CiiAP. XIV. SEXUAL SELECTION : BIEDS. : , .99i i^*^ 



CHAPTEE XIV. 



Birds — continued. 



Choice exerted by the female — Length of courtship — Unpaired 

 birds — Mental qualities and taste for the beautiful — Preference 

 or antipathy shewn by the female for particular males — Vari- 

 ability of birds — Variations sometimes abrupt — Laws of varia- 

 tion — Formation of ocelli — Gradations of character — Case of 

 Peacock, Argus pheasant, and Urosticte. 



When the sexes differ in beauty, in tlie power of 

 singing, or in producing what I have called instru- 

 mental music, it is almost invariably the male which 

 excels the female. These qualities, as we have just 

 seen, are evidently of high importance to the male. 

 When they are gained for only a part of the year, this 

 is always shortly before tlie breeding-season. • It is the 

 male alone who elaborately displays his varied attrac- 

 tions, and often performs strange antics on the ground 

 or in the air, in the presence of the female. Each 

 male drives away or, if he can, kills all his rivals. 

 Hence we may conclude, that it is the object of the 

 male to induce tlie female to pair with him, and for 

 this purpose he tries to excite or charm her in various 

 ways ; and this is the opinion of all those who have 

 carefully studied the habits of living birds. But there 

 remains a question which has an all important bearing 

 on sexual selection, namely, does every male of the 

 same species equally excite and attract the female ? or 

 does she exert a choice, and prefer certain males ? This 

 question can be answered in the affirmative by much 



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