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

BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 379
has described a large bird from Bolivia/^ which must stand as
GnoHmopsar c. megistus (one skin seen in United States National
Museum), but which can have no relation to the bird of almost
equal size from far distant Uruguay. Gnorinwpsar sulcirostris
(Spix) said doubtfullj'^ to come from Minas Geraes, according to
Hellmayr," is a distinct species with a wing measurement of 155
mm. The Uruguayan skin is listed here with these comments, though
it can not be considered typical chopi.
The chopi or tordo (the latter a name shared with the cowbird)
was partial to marshy meadows where it fed in little bands that
flew up at intervals with musical calls to rest in the sun in scattered
clumps of trees. It was not unusual to see them at dusk in flight
to a roost in some reed bed, and it was reported that bands gathered
in late summer in such numbers as to damage fields of corn. Though
their ordinary call was a harsh chuck^ when several were gathered
they uttered slow whistled calls that formed a pleasing medley.
They much resembled grackles in their direct flight and general
habits. Near Puerto Pinasco they came about dwellings and ranch
buildings to investigate garbage cast out from the kitchen, varying
their search for food by whistled concerts from near-by shade trees.
By the middle of August males Avere seen circling with set wings
in short spirals before females, and by the end of September they
had scattered to breeding grounds. In January, in eastern Uruguay,
I found them among groves of palms where they seemed to be nest-
ing as they scolded with rattling calls, while they walked about
on the palm fronds overhead or occasionally gave a burst of song.
An adult male, taken September 18, had the bill, tarsus, and toes
black, and the iris Hay's brown. The genus is remarkable for the
sharply rounded ridge that passes obliquely across the base of the
mandible.
AGELAIUS TmLIUS CHRYSOPTERUS Vieillot
Arielaius chrysoptenis Vieillot, Nouv. Diet. Hist. Nat., vol. 34', 1819, p. .539.
(Paraguay.)
The yellow-shouldered blackbirds of the west coast and the Andean
region from Chile (the type-locality of Turdus thilius of
Molina ^^) north to Galea, Peru, have the wing distinctly longer than
those from east of the Gordillera. Average measurements of four
males from Ghile are, wing, 94; tail, 63.5 mm. ; of three females, wing,
86; tail, 67.8 mm. Eleven males from Argentina (Buenos Aires and
Santa Fe) measure, wing, 85.1; tail, 65.6 mm.; seven females, wing,
79.6; tail, 60.4 mm. These differences are sufficient to warrant the
"4p7io6MS megistus Levcrkiilin, Journ. fiir Orn., 1889, p. 104. (Santa Cruz and
San Miguel, Bolivia.)
T*Abh. Kon. Bayerischen Al^ad. Wiss., Kl. 2, vol. 22, Abt. 3, 1906, pp. 614-615.
" TwrfZifs Thilius, SajiR. Stor. Nat. Chili, 1782. p. 250.