1. Department of Wildlife and Fisheries Sciences, South Dakota State University, Brookings, South Dakota 57007, USA
2. Current address: Badlands National Park, 25216 Ben Reifel Rd., Interior, South Dakota 57750, USA
3. United States Geological Survey, Oklahoma Cooperative Fish and Wildlife Research Unit and Department of Natural Resource Ecology and Management, Oklahoma State University, Stillwater, Oklahoma 74078, USA
4. Department of Veterinary Science, South Dakota State University, Brookings, South Dakota 57007, USA