EVOLUTION OF BIRD- SONG 



That the habit of singing is sometimes quite inde- 

 pendent of love is clear, for a sterile hybrid canary- 

 bird has been described as singing whilst viewing 

 itself in a mirror, and as then dashing at its own 

 image ; it likewise attacked with fury a female canary 

 when put into the same cage. The jealousy excited 

 by the act of singing is constantly taken advantage of 

 by bird-catchers : a male, in good song, is hidden 

 and protected, whilst a stuffed bird surrounded by 

 limed twigs is exposed to view. In this manner, as 

 Mr. Weir informs me, a man has in the course of a 

 single day caught fifty, and in one instance seventy, 

 male chaffinches. That male birds should sing from 

 emulation as well as for charming the female is not 

 at all incompatible ; and it might have been ex- 

 pected that these two habits would have concurred, 

 like those of display and pugnacity. Some authors, 

 however, argue that the song of the male cannot 

 serve to charm the female, because the females of 

 some few species, such as the canary, robin, lark, 

 and bullfinch, especially in a state of widowhood, as 

 Bechstein remarks, pour forth melodious strains." 



It may be presumed that these latter individuals 

 were caged birds, having abundant leisure and plenty 

 of food, incidents the effects of which I shall venture 

 to discuss in subsequent pages. Darwin continues : 



