GARDEN WARBLER 



quickly in their wake that it is seldom we find two or three 

 adjoining territories occupied by single individuals ; a female 

 is generally present in one of them, and her presence seems to 

 stimulate the sexual instinct of all the males in the immediate 

 vicinity, and to render the corresponding emotion of pugnacity 

 proportionately active. It is, moreover, by no means easy to 

 discover the female when the foliage is well advanced, a fact 

 which adds to the difficulty of obtaining reliable information. 

 I have, however, noticed some males fighting early in the 

 season when there was no reason to suspect the presence of 

 a female. Quarrels become of frequent occurrence when a 

 fair proportion of the males have arrived and taken possession 

 of adjoining territories, and such quarrels are more frequent 

 on the boundaries than in the centre of a territory. Since 

 the migration of the females is spread over some considerable 

 time, it often happens that one of two males with territories 

 adjoining obtains a female some few days before his neighbour, 

 and this results in much disturbance. The female wanders 

 about the territory in which she has settled, but does not 

 confine herself so strictly to the limits as her mate ; when 

 therefore she intrudes upon a neighbouring preserve and is 

 followed by her mate, considerable excitement ensues. The 

 male, whose territory is invaded, flies towards the intruder, 

 spreads his tail, raises the feathers of his body, and gives vent 

 to his feelings by uttering his song or harsh alarm note, 

 which is sometimes sufficient to make the intruder beat a 

 retreat, but if it does not do so, the disturbance is liable 

 to be continued, and the excitement may even become so 

 acute as to cause a commotion in the bird life of the surround- 

 ing district. The owner then follows the intruder, and con- 

 flicts occur in which there is much fluttering of wings and 

 snapping of bills. One of the most interesting features of 

 the accompanying behaviour is the- passionate utterance 

 of the song. The usual song of the species is an even flowing- 

 warble, but on occasions such as I am describing it is more 

 suffused with feeling tone, and may even deteriorate into 



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