NATURAL HISTORY OF SOUTH AFRICA 



also on poles out on the lands. The majority of the 

 many species of swallows and martins build nests of 

 mud, and unless there are muddy puddles in the near 

 neighbourhood, these must be provided. A shallow 

 dish of water and another of mud will fulfil all their 

 requirements if they are replenished as often as needful. 

 A shallow puddle of mud is the best. This can be kept 

 from drying up by fixing a water barrel or other 

 receptacle at the edge, and allowing the tap to drip. 



DESTRUCTIVE BIRDS 



Owing to the reduction of their natural enemies 

 and an abundant supply of insects, certain species of 

 granivorous and frugivorous birds breed and multiply 

 so rapidly that they constitute a serious menace to 

 the farmer. Those which are specially apt to increase 

 unduly are the Cape sparrow, weaver, bishop, and 

 widow birds. These are, with the exception of the 

 sparrows, popularly termed " vinks." They often 

 assemble in vast flocks and attack the ripening grain 

 in the fields and do serious damage. I have seen 

 large fields of wheat and millet completely destroyed 

 by them. In these instances it is necessary to consider- 

 ably reduce their numbers. Destroying their nestlings 

 has been strongly advocated and is often practised. 

 This is a wrong policy, because the birds at this period 

 are at the zenith of their usefulness. When the fields 



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