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

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BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 95
trees scattered across a prairie, and at my appearance greeted me
with harsh squalls. An adult female was taken. Another was ob-
served on July 30. At the Riacho Pilaga, Formosa, a female in
streaked juvenal plumage was killed on August 7, and an adult
female on the following day. Others were recorded here until Au-
gust 19, and one Avas seen near the town of Formosa on August 24.
In the region about Puerto Pinasco, Paraguay, they were fairly
common and an adult male was collected September 15.
This form has customs similar to that of Mtlvago chimango, a
species that it replaces in the north, but is more of an inhabitant
of wooded areas. The partly open, partly forested Chaco seemed
fitted especially for its needs, and here it was encountered where
scattered trees furnished shelter. The birds are scavengers in habit
and feed on any waste animal food that is available. They also
bear a bad reputation among the housewives on the estancias for
their propensity to filch young chickens and ducks, and, as the kiriri
comes familiarly about buildings, its depredations maj^ at times be
considerable. My " squeaking " to attract small birds from dense
coverts always drew these small hawks when they were about, and
their squalling calls were often annoying when I was straining my
ears to catch some faint bird note from the surrounding thickets
or trees. Carrion hawks often came while I was engaged in clean-
ing bird skeletons, and walked about on the ground to pick up bits
of flesh that I threw out to them, while it was necessary to hang
skeletons put out to dry in places where they were secure from the
sharp eyes of these prying marauders. The ohimango is a bird of
weak flight, flapping and sailing rather slowly, and never, so far
as I am aware, is it directly aggressive to other birds unless it en-
counters young or individuals that have been injured in some way.
Adults when on the wing appear light in color on the body and tail,
with a light bar in either wing. Their call, a harsh squall, is remi-
niscent of that of Ihycter ater.
POLYBORUS PLANCUS PLANCUS (Miller)
Falco Planeus Millee, Var. S'ubj. Nat. Hist., 1777, pi. 17. (Tierra del
Fuego.
The carancho was almost universal in occurrence throughout Ar-
gentina and Uruguay, as it ranged throughout wooded regions as
well as on the open pampas. None were observed at the localities
worked in Rio Negro and Neuquen in northern Patagonia, but this
was due in all probability to the short time occupied in field work
in those regions. The carancho, as the bird is known in the south,
is a bird of strong flight, though it does not delight in soaring or
circling in the air as is customary in vultures and many hawks.
Its vigorous form, with contrasted light and dark colors, is one that