GARDEN WARBLER 



outlines become indistinct, and by a rapid sidelong motion 

 of the legs slides gracefully in the direction of the female, 

 uttering a quiet call-note meanwhile. Yet this manifestation, 

 surprising as it is, is not without a parallel in the lives of 

 other species, for both the House Sparrow and Blackbird 

 nutter their wings similarly at a corresponding period, and 

 the Pied Wagtail not only flutters its wings, but, with a 

 similarly rapid motion of its legs, seems to glide this way and 

 that around the female. 



After the arrival of a female in a territory, the owner is 

 usually to be found in close proximity to her. Not always, 

 however, for at one moment she wanders outside his accus- 

 tomed circle and at another he deserts her for a short space 

 of time. But, as a rule, they can be seen together, and their 

 companionship becomes more intimate after the actual con- 

 struction of the nest has commenced. The three principal 

 factors which evoke emotional response in the male during the 

 period of sexual activity are as follows : the presence of 

 a second male, the presence of an individual of either sex 

 of another species, and the sexual instinct. The first two 

 of these we will discuss later ; the third, the sexual instinct, is 

 doubtless indirectly responsible for the first two, but for the 

 moment we will confine ourselves to the manifestations of 

 it when the pairing situation is not complicated by the presence 

 of a third individual. Maximum activity is reached during or 

 just prior to the actual discharge of the sexual function. 

 A partial expansion and slight quivering of the wings and 

 a partial spreading of the tail on the part of the male can 

 frequently be seen, and often occurs when he is above the 

 female, high up perhaps in some tree while she is in the 

 bushes beneath, and is usually the prelude to a pursuit of or 

 a sporting with her. Or, instead of flying directly to her, he 

 may float slowly downwards on outspread wings, singing as 

 he flies. The rapid fluttering of the wings already referred 

 to is the most striking manifestation, and the intensity of this 

 action varies at different times but reaches its maximum 



