1. Biology Department; Northern Michigan University; 1401 Presque Isle Avenue Marquette MI 49855, USA
2. Minnesota Cooperative Fish and Wildlife Research Unit; Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota; St. Paul MN 55108, USA
3. U.S. Geological Survey; Minnesota Cooperative Fish and Wildlife Research Unit; Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota; St. Paul MN 55108, USA
4. Department of Wildlife Ecology; University of Wisconsin-Madison, 226 Russell Labs, 1630 Linden Drive; Madison WI 53711, USA