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158 BULLETIN 133, UNITED STATES NATIONAL MUSEUM
Buenos Aires, where they arrived from regions farther south, tarried
for a time, and then continued their north^yard flioht.
The birds ranged in small flocks that occasionally fed with other
sandpipers in the shallows or on muddy shores, but more frequently
worked a short distance farther back on alkaline barrens where
the surface was damp from the salt in the soil, but there was no
standing water, and where vegetation was reduced to stumps of
herbaceous growth that had been killed by concentration of alkali.
They walked nervously, picking at the ground, and were active and
quick in all their movements, constantly in motion, occasionally
running a few feet to join others that had passed on ahead. When
in the air or on the ground they are distinctly buff in color, with
a glimpse of the marbled underAving surface as they rise or pass,
and a flash of the gray tail with its darker markings as they alight.
On the ground in profile, they show a long neck and long legs,
while the short bill is suggestive of that of a pigeon. The neck
is drawn in during flight. As they rise they may give a Ioav call
that resembles chump^ somewhat robinlike in tone; a second call
note is a low trilled fr-r-r-reet. The species is to be confused in
the field Avith no other shore bird.
An adult male shot September 21 had the bill black, shading to
deep olive gray at the base of the maxilla ; iris cameo brown ; tarsus
olive ocher, changing to dark olive buff on the toes, with a shading
of the same color on the crus and the tarsal joint; nails black.
Another male taken March 3 had the tarsus yellow ocher, shading
to honey yellow on the toes.
A male shot September 21 was in worn breeding plumage. Others,
secured March 3 and 5 that were completing the molt, had the outer
primaries not quite grown and new contour feathers still develop-
ing. Specimens secured in March were extremely fat and difficult
to prepare.
MICROPALAMA HIMANTOPUS (Bonaparte)
Tringa himantopus Bonaparte, Ann. Lye. Nat. Hist. New York, vol. 2,
1826, p. 157. (Long Branch, New Jersey.)
The stilt sandpiper was encountered only in the Chaco, west of
Puerto Pinasco, Paraguay, though it has been said that it is common
in some parts of the Province of Buenos Aires in winter. At Kilo-
meter 80, on September 20, 1920, the first arrivals, a flock of a dozen,
were recorded at the border of a lagoon; as I watched thev rose
suddenly to whirl rapidly away to the southward. On the following
day about 20 were seen and an adult female was taken. At
Kilometer 170 on September 24 a small flock passed down the
nearly dry channel of an alkaline stream known as the Riacho
Salado, while at Laguna Wall (Kilometer 200) about 30 were seen
September 24. and 40 on the day following. The birds were found