Aaron W. Aunins Robin L. Johnson David C. Kazyak 2020 <p>The Red Knot, <i>Calidris canutus</i>, is a highly migratory shorebird with a cosmopolitan distribution. Six subspecies have been identified, two of which occur regularly in North America (<i>C.c. rufa</i> and <i>C.c. roselaari</i>). Given their long-distance migrations through many jurisdictions and conservation status, tools are needed to reliably distinguish the subspecies when captured away from their breeding areas and to examine potential population substructure within each taxa. We used a suite of molecular approaches to develop tools to support Red Knot research and management. Although our microsatellite markers were not able to reliably distinguish <i>C.c. rufa</i> and <i>C.c. roselaari</i>, we did find evidence of population substructure within <i>C.c. rufa</i>.</p> application/pdf 10.3133/ofr20201050 en U.S. Geological Survey Red Knot (<i>Calidris canutus</i>) research—Preliminary results and future opportunities reports