_Plumages._--The downy young Baird sandpiper is well colored to escape detection on the brown tundra moss. The crown and upper parts are variegated with black and "tawny" in an irregular pattern and dotted with white terminal tufts; the crown is centrally "tawny," with a median black stripe, and is bordered with black; the forehead, back to eyes, sides of the head and all under parts are pure white; there is a black spot in the center of the forehead, a black stripe from the bill, through the eye, to the occiput and another below it and parallel to it; there is a white superciliary stripe and some white mottling on the back of the head and neck. The juvenal plumage is equally concealing. The crown is sepia with buffy edgings; the back and scapulars are dark sepia with broad white edgings; the wing is like the adult except that the coverts and tertials are edged with "pinkish buff" and tipped with white; the under parts are like the adult but the breast is more pinkish buff and more faintly streaked. A partial postjuvenal molt, including most of the body plumage and some of the scapulars, wing coverts, and tertials and takes place in October or later. I have seen birds in full juvenal plumage as late as October 3; young birds migrate in this plumage. At the first prenuptial molt the following spring young birds become indistinguishable from adults. Adults have a partial prenuptial molt in April and May, including only part of the body plumage. The postnuptial molt begins in July, when the body plumage is molted before the birds migrate; the wings are molted after the birds reach their winter home, from December to February, not long before they started to migrate north again. I have seen birds in full nuptial plumage as early as May 1 and as late as July 29, and in full winter plumage as late as April 5. The adult nuptial and winter plumages are somewhat different; the colors are brighter and richer in the spring and the markings are more distinct; in the fall the upper parts are nearly uniformly buffy brownish with dusky shaft streaks; the chest and sides of the breast are dull brownish buff and not distinctly streaked. _Food._--Preble and McAtee (1923) found in the stomachs of three Baird sandpipers, taken on the Pribilof Islands, amphipods, algae, ground beetles, and a weevil. Mr. McAtee (1911) includes this species among those that eat mosquito larvae, crane-fly larvae, grasshoppers, and the clover-root curculio, all injurious insects. It feeds on the open mud flats with other species of sandpipers, but seems to prefer to feed about the edges of the shallow inland pools or where the muddy flats are partially overgrown with grass. William Brewster (1925) watched some of them feeding, of which he says: