8 THE FOOD OF WOODPECKERS. 
of the birds’ range, becomes more and more trustworthy as it increases 
in size; 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 (Dryobates pubescens), the Hairy Woodpecker (D. villosus), 
the Flicker or Golden winged Woodpecker (Colaptes auratus), the 
Red-headed Woodpecker (Melanerpes erythrocephalus), the Red-bellied 
Woodpecker (Melanerpes carolinus), the Yellow-bellied Woodpecker 
(Sphyrapicus varius), and the Great Pileated Woodpecker (Ceophloeus 
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, 
Redhead, and Yellow-bellied to the Red-bellied, which takes the 
smailest quantity of insects. Prof. Samuel Aughey stated that all of 
these species except the Pileated (which was not present) fed upon 
locusts or grasshoppers during the devastating incursions of these 
insects 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 Redhead, very little by the Downy and 
Hairy, and none at all by the Yellow-bellied and Pileated. 
The stomachs of all of the 7 species except the Redhead and Red- 
bellied contained the substance designated as ‘cambium’ in the 
accompanying list of vegetable food. This is the layer of mucilagi- 
nous material lying just inside of the bark of trees, and from which 
both bark and woed 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 bear out this view, since cam- 
bium, if present at all, was in such sinall 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 foundin 37 stomachs, 
most of which were taken in April and October. Of 18 stomachs col- 
lected in April, 16 contained cambium, and 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 
sufficiently numerous in most parts of the country to do much damage. 
