White-rumped Sandpiper Calidris fuscicollis breeds in high-Arctic Alaska and Canada, wintering mainly in South America; rarely reaches Japan and even more rarely the coast of China (Beidaihe). HABITAT Wetter habitats than Baird’s Sandpiper C. bairdii. With primaries projecting more than a centimeter beyond tail tip, and with its short legs, has low, elongated profile, like Baird’s. Unlike Baird’s, has U-shaped white uppertail coverts, conspicuous in flight, a distinct white supercilium, and bold triangular marks along breast, belly, and flanks and in breeding plumage is more rufous than buff on crown and upperparts. (Streaking of Baird’s is fainter and absent on flanks.) Juvenile shows distinct rufous color on mantle and streaked crown and ear coverts, and two white bands along mantle and scapulars. Winter greyer than Baird’s, with prominent white supercilium and flank streaking. Feeds in “sewing machine” fashion like Dunlin C. alpina, but Dunlin larger and has shorter primary projection (and has black central band from rump to tail. BARE PARTS Bill black with pinkish-brown base (bill of Baird’s and Dunlin completely black); legs black. VOICE Thin, squeaky call. — Craig Brelsford
Daniel Bengtsson served as chief ornithological consultant for Craig Brelsford’s Photographic Field Guide to the Birds of China, from which this species description is drawn.