CRESTED DUCK 
135 
Mr. R. M. Beck I carried away the impression that these birds seldom if ever 
travel in large flocks, for only pairs or family parties were met with in the Straits of 
Magellan and the Tierra del Fuego region. Mr. Peters says he never saw more 
than two together in the Rio Negro Province of Argentina. 
Association with other Species. These ducks are of a very jealous nature and 
pairs do not associate even with their own kind (J. L. Peters, MS.). Captain 
Abbott (1861) speaking of the Falkland Islands, says the pairs have “certain 
boundaries of water” along the coast, upon which they will not allow others of their 
species to encroach. 
Voice. The notes of this duck have not been adequately described. Crawshay 
(1907) speaks of a curiously harsh quack, resembling that of a land rail. On the 
whole it is a silent bird, and the only note heard (probably that of the female) was 
a high-pitched feeble quack (J. L. Peters, VIS.). 
The trachea of the male is 180 mm. long and at the lower end is a left-sided hulla 
ossea very similar to that of Anas specularis. It is 22 mm. long and 15 mm. broad, 
and roughly spherical in shape. 
Food. The diet probably consists chiefly of marine animals throughout the 
greater part of the year. Abbott (1861) noted their feeding on shell-fish in the Falk- 
lands, and in the Straits of Magellan Cunningham (1871) saw them on the kelp beds 
some distance from shore. In Tierra del Fuego (Phillips Bay), Mr. Blaauw (1916a) 
found them especially numerous and feeding with gulls, skuas and oyster-catchers 
on the refuse from a sheep-refining plant. 
Mr. J. L. Peters brought back two stomachs from Huanuluan, Rio Negro, taken 
September 25, 1920, and they contained from 88 to 95% of animal matter. This 
consisted of ground-up small crustaceans, and there were also a few seeds of Myrio- 
phyllum, Carex, bits of grass-root and stem and the trace of a weevil. 
Two more collected by Lord WiUiam Percy at Lake Junin, Peru, in April, 1920, 
contained mostly vegetable matter, representing both Naias and Potamogeton. 
Courtship and Nesting. The breeding season in Patagonia, southern Chile and 
the Falklands is well defined, extending from early October into November. Ex- 
ceptionally late dates were noted by R. M. Beck (MS.) who found a nest and two 
eggs on Bleeker Island on December 13, and on London Island came across young 
just able to fly on January 18. In the Falklands, W. S. Brooks (1917) found the first 
brood of downy young on November 19 and the last on February 8. He considers 
the latter date extremely late. Farther north in Tucuman a nest and eggs were 
found at an altitude of 4300 meters in early February (Hartert and Venturi, 1909), 
