1. National Park Service, Biological Resource Management Division, 1201 Oak Ridge Drive, Suite 200, Fort Collins, Colorado 80525, USA
2. Natural Resource Ecology Laboratory and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado 80523, USA
3. Colorado State Diagnostic Laboratory, College of Veterinary Medicine, Colorado State University, Fort Collins, Colorado 80523, USA
4. United States Department of Agriculture, Agricultural Research Service, Animal Disease Research Unit, 3003 Animal Disease Biotechnology Facility, Washington State University, Pullman, Washington 99164, USA
5. Current address: Department of Veterinary Microbiology and Pathology, School of Veterinary Medicine, Washington State University, Pullman, Washington 99164, USA