1. Department of Natural Resource Management, South Dakota State University, North Campus Drive, Box 2140B, Northern Plains Biostress Lab, Brookings, South Dakota 57007, USA
2. Current address: Department of Biological Sciences, Western Illinois University, 1 University Circle, Macomb, Illinois 61455, USA
3. US Geological Survey, Iowa Cooperative Fish and Wildlife Research Unit, 342 Science II, Iowa State University, Ames, Iowa 50011, USA
4. College of Natural Resources, University of Wisconsin-Stevens Point, Trainer Natural Resources Building, 800 Reserve Street, Stevens Point, Wisconsin 54481, USA