BIRDS. 131 



It is not true that we could not live upon the 

 earth another day if all birds were killed, but life 

 would not be so pleasant without them. Farming 

 and gardening would not be so profitable; neither 

 could shade and fruit trees be grown successfully 

 because of the great numbers of insects that would 

 thrive if left unmolested. We shall study birds, 

 then, mainly with reference to the good they do in 

 killing pernicious and injurious insects. 



THE FOOD OF BIRDS. 



Birds, like other animals, require food. Some 

 eat one thing and some another. Some live 

 entirely upon a vegetable diet, some on an animal 

 diet, and some on a mixture of both vegetable and 

 animal food. The greatest number of birds 

 belongs to the last class; that is, the kind that eats 

 both vegetable and animal food. The diet of 

 birds, at first thought, seems to be of little impor- 

 tance; but, upon careful study, it is found to have 

 a vital relation to the success of farmers and gar- 

 deners, and to be of general importance to all. 



In studying the food of birds, we shall find out 

 many important things about their structure and 

 habits. For instance, as winter approaches in our 

 northern latitude, food becomes scarce. This 

 compels some of our birds to fly to warmer 

 regions, where food is abundant. Then, again, as 

 summer approaches, they come back to the fresh 

 and unoccupied fields where there is no lack of 



