24O REPORT OF THE FOREST, FISH AND GAME COMMISSION. 



rounding muscular sheath, the tongue can be protruded from the bird's mouth 

 a considerable portion of its length, and can thus be inserted into the burrows of 

 wood-boring larvae. In order to secure grubs or other insects, it is usually fur- 

 nished with a sharp point and is barbed on the sides (Fig. 1, b). It is evident 

 that a bird possessing such an apparatus must be capable of doing work which less 

 advantageously endowed species can not accomplish. Hence, while most birds 

 content themselves with eating such insects as they find upon the surface, wood- 

 peckers seek those larvae or grubs which are beneath the bark, or even in the 

 very heart of the tree. To render more effective the mechanism here described, 

 these birds are gifted with a remarkably acute sense of hearing, by which to 

 locate their prey within the wood. That they do so with great accuracy is proved 

 by examination of their work, which shows that they cut small holes directly to the 

 burrows of the grubs. 



The name " sapsucker " has been applied to two or three of the smaller kinds 

 of woodpeckers, in the belief that they subsist to a great extent upon the juice of 

 trees obtained from small holes which they peck in the bark. There can be little 

 doubt that one species, the yellow-bellied woodpecker {Sphyrapicus variics), does live 

 to a great extent upon this sap. Observation does not show that other species have 

 the same habit, but it is a difficult point to decide by dissection, as fluid contents 

 disappear quickly from the stomach. The rings of punctures often seen around 

 the trunks of trees are certainly the work of the sapsucker, though sometimes 

 attributed to the downy and hairy woodpeckers. It is true, however, that wood- 

 peckers sometimes do serious harm by removing large areas of the outer bark from 

 trunks of trees, but this work has been definitely fixed upon the sapsucker alone. 

 It is supposed that the object is to get at the mucilaginous layer called cambium, 

 lying just inside of the bark, and from which both bark and wood are formed. 

 Except in the case of this one species, stomach examination does not bear out 

 this view, since cambium, if present at all, was in such small quantities as to be 

 of no practical importance. The yellow-bellied woodpecker, however, is evidently 

 fond of this substance, for the stomachs of this, species were found to contain it 

 in very considerable quantities. Moreover, as the true cambium is a soft and easily 

 digested substance, it is probable that what is usually found in the stomach is 

 only the outer and harder part, which therefore represents a much larger quantity. 



Among the insects which enter into the diet of the woodpeckers the most 

 important are the larvae of the woodboring beetles belonging to the families of 

 longicorns (Cerambycidae), and the metallic woodborers (Buprestidae), with some 

 woodboring caterpillars, the larvae of carpenter moths (Cosiidae), or the clear 

 winged moths (Sesiidae). During all seasons of the year these larvae constitute 



