1. Department of Zoology and Wildlife Science, Auburn University, Auburn, Alabama 36849–5414, USA;
2. Department of Zoology and Wildlife Science, Auburn University, Auburn, Alabama 36849, USA, and Savannah River Ecology Laboratory, Drawer E, Aiken, South Carolina 29802, USA; and
3. Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada