76 ■ BULLETIN 133, UNITED STATES NATIONAL MUSEUM 



Department of Rocha. Others were recorded at Lazcano, in the same 

 general region, on February 7. 



Around the Laguna del Monte at Guamini, Province of Buenos 

 Aires, Argentina, the species was common from March 3 to 8. I 

 was surprised to note occasional true pairs of these birds here, 

 though the breeding season was past, as fall was well advanced. I 

 judged that these were pairs that for some reason had been unsuc- 

 cessful in nesting during the summer and that had not as yet parted 

 company. Near Tunuyan, Mendoza, a flock of 25 pintails was seen 

 on March 25, and others the following day. Early on the morning 

 of March 28 a flock of 100, and later two smaller groups, passed 

 due north, flying high in air. These last seemed to be flight birds 

 in fall migration. 



In general appearance and habits Dafila spinicauda is similar to 

 Daflla acuta. The birds frequent the open water of lagoons or rest 

 on bars, muddy shores, or projecting points where they have open 

 outlook. They impress one as alert and intelligent, eminently able 

 to care for themselves. In wilder sections, Avhere not molested, they 

 exhibit little fear, but when hunted it was many times almost im- 

 possible to come within range of them, especially on open pampa, 

 where there was little or no opportunity for concealment. The birds 

 often feed by immersing the head and neck as they paddle across 

 shallow pools or bays, or in deeper water tip in order to reach the 

 bottom. Where heavy winds or rising waters flood areas of muddy 

 flat the pintails follow the creeping advance of the water line to 

 reed eagerly in the windrow of seeds and dead or drowning insects 

 that it carries with it. Recently flooded areas of shallow water 

 are always attractive. The flight is swift and direct. On the wing 

 the birds resemble D. acuta., but appear heavier in the neck. Though 

 females resemble males, they may be distinguished sometimes when 

 in the air by the shorter, less-pointed tail, especially when flocks 

 swerve in passing OA'erhead. The call of the male is a mellow, 

 trilled whistle, a purling sound pleasing to the ear, resembling that 

 of the northern pintail. It is given frequently as parties of males 

 pass on the wing. The note of the female is a low ha-ach or qua-ack., 

 slightly lower in tone than that of our pintail. 



The species is one of the abundant ducks of the pampas and was 

 common among birds offered for sale during winter in the great 

 markets of the city of Buenos Aires. 



PAECILONITTA BAHAMENSIS RUBRIROSTRIS (Vicillot) 



Anas ruhrirostris Vieiixot, Kouv. Diet. Hist. Nat., vol. 5, 1816, p. 108. 

 (Buenos Aires.) 



Near Carhue, in western Buenos Aires, the southern Bahama duck 

 was common from December 15 to 18, 1920. The birds ranced in 



