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

BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 351
attracted frequently about farmhouses or courtyards. It was common
in the Chaco, was less numerous on the pampas because of lack
of suitable coverts, and Avas found in fair numbers on the Kio Negi'o
of Patagonia, where it finds its southern limit. It reached its
greatest abundance in the dry, thorny scrubs of the Pampa Central,
where, near Victorica, it was one of the common birds. It appears
to be sedentary in habits, and individuals may be observed in the
same vicinity day after day perched above some dense tangle of
brush. During winter it indulged in occasional snatches of song, but
wuth the coming of spring gave utterance to the melody that caused
such pleasure and admiration in Hudson and occasioned his eulogy of
its vocal powers. The song strongly resembles that of Mimus polyglottos^
and is accompanied frequently by aerial gyrations, in which
the birds spring into the air and support themselves with sIoav beats
of the widely opened wings, that, with the spread tail, display their
contrasted markings to the utmost. They are excellent mimics, a
frequent imitation being that of the low chur-r-r-ri of the vermilion
flycatcher. In ordinary flight the extensive white markings of the
tail, with a flash of white in the wings, are prominent characteristics,
while in proper light the brown coloration of the back may be dis-
tinguished.
The Anguete Indians called this species pihn mukh.
A nest found December 26 near Victorica, Pampa, was placed 2
meters from the ground in a small shrub near the center of an open
thicket. The structure was composed of thorny branches, lined with
various soft materials, while a bulwark of coarse, very spiny twigs,
erected to a height of 50 mm., protected the rim on all sides. The
nest contained six eggs, heavily incubated, of which one is that of
Molothrus honariensis. Four of the others, unquestionably those of
Alimus tnu7'us, are pale Niagara green, spotted throughout Avith a
color varying from Avalnut to Rood's browm, varied with occasional
markings of dull lavender. The spots are most numerous at the
larger end. These four measure: 26.2 by 18.3; 25.7 by 18.6; 25.5 by
18.2; and 25.2 by 18.7 mm. The sixth egg has the background dull
white, with a faint greenish tinge, and is blotched boldly with hazel
and chestnut brown, with a few markings of light plumbago gray.
It is distinctly different in type from the four described above but
may be an aberrant ^gg of fnurus. It measures 24.6 by 19.1 mm.
Young mockers, seen at the end of December, rested quietly on
open shaded perches, but hopped alertly to cover among heavy
branches when at all alarmed.