Robert M Zink1,2,3, Erica F Stuber4. 1. School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE 68583, USA rzink2@unl.edu. 2. School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583, USA. 3. Nebraska State Museum, University of Nebraska-Lincoln, Lincoln, NE 68583, USA. 4. School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE 68583, USA.