1. Illinois Natural History Survey, Prairie Research Institute, and Department of Natural Resources and Environmental SciencesUniversity of Illinois Urbana–Champaign 1816 S. Oak Street Champaign IL 68120 USA
2. Illinois Natural History Survey, Forbes Biological Station–Bellrose Waterfowl Research Center, Prairie Research InstituteUniversity of Illinois Urbana–Champaign 20003 CR 1770 E Havana IL 62644 USA