178 THE IMPORTANCE OF BIRD LIFE 



nual production of a million pounds of feathers, 

 worth roughly $13,500,000. 



In many respects ostrich farming resembles 

 poultry raising. The eggs are incubated by one of 

 two systems, officially termed "natural" or " arti- 

 ficial. " In the former method, as implied by its 

 name, the eggs are hatched by the birds them- 

 selves, just as they are in the wild state. The 

 nest consists of a large depression in the ground 

 scooped out by the breast-bone of the bird. Its 

 construction is simple. The ostrich merely squats 

 down, with its breast thrust forward, and revolves 

 slowly until a hollow of the required size is 

 formed. The female then lays an egg every other 

 day until the clutch of twelve or fourteen is com- 

 plete. The eggs are heavy and large, averaging 

 about three and a half pounds apiece, and their 

 contents are equivalent to about thirty chicken 

 eggs. The male performs almost the entire duty 

 of incubation. If the sun is very hot the eggs are 

 often left covered during the day with a thin layer 

 of sand ; if the weather is inauspicious the female 

 rests upon the eggs from nine in the morning 

 to five in the afternoon not a minute longer. 

 The male sits regularly for the remaining sixteen 

 hours of the twenty -four. 



But the natural method of hatching eggs is not 

 the most economical, and has virtually everywhere 

 been displaced by the artificial, or incubator, sys- 

 tem. The ostriches are allowed to excavate a nest 



