Bulletin - United States National Museum - si-pddr - Smithsonian ...

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 whiterumps
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