CHILIAN PINTAIL 
335 
28 to 100% and averaged 86%. It consisted chiefly of the seeds of Myriophyllum 
(water milfoil), Rumex (dock) and Carex (sedge) with remains of Batrachium (water 
crowfoot) seeds in a few cases. There were also shreds of grass-glumes, unidentified 
seeds and vegetable debris. The favorite food appeared to be the seeds of the 
water milfoil, which were present in all stomachs up to as many as 600. 
The animal matter was mostly unimportant and would probably be even less 
so in the winter season. It consisted of stratiomyiid larvae (flies), remains of 
Corixidae (bugs), snails, caddis cases and larvae, dragon-fly nymphs, dytiscid larvae 
(water-bugs), the jaw of a cricket and traces of a mollusk shell. 
Courtship and Nesting. The pairing season is irregular, though generally 
earlier than that of other ducks. In northwestern Patagonia pairing had certainly 
begun late in August, although flocks were still in evidence. Specimens shot on 
September 6 showed only slight traces of sexual activity and were completing a pre- 
nuptial moult. A week later a male with fully developed sex glands was taken 
(Peters, MS.). The only live pair which I ever kept showed no courtship activity 
of any sort, and neither Peters nor Wetmore (MS.), on recent journeys to South 
America, observed any display in the field. The reason for this is not clear. A char- 
acteristic mating flight was, however, seen by Wetmore, near Lavalle (Province of 
Buenos Aires). A pair circled over a flooded meadow, high in the air, the male at 
short intervals swinging under and slightly in front of the female, while she at each 
approach swerved to one side or the other, leaving the male again behind. In other 
words this exhibition seems to be exactly the same as in the Common Pintail. 
In southern Patagonia and Tierra del Fuego the nesting season begins about the 
middle of October and is over by December. In northwestern Patagonia it is some- 
what earlier. Peters (MS.) found the first nest on September 24 and he thinks laying 
had commenced even earlier. In the last of September and early October nests could 
be found almost daily. The latest clutch found was on December 4; the six eggs 
were ready to hatch. It is noteworthy that even through the height of the breeding 
season small flocks of non-nesting birds are commonly seen. Peters collected some 
such on November 3 and 11, and even on November 29 females were shot that had 
not moulted the previous season’s primaries or tail-feathers. From March 3 to 8, 
long after the breeding season was past, occasional pairs, which for some reason had 
not bred, were seen in the Province of Buenos Aires (Wetmore, MS.). 
In this Province the earliest breeding seems to be in late September (Beck, MS.). 
E. Gibson’s (1920) earliest nest was on October 3, and his latest on November 30. 
Still farther north the season is undoubtedly even more irregular and extended. On 
the great plateaus of Chile and Peru the nesting-time is also very irregular. Ac- 
cording to Lane (1897) it extends from October to February in northern Chile. Out 
of nine males taken by Beck (Brewster-Sanford collection) near Lake Junin, Peru, 
