On first noticing me draw near they stood erect, with upstretched necks, regarding me intently and distrustfully, but their feeding operations were resumed soon after I ceased to advance. By successive runs, 8 or 10 feet in length and often executed very swiftly, they moved about quickly in various directions over soft mud or through shallow water, frequently stooping to pick up small morsels of food, but not once using their bills for probing under ground or water.
Voice.—Dr. Charles W. Townsend (1905) says that the note, which he heard several times, seemed to him "exactly like that of the semipalmated sandpiper, a rather shrill, trilling whistle." Mr. Brewster (1925) says that—
the kreep call they utter in flight is sufficiently unlike that of any other wader of similar size and general coloring to be of service as a means of field identification when the birds are seen on wing. It is appreciably different from the call of any other sandpiper known to me, although not so very unlike that of the sanderling.
Field marks.—The Baird sandpiper is one of the most difficult of all this group to recognize in the field, because it has no prominent distinguishing field marks peculiar to itself. It has characters in common with any one of several small sandpipers. In color and general appearance it is most like the least sandpiper; it is decidedly larger, but size is of little value unless the two are side by side for comparison; it is lighter colored above, more extensively buffy on the breast, and has darker legs. It is a size larger than the semipalmated and western sandpipers, more buffy on the breast than either, and has a shorter bill in proportion to its size than the latter. It is about the size of the white-rumped sandpiper, but is less distinctly streaked on the crown and back; the buff breast of the Baird will distinguish it when standing or even in flight; and the white rump of fuscicollis is a sure flight mark when visible. From the red-backed sandpiper, about the same size, it can be distinguished by its shorter and straighter bill and by marked color differences. It might be mistaken for a female pectoral, but the latter is more conspicuously striped above, more like a snipe in this respect, the crown is darker, more contrasted, and the breast is darker, more abruptly separated from the white belly, and more sharply streaked with dusky; when flying the pectoral shows more white in the wings. The Baird is but slightly smaller than the buff-breasted sandpiper and very much like it; but Prof. William Rowan (MSS.) has pointed out some differences. The patterns of the backs are very similar, but the buff breasted has a much paler crown and lacks the white throat and eye stripe, as well as the clear-cut white sides and black center of the rump of the Baird. The buff breasted has yellow legs and the Baird has black. The Baird shows no white in the wings in flight. Young Bairds in juvenal plumage are easily recognized by the scaled appearance of the mantle produced by dark feathers with broad white edges.
Fall.—Baird sandpipers leave their northern breeding grounds rather early. Mr. Murdoch (1885) reported the last one seen at Point Barrow on August 12, and Mr. Dixon (1917) saw none after August 15 in northern Alaska. E. A. Preble (1908) saw several flocks on migration at Great Slave Lake as early as July 10.
The main flight seems to be directly south through the Mackenzie Valley and between the Rocky Mountains and the Mississippi River to Mexico and South America, where it probably migrates down the west coast to its winter home. But the route is also extended both east and west in the fall. Some birds fly southeastward, through the Great Lakes, to the coast of New England, whence they apparently migrate over the ocean to South America. Others migrate southward through the extreme western States.
Mr. Brewster (1925) says that they "visit Lake Umbagog (Maine) early in September, appearing oftenest during the first week in the month." My Massachusetts dates run from August 7 to September 15. E. W. Hadeler records it in his Ohio notes from September 2 to October 11; and Edward S. Thomas has seen it there as early as August 12. It is an abundant migrant in Manitoba; we collected adults there on July 29; and C. G. Harrold tells me that birds passing through in August and September are practically all juveniles. Professor Rowan refers to it as probably the most plentiful wader in Alberta in the first half of September; he has taken it there as late as November 8. J. A. Munro calls it a regular fall migrant at Okanagan Landing, British Columbia; his earliest and latest dates are July 16 and September 18. J. H. Bowles (1918) observed it on the Tacoma Flats, Washington, from July 26 to September 5, and says:
They were found in singles, pairs, or trios, most often associating with the semipalmated plover (Aegialitis semipalmata) when any were to be found. When flying with a company of the other small sandpipers they would separate as soon as the flock alighted to feed, the Baird's going to comparatively dry ground for their food while the others waded about in the water and at the water's edge. They could not have been called common, but from one to three or four were to be found on almost any day.
John T. Nichols has observed Baird sandpipers on the Pacific Ocean and writes to me as follows: