BIRDS. 133 



during the winter as it is at any other season of 

 the year. 



Woodpeckers feed largely upon those grubs of 

 insects which burrow in the trunks and branches 

 of trees. Their feet are fitted for clinging to the 

 bark; their tails for supporting them while at work; 

 their long, sharp bills for pecking holes in the wood 

 to the grubs; and their slim, barbed tongues for 

 piercing and dragging out the victims. So the 

 structure of woodpeckers, to a large extent, 

 depends upon the food they eat. 



The same is true of hawks and owls (see p. 135), 

 which kill and eat birds and other animals. 

 Their feet are fitted for catching and holding their 

 prey, and their sharp, curved bills for cutting and 

 tearing the flesh. The structure of the swallow's 

 wings, tail, and mouth, is due to the fact that it 

 lives upon winged insects and must catch them in 

 mid-air. 



Birds that catch fish and other small animals in 

 the shallow water of swamps and streams, have 

 long legs for wading, and long bills and necks for 

 reaching deep into the water. Ducks and geese 

 secure their food in either deep or shallow water, 

 and have bills especially fitted for straining out the 

 indigestible mud and other material. So the list 

 continues, each bird having something peculiar 

 and interest' ^g about it, due to the food upon 

 which it subsk s. 



