CHAPTER IV 



HOME LIFE OF BIRDS 



The eggs. The most common colors found among 

 birds' eggs are white and various shades of brown and 

 blue. It seems to be a general rule that eggs which 

 are laid in cavities, where they are not easily seen, 

 like the woodpeckers', are white; and those which 

 are laid in more exposed positions take on some 

 brighter color. But there are exceptions to these 

 generalizations. Some eggs are of a uniform color, 

 while others are spotted or mottled. The number 

 of eggs laid varies from one to twenty. For most of 

 our common land-birds the number ranges from four 

 to six. 



Incubation. The period of incubation ranges from 

 twelve days for a small bird like the chipping spar- 

 row to twenty-eight days for a large bird like the 

 osprey. The larger the egg, the longer the time usu- 

 ally required for incubation. The work of incubation 

 is done chiefly by the female, but in some cases the 

 male may help, or the male may feed the female on 

 the nest. While the female is incubating the eggs, 

 one of the chief duties of the male is to drive away 

 any intruding birds or animals that may come within 

 a certain distance. 



