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

BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 367
Berazategui is peculiar in having the chestnut superciliary extended
behind the eye thus suggesting viridis. An adult male, taken
January 30, had the tip of the culmen fuscous; rest of maxilla
benzo brown: base of mandible light brownish drab; rest pallid
quaker drab becoming fuscous at tip ; iris brick red ; tarsus and toes
deep green-blue gray.
Like its congener, this pepper shrike frequented brush where it
hopped slowly about among the dense limbs with all the assurance of
a tyrant flycatcher.
Attention was often drawn to the bird by its rollicking, warbling
song that carried for a considerable distance. A second song given
with bill pointed toward the sky resembled too too too wheur.
In addition to its songs, the species has several peculiar calls uttered
in a loud tone. Those seen in January were accompanied by grown
young.
Where color may not be distinguished, the strong, heavy bill of
this bird is a prominent field mark.
Family VIREONIDAE
VIREO CHIVI CHIVI (Vieillot)
Sylvia chivi Vieillot, Nouv. Diet. Hist. Nat., vol. 11, 1817, p. 174. (Para-
guay.)
Eight skins preserved offer certain differences in coloration, but
may be referred to typical chivi. An adult male shot September 30,
1920, on the Cerro Lorito opposite Puerto Pinasco, Paraguay, may
represent the usual form of the type race. Four adult males from
San Vicente, Uruguay (January 28, 29, and 30, 1921), and a pair
from the Rio Cebollati, near Lazcano (February 6), are somewhat
duller in coloration. Deeper coloration also characterizes an adult
male from Tapia, Tucuman, shot April 9, 1921.
On September 30 the species was common in the forests near the
Rio Paraguay, apparently newly come in spring migration, since
none had been seen previously. One was recorded at Asuncion,
Paraguay, on October 6. In eastern Uruguay, the species bred commonly
on brush-grown slopes of canj^ons in the rocky hills near
San Vic nte (January 28 to 30, 1921), and was fairly common in
the dense thickets along the Rio Cebollati, below Lazcano (February
6 and 8). Spring and summer birds sang as persistently as does
V. olivaceus in the north, a species of which chivi is so much a
counterpart in appearance, actions, and notes that it is recognized
at first glance. Their smaller size and yellow-green sides and
flanks are apparent on close scrutiny, while in the hand it is found
that the iris is duller, as it varies from Rood's to Vandyke brown.
The birds work quietly through the limbs, pausing frequently to