BIOLOGICAL VALUE OF THE WARFARE 243 



it provided an adequate supply of food in the 

 vicinity of the nest, and thus obviated the 

 necessity of the parents being absent from them 

 for long. But manifestly no matter how active 

 a male may be in driving away members of 

 its own sex and kind, it will neither make 

 its position secure, nor insure a supply of food 

 for its young, so long as any number of 

 individuals of different kinds are allowed to 

 establish themselves in the same space of 

 ground. On the one hand, then, we have the 

 fact that there is constant strife between males 

 of close affinity, whilst on the other, we know 

 that many species require like conditions of 

 existence- and are bound to assemble wherever 

 these conditions are suitable ; and we can infer 

 that the territory would fail to serve its purpose 

 if no restriction were imposed upon the measure 

 of such assemblies. 



The question then arises : Does all this 

 warfare contribute towards the attainment of 

 reproduction ? Not far from my house there is 

 a small water meadow, three acres in extent, 

 which for some years has been derelict and is 

 now overgrown with the common rush {J uncus 

 communis) and small alder trees. For three 

 successive seasons I watched the bird life of this 

 meadow, and more especially the Reed-Buntings 

 whose behaviour I was studying at the time. 

 In every respect the meadow was suitable for 

 this bird ; there was an abundance of food and 

 numberless situations in which nests could be 

 placed. Each year all the pairs were successful 



