434 Hawkins, Sexual Selection and Bird Song. [q£ 



the males select the mate with the best cluck or call for the pro- 

 tection of her brood? It would certainly be a theory far more in 

 harmony with nature's plans. But, while no person would proba- 

 bly have the courage to prove such a theory, it cannot be doubted 

 that the female has a language and that it is far more important 

 in the preservation of the race than the more modulated language 

 of the male. 



All of these facts must be taken into consideration before we can 

 adequately account for the song of birds. The sexual selection 

 theory is based too exclusively upon one period in the bird's life. 

 The bird has more than one season of song and there is no month 

 of the year when his voice does not play some part in his life. The 

 female has a language as well as the male. It must be evident that 

 any explanation which will be adequate to account for bird language 

 must cover every season and must be found in the inner life of the 

 bird rather than in outward circumstances or choices. 



Again there are certain types of sign language which are much 

 more universal among birds than has generally been assumed. 

 Much emphasis has been placed upon the displays and love dances 

 of pheasants and birds of paradise which, it has been assumed, was 

 the cause of the beautiful plumage of these birds. The female 

 choosing the best performer or the most highly colored male has 

 resulted through slight modification, generation after generation, 

 in these elaborate decorations. But we have, since Darwin, dis- 

 covered that the love dance or display is in some measure used 

 by many birds, often birds of dull color, like the English Sparrow, 

 and they are still, in spite of the love dance, dressed in gay or 

 sober plumage. Howard, in his remarkable ' History of the British 

 Warblers,' has shown "that these birds of sober hues perform 

 during moments of sexual exaltation, antics which in every way 

 reflect the display supposed to be peculiar to birds of brilliant 

 plumage." Savi's Warbler, also, indulges in these antics even 

 when feeding his young. Furthermore, these dances are not 

 confined to the period of courtship. 



From whatever point of view we approach this subject the 

 evidence is so strong that we are compelled to look for our explana- 

 tion in the internal life of the bird rather than in any external, 

 exciting cause. Most of the theories thus far set forth have in 



