1. U.S.G.S. Biological Resources Division, Pacific Island Ecosystems Research Center, P.O. Box 218, Hawaii National Park, Hawaii 96718, USA
2. Current Address: Department of Pathobiology, College of Veterinary Medicine, University of Florida, Gainesville, Florida 32610, USA
3. U.S.G.S. Biological Resources Division, National Wildlife Health Center, 6006 Schroeder Road, Madison, Wisconsin 53711, USA
4. Current Address: U.S.G.S. Biological Resources Division, Midcontinent Ecological Science Center, 4512 McMurry Ave., Fort Collins, Colorado 80525, USA