454 Mr. F. E. Blaauw on Plumage-development. [Ibis, 



XXIII. — On the Plumage-development q/Nettion torquatum, 

 Poecilonetta erythrorhyncha, and Anas undulata. By 

 F. E. Blaauw, M.B.O.U. 



Nettion tobquatum has been for many years a Duck which 

 was hardly ever found in collections of live birds, and only 

 during the last few years have I been able to procure it. 



The birds have proved to be easy to breed, and I am now 

 able to give some details about their development. 



The number of eggs laid in one brood was generally 

 about seven, and they were deposited in a box hanging 

 over the water. 



The time of incubation lasts about 23 days. 



The chick in down is in so far remarkable that, contrary 

 to what is the case with most of the other Ducks, there is 

 no yellow in the coloration of the down. It is a mixture of 

 pearly white and blackish grey distributed as follows : — 



The whole of the under side including the sides of the head 

 and neck is pearly white or pure white. A blackish-grey band 

 runs from the frontal base of the bill, over the occiput and 

 the back of the neck and joins the blackish-grey upper side. 

 A nearly pure black streak runs through the eyes from the 

 base of the bill to the back of the head. The dark colour 

 of the upper side includes the tail and the back part of the 

 thighs. There is a whitish streak over each wing which runs 

 into a spot of the same colour on each side of the back. On 

 each side at the base of the tail there is a white spot, and 

 one above each thigh. Bill pale lead-colour. Legs and feet 

 greyish flesh-colour. 



In the first plumage the young females of Nettion tor- 

 quatum are like the adult females, although the different 

 markings are slightly less conspicuous. 



The young males in first plumage have a special plumage- 

 dress, which may be described as follows : — 



The upper part of the head- to below the eyes is of a rufous 

 grey-brown, the occiput being darkest. The back of the neck 

 is of the same colour, but lighter than the occiput. The 

 remaining parts of the upper side, including the scapulars. 



