1920.] South African Accipitres. 435 



as I have examined several specimens which are evidently 

 young- or immature, in my opinion, all of which have 

 pure white tarsi. On the other hand, I have examined 

 several others which I consider are fully adult, and 

 which have streaked tarsal feathers. The only certain 

 sign that I have found which indicates immaturity is that 

 in all examples of what I consider to be young- birds, the 

 white bases of the outer webs of the piiinai'ies are more or 

 less barred and freckled with brown, whereas in adults these 

 feathers are uniform white at the base. I am also of the 

 opinion that the youngest liii-ds are palest in colour, and 

 tliat as they grow older tiie [)lumage becomes darker. 

 There are two s[)ecimens of this sjiecies in the Transvaal 

 ]\ruseum, one from Rhodesia and the other from German 

 East Africa, which are remarkably dark in colouring, 

 almost black in fact, with the back of the neck, which is 

 usually of a lighter colour, as dark as the rest of the 

 plumage; they also have the tarsi streaked with dark brown. 

 These I take to be fully adult and pi'obably very old birds. 

 I have a painting of a similar specimen, shot by mvself 

 in eastern Pondoland some years ago. 



33. Nisaetus bellicosus (Daud.). Martial Hawk-Eagle. 



My experience of this Eagle is very small. It appeared 

 to be a rare species in every district where I have collected. 

 I saw the skin oC an immature bird in eastern Pondoland, 

 which was shot in the act ot" attacking a young pig ; and 

 in the South-West Protectorate a few specimens, one 

 of which made a very determined stoop at a Francolin 

 I had put up. However, it did not succeed, as the bird 

 dropped like a stone into some long grass. This species 

 must be fairly numerous in the King William's Town 

 district, as I saw a number of specimens in the Museum 

 at that place which had been collected there. Th'ese were 

 principally young birds. 



1 have not had an opportunity of examining a sufficient 

 number of individuals to enable me to discuss the plumage- 

 cluiuges, but from what I have seen I should think that 



SEU. XI. VOL. II. 2 G 



