196 BIRD BEHAVIOUR 



Cuckoo, and I have in Calcutta seen tame Guinea- 

 Fowls and wild Crows distinctly impressed and 

 apparently alarmed by one of these young birds 

 which came into my possession, just as in the Zoo 

 the keepers find that their small birds from many 

 countries kept in the West Aviary are frightened 

 if a common Cuckoo is introduced to them. 



A fairly good general resemblance is therefore 

 sufficient to impress birds, but the point of it 

 seems to be wanting. If the Hawk-like appear- 

 ance of certain Cuckoos scares the fated fosterers 

 from their nest, what end is served by the Hawk- 

 like appearance of the fostered young ? Besides, 

 many parasitic Cuckoos are not like Hawks, or 

 resemble Hawks found in a different country. 

 Thus, the large New Zealand Cuckoo, as noted by 

 BuUer, is extremely hke an American Hawk {Acci- 

 fiter cooferi), but does not so closely resemble 

 any native Hawk ; and the same Babblers which 

 foster the Brain-fever-bird also rear, as has been 

 said, the pied Crested Cuckoo which, with its 

 crested head and plumage black above and white 

 below, is like no Indian Hawk. Neither is any 

 Hawk anywhere like the splendid Emerald, Bronze, 

 and Violet Cuckoos, for adult Hawks and other birds 

 of prey, like the downy yoUng birds we have been 

 considering, follow mammalian rules of colour, and 

 eschew brilliant tints except on bare parts. 



Some even of the non-parasitic Cuckoos may 

 have a rather Hawk-like coloration, like the large 

 fruit-eating Cuckoo, C<arfocov£yx radiatus, of the 



