THE INFLUENCE OF COMBAT 37 



There is, however, much better evidence that 

 defiance influences the vocal utterances of certain 

 birds. 



The cock does not crow when calling a hen 

 towards him, but invariably crows when he has de- 

 feated an adversary, and generally before combat. 

 The males of the American pinnated grouse (Tetrao 

 cupido] utter a " cackling, screaming, and discordant 

 cry when fighting at their scratching places, where 

 they meet at break of day" (Wilson, Amer. Ornith., 

 vol. ii. p. 399). The kingbird (Tyrannus Carolinensis] 

 twitters when attacking the eagle (Wilson, op. cit. 

 vol. i. p. 2 1 8). Of the snow-bunting, Saxby stated, 

 "They chirp as they fly, and the sudden jarring 

 sound is heard which is uttered by the bird when 

 suddenly directing its course towards a neighbour. 

 That the note in question is sometimes one of 

 anger I have repeatedly observed, when two of 

 the birds have been quarrelling over their food " 

 (Birds of Shetland, p. 91). I have often observed that 

 in early spring yellow buntings and larks utter a 

 kind of chattering song when they contest among 

 themselves the possession of favourite spots. These 

 birds are then appropriating situations for nesting, 

 and are seeking mates. Twice I have heard 

 chaffinches cry pink pink, and that cry only 



