BIRD LIFE IIT THE UEUBAMBA VALLEY OF PERU. 57 



Order ACCIPITRIFORMES. 



Family FALCONIDAE. 



CARACARAS, FALCONS, HAWKS, Etc. 



(576) IBYCTER MEGALOPTERUS (Meyen). 



Aquila megaloptera Meyen, Nov. Art. Caes., vol. 16, Siippl. 1, 1834, p. 64, pi. 7 



(Chile). 

 Milvago viegalopterus Sclater and Salvin, Proc. Zool. Soc, 1869, p. 155 (Tinta)^ 



Inhabits the Puna Zone. 



Above Torontoy, 14,000 feet, 1 male; Lucma, 13,000 feet, 1 male. 



(583) CIRCUS CINERELS Vieillol. 



Circus cinereus Vieillot, Nouv. Diet. d'Hist. Nat., vol. 4, 1816, p. 454 (Para- 

 guay). — Sclater and Salvin, Proc. Zool. Soc, 1869, p. 155 (Tinta). 



Ttica-Ttica, 1 male adult. 



(593) PARABUTEO LNICINCTUS (Temmlnck). 



Falco unicinctus Temminck, PI. Col., vol. 1, 1824, pi. 313 (Brazil). 



Anterior unicinctits Berlepsch and Stolzmann, Ornis, 1906, p. 99 (Santa Ana). 



(615) BUTEO ERYTHRONOTUS (King). 



Haliaetus erythrojiotus, King, Zool. Journ., vol. 3, 1827, p. 424 (Straits Magellan). 

 Buteo erythronotus Sclater and Salvin, Proc. Zool. Soc, 1869, p. 155 (Tinta). 



We did not secure this species in the Urubamba region but in 

 identifying the specimens of Buteo poecilochrous mentioned later, 

 I have had occasion to examine our remaining specimens of this 

 group from Puno, Lake Titicaca and southward to the Falkland 

 Islands, and conclude that they are aU referable to Buteo erythronotus. 

 The series includes adults, or nearly adult birds, which are unmis- 

 takably erythronotus, from Puno, Lake Titicaca, Tofo, 60 miles north 

 of Coquimbo, Chile; Tafi del VaUe, Province Tucuman, Argentina; 

 Uspallata Pass above Mendoza, Argentina, and the Falkland Islands. 

 The remaining specimens present much variation due to age and 

 dichromatism. Generally speaking, immature birds, in what I assume 

 is postjuvenal plumage (firstyear) are broadly streaked below with black, 

 or dark brown, the upper parts are fuscous with a minimum amount 

 of ochraceous, the tail is dark gray narrowly and evenly barred with 

 black, with no broader subterminal bar. In the succeeding plumage 

 (second ^-^ear) only the throat and breast are streaked, the abdominal 

 region being thicldy covered with broad, sometimes confluent ferm- 

 ginous bars; there is usually more ochraceous or ferruginous in the 

 dorsal surface, and at least a trace of a broad subterminal bar in 

 some of the rectrices. In the following plumage (third year) the 

 streaks have largely or wholly disappeared from the white breast, 

 leaving the abdomen as in the preceding plumage; the ferruginous 

 in the back has increased, in some specimens occupying the greater 

 part of the dorsal surface much as in the adult, the subterminal tail 

 bar is nearlv if not ouite as broad as in the adult, the rectrices are 



