130 BIRDS OF PENNSYLVANIA. 



this bird, oftentimes, like the Common Pewee or other fly -catchers, 

 may be seen to start from -a limb and seize its passing prey. This 

 bird, like the Hairy and Downy Woodpeckers, is frequently seen 

 clinging to the small twigs of various trees and bushes collecting in- 

 sects or picking at berries. The Yellow-bellied Woodpecker is the 

 only representative of the genus Sphyrapicus found east of the Mis- 

 sissippi river; two species and one sub-species of this genus occur in 

 the Rocky mountain and Pacific coast regions of the United States. 



FOOD. 



In referring to these sap-sucking Woodpeckers, Dr. Ooues says : 

 " Birds of this remarkable genus feed much upon fruits, as well as 

 insects, and also upon soft inner bark (cambium) ; they injure fruit- 

 trees by stripping off the bark, sometimes in large areas, instead of 

 simply boring holes. Of the several species commonly called " Sap 

 suckers," they alone deserve the name. In declaring war against 

 Woodpeckers, the agriculturist will do well to discriminate between 

 these somewhat injurious and the highly beneficial species." My field 

 observations, also the post mortem examinations of some twenty odd 

 Yellow-bellied Woodpeckers (taken chiefly during the fall migrations), 

 lead me to think that in this region these birds subsist mainly on in- 

 sects, such as beetles, large flies, ants, spiders and larvae. In the vis- 

 cera of specimens taken in the late autumn and winter, I have found 

 sometimes small seeds and berries. In the stomachs of two birds 

 which were shot in apple trees, I detected a small amount of a vege- 

 table substance, which may have been inner bark. On one occasion 

 I opened the stomach of an adult male, taken in the spring, and no- 

 ticed that it contained a considerable quantity of fluid, of a yellowish 

 color ; a drop of this fluid touched to my tongue was found to be ex- 

 ceedingly sweet. 



u Dr. Bryant, who has paid some attention to the examination of 

 the food of this bird, in the Proceedings of the Boston Society of 

 Natural History,' vol. X, 91, makes the following remarks : ' It has 

 long been known that some of our smaller Woodpeckers pick out 

 portions of the sound bark of trees, particularly of apple trees, where 

 there are no larvae, and apparently no inducement for them to do so. 

 W T hat their object is has never been satisfactorily established. In 

 Massachusetts, I am not aware that these holes are ever sufficiently 

 large or numerous to cause any material injury to the apple-trees; 

 they are generally seen in circles round the limbs or trunks and con- 

 sist of small, irregularly rounded holes, and in this vicinity are made 

 almost exclusively by the Downy Woodpecker (D. pubescens), aided 

 occasionally by the Hairy Woodpecker (D. villosus). In certain 

 parts of the west, however, it is said that great damage is done in or- 



