80 



ANIMAL BIOLOGY 



hatched, are helpless in the 

 nests and are unable to feed 

 themselves. Most of the 

 food of young birds consists 

 of the larvae of insects and 

 some of the families, e.g. the 

 fly-catchers (Fig. 69), feed 

 upon insect food through- 

 out their life. The sparrow 

 family (Fig. 70), on the other 

 hand, choose largely a diet of 

 seeds. Almost every kind of 

 food, however, is eaten by 

 some of the perching birds. 



64. Migration of birds. 



Some of the birds like the 

 chickadee and downy woodpecker, remain in the middle and northern 

 United States throughout the year, and hence are known as permanent 

 residents of these regions. Many birds, however, spend the winter 



FIG. 67. Male and female bobolink. 



FIG. 68. Wood thrush. 



