1. US Geological Survey, Western Ecological Research Center, 21803 Cactus Avenue, Suite F, Riverside, California 92518, USA
2. Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida, Gainesville, Florida 32611-0880, USA
3. 179 Niblick Road, PMB 272, Paso Robles, California 93446, USA
4. Current address: Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, 100 8th Ave. SE, St. Petersburg, Florida 33701, USA
5. PO Box 765, Challis, Idaho 83226, USA
6. Comisión de Ecología y Desarrollo Sustentable del Estado de Sonora, Reyes y Aguascalientes esq. S/N, Col. San Benito, C.P. 83190, Hermosillo, Sonora, Mexico