8 



FOOD OF WOODPECKERS OF UNITED STATES. 



FIG. 1. Tongues of woodpeckers. 



From these considerations it is at once apparent how important 

 must be any agency that restrains or limits this great army of tree 

 destroyers. Of all birds that further the welfare of trees, whether 



of forest or orchard, woodpeckers are the 

 most important. The value of their work 

 in dollars and cents is impossible to cal- 

 culate, but careful study of their food in 

 both field and laboratory has brought out 

 many facts of practical importance. 



Woodpeckers are essentially arboreal in 

 their habits and obtain the greater part of 

 their food from trees. Their physical con- 

 formation eminently adapts them to this 

 mode of life. Their legs are rather short 

 and stout, and the toes are furnished with 

 strong, sharp claws. With the exception 

 of the genus Picoides, all North American 

 woodpeckers have four toes, two of which 

 point forward and two backward. To 

 further aid in maintaining themselves on 

 the trunks of trees, their tails are com- 

 posed of stiff feathers terminating in sharp 

 spines, which can be pressed against the 

 bark and so serve as a prop to hold the bird in an upright position 

 while it is at work. Woodpeckers are thus enabled to cling easily 

 to the trunks and branches and to strike effective blows with their 

 beaks upon the bark 

 or wood 



As much of the food 

 of woodpeckers is ob- 

 tained from solid wood, 

 Nature has provided 

 most of them with a 

 stout beak having a 

 chisel - shaped point, 

 which forms an ex- 

 ceedingly effective 

 wood-cutting instru- 

 ment. But the most ^^_ 



peculiar and interest- b 



ing point in the anat- FlG> 2 - s P eclal development of tongues of woodpeckers. 



omy of these birds is the tongue. This is more or less cylindrical 

 in form and usually very long (fig. 1, a). At the anterior end it 

 generally terminates in a hard point, with more or less barbs upon 

 the sides (fig. 1, &). Posteriorly the typical woodpecker tongue is 



