CHAPTER II 



THE DISPOSITION TO SECURE A TERRITORY 



Those who have studied bird life throughout 

 the year are aware that the distribution of 

 individuals changes with the changing seasons. 

 During autumn and winter, food is not so 

 plentiful and can only be found in certain places, 

 and so, partly by force of circumstances and 

 partly on account of the gregarious instinct 

 which then comes into functional activity, 

 different individuals are drawn together and 

 form flocks of greater or less dimensions, which 

 come and go according to the prevailing climatic 

 conditions. But with the advent of spring a 

 change comes over the scene : flocks disperse, 

 family parties break up, summer migrants begin 

 to arrive, and the hedgerows and plantations are 

 suddenly quickened into life. The silence of 

 the winter is broken by an outburst of song 

 from the throats of many different species, and 

 individuals appear in their old haunts and vie 

 with one another in advertising their presence 

 by the aid of whatever vocal powers they 

 happen to possess — the Woodpecker utters its 

 monotonous call from the accustomed oak ; the 



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