IN SCOTLAND 171 



but he also sometimes calls in flight, especially 

 when pursuing the female. 



When flying, the cuckoo strongly resembles 

 our smaller birds of prey. The slate-coloured 

 upper parts with the strongly barred light- 

 coloured lower parts, the long wings and tail 

 and well-feathered legs of the bird in its more 

 ordinary plumage, are markedly suggestive of 

 the sparrow-hawk. The younger females, how- 

 ever, are often very differently coloured, the 

 slate and ash colour being replaced by a more 

 or less rufous brown, and this again gives them 

 a striking resemblance to the kestrel. This 

 rufous plumage frequently persists even after 

 the first and subsequent moults, so that earlier 

 observers were inclined to suspect a specific 

 difference, and named it C. hepaticus ; but further 

 investigation proved this to be erroneous. This 

 resemblance to our lesser birds of prey appears 

 to be sufficient to deceive the little birds of 

 various sorts that may often be seen following 

 and mobbing the cuckoo, as if taking it for one 

 of their natural enemies. 



The male cuckoo, on arrival at its chosen 

 summer quarters, selects for himself a certain 

 locality or district, which it defends strenuously 

 against all comers of his own sex. The females, 

 which are said to be proportionately much fewer 



