BRITISH WARBLEKS 



advantage. We should then have to regard them solely as 

 practice for the more serious side of life. But none of these 

 possibilities are fulfilled; the conflicts are not of the type 

 that would justify our relegating them to the category of 

 "play" in Professor Groos's sense of the word; they are no 

 less intense, though admittedly less frequent in occurrence, 

 than those which occur after the arrival of a female ; they bear 

 the impress of earnestness, and, if I interpret them aright, are 

 directly related to invasion of territory and thus become one 

 stage in a series of events^ which follow one another in orderly 

 sequence and make towards the goal of reproduction. In con- 

 sidering the determining influence of territory as opposed to 

 that of the female, can we attach any significance to a contest 

 between two females described in the life of the Whitethroat ? 

 Certainly not, if it were simply an accidental departure from 

 the normal routine of female activity. But further observa- 

 tions show that it was no mere isolated incident, though the 

 evidence is scarcely sufficient to admit of such behaviour 

 being spoken of as a general accompaniment of the sexual life 

 of birds. So long as the evidence seemed to show that a direct 

 appeal to strength was the special prerogative of maleness, so 

 long were we justified in regarding the possession of a female 

 as a possible incentive ; we now know however that male will 

 fight with male, female with female, pair with pair, and that 

 even male and female will combine to attack a single male or 

 a single female. Here then we have a complexity of strife 

 which is very difficult to explain if it be attributed primarily 

 to an impulse in the male to acquire a female ; and if it does 

 not spring from the securing and defence of a territory, I know 

 not in what direction to seek the real factor. 



The working of the whole theory of breeding territory 

 is explained in some detail in the earlier part of the life 

 of the Beed Warbler. I have there made some attempt to 

 show how by its assistance we can interpret, on the one hand, 

 the singular desertion of the females by the males in the race 

 to the breeding grounds, the equally singular banishment of 



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