BRITISH WARBLERS 



that the males, in their great excitement, indulge in a medley 

 of imitations of the songs and call-notes of alien species ? 



The fact that birds with gorgeous plumage do not as a 

 rule possess any great powers of song, and, on the other hand, 

 that the best singers are as a rule dull-coloured, is regarded 

 as an indication of the reality of sexual selection, in so far as 

 it proves that the excitement of the female has been essen- 

 tially affected by only one of the characters of the male. 

 If this were a true interpretation of the facts, which are not 

 disputed, we should, by the same train of reasoning, expect 

 to find that the bodily and vocal antics have been mutually 

 exclusive, that the best singers do not, during their court- 

 ship, perform in a manner which could be interpreted as 

 a display of plumage. But we do not do so. The best 

 singers do perform in the most extravagant manner possible, 

 and this seems to me to lessen the importance that is 

 attached by the advocates of this theory to the mutual 

 exclusiveness of gorgeous colouring and beautiful song. 



The view I hold with regard to these extravagant bodily 

 antics is that they are reflex actions directly resulting from any 

 excessive excitement, that they are not confined solely to 

 courtship, and do not in any way influence the female. This 

 view, as I am inclined to believe, gains considerable support 

 from the fact that we find a parallel case in the vocal organs, 

 namely, that whenever the excitement reaches a certain 

 degree of intensity, no matter how different the stimulus 

 may be, the reactions that follow are always similar. 



If you watch a pair in the evening of the same day upon 

 which the mating has first taken place, you will notice a 

 remarkable change. The excitement has for the time passed 

 away ; never, in fact, to return in the same degree of intensity 

 until the following season. Instead of the restless pair that 

 were following one another about during the first hours of 

 daylight, you find a pair simply contented to remain in one 

 another's company. They are often close together, very close 

 sometimes, almost touching one another on the same branch, 



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