54 BIRD BEHAVIOUR 



Australian region, where these otherwise universally 

 distributed birds are absent. 



The chief grub-eaters are the Black Cockatoos 

 (Calyftorhynehus) of Australia and the curious New 

 Zealand Pasrots known as Kakas (Nestor) ; ibut the 

 habit is probably commoner than is supposed, since 

 most (Parrots in captivity evince a liking for animal 

 '-^d, although too much of this is bad for them, 

 often causing a skin-tirritatton and the adoption of 

 the feather-plucking habit. This, however, has 

 probably more to do with the want of exercise. 



It seems improbable that ithe fParrots should have 

 devdoped their extraordinary deep-curved bill, 

 unique among vertebrates in its hinged upper jaw 

 :and extreme biting power, merely to feed on seeds 

 rand fsuit, and it is noteworthy that the Parrot 

 iwhich has the least typical beak, Pesquet's Parrot 

 of New Guinea {Dasyptilus fesqueti), in which the 

 (Upper jaw at any rate is more like an Eaglets than 

 a Parrot's, tears at its food of fruit like a carnivorous 

 bird at flesh, and also has less Parrot-ilike movements 

 than the rest of 'its tribe, Ihopping iioxa. bough to 

 bough with affiioking actionof the wings-^evidently 

 it has notiuUy attained the Parrot specialization in 

 form or action, and corresponds among the Parrots 

 to 'the Magpie-Goose among -the Ducks. 



The White Cockatoos, which are generally 



,gifOuad-f eedera, use itheir ibills much in digging up 



bulbs and fthe e^g-caaes of locusts ; in the tLong- 



nosed Cockatoos (^Licmetis), which are (especially 



addicted tto s. idiet of roots, :the upper bill is jxai- 



