1. Department of Fisheries and Wildlife, University of Minnesota, St. Paul, Minnesota 55108, USA.
2. Research Service, Veteran's Administration Medical Center, Minneapolis, Minnesota 55417, USA and Departments of Biochemistry and Fisheries and Wildlife, University of Minnesota, St. Paul, Minnesota 55108, USA.
3. Forest Wildlife Populations and Research Group, Minnesota Department of Natural Resources, Grand Rapids, Minnesota 55744, USA.