Least Sandpiper in basic (winter) plumage. Note bill shape, lack of primary projection and yellowish legs. Distinction from similar Long-toed Stint (C. subminuta) of Asia is tricky. Long-toed Stint has a vertical dark mark in front of the eye and a thin sub-loral loop which forms a sideways "J" mark. Least Sandpiper has a straight lore stripe as seen here. Least is the smallest of the North American sandpipers.