NATURAL HISTORY OF SOUTH AFRICA 



bite on man or beast for the good reasons that (i) they 

 are exceedingly timid and seldom attempt to bite ; and 

 (2) their venom fangs are set so far back in the jaw 

 that when they do bite with malicious intent, they 

 rarely succeed in driving their fangs home. This great 

 host of snakes preys on rats and mice. These rodents 

 are amongst man's worst enemies. They prey inces- 

 santly upon the products of his hands and his brain. 

 They rob him of a large percentage of his food. 

 They not only do this. They devour the eggs and 

 nestlings of birds, and attack and destroy adult birds 

 during the hours of darkness. In these ways they 

 largely contribute to the increase of noxious insect 

 life. There are, however, a few snakes in South 

 Africa which are inveterate enemies of bird life. 

 They are the mamba (Dendraspis angusticeps), egg- 

 eater (Dasypeltis scabrd), boomslang (Dispholidus 

 typus), and bird snake {Theltornis kirtlandii). The 

 egg-eater preys chiefly on the eggs and nestlings of 

 birds. The boomslang and bird snake feed not only 

 on the eggs and young, but on adult birds. In 

 addition, a favourite food of theirs is that most useful 

 of all lizards — the chameleon. This lizard feeds 

 exclusively on insects which it finds amidst the 

 foliage of trees and shrubs. 



If these snakes confined themselves only to those 

 species of birds such as the weaver, bishop, and widow 

 birds, not much, if any, harm would be done ; but 

 they feed indiscriminately on all the smaller species 

 of birds. 



The Nilotic monitor lizard (Varanus niloticus) robs 

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