FIGHTING IN NATURE 235 



The only other things over which fighting is likely to 

 arise are food and nesting sites. 



It frequently happens that birds of different species 

 want the same food. But this rarely leads to anything 

 in the nature of a battle. In such contests the weaker 

 almost invariably gives way to the stronger without any 

 fighting. 



A familiar instance of this is afforded by the 

 behaviour of the white-backed (Pseudogyps bengal- 

 ensis) and the black vultures (Otogyps calvus) when 

 they gather round a carcase. 



Jesse writes, and my experience bears out what he 

 says : " Often I have been watching the vulgar white- 

 backed herd, with a disreputable following of kites 

 and crows, teasing and fighting over a body, when 

 one of these aristocrats (i.e. Otogyps calvus), in his red 

 cap and white waistcoat, has made his appearance. 

 Way is immediately made for him, the plebeian herd 

 slinking back as if ashamed or afraid, and I cannot 

 remember the last comer ever being obliged to assert 

 his authority." 



If the smaller vultures, which are the more numer- 

 ous, chose to combine, they could drive off the black 

 vultures, but in doing this some of them would run 

 the risk of sustaining injuries. Now, it seems to be 

 a rule in nature that no creature will willingly run 

 such a risk. Rather than do this an animal will flee 

 before a comparatively puny adversary. 



The instinct of self-preservation, which includes the 

 preservation of the body from injury, is strongly 

 developed in all organisms. Natural selection tends 



