A BIRD OF THE OPEN PLAIN 205 



to its fellow-creatures. However, there are a number 

 of nocturnal mammals, such as our Indian ratel 

 [Mellivora indica), of which the fur is light-coloured 

 above and dark below^ These cannot be examples 

 of warning colouration. The same must be said of 

 the inoffensive little finch-lark, with its dark under 

 parts. 



The fact that there exist so few creatures of which 

 the under parts are of darker hue than the upper 

 parts must, I think, be attributed to two causes. The 

 first is that few species ever vary in that manner ; the 

 tendency is all the other way. The second is that such 

 rare variations, when they do occur, are in most cases 

 not conducive to the welfare of the individual, since 

 they tend to make it conspicuous to its foes or its 

 quarry. In certain cases, however, as in that of crea- 

 tures like the shunk, which are not preyed upon, or that 

 of nocturnal animals, the possession of dark under 

 parts does not affect the chances of the possessor in 

 the struggle for existence. So this variation has not 

 been eliminated by natural selection. This, I believe, 

 is the case with the finch-lark. The bird has very 

 short legs, so that when it is on the ground its black 

 under parts are scarcely visible even to a human being 

 walking on the ground, and certainly would not be seen 

 by a bird of prey flying overhead. My experience is 

 that the cock finch-lark is not more conspicuous than 

 the hen. Both, when they alight on a ploughed field, 

 are lost to human sight until they move. 



I believe finch-larks feed exclusively on the ground. 

 I have not seen one perch in a tree. What they hve 



