An elegant, boldly patterned large shorebird of high Andean salt lakes, bogs, and lagoon shores. White head and body contrasting with glossy black upperparts are distinctive even at long range; at closer range note bluish legs and long fine bill with upswept tip. Often in pairs or small groups; feeds while wading in shallows, sweeping its bill through the water. Sexes look similar but female’s bill is more strongly upcurved. Gives noisy calls when agitated, especially near nest.