2005 Annual Report 4d.Progress report. This report serves to document research conducted under Non-Funded Cooperative Agreement #58-5410-4-125N between ARS and the University of Wyoming, College of Agriculture, Laramie, WY. Additional details of research can be found in the report for the parent project 5410-32000-014-00D. Cooperative efforts with the University of Wyoming have shown that West Nile virus has had a serious impact on the Western sage grouse; this bird has no apparent resistance to West Nile virus.