_Breeding range._--The pectoral sandpiper breeds mainly on the Arctic coasts of Alaska and Mackenzie. North to Siberia (Kolyma Delta); Alaska (Cape Lisburne, Cape Smythe, Point Barrow, Colville delta, Collinson Point, Barter Island, and Demarcation Point); Yukon (Herschel Island); northeastern Mackenzie (Cambridge Bay); and northeastern Manitoba (York Factory). East to northeastern Manitoba (York Factory). South to Manitoba (York Factory); Mackenzie (Clinton-Colden Lake and Lac de Gras); and Alaska (Tacotna Forks and Hooper Bay). West to Alaska (Hooper Bay, Fort Clarence, Point Hope, and Cape Lisburne); and northeastern Siberia (Kolyma Delta). It has also been reported in summer at Fort Anderson and Bernard Harbor, Mackenzie, and in northwestern Greenland (Cape Hatherton). Summer occurrence outside the range above outlined are Keewatin (Cape Eskimo); Manitoba (Button Bay); southwestern Alaska (Nushagak); and northeastern Siberia (Cape Serdze, and Nijni Kolymsk). _Winter range._--South America. North to Ecuador (near Quito); Bolivia (Falls of the Madeira, San Luis, and Caiza); and Paraguay (Colonia Risso). East to Uruguay (Santa Elena); and Argentina (Buenos Aires, La Plata, Barracas, Chubut Valley, Port Desire, and Colonia Rouquand). South and west to Argentina (Colonia Rouquand). West also to Chile (Santiago, Huasco, Antofagasta, Atacama, and Tarapaca); Peru (Chorillos and Junin); and Ecuador (near Quito). _Spring migration._--Early dates of arrival are: Florida, Fort De Soto, February 22, and Orange Hammock, February 25; Alabama, Greensboro, March 20; South Carolina, Frogmore, March 20; North Carolina, Raleigh, March 21; District of Columbia, Washington, March 26; Pennsylvania, Carlisle, March 28, Beaver, April 1, and Harrisburg, April 7; New York, Canandaigua, April 14, Buffalo, April 18, Gaines, May 5, and Orient, May 7; Massachusetts, Thompson's Island, March 30, Monomoy Island, April 11, and Dennis, April 16; Maine, Scarboro, April 13; Quebec, Quebec, May 2; Louisiana, Lake Borgne, March 12, New Orleans, March 18, and Baton Rouge Parish, March 19; Mississippi, Biloxi, February 28; Arkansas, Glenwood, March 27; Kentucky, Bowling Green, April 29; Missouri, St. Louis, March 2, Warrenburg, March 11, Fayette, March 16, and Independence, March 18; Illinois, Englewood, March 9, Rantoul, March 14, Mount Carmel, March 15, Canton, March 26, and Chicago, March 29; Indiana, Bloomington, March 15, Terre Haute, March 17, Bicknell, March 18, and Greencastle, March 22; Ohio, Columbus, March 1, New Bremen, March 24, Columbus, March 25, Oberlin, March 25, Cincinnati, March 28, and Youngstown, March 31; Michigan, Ann Arbor, April 8, and Detroit, April 12; Ontario, Ottawa, April 27, and Fort Williams, May 10; Iowa, Keokuk, March 14, La Porte, March 25, Sigourney, March 26, and Des Moines, March 31; Wisconsin, Milwaukee, March 26, and Madison, March 31; Minnesota, Heron Lake, April 1, Hutchinson, April 5, and Wilder, April 6; Texas, Santa Maria,