HOW KIRDS HAVE BEEN STUDIED 



351 



The cultivated fields and garden beds, 

 Hosts of devouring insects crawled, and found 

 No foe to check their march, till they had made, 

 The land a desert, without leaf or shade." 



It is believed that if it were not for the birds, success- 

 ful agriculture would not be possible. They not only 

 check the ravages of 

 many harmful insects, 

 but they also eat up tons 

 of weed seeds. 



258. How Birds have 

 been Studied. It is diffi- 

 cult to follow a bird day 

 after day to watch what 

 it eats. Some may be 

 seen eating caterpillars 

 one hour, and grain the 

 next, so that the good 

 they are known to do 

 may be offset by the 

 damage. Some years 

 ago, in order to have re- 

 liable information, com- 

 petent men, in the em- 

 ploy of the United States 

 Department of Agricul- 

 ture, undertook to an- 

 alyze the stomachs of many specimens of all the com- 

 mon farm birds. The results of this work have re- 

 moved all doubt as to the fact that most birds pay 

 well for their board and lodging. The following 

 contents, found in the stomachs of a few of the 

 birds examined, show the main articles of diet of those 

 specimens. 



RED-HEADED WOODPECKERS. 



All woodpeckers feed on insects harmful 

 to farmers. 



