Some European writers have called it the Siberian pectoral sandpiper, which its resemblance to our common bird of that name seems to warrant. It is so much like our pectoral sandpiper in appearance, behavior, and haunts, that it has probably often been overlooked; it may therefore occur on our northwestern coast much oftener than we suspect. _Nesting._--The sharp-tailed sandpiper is supposed to breed in Mongolia and eastern Siberia; it has been seen and collected on its breeding grounds in northeastern Siberia, Cape Wankarem, the Chuckchi Peninsula, and the Kolyma Delta, but apparently its nest has never been found and its eggs are entirely unknown. _Plumages._--The downy young is entirely unknown. This sandpiper is handsomely and richly colored in any plumage, but the rich buff and bright browns of the juvenal plumage are particularly noticeable. The body plumage is molted in the fall, the wings and tail in late winter, and the body plumage is partially molted again in the spring. The plumages are well described in the manuals. _Food._--Preble and McAtee (1923) report on the food of this species, as follows: Eight well-filled and one nearly empty stomach of the sharp-tailed sandpiper are available to illustrate the food habits. This number is too small to furnish reliable results, and too great dependence must not be placed in data as to the relative ranks of food items as here stated. The percentages found for the limited material, then, are flies (Diptera), 39.1 per cent; crustaceans, 18.1 per cent; mollusks, 14.2 per cent; caddisflies, 11.8 per cent; beetles, 8.8 per cent; Hymenoptera, 1.8 per cent; and vegetable matter, 3.9 per cent. Mr. Hanna notes that flocks of this species frequent the seal-killing fields, feeding on fly maggots, a statement receiving confirmation from stomach analysis. _Behavior._--Dr. E. W. Nelson (1887) tells us a little about the habits of this rare species, as follows: