58 SEXUAL SELECTION : BIRDS. [Pari II. 



the female. The soft cooing of the turtle-dove and of 

 many pigeons, it may be presumed, pleases the female. 

 When the female of the wild-turkey utters her call in 

 the morning, the male answers by a different note from 

 the gobbling noise whicli he makes, when with erected 

 feathers, rustling wings, and distended wattles, he puffs 

 and 'Struts before her. 48 The spel of the blackcock cer- 

 tainly serves as a call to the female, for it has been known 

 to" bring four or five females from a distance to a male 

 under confinement ; but, as the blackcock continues his 

 spel for hours during successive days, and in the case of 

 the capercailzie "with an agony of passion," we are led 

 to suppose that the females which are already present are 

 thus charmed. 49 The voice of the common rook is known 

 to alter during the breeding-season, and is therefore in 

 some way sexual. 60 But what shall we say about the 

 harsh screams of, for instance, some kinds of macaws ; 

 have these birds as bad taste for musical sounds as they 

 apparently have for color, judging by the inharmonious 

 contrast of their bright-yellow and blue plumage ? It is 

 indeed possible that the loud voices of many male birds 

 may be the result, without any advantage being thus 

 gained, of the inherited effects of the continued use of 

 their vocal organs, when they are excited by the strong 

 passions of love, jealousy, and rage ; but to this point we 

 shall recur when we treat of quadrupeds. 



We have as yet spoken only of the voice, but the 

 males of various birds practise, during their courtship, 

 what may be called instrumental music. Peacocks and 

 Birds of Paradise rattle their quills together, and the 



48 C. L. Bonaparte, quoted in the ' Naturalist Library : Birds,' voL 

 xiv. p. 126. 



49 L. Lloyd, ' The Game-Birds of Sweden,' etc., 186V, pp. 22, 81. 



50 Jenner, ' Philosoph. Transactions,' 1824, p. 20. 



