1. U.S. Geological Survey, Wisconsin Cooperative Wildlife Research Unit, University of Wisconsin, Madison, Wisconsin, USA
2. Natural Resources Institute, University of Manitoba, Winnipeg, Manitoba, Canada
3. Northern Great Plains Program, World Wildlife Fund, Bozeman, Montana, USA
4. U.S. Geological Survey (emeritus), Northern Prairie Wildlife Research Center, Jamestown, North Dakota, USA
5. U.S. Forest Service, Research and Development, Madison, Wisconsin, USA