1. Colorado Division of Wildlife, Wildlife Research Center, 317 West Prospect Road, Fort Collins, Colorado 80526-2097, USA
2. Department of Veterinary Sciences, University of Wyoming, 1174 Snowy Range Road, Laramie, Wyoming 82070, USA
3. Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado 80523, USA
4. Present address: Windward Islands Research and Education Foundation, Saint George's University School of Medicine, Grenada, West Indies
5. Colorado State Diagnostic Laboratory, Colorado State University, Fort Collins, Colorado 80523, USA
6. Wyoming Game and Fish Department, 2362 Highway 34, Wheatland, Wyoming 82006, USA
7. Wyoming Game and Fish Department, 5400 Bishop Boulevard, Cheyenne, Wyoming 82006, USA