8 THE FOOD OF WOODPECKERS. 



of the birds' range, becomes more and more trustworthy as it increases 

 in size J in other words, the more stomachs examined the nearer correct 

 will be the result as to the birds' annual diet. 



The present paper is merely a preliminary report, based on the exami- 

 nation of 679 stomachs of Woodpeckers, and representing only 7 spe- 

 cies — all from the eastern United States, These species are the Downy 

 Woodpecker {Dryohates ptibesceiis), the Hairy Wood^Decker {D. villosus), 

 the Flicker or Golden winged Woodpecker {Colaptes auraUis), the 

 Redheaded Woodpecker {Melanerjyes erythrocephalus), the Eed-bellied 

 Woodpecker {Melanerpes carolmus), the Yellow-bellied Woodpecker 

 {Sphyrapicus varius), and the Great Pileated Woodpecker {CeopJilceus 

 pileatus). Examination of their stomachs shows that the percentage 

 of animal food (consisting almost entirely of insects) is greatest in 

 the Downy, and grades down through the Hairy, Flicker, Pileated, 

 Eedhcad, and Yellow-bellied to the Eed-bellied, which takes the 

 smallest quantity of insects. Prof. Samuel Aughey stated that all of 

 these species except the Pileated (which was not j)resent) fed upon 

 locusts or grasshoppers during the devastating incursions of these 

 iusects in Nebraska. The vegetable matter, of course, stands in inverse 

 order. The greatest quantity of mineral matter (sand) is taken by the 

 Flicker, somewhat less by the Eedhcad, very little by the Downy aud 

 Hairy, and none at all by the Yellow-bellied and Pileated. 



The stomachs of all of the 7 species except the Eedhead aud Eed- 

 bellied contained the substance designated as 'cambium' in the 

 accompanying list of vegetable food. This is the layer of nuicilagi- 

 iious material lying just inside of the bark of trees, and from whi<;h 

 both bark and wood are formed. It is supposed by many to be the 

 main object sought by woodpeckers. Except in the case of a single 

 species the stomach examination does not l)ear out this view, since cam- 

 bium, if present at all, Avas in such small quantities as to be of no 

 practical importance. The Yellow-bellied Woodpecker, however, is evi- 

 dently fond of this substance, for in the stomachs examined it formed 

 23 percent of the whole food of the year. It was found in 37 stomachs, 

 most of which were taken in April and October. Of 18 stomachs col- 

 lected in April, 10 contained cambium, aud one of the remaining con- 

 tained no vegetable food whatever. Moreover, as the true cambium is 

 a soft and easily digested substance it is probable that what is usually 

 found in the stomachs is only the outer and harder part, which there- 

 fore represents a much larger quantity. The extent of the injury done 

 by destroying cambium must depend on the quantity taken from indi- 

 vidual trees. It is well known that woodpeckers sometimes do serious 

 harm by removing the outer bark from large areas on the trunks of 

 fruit trees. The rings of punctures often seen around the trunks of 

 apple trees are certainly the work of the Sapsucker, though sometimes 

 attributed to the Downy and Hairy Woodpeckers. But the bird is not 

 sutticiontly numerous in most parts of the country to do much damage. 



