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

98 BULLETIN 133, UNITED STATES NATIONAL MUSEUM
northern Paraguay northward through Brazil. The status of the
bird from the coastal region of extreme southern Brazil (Santa
Catherina and Rio Grande do Sul) is uncertain. From September
6 to 30, 1920, I found caracaras common in the country about
Puerto Pinasco. As they were not persecuted in this region they
came in numbers about ranch buildings in search of offal from the
killing pens. Their habits do not differ from those of the southern
form.
HERPETOTHERES CACHINNANS QUERIBUNDUS Bangs and Penard
Herpetotheres cachinnans queribundus Bangs and Penard, Bull. Mus.
Conip. Zoul., vol. 63, June, 1919, p. 23. (Pernambueo, Brazil.)
The southern laughing falcon was seen first on July' 21, 1920, near
Las Palmas, Chaco, when an adult female was taken as it rested on
a dead stub in an opening in the forest. Farther northward at the
Riacho Pilaga, in central Formosa, from August 8 to 20 the species
was more common, and two additional females were shot on August
14 and 20 (the latter preserved as a skeleton). At Kilometer 80,
west of Puerto Pinasco, Paraguay, one was seen September 12, and
at Kilometer 200 two were found on September 25. The birds,
usually in pairs, inhabit the taller growths of heavy forest where
they rest on open perches surrounded b}'^ dense heavy growth.
Where not molested they come out into more open regions.
Though of heavy build, seeming strong and powerful, they ar2
sluggish in ordinary habit and are seldom seen save at rest. On
only one occasion did I observe one turning in circles in the air
above the trees.
One is not long in the haunts of the laughing falcon without becoming
familiar with its strange loud notes, though it may be some
time before the bird is seen. The call begins as a single note, given
at short intervals, and then changes to a more rapid repetition of
varied sounds. After two or three minutes the mate of the performer
may join in and the birds call rapidly, first in alternate short
notes and then in a strange medley, a weird, unearthly concert, start-
ling indeed to one not familiar with its source, that may be continued
without cessation for 10 minutes. These strange duets were
especially impressive when heard at dusk. Countrymen related
that the birds were very observant and announced by their calls the
passage of men through the forest.
The falcons themselves are handsome birds, their heavy white
crests and boldly marked black head being no less impressive than
their notes. The Toba Indians knew them as gua kow in evident
imitation of their calls, while in Guarani they were called Guaycuru,
a word signifying a Chaco Indian, usually designating a warlike
type.