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