This shorebird is one of the last North American sandpipers to be described. It breeds in northern-most Canada, Alaska, and parts of Russia. In 1861, Elliot Coues named it for Spencer Fullerton Baird, the secretary of the Smithsonian Institution. It makes a rapid migration, in as few as five weeks, to South America—some all the way to Tierra del Fuego (Moskoff and Montgomerie 2002).
Spotted Sandpiper behave similarly. Female Spotted Sandpipers gape when courting males. The Baird’s fed close to a Short-billed Dowitcher and a few Killdeer. Possibly the Baird’s was defending a feeding territory—other shorebirds defend feed territories during migration—or perhaps it was regurgitating arthropod shells. The Baird’s also stretched its wings, which is also similar to breeding territory displays. In this case, wing stretching may have served as an intra-species feeding territory defense. At the time, however, I assumed the sandpiper was only stretching.