1. Kansas Cooperative Fish and Wildlife Research Unit, United States Geological Survey, Division of Biology, Kansas State University, Manhattan, Kansas 66506, USA
2. Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506, USA
3. Current address: Central States Veterinary Pathology Service, P.O. Box 577, Manhattan, Kansas 66506, USA
4. Division of Biology, Kansas State University, Manhattan, Kansas 66506, USA
5. Natural Resources Division, Fort Riley Army Base, Kansas 66442, USA.