NATURAL HISTORY OF SOUTH AFRICA 



on this class of food breed at that time. I made a 

 large number of observations in this connection, and 

 found that the nestlings of the majority of the smaller 

 birds were hatching from the eggs at the time the 

 species of caterpillars which formed the bulk of their 

 food were very young. These caterpillars provided 

 the small and delicate young birds with the very food 

 needed at this critical period of their lives. As they 

 grew older and more robust, they required a greater 

 quantity of food, and the caterpillars, which by this 

 time had grown considerably, furnished exactly what 

 was needful. A few species of birds rear their young 

 in the winter. The sugar bird (Promerops) of South 

 Africa is an example. The proteas and the aloes 

 flower in the winter, and these birds feed their nestlings 

 largely on the insects which infest the flowers of these 

 plants. 



THE EGGS 



The eggs of the majority of small birds hatch in 

 from twelve to fourteen days. Those of the larger 

 birds vary considerably, according to the species. 

 The time for incubation usually ranges from fourteen 

 days to a month. Many species of hawks take from 

 twenty-one to twenty-eight days, and various of the 

 duck tribe thirty days. Large birds, such as the 

 ostrich and emu, take five to six weeks. When the 



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