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

BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 377
ruary 5 to 9 (adult male, February 5) ; and Rio Negro, February 15.
Specimens from Uruguay appear to have slightly shorter bills* than
those from Buenos Aires, but the species is somewhat variable in
length of culmen.
These blackbirds were found in little scattered flocks at the borders
of marshes or in wet localities on the open pampa, where they walked
about like grackles in preoccupied search for food. Thej'^ were
common near the beach below Cape San Antonio, Buenos Aires, and
many were noted about the caiiadones farther inland. During October
and November the birds often scolded me as I traveled through
the rushes, and on November 13 I saw young recently from the nest.
In fall and winter it was usual for them to rest in clumps of saw
grass to warm themselves in the earlj^ morning sun. Their calls,
given usually on the wing, were musical and pleasant to the ear.
An adult male killed October 23 had the bill and tarsus black;
iris sayal brown.
AMBLYRAMPHUS HOLOSERICEUS (Scopoli)
XantJwruiis holosericens Scopoli, Del. Flor. Faun. Ins., pt. 2, 17S6, p. 88.
(Islands of the Parana Delta.")
This brilliant inhabitant of rush-grown marshes was fairly common
in central and northern Argentina. At Las Palmas, Chaco,
from July 14 to 28, 1920, it was observed occasionally in flight
overhead, in usual blackbird fashion, and my acquaintances among
the people of the little village were not satisfied with my daily bag
of specimens until, on July 28, I had added a beautiful male to my
collection. An immature male with only scattered orange feathers
on the otherwise black head and chest was frowned upon as hardly
worth preservation, but to me w-as as interesting as the adult. This
bird is in slow molt into the adult plumage.
These blackbirds were recorded frequently about the lagoons near
Kilometer 182, Formosa, August 9 to 21, and on the latter day were
noted in numbers in the esteros between Fontana and Formosa. A
few Avere found with flocks of Agelaius rwficapillus September 17,
near Kilometer 80, west of Puerto Pinasco, Paraguay, where a male
taken had nearly completed the molt into the adult stage. The spe-
cies was seen at Dolores, Buenos Aires, October 21, and a female
about to breed was shot at Lavalle, Buenos Aires, October 29. Another
was noted near here November 16. One was seen at the Paso
Alamo on the Arroyo Sarandi north of San Vicente, Uruguay, February
2, 1921.
These blackbirds are found universally in marshes where often
the}^ rest concealed among the rushes and seem rather shy. They
" See Dabbene, An. Mus. Nae. Hist. Nat. Bubdos Aires, vol. 23, Dec. 26, 1912, p. 372.
The originaJ locality cited by Scopoli "Antigua, Panay," was in error. Brabourne and
Chubb (Birds South America, December, 1912, p. 436) cite Brazil.