NATURAL HISTORY OF SOUTH AFRICA 



for instance, which involves the death of four to six 

 nestling birds, means the increase of a minimum of 

 30,000 caterpillars and grubs within six weeks. These 

 caterpillars soon reach the adult condition, change into 

 chrysalides, and emerge as moths, butterflies, and 

 beetles. Each of the females lays thousands of eggs, 

 which bring forth a vast and destructive army of 

 larvae, and from the 30,000 caterpillars and grubs 

 there will arise within a few short months an un- 

 countable host. All because of the thoughtless or 

 wanton destruction of a pair of breeding insectivorous 

 birds. 



Many years ago the English press gave colour 

 to the erroneous and stupid belief that owls were 

 birds of evil omen, and that they were destroyers of 

 chickens and useful birds. Some of the farmers, 

 believing these false statements, mercilessly persecuted 

 the owls, and the survivors retreated to the wilds. 

 The following season loud and bitter were the com- 

 plaints about the damage done to the crops and young 

 poultry by rats and mice. The second season proved 

 still worse, and many a farmer was ruined. 



There has been much controversy as to whether 

 the English sparrow (Passer domestkus) does more harm 

 than good. The chief indictment is that it eats the 

 buds of fruit trees, with a consequent serious diminution 

 of the subsequent crop. There is no doubt at all when 

 this species of bird increases abnormally in numbers 

 it does become a pest, as is the case with some of the 

 South African seed-eating birds, whose ranks have to 

 be thinned when their attacks assume formidable 



16 



