VII Wizard Cuckoos 



As spring advances, the voice of the cuckoo pene- 

 trates further and further to northward, until even 

 the wind-beaten Shetlands have heard its signal. 

 Possibly it is owing to the cuckoo's habit of shirking 

 the duties of parentage that it is able to extend 

 its wanderings so far afield in the brief northern 

 summer. It begins to return to the south before 

 the diminution of its insect diet in the shortening 

 August days threatens it with a failure of supplies ; 

 and the young which it leaves behind for several 

 weeks longer are safeguarded by being nursed, for 

 their first British summer, on the special food of 

 infancy proper to young birds of various other 

 kinds. 



Old cuckoos, however, live largely on the hairy 

 caterpillars which few other birds will eat ; and 

 their main body arrives in the south of England 

 about the end of the second week in April. This 

 is the average date when the caterpillars awake 

 from hibernation and resume their pasturage, which 

 has been interrupted by seven or eight months' 

 torpor. In most years it is also just the time when 

 the grass begins to shoot luxuriantly, covering the 

 meadows and hedge-banks with a new and vivid 

 growth. The caterpillars feed on the grass, and 

 the cuckoos on the caterpillars ; and grass and 



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