180 DENDROCYGNA EYTONI 



Keartland (North, 1913) mentions killing five of the former and six of the latter at 

 one shot. Females and young must at times associate with other species of ducks, 

 for Rogers (Mathews, 1914-15) found a brood of Dendrocygna eytoni together with 

 broods of Anas swperciliosa and Nyroca australis. The small aggregations in New 

 Zealand are said to have fed freely with Anas superciliosa and other species. 



Voice. The note is a shrill whistle that can be heard at a considerable distance. 

 This note seems to be uttered chiefly during flight. It is probably the same in both 

 sexes, although the female's trachea resembles that of the females of Dendrocygna vid- 

 uata, Dendrocygna bicolor and Dendrocygna javanica in having the lower rings im- 

 perfect posteriorly, and closed by a membrane (Heinroth, 1918). I have heard speci- 

 mens in zoological gardens utter a low note, like cheep-cheep. All Tree Ducks seem 

 to have low chirping or "twittering" calls besides the loud flocking whistle. 



Food. The food is chiefly vegetarian, consisting of tender buds of aquatic plants 

 (North, 1913) and probably the seeds of grasses on the plains (North, 1898). Ma- 

 thews (1910) examined stomachs that contained seeds and grit. A small group of 

 these birds that lived on Ashburton Domain fed on oats and wheat scattered on the 

 water's edge (W. W. Smith, 1897). 



Courtship and Nesting. In New South Wales the months from September to 

 December constitute the breeding season, while in the North Territory of South 

 Australia breeding begins in the rainy season, in February, and extends to the end 

 of May or middle of June (North, 1913). In North Queensland eggs were taken in 

 February (Berney, 1907). 



The real breeding grounds of these birds are the interior and northern rivers, 

 lagoons and water-holes. From time to time, so Mr. Ashby writes me, all these in- 

 terior regions suffer from severe drought. In such years, most of the ducks leave, 

 and come southeast and south, where they remain until the drought is over. But 

 during their stay in the south, strange as it may appear, they never breed. Of this 

 Mr. Ashby seems certain. Robinson (North, 1913) states that in 1897, for example, 

 no water-fowl could breed in New South Wales, because of the drought. The reed- 

 beds, he said, were dried up and eaten or burned off to destroy the wild pigs and 

 water rats. 



Although there are no observations on the display of Eyton's Tree Duck, beyond 

 the general notes of Heinroth (1918, p. 241) and a curious posture noted by myself 

 under Captivity, it is very interesting to speculate as to whether the remarkable flank 

 feathers of this species are more elevated at this time. These feathers, which are so 

 highly developed in the present species, are to be found also in Dendrocygna arcuata. 

 In Mathews' (1914-15) plate, the flank feathers of Dendrocygna eytoni are repre- 



