(RED-BACKED BUZZARD.)
+Buteo erythronotus+, _Sharpe, Cat. B._ i. p. 172; _Scl. et Salv.
Nomencl._ p. 119; _Scl. P. Z. S._ 1872, p. 536 (Rio Negro);
_Durnford, Ibis_, 1877, p. 38, et 1878, p. 397 (Patagonia);
_Salvin, Ibis_, 1880, p. 362 (Salta); _Barrows, Auk_, 1884, p.
109 (Azul); _Withington, Ibis_, 1888, p. 469 (Lomas de Zamora).
+Buteo tricolor+, _Burm. La-Plata Reise_, ii. p. 436 (Mendoza and
Tucuman).
_Description._--Above slaty blue; wing-feathers slaty, with narrow
transverse bars of black; upper tail-coverts and tail white, the
latter with a broad black subapical band and numerous narrow grey
cross bars: beneath white, with slight grey cross bars on the belly;
bill black; feet dirty yellow: whole length 25 inches, wing 18·5,
tail 10·0. _Female_ similar, but back deep chestnut.
_Hab._ Southern portion of South America.
This is a fine bird--the king of South-American Buzzards. In the adult
female the three colours of the plumage are strongly contrasted; the
back being rusty rufous, the rest of the upper parts grey, the whole
under surface pure white. It is occasionally met with in the northern
provinces of the Argentine Republic, but is most common in Patagonia;
and it has been said that in that region it takes the place of the
nearly allied _Buteo albicaudatus_ of Brazil. In habits, however, the
two species are as different as it is possible for two raptores to be;
for while the northern bird has a cowardly spirit, is, to some extent,
gregarious, and feeds largely on insects, the Patagonian species has the
preying habits of the Eagle, and lives exclusively, I believe, or
nearly so, on cavies and other small mammals. When Captain King first
discovered it in 1827, he described it as "a small beautiful Eagle." In
Patagonia it is very abundant, and usually seen perched on the summit of
a bush, its broad snowy-white bosom conspicuous to the eye at a great
distance--one of the most familiar features in the monotonous landscape
of that grey country. The English colonists on the Chupat, Durnford
says, call it the "white horse," owing to its conspicuous white colour
often deceiving them when they are out searching for strayed horses
in the hills. It is a wary bird, and when approached has the habit of
rising up in widening circles to a vast height in the air. When sailing
about in quest of prey it usually maintains a height of fifty or
sixty yards above the surface. The stomachs of all the individuals I
have examined contained nothing but the remains of cavies (_Cavia
australis_).
The nest is built on the top of a thorn bush, and is a large structure
of sticks, lined with grass, fur, dry dung, and other materials. "The
eggs are greyish white in colour, blotched and marked, principally
towards the large end, with two shades of umber-brown" (_Gould_).