BRITISH WARBLERS 



of active hostility. This is the most interesting phase of 

 emotional reaction which I have witnessed, but then I am 

 ignorant of what takes place when their behaviour is 

 dominated by the sexual or parental instinct. It may be that 

 the reactions are similar at different emotional periods, or it 

 may be that the expansion of one wing is a particular expres- 

 sion of the emotion which corresponds to the instinct of 

 pugnacity, and if this is so it is the most remarkable of all 

 the manifestations that I have yet observed in bird life. 



A feature of the bird's behaviour which arrested my atten- 

 tion was the general resemblance that some of its movements 

 and some of its notes bear to those of the Whitethroat ; the 

 call-note especially is remarkably alike in the two species, but 

 there is a difference which can readily be detected though 

 with difficulty put into words. At times the song resembles 

 that of the Stonechat almost as much as that of the White- 

 throat, but the quiet warbling during periods of emotion 

 might easily be mistaken for the warbling of the Whitethroat 

 at a corresponding period. The resemblance in the behaviour 

 of the two species is most marked in the aerial flight or dance. 

 The Dartford Warbler springs up into the air whilst singing 

 and remains poised as if suspended upon wires, and a similar 

 performance is a strong characteristic of Whitethroat 

 behaviour. But the position of the Dartford Warbler whilst 

 in the air is somewhat different from that assumed by the 

 Whitethroat ; it is more horizontal and the wings are more 

 fully expanded. 



Much of their time is occupied in searching for food, 

 principally amongst the heather, where for long periods they 

 are hidden from view. They are by no means shy and it is 

 possible to approach them closely at all times, whether they 

 are slowly wending their way amongst the heather, or washing 

 themselves in convenient pools of water, or singing, or even 

 when their movements are restless and their behaviour highly 

 emotional. 



