NATURAL HISTORY OF SOUTH AFRICA 



When this strenuous and all-important business is 

 over, they moult and migrate to distant countries, 

 retire to winter quarters, or go to other parts of the 

 country where food is most plentiful at this season 

 of the year. Some species live in the same environ- 

 ment throughout the year. Birds always select 

 localities for nest building where food 

 is plentiful. The time chosen for 

 rearing the young will always coincide 

 with the time the favourite food is at 

 its greatest abundance. During the 

 spring and early summer the trees 

 are putting on foliage, grass and 

 other plant life is growing rapidly, 

 and the crops are young and tender. 

 Consequently it is at these times 

 that tree and plant destroying insects 

 are most abundant, and these enemies 

 of plant life furnish the birds with 

 ample nourishment for their children 

 and themselves. Birds work so hard 

 when rearing their young that they 

 require twice and three times as much food as they 

 do at other periods of the year. 



It will be noticed that some species of birds build 

 their nests in the very early spring ; others a little 

 later; while other sorts build at varying periods during 

 the spring and summer. The time is determined by 

 the character of the food and its abundance at these 

 various times of the year. For instance, when cater- 

 pillars are plentiful, the birds which feed their young 



The Chrysalis of the 

 Butterfly strapped 

 to a twig is a dainty 

 morsel for a bird. 



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