lio How to Sex Cage Birds. 



and irregular black bars, and passing into yellowish-red underneath 

 and into sulphur-yellow on the inner margins of the feathers." 

 (Salvadori, Catalogue of Birds, vol. xx. p. 110). 



Western Black Cockatoo (Calyptorhynchus stellatus). 



Count Salvadori does not describe the sexes of this species ; 

 indeed, he tells us that the Museum specimens "are few in number, 

 without having locality or sex marked," but as it appears chiefly to 

 differ from C. macrorhynchus in the character of its beak and crest, 

 and the female of that species is said to differ from C. bank-si in 

 having "the coloured part of the tail mingled yellow and scarlet," 

 we have a guide by which to recognise the sexes. 



Ganga Cockatoo (Callocephalon galeatum). 



The female differs from the male in having "the crest grey; the 

 quills and the tail-feathers with light grey bars ; the feathers of the 

 under surface are margined with sulphur-yellow and dull red ; the 

 under tail-coverts have dull yellow bars" (Salvadori; cf Gould, 

 Handbook of Birds of Australia, ii. p. 30, 1865). 



We now come to the White Cockatoos, which are not so easily sexed, 

 but the hens are generally slightly smaller than the cocks, have paler 

 eyes, and a shorter beak, narrower at its base. 



Greater Sulphur-crested Cockatoo (Cacatua galerita). 



The female is smaller than the male. Her beak is also shorter, 

 and has a shorter terminal hook. 



Triton Cockatoo (Cacatua iriton). 



The female is smaller than the male. Her beak is smaller, 

 narrower when viewed in profile, with a slightly shorter terminal 



hook. 



Lesser Sulphur-crested Cockatoo (Cacatua sulphurea) 



The female is slightly smaller than the male, with a rather shorter 

 and narrower beak (viewed from above), and a shorter terminal 

 hook. 



Citron-crested Cockatoo (Cacatua citrinocrislata). 



Only one female sexed, but the sexual differences would probably 

 be much the same as in the preceding species. 



Leadbeater's Cockatoo (Cacatua leadbeateri). 



The male is larger than the female, and has a more finely-formed 

 beak, in which the upper mandible is much narrower, and has a 

 longer terminal hook. 



Greater Wiiite-crested Cockatoo (Cacatua alba). 



In the female the culmen of the beak is much narrower than in 

 the male, and less arched ; the terminal hook, viewed in profile, is 

 seen to be narrower towards its base. 



