156 BULLETIN 133, UNITED STATES NATIONAL MUSEUM 



ment that carried the birds southward, as on March 6 there was a 

 noticeable decrease in their numbers, and by March 8, though the 

 birds were still common, the bulk of individuals had passed. They 

 arrived in flocks from the southward, often of several hundred 

 individuals, that whirled in and circled back and forth along the 

 lake shore to decoy to birds feeding on the strand or to rise again 

 and continue swiftly northward. Those that paused kept up a busy 

 search for food along the muddy beaches in or near shallow water, 

 or in company with little parties of buff-breasted sandpipers on 

 the drier alkaline flats back of the shore line. In early morning 

 they were especially active and were in continual movement. Occa- 

 sionally they worked out into comparatively deep water where in 

 feeding it is necessary to immerse the head over the eyes nearly 

 to the ear openings. When disturbed flocks rose with soft notes 

 that resembled tseet tseet or tseup to circle to new feeding grounds 

 on the lake shore. 



Occasional parties of males, animated by the approaching breed- 

 ing season, broke into soft songs and called and twittered, often for 

 several minutes, in a musical chorus in low tones that had so little 

 carrying power that they merged in the strong wind, and it was some 

 time before I succeeded in picking out the sweet individual songs 

 tsep a tsej) a tsep a or twee tmee tee tee ty tee given as the head 

 was bobbed rapidly up and down. Occasionally when the fall sun- 

 light came warmly I sat in the mud and let little bands of white- 

 rumps work up around me until they were feeding and calling within 

 a meter or so, eyeing me sharply for any cause of alarm. At 

 such times their twittering choruses came sweetly and pleasantly, 

 clearly audible above the lap of waves and the rush of the inevitable 

 winds of the pampas. Between songs the search for food continued 

 without cessation. At short intervals, activated by the warmth of the 

 sun, they suddenly indulged in dozens of combats with their fellows, 

 bloodless affrays, of bluff and retreat, where they lowered their heads 

 and with open mouths ran at one another pugnaciously. The one 

 attacked sidled quickly away or fluttered off for a short distance, save 

 where two of equal temperament chanced to clash when first one 

 and then the other threatened with raised wings in alternate advance 

 and retreat until the fray was concluded to their mutual satisfaction. 

 At such times the movements of these otherwise plain little birds 

 were sprightly and vivacious to a degree. Their loquacity at this sea- 

 son was marked as it contrasted strikingly with their silence and quiet 

 during the resting period of southern summer. Flocks frequently 

 rose to perform intricate evolutions and then returned with a rush 

 to sweep along the shore and join less ambitious comrades. As they 

 passed the white runjp flashed plainly, certain advertisement of the 



