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

76 BULLETIN 133, UNITED STATES NATIONAL MUSEUM
Department of Rocha. Others were recorded at Lazcano, in the same
general region, on February 7.
Around the Laguna del Monte at Guamini, Province of Buenos
Aires, Argentina, the species was common from March 3 to 8. I
was surprised to note occasional true pairs of these birds here,
though the breeding season was past, as fall was well advanced. I
judged that these were pairs that for some reason had been unsuc-
cessful in nesting during the summer and that had not as yet parted
company. Near Tunuyan, Mendoza, a flock of 25 pintails was seen
on March 25, and others the following day. Early on the morning
of March 28 a flock of 100, and later two smaller groups, passed
due north, flying high in air. These last seemed to be flight birds
in fall migration.
In general appearance and habits Dafila spinicauda is similar to
Daflla acuta. The birds frequent the open water of lagoons or rest
on bars, muddy shores, or projecting points where they have open
outlook. They impress one as alert and intelligent, eminently able
to care for themselves. In wilder sections, Avhere not molested, they
exhibit little fear, but when hunted it was many times almost impossible
to come within range of them, especially on open pampa,
where there was little or no opportunity for concealment. The birds
often feed by immersing the head and neck as they paddle across
shallow pools or bays, or in deeper water tip in order to reach the
bottom. Where heavy winds or rising waters flood areas of muddy
flat the pintails follow the creeping advance of the water line to
reed eagerly in the windrow of seeds and dead or drowning insects
that it carries with it. Recently flooded areas of shallow water
are always attractive. The flight is swift and direct. On the wing
the birds resemble D. acuta., but appear heavier in the neck. Though
females resemble males, they may be distinguished sometimes when
in the air by the shorter, less-pointed tail, especially when flocks
swerve in passing OA'erhead. The call of the male is a mellow,
trilled whistle, a purling sound pleasing to the ear, resembling that
of the northern pintail. It is given frequently as parties of males
pass on the wing. The note of the female is a low ha-ach or qua-ack.,
slightly lower in tone than that of our pintail.
The species is one of the abundant ducks of the pampas and was
common among birds offered for sale during winter in the great
markets of the city of Buenos Aires.
PAECILONITTA BAHAMENSIS RUBRIROSTRIS (Vicillot)
Anas ruhrirostris Vieiixot, Kouv. Diet. Hist. Nat., vol. 5, 1816, p. 108.
(Buenos Aires.)
Near Carhue, in western Buenos Aires, the southern Bahama duck
was common from December 15 to 18, 1920. The birds ranced in