53711, USA