132 



LIFE ON THE FARM. 



food during warm weather. Hence, the migration 



of birds is almost wholly dependent upon their 



food supply. 



Some birds stay north during the cold winter,when 



the ground is 

 covered with 

 snow and ice, 

 and all in- 

 sects are 

 dead or hid- 

 de n away 

 in a dormant 

 state. Such 

 birds are 

 found to be 

 well fitted to 

 secure a liv- 

 ing even dur- 

 ing the se- 

 vere winter, 

 though the 

 odds seem to 

 b e against 

 them. 



The wood- 

 pecker is a 

 good exam- 

 ple of this 

 kind. He 



stays north because his food is as easily secured 



