#4150. 
150a. 
150b. 
85 
Buteo erythronotus erythronotus (King), Zool. 
Jnl. iii, p. 424 (1827). [Port Famine, 
Tierra del Fuego.) 
Red-backed Buzzard. 
Wing 3 368-380, 2 405-425 mm. ; ¢ above 
light slate grey, below white, usually with 
some fine verniculations of rufous brown on 
abdomen ; tail white with 8 or 10 narrow 
grey lines (except in very old birds) and 
sub-terminal blackish band; @2 back and 
scapulars brick red?. 
Buteo erythronotus simonsi subsp. nov. [2 
Challapata, Bolivia, P. O. Simons, Oct. 14th 
1901, type in Brit. Mus., reg. no. 1902, 3, 
13, 1600.] 
Bolivian Red-backed Buzzard. 
Larger; wing ¢ 407, 9 455-470? ; much 
darker than B. e. erythronotus ; upper parts 
and wings blackish slate instead of light 
slate grey (but mantle red in 9) ; tail with 
the cross lines wider and blacker ; below 
white ; cross lines on belly (when present) 
blackish brown instead of rufous. 
Buteo erythronotus peruviensis subsp. nov. 
[$ Eten, prov. Lambayeque, Peru, P. O. 
Simons, Sept. 21, 1899, type in Brit. Mus., 
reg. no. 1902, 3, 13, 1603.] 
Northern Red-backed Buzzard. 
Falkland Is., 
Tierra delFuego, 
Patagonia, 
Argentina (to 
Buenos Ayres), 
Chile. 
Bolivia, 
N. Chile 
(Iquique), 
S. Peru (Andes), 
Ecuador 
(Andes) ? 
N.W. Peru 
(W. of Andes). 
rt Males, until fully adult, often show a small amount of red on the inter- 
scapulary region, although the grey upper and white lower plumage have been 
acquired. Occasionally the red is so extensive as to make them resemble the 
females, although the red in these cases is generally mottled with grey teathers. 
2 The wing of the 9 type measures 470 mm., and of two other females from 
Iquique, Chile, and “‘ High Peru,’’ 467 and 460 mm. respectively. Other Bolivian 
birds from prov. of Cochabamba and Oruro measure @ (?) 407, and Q (?) 405. 
All the Bolivian birds have the blackish upper parts, although there is a puzzling 
variation in size. 
