THE INFLUENCE OF COMBAT 39 



series, 1834, p. 252), and he recorded that a 

 blackbird, after beating a cat away from its young, 

 celebrated the victory with a song {torn, cit, p. 

 248). The hedge-accentor twitters when fighting. 

 I have often observed chiffchaffs and willow-wrens, 

 and occasionally goldcrests, singing while fighting. 

 In spring brown wrens challenge each other in 

 song. In The Zoologist for 1869 (p. 1645) is an 

 account of brown wrens which were fighting, and 

 after being separated three times, " sounded notes of 

 battle and began to fight again." I have twice 

 similarly separated fighting wrens, and on each occa- 

 sion the victor immediately began to sing, and in 

 his song omitted to utter the coarse call -note, 

 which is generally included. 



Darwin says, " Rival males try to excel and 

 challenge each other by their voices, and this leads 

 to daily contests. . . . Thus the use of the voice 

 will have become associated with the emotion of 

 anger" {Expression of the Emotions^ p. 85). It 

 is possible that rivalry may sometimes induce 

 definite defiance, as in autumn it appears to do in 

 robins, which, after singing near each other, approach 

 and fight. Some observers seem to have been of 

 this opinion, for Darwin states, " Many naturalists 

 believe that the singing of birds is almost ex- 



