THE EUROPEAN CUCKOO 257 



dense fur. This diet is an inherited rather than an acquired taste, which 

 develops once the cuckoo has left the care of its foster-parents — no 

 matter what form of food it has previously received from them. 



When the cuckoo returns from its winter quarters in Africa, the 

 female selects a territory for herself, preferably in rather open country. 

 Sometimes she returns to the same area several years running. In the 

 case of the European cuckoo the territory is a few acres in extent, but 

 in some African species such as the small golden cuckoo [Lampromorpha 

 caprius), which victimises colonial-nesting weavers, it may be restricted 

 to one tree. She defends this territory against all other female cuckoos 

 parasitising the same fosterer as herself Although successful invasions 

 sometimes occur it is unusual to find two female cuckoos in the same 

 area laying in the nests of the same species of small bird. Individuals 

 parasitising other hosts are tolerated. Occasionally a young bird which 

 has failed to establish a territory of her own will roam across country, 

 laying at random in any available nest she can find. 



The male cuckoo also establishes a territory, but in the case of the 

 British species it rarely coincides with the territory of any particular 

 female. He favours wooded areas or the edge of small copses rather 

 than open country. The cuckoo's relations with the opposite sex are 

 distinctly casual and very promiscuous. Sometimes numerous males 

 gather when they hear a female's amorous bubbhng and she may 

 copulate with one, two, or all of them. At other times one particular 

 male may seek her out persistently and thus give the impression that 

 they are permanently paired. Again, a male bird may haunt several 

 adjacent territories, bestowing his favours freely on all the female 

 owners. 



The female cuckoo hunts systematically for the nests of her victims, 

 which are generally small passerine birds— chiefly those which feed on 

 insects. Quite often though, the linnet, which is a seed eater, is chosen. 

 When she locates a pair building she begins a careful and prolonged 

 vigil, observing the behaviour and movements of the future fosterers 

 from a point of vantage and sometimes gliding down to examine the 

 nest at close quarters. The visual stimulus thus received appears to 

 excite ovulation and the cuckoo's egg reaches maturity and is ready for 

 laying about five days later, in fact shortly after the fosterers have them- 

 selves begun to lay. 



Most birds deposit their eggs early in the morning, but the cuckoo 

 does so in the early afternoon, a period at which the parent birds — 



