120 ANSEKES SARCIDIORNIS 



Description. Adult Male. Head, neck all round and whole of 

 the under surface white, except the sides and flanks, which are 

 greyish; the sides of head and neck with metallic purplish spots 

 which on the top of the head and along the nape coalesce and form 

 a black band ; the feathers along this region erect and curly ; upper 

 surface of the body black, glossed with purple, green and coppery 

 metallic sheen on the scapulars, wing coverts and tail ; a whitish 

 patch in the centre of the back. According to Bohm the male, 

 during the breeding season, has a bunch of orange yellow feathers 

 on the sides of the lower abdomen. 



Iris dark brown ; bill, on which is an erect compressed semi- 

 circular elevation, black ; legs dark plumbeous. 



FIG. 35. Head of Sarcidiornis melanonota, <? . x 1 



Length about 31-0 ; wing 14-5 ; tail 6-0 ; culmen 3-0 ; tarsus 

 2-25. Excrescence on the bill, length along base 2-0, height 1-75, 

 present in the breeding season, inconspicuous at other times of the 

 year. 



The female is like the male but smaller ; the head and neck is 

 more spotted and there is less metallic gloss ; the excrescence on the 

 bill is absent ; wing 11-0 to 11-5. The young bird is like the female 

 but without any metallic gloss. 



Distribution. The Knob-billed Duck is found in India, including 

 Ceylon and Burma, and also throughout Africa from Gambia and 

 Khartoum southwards, as well as in Madagascar. 



Its headquarters in South Africa are in Bechuanaland about 

 Lake Ngami and the Upper Zambesi, where it appears to be fairly 



