302 PET BIRDS OF BENGAL 



according to Cunningham, with their para- 

 sitic tendency. Says he, *'The possession 

 by the male cuckoo of an insistent and 

 distracting call is not enough to give the 

 female such a good chance of doing her 

 part, as it will where she has to deal with 

 birds of lower mental and physical power ; 

 and it has accordingly been reinforced by 

 the evolution of differences in plumage, 

 serving to render the one sex very cons- 

 picuous, and the other protectively obs- 

 cure. The shining black plumage and 

 bright red eyes of the male Koel are 

 specially adapted to attract attention in 

 the sites he chooses to call from, while 

 the subdued greenish- grey tints and white 

 spots and bars of the feathering of the 

 female serve to make her almost invisible 

 among the broken lights and shades of 

 the coverts in which she lurks when await- 

 ing a chance for depositing her eggs". 



If this sort of 'adaptive' coloration be 

 true of the Koel, it is not true of the 

 common Hawk-cuckoo — our Papiya, {Hiero- 



