FIGHTING CONTROLLED 91 



think that the close relationship between the 

 warfare on the one hand and the territory on the 

 other will be fully admitted. 



Formerly I deemed the spring rivalry to 

 be the result of accidental encounters, and I 

 believed that an issue to a struggle was only 

 reached when one of the combatants succumbed 

 or disappeared from the locality, a view which 

 neither recognised method nor admitted control. 

 Recent experience has shown, however, that I 

 was wrong, and that there is a very definite 

 control over and above that which is supplied by 

 the physical capabilities of the birds. 



Let us take some common species, the 

 Willow- Warbler being our first example ; and, 

 having found three adjoining territories occupied 

 by unpaired males, let us study the conflicts 

 at each stage in the sexual life of the three 

 individuals, observing them before females have 

 arrived upon the scene, again when one or two 

 of the three males have secured mates, and yet 

 again when all three have paired. Now we 

 shall find that the conditions which lead up 

 to and which terminate the conflicts are remark- 

 ably alike at each of these periods. A male 

 intrudes, and the intrusion evokes an immediate 

 display of irritation on the part of the owner 

 of the territory, who, rapidly uttering its song 

 and jerking its wings, begins hostilities. Flying 

 towards the intruder, it attacks viciously, and 

 there follows much fluttering of wings and 

 snapping or clicking of bills. At one moment 

 the birds are in the tree-tops, at another in the 



