ALARM-NOTES 23 



sudden appearance of a little rough terrier, was 

 uttering loud simple screams ; the others hurried to 

 the spot and joined in a chorus of alarms. 



When a bird is greatly excited by fear, either for 

 its own safety or on account of its young, and 

 generally when other birds are near, it usually 

 utters its common alarm-cry many times in succes- 

 sion. In some species certain alarm-cries consist of 

 a rapid repetition of a single note (the alarms of the 

 mistle- thrush and magpie are examples), and in 

 other birds they are single cries repeated at 

 intervals, as in the nightingale, chiffchaff, chaffinch, 

 and crow. But sometimes a bird with a single 

 alarm-note will repeat this cry so many times in 

 rapid succession that a kind of exclamation is pro- 

 duced of the same character as the set or arbitrary 

 alarms of the mistle-thrush and magpie. 



Thus, I have heard a nightjar utter its sharp, 

 clicking alarm at first slowly, then more and more 

 rapidly, until the notes became blended into one 

 rattling cry. I have twice heard a magpie similarly 

 utter short cahs, and rapidly increase their number, 

 slightly changing their tone, until the common 

 shushiishushu alarm-cry was rendered in its accus- 

 tomed style. On several occasions I have also 

 heard a male house - sparrow begin his continuous 



