30 HIRUNDINID/E. 



28. PETROCHELIDON PYRRHONOTA (VieilL). 

 (RED-BACKED ROCK-MARTIN.) 



Petrochelidon pyrrhonota, Scl.et Salv. Nomencl.-p. 14; Durnford, Ibis, 1877, 

 p. 169; White, P. Z. S. 1882, p. 595 (Buenos Ayres) ; Sharpe, Cat. B. x. 

 p. 193. Cotyle pyrrhonota, Burm. La-Plata Reise, ii. p. 477 (Tucuman). 



Description. Above glossy dark steel-blue ; lower back and rump cinnamon- 

 rufous ; the upper tail-coverts brown, with grey margins ; wings black ; tail 

 black, with greenish gloss ; crown steel-blue ; forehead sandy buff ; cheeks and 

 sides of face chestnut, spreading to the sides of the hind neck ; chin chestnut ; 

 the lower throat steel-blue ; fore neck, chest, and sides of body and flanks light 

 ashy brown ; centre of breast and abdomen white, tinged with brown ; under 

 tail-coverts, also under wing-coverts and axillaries, ashy brown : total length 

 5*3 inches, wing 4-35, tail 2-05. Female similar. 



Hab. South America. 



This species does not breed in Buenos Ayres, and is only seen there 

 in spring, flying south or south-west, and again in much larger numbers 

 on its return journey in autumn. On the Rio Negro, in Patagonia, I 

 did not meet with it, and suppose its summer resort must be south of 

 that locality; and, judging from the immense numbers visible in some 

 seasons, I should think that they must, in their breeding-place in 

 Patagonia, occupy a very extensive area. They do not seem to be as 

 regular in their movements as other Swallows here ; some years I have 

 observed them passing singly or in small parties during the entire hot 

 season : usually they begin to appear, flying north, in February ; but in 

 some years not until after the middle of March. They are not seen 

 passing with a rapid flight in close flocks, but straggle about, hawking 

 after flies : first one bird passing, then two or three, and a minute or 

 two later half a dozen, and so on for a greater part of the day. So 

 long as the weather continues warm they journey in this leisurely 

 manner; but I have known them to continue passing till April, after all 

 the summer migrants had left us, and these late birds flew by with great 

 speed in small close flocks, directly north, as if their flight had been 

 guided by the magnetic needle. 



While flying this species continually utters sharp twitterings and 

 grinding and squealing notes of various lengths. 



29. TACHYCINETA LEUCORRHOA (VieilL). 

 (WH1TE-RUMPED SWALLOW.) 



Hirundo leucorrhoa, Hudson, P. Z. S. 1872, pp. 606, 845 (Buenos Ayres) ; Sol. 

 et Salv. Nomencl. p. 14; Durnford, Ibis, 1877, p. 32 (Chupat), 1878, p. 392 

 (Central Patagonia) ; White, P. Z. S. 1882, p. 696 (Corrientes) ; Barrows, 



