1. US Geological Survey—National Wildlife Health Center, 6006 Schroeder Road, Madison, Wisconsin 53711, USA
2. CTDS Veterinary Laboratories, Brookfield Court, Selby Road, Garforth, Leeds LS15 7BD, UK
3. Wisconsin Department of Natural Resources, Box 7921, 101 S Webster Street, Madison, Wisconsin 53707, USA
4. Current address: International Crane Foundation, E-11376 Shady Lane Road PO Box 447, Baraboo, Wisconsin 53913, USA