The U.S. Geological Survey (USGS) Northern Prairie Wildlife Research Center (NPWRC) is offering a funding opportunity to a CESU partner for research to support refinement of monitoring techniques for Interior Least Tern (Sterna antillarum) and Piping Plover (Charadrius melodus) nests within the Missouri River Basin. Interior least terns and piping plovers are federally listed species nesting in the upper Missouri River system. Extensive annual monitoring of the reproduction and productivity of these two species is conducted by the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers. Such monitoring facilitates management of this dynamic river system which serves as an important breeding area for these listed species. Both species nest in open sand, gravel, or shell-covered substrates along rivers, coastal areas, and lake edges. Researchers conduct grid searches to locate nests and monitor them every 2-3 days to determine nest fate. Nest fates are classified using sign at the nest, but this method has not been rigorously evaluated to determine if misclassification occurs, and if so, how often for each species.