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

BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 339
The fork-tailed flycatcher was frequent throughout the open
pampas, but was most abundant where there was scattered tree
growth. In habits these birds resembled kingbirds. They in-
variably sought perches in the open on fences, low bushes, or the
tops of small trees, where they rested quietly. Though in appearance
they suggested Muscivom forfcata. they were less noisy and
active. Most of their notes were flat, with little carrying power
against the force of the pampan winds. The call of young re-
cently from the nest was a low tsip that suggested a note of
Brachyspiza, while adults uttered an explosive call note, somewhat
flat in tone, A'liried by a staccato rattle when tilting among them-
selves or in pursuit of other birds. Hawks and other large birds
were attacked viciously, and the flycatchers frequently darted out
at any bird that passed too near.
Fall migration among fork-tailed flycatchers began by the first
of Februar}'. On February 2, while passing through a region of
rolling hills north of San Vicente, Uruguay, I recorded at least
2,000, many of them young with partly grown tails. The birds
were found in small flocks, and were spread along wire fences for
a distance of several miles. B}^ Februarj^ 9 they had lessened
in abundance but continued common in Uruguay until February
19. Throughout this period they were obviously traveling north-
ward. Shortly after daybreak on Februarj' 18, near Lazcano, a
band of 16 individuals paused to rest for a few minutes in bushes
bordering a lagoon, and then, in straggling formation, passed on
to the northeast. On March 2 occasional individuals were recorded
from a train, from the suburbs of Buenos Aires as far south as 25
de Mayo in the Province of Buenos Aires, but none were seen
beyond that point. The last one recorded was observed from a train
near Franklin, Buenos Aires, on March 11.
The species is known universally as tiierita.
Family PHYTOTOMIDAE
PHYTOTOMA RUTILA Vieillot
Phytotoma nttila Vieillot, Nouv. Diet. Hist. Nat., vol. 26, 1818, p. 64.
(Paraguay.)
During winter, near Las Palmas, Chaco (July 26 and 31, 1920),
this strange bird was found in small flocks in bush-grown pastures,
and occasional individuals were recorded at the Riacho Pilaga, Formosa
(August 14, 18, and 21). Near Las Palmas a pair of adult
birds was secured July 26. The species seemed irregular in its
occurrence in the Chaco region, and may have been only a winter
visitant. The birds were found quietly at rest on the tops of low
bushes, with crest erect, and were usualty difficult to approach. The