Chap. XIII. DISPLAY BY THE MALE. 97 



certainly of the highest importance to tliem, for they 

 have been acquired in some cases at the expense of 

 greatly impeded powers of fli,2;ht or of running. The 

 African night-jar {Cosmetornis), which during the pair- 

 ing-season has one of its primary wdug-feathers deve- 

 loped into a streamer of extreme length, is thus much 

 retarded in its fiiglit, althougli at other times remark- 

 able for its swiftness. The " unwieldy size " of the 

 secondary wing-feathers of the male Argus pheasant 

 are said "almost entirely to deprive the bird of flight." 

 The fine plumes of male Birds of Paradise trouble them 

 during a high wind. The extremely long tail-feathers 

 of the male widow-birds (Vidua) of Southern Africa 

 render "their flight heavy;" but as soon as these are 

 cast off they fly as well as the females. As birds always 

 breed when food is abundant, the males probably do 

 not suffer much inconvenience in searching for food 

 from their impeded powers of movement ; but there can 

 hardly be a doubt that they must be much more liable 

 to be struck down by birds of prey. Nor can we doubt 

 that the long train of the peacock and the long tail 

 and wing-feathers of the Argus pheasant must render 

 them a more easy prey to any prowling tiger-cat than 

 would otherwise be the case. Even the bright colours 

 of many male birds cannot fail to make them conspi- 

 cuous to their enemies of all kinds. Hence it probably 

 is, as Mr. Gould has remarked, that such birds are 

 generally of a shy disposition, as if conscious that their 

 beauty was a source of danger, and are much more diffi- 

 cult to discover or approach, than the sombre-coloured 

 and comparatively tame females, or than the young 

 and as vet unadorned males.^^ 



s^ On the Cosmetornis, see Livingstone's ' Expedition to the Zam- 

 besi,' 1865, p. QQ. On the Argus piieasanr, Jardinc's ' Nat. Hist. T>ib. : 



VOL. II. H 



