BRITISH WARBLERS 



time to time have been suggested by those who have given 

 thought to the problem. Now this theory in all its inter- 

 pretations has but one end in view, namely, that the fitter 

 individuals shall attain to reproduction ; and inasmuch as the 

 struggle for territory makes towards a similar goal, it is a 

 matter of some difficulty to assign a place to both in the 

 drama of bird life. Therefore when discussing the theory 

 of breeding territory in the life of the Eeed Warbler, I gave 

 my reasons for attributing to those battles, which precede 

 reproduction, the elimination of the weaker individuals. 

 Frequent, however, as these struggles are, much as they 

 appeal to our imagination, yet there is no gainsaying the fact 

 that in each season a proportion of both males and females 

 will escape the necessity for a struggle; and just in so far 

 as the unfit elude its meshes the sieve may be said to be 

 imperfect in operation. Here the advocates of an emotional 

 test will doubtless take their stand; a second ordeal, they 

 will say, must be all to the good, ensuring, as it will, a more 

 complete elimination of the unfit. This second test must be 

 complementary, not antagonistic to the first, otherwise the 

 securing of a territory will ensure nothing ; it must operate 

 not on those wanderers with no settled home, nor on the 

 victims of many struggles, but on the weaker members who 

 without being challenged have become possessed of territories 

 and thus undeservedly qualified to propagate their kind. If 

 this be really true, it is manifest that each season there must 

 be a certain proportion of males who, though possessing 

 territories, are nevertheless doomed to remain without a mate. 

 My experience does not bear this out. No single instance 

 of a male possessing a territory and yet failing to attain 

 to reproduction has ever come to my knowledge ; and of all 

 the objections to a second test, this is perhaps the most serious. 

 We must therefore wait before unreservedly accepting it, 

 until we are in possession of a body of observations serving 

 to show that the securing of a territory does not suffice 

 to ensure the attainment of reproduction ; and such observa- 



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