ARGENTINE GRAY TEAL 
405 
the Brown Pintail has always outnumbered all other species. Besides being a swift 
flier, these birds are erratic on the wing. The flocks are very compact and the turns 
are made, as in other Teal, without breaking the formation (Peters, MS.). 
Associaton with other Species. Although they are not particularly sociable, 
they were found mingling with Yellow-billed and Cinnamon Teal in northwestern 
Patagonia. More rarely Brown Pintail and Chiloe Widgeon were mixed with them 
(Peters, MS.). In Uruguay they were once seen in the company of Shovellers (Aplin, 
1894), but Durnford (1878) speaking of Buenos Aires Province, says the flocks never 
mix with those of other species. 
Voice. The voice of the male is very peculiar and does not resemble the whistled 
calls of many of the smaller ducks. Pintail and Widgeon. Hudson (P. L. Sclater and 
Hudson, 1889) long ago described it as resembling in sound the “muflSed stridulating 
of the mole-cricket.” Those who have never heard the mole-cricket will perhaps get 
a better idea of the note from Mr. Peters’s (MS.) comparison. He likens it to the 
“ quick winding of a cheap watch ” and the note which he heard in flight is slightly 
ventriloquial and audible for a short distance. 
The female’s voice is entirely different and consists of a low sound perhaps half- 
way between a quack and a croak (Peters, MS.). When they are frightened, Hein- 
roth (1911) says they utter a rather loud quack, when restless a much softer quack. 
The trachea of the male is very peculiar and interesting. The upper middle part is 
expanded and flattened for a distance of 55 mm., forming a chamber 14 mm. in 
breadth and about 10 mm. across. The tracheal bulb is large, irregular, facing to the 
left and back, and measures 20 to 23 mm. in its longest diameter by 15 mm. in its 
shortest. It is very robust and solid for so small a duck. The female’s trachea is, of 
course, simple, but in newly hatched young males the tracheal bulb is easily recog- 
nizable and is about 4 mm. in diameter. The female at the same age also has a bulb, 
which appears somewhat smaller, less rigid and in process of retrogression. 
Food. Mr. Peters collected seven stomachs from Huanuluan, Rio Negro Province 
of Argentina, in August and September, 1920. Mr. W. L. McAtee kindly examined 
these and reports vegetable matter in the proportion of 40 to 98 % with an average 
of 81 %. The principal vegetable foods were the same as in other ducks from that 
region, consisting of the seeds of Myriophyllum (water milfoil), Carex (sedge), 
Scirpus americanus (rush) and other sedges, Rumex (dock) and a few of Zan- 
nichellia palustris (horned pond-weed) a,nd Batrachium (water crowfoot). Besides 
this there were shreds of grass and other vegetable debris. 
The animal food, which is in somewhat greater proportion than in other ducks, 
consists of amphipods, caddis larvae and their cases, hydrophilid larvae (water- 
