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BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 113
RUPORNIS MAGNIROSTRIS SATURATA (Sclater and Salvin)
Asturina saturata Sclater and Salvin, Proc. Zool. Soc. London, 1876, p.
357. (Apolo"' and Tilotilo, Bolivia.)
A male in fresh fall plumage that agrees with the characters
assigned to this form was taken near Tapia, Tiicuman, on April 18,
1921. From B. m. j)uchc7'ani of areas farther east it is distinguished
by darker coloration throughout, and by the much bolder, heavier
markings of the under surface. The bird was killed as it rested in
a tree in low scrubby forest. On April 12 another was observed as
it turned in short circles far above the earth and gave the shrill
squealing calls common in hawks of this species more especially in
spring. This subspecies does not seem to have been recorded pre-
viously in Argentina.
HETEROSPIZIAS MERIDIONALIS MERIDIONALIS (Latham)
Falco meridionalis Latham, Ind. Orn., vol. 1, 1790, p. 36. (Cayenne.)
An adult female of this hawk taken at Kilometer 80, west of
Puerto Pinasco, Paraguay, on September 7, 1920, appears to be a
representative of the typical northern form as it has the following
measurements: Wing, 412; tail, 214; culmen from cere, 23; and
tarsus, 100 mm. The species was fairly common both at Puerto
Pinasco and in the Chaco to the westward from September 1 to 23.
At this season the birds were found in pairs and the female secured
showed some growth in size of the ovary, so that the breeding season
seemed near. The birds frequented open savannas dotted with small
trees that offered convenient resting places. Though in appearance
(save in color) and in action they resemble the red-tailed hawk
(Buteo horealis) they seem slower and less aggressive. On one
occasion I saw one stoop at a guira cuckoo on the ground but miss
it, and the cuckoo was then able to escape in spite of its slow, weak
flight. On windy days tlie hawks rested facing the wind with head
lowered to a level with the body, and the tail raised so as to offer
as little resistance to the gusts as possible. Sparrow hawks drove at
them occasionally but the large hawks merely dropped their heads
to avoid being struck, and made no attempt to punish their assail-
ant. The call note of this large hawk is a high pitched note resem-
bling kree-ee-ee-er that terminates in a drawn out wail. It suggests
in a way the squealing call of Buteo horealis^ but is less forceful and
vigorous. Occasionally a pair circled about in the air a hundred
meters from the earth and emitted a snarling, grunting kweh hioeh
hwuhrh kweh kweh. To the Anguete Indians they were known as
so has gookh., and to the Lenguas as nata pais shar o.
»s So spelled in the Century Atlas of the World.