

TACHYCINETA LEUCORRHOA. 31 



Bull. Nntt. Orn. Cl. viii. p. 89 (Concepcion). Cotyle leucorrhoea, Burm. 

 La-Plata Iteise, ii. p. 478 (Parana). Tachycineta leucorrhous, Sharpe, 

 Cat. B. x. p. 114. 



Description . Above glossy dark green ; rump white ; quills black, wasbed 

 with green ; upper tail-coverts dark green ; tail-feathers black with greenish 

 gloss ; base of forehead white, extending a little backward over the lores ; 

 cheeks and whole under surface white ; flanks and sides washed with smoky 

 brown ; axillaries and under tail-coverts pale smoky brown ; bill and feet black : 

 total length 5-5 inches, wing 4*45, tail 2-0. Female similar. 



Hab. Brazil , Paraguay, and Argentina. 



This is the most abundant and best known of our Swallows ; a pretty 

 bird in its glossy coat of deep green, and rump and under surface 

 snowy white ; exceedingly restless in its disposition, quick and graceful 

 in its motions ; social, quarrelsome, garrulous, with a not unmusical song, 

 beginning with long, soft, tremulous notes, followed by others shorter 

 and more hurried, and sinking to a murmur. They are the last of all 

 our migrants to leave us in autumn, and invariably reappear in small 

 numbers about the houses on every warm day in winter. Probably many 

 individuals in Buenos Ayres remain through the winter in sheltered 

 situations, to scatter over the surrounding country whenever there 

 comes a warm bright day. I once saw three together, skimming over 

 the plains, 011 one of the coldest days I ever experienced on the pampas, 

 the thermometer having stood at 29Fahr. that morning. 



Further south their migration is more strict ; and on the Rio Negro, 

 in Patagonia, from March to August I did not meet with a single 

 individual. In Buenos Ayres the autumnal migration of the Hirundines 

 begins about the middle of February, and from that date vast numbers 

 of this Swallow are seen travelling north, and, in some seasons, they 

 continue passing for over a month. One autumn, in April, several days 

 after the Swallows had all disappeared, flocks of the Common Swallow 

 began again to appear flying north, and for ten days afterwards they 

 continued to pass in large numbers. They would stoop to dip them- 

 selves in a pool where I observed them, and then alight on the reeds 

 and bushes to rest, and appeared quite tired with their journey, rising 

 reluctantly when approached, and some allowing me to stand almost 

 within arm's length of them without stirring. I had never before 

 observed any later or supplementary migration like this ; for, as a rule, 

 the causes which in some years delay the departure of birds seems 

 to affect them all alike. Possibly these late birds come from some 

 remote district, where exceptionally cold weather had retarded breeding- 

 operations. 



The White-rumped Swallow sometimes lays in a tree, in the large nest, 

 previously abandoned, of the Lenatero (Anumbius acuticaudatus). Its 



