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

96 BULLETIN laS, UNITED STATES NATIONAL MUSEUM
constantly attracts attention when traveling through its range,
whether the birds are observed at rest in the top of some tree that
commands an outlook over open country, or in steady direct flight
toward some distant point. In the Chaco the caracara, as the bird
is called in Guarimi, is Imown as a scavenger that is tolerated so
that it is tame, and at times almost aggressive in its approach to
man. In the pampas these hawks are killed relentlessly because of
their depredations in eating out the eyes of newly-born lambs, and
in many districts the bird is becoming rare.
At Las Palmas, Chaco, caracaras were common from July 13 to
August 1, 1920. When waste from a sugar factory killed many fish
in a small stream caracaras gathered in bands to feed on them, and,
it may be added, filched a number of mouse traps that I had supposed
were securely hidden in the brush along the bank. One was
observed eating a cavy, found lying dead, which like all large prey
was held firmly under one foot and torn into small bits with the
heavy bill. Near the Riacho Pilaga, Formosa, caracaras were recorded
from August 7 to 19. One flew down frequently to disturb
feeding flocks of monk parrakeets {Myiopsitta in. cotorra) in a
sweet-potato field in hope that some cripple, wounded by the shoot-
ing of Indians, might fall into its clutches. It was not able to
seize the uninjured birds. On August 12 one flew to a large stick
nest, 9 meters from the ground in a quebracho tree standing in an
open savanna, to bring a bit of stick to add to the structure. After
this had been arranged satisfactorily the bird settled for an instant
in the nest cavity, and then flew to a limb overhead and surveyed
the nest carefully. At the town of Formosa, on August 23, caracaras
flew back and forth above the strong current of the Paraguay
River in search for any carrion that might come downstream.
In the vicinity of Lavalle, Buenos Aires, caracaras were observed
frequently from October 27 to November 15. The skull of a male
was secured on October 31. The birds were wary here as they were
shot relentlessly by the estanceros because of their destructiveness
to young stock. During the day carranchos ranged over the open
pampa but returned at nightfall to roost in trees in occasional
groves of ombu, tala, or eucalyptus. On November 6 I collected a
set of two fresh eggs near the coast about 25 kilometers south of
Cape San Antonio. The site was a small tree in a little grove
planted about a water hole, a spot remote from habitation and the
only suitable one available in a radius of several kilometers. The
nest, placed about 6 meters from the ground, was an untidy struc-
ture, bullry^ and heavy in appearance, made of dried stems of a
sharp-pointed rush, with broken ends stuck out in all directions.
The deeply cupped interior was lined in part with a felted mass
of pellets ejected by the parents, that formed a soft bed for the