included four species of the Caracara or Polyborus, the Turkey buzzard,
the Gallinazo, and the Condor. The Caracaras are, from their
structure, placed among the eagles: we shall soon see how ill they
become so high a rank. In their habits they well supply the place of
our carrion-crows, magpies, and ravens; a tribe of birds widely
distributed over the rest of the world, but entirely absent in South
America. To begin with the Polyborus Brasiliensis: this is a common
bird, and has a wide geographical range; it is most numerous on the
grassy savannahs of La Plata (where it goes by the name of Carrancha),
and is far from unfrequent throughout the sterile plains of Patagonia.
In the desert between the rivers Negro and Colorado, numbers constantly
attend the line of road to devour the carcasses of the exhausted
animals which chance to perish from fatigue and thirst. Although thus
common in these dry and open countries, and likewise on the arid shores
of the Pacific, it is nevertheless found inhabiting the damp impervious
forests of West Patagonia and Tierra del Fuego. The Carranchas,
together with the Chimango, constantly attend in numbers the estancias
and slaughtering-houses. If an animal dies on the plain the Gallinazo
commences the feast, and then the two species of Polyborus pick the
bones clean. These birds, although thus commonly feeding together, are
far from being friends. When the Carrancha is quietly seated on the
branch of a tree or on the ground, the Chimango often continues for a
long time flying backwards and forwards, up and down, in a semicircle,
trying each time at the bottom of the curve to strike its larger
relative. The Carrancha takes little notice, except by bobbing its
head. Although the Carranchas frequently assemble in numbers, they are
not gregarious; for in desert places they may be seen solitary, or more
commonly by pairs.
The Carranchas are said to be very crafty, and to steal great numbers
of eggs. They attempt, also, together with the Chimango, to pick off
the scabs from the sore backs of horses and mules. The poor animal, on
the one hand, with its ears down and its back arched; and, on the
other, the hovering bird, eyeing at the distance of a yard the
disgusting morsel, form a picture, which has been described by Captain
Head with his own peculiar spirit and accuracy. These false eagles
most rarely kill any living bird or animal; and their vulture-like,
necrophagous habits are very evident to any one who has fallen asleep
on the desolate plains of Patagonia, for when he wakes, he will see, on
each surrounding hillock, one of these birds patiently watching him
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