74 BULLETIN 133, UNITED STATES NATIONAL MUSEUM 



with buffy brown, on hind crown, and hind neck; loral region and 

 stripe extending under eye biiffy brown, with a faintly indicated 

 whitish spot at base of bill on loral region ; streak behind eye clove 

 brown; superciliary streak, lower eyelid, and poorly defined auri- 

 cular streak whitish ; lower hind neck, upper back, and wings with 

 down clove brown basally, buffy brown distally, the lighter color 

 predominating and extending down on sides of breast ; rest of upper 

 parts deeper than clove brown; streak extending across posterior 

 side of forearm to base of wing, and from there in a somewhat ir- 

 regular line on either side of back to line of thighs whitish ; under- 

 parts whitish with a slight buffy tinge; and indistinct collar of buffy 

 brown across upper breast. The specimens taken are very uniform 

 in color. 



The southern pintail was common in the fresh water of marshy 

 pools and channels near Lavalle in the Province of Buenos Aires at 

 the end of October, 1920. On November 6, following a severe storm 

 of wind and rain that flooded large areas and killed many thousand 

 sheep, a great migration of these birds came in from the south, the 

 flight continuing during morning and evening for a period of three 

 days. At the time I was in camp in the sand-dune area on the 

 east coast of the Province of Buenos Aires, about 24 kilometers south 

 of Cape San Antonio. 



In flocks and pairs pintails came swinging in to feed on areas of 

 flooded land adjacent to the dunes. The birds showed little fear, 

 and if I merely crouched on the ground had no hesitancy in passing 

 within 60 meters, so that I killed four without difficulty. On the 

 evening of November 7 the flight from the south was greatly in- 

 creased, the birds passing in flocks of half a dozen to one hundred. 

 The larger flocks traveled in irregular lines, the birds more or less 

 abreast, passing steadily to the northward from 30 to 60 meters from 

 the ground, while occasional bands swung around to drop in on some 

 suitable feeding ground. At intervals I noted pairs of ducks, male 

 and female flying together, alone or in company with flocks, but 

 during the entire movement certainly more than 95 per cent of the 

 pintails seen were males. The following morning the flight began 

 again at daybreak and continued until about 10 in the morning. 

 Flocks scattered out to feed over the pampa covered with shallow 

 water from the rains. The total number of birds seen on this day 

 between 5 o'clock in the morning and noon was estimated at between 

 15,000 and 20,000 individuals. As before, more than 95 per cent of 

 those observed near at hand were males, and it was assumed that 

 this proportion held among those noted at a greater distance. Male 

 birds that I shot were still in full breeding condition. From the 

 make-up of the flocks it was my belief that in Dafla spinicauda^ as 



