PRELIMINARY REPORT ON THE FOOD OF WOODPECKERS. 
By F. E. L. Brat, Assistant Ornithologist. 
GENERAL REMARKS. 
With the possible exception of the crow, no birds are subject to more 
adverse criticism than woodpeckers. Usually no attempt is made to 
discriminate between the numerous species, and little account is taken 
of the good they do in destroying injurious insects. The name ‘Sap- 
sucker’ has been applied to two or three of the smaller kinds, in the 
belief that they subsist to a great extent upon the juices of trees, 
obtained from the small holes they make in the bark. There can be 
little doubt that one species, the Yellow-bellied Woodpecker (Sphyra- 
picus varius), does live to a considerable extent upon this sap. Obser- 
vation 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. 
Many observers have testified to the good work these birds do in 
destroying insects, while others have spoken of harm done to fruit or 
grain. Both are correct within certain limits. 
Field observation on the food habits of birds is attended with so 
many difficulties as to render it a very unreliable source from which to 
draw general conclusions. The most conscientious and careful person 
is often deceived, not only as to the quantity of a particular kind of 
food eaten by a bird, but as to the fact that it is eaten at all. The 
further difficulty of keeping a number of birds, or even a single one, 
under constant observation makes an estimate of relative proportions 
of different kinds of food impossible. When much mischief is done 
the fact is apparent, but there is no way to find out how much good is 
done during the same time. For these reasons it often happens that 
reports on food habits, based on observations of wild birds, not only 
conflict with each other but also disagree with the results obtained 
from stomach examinations. This last method must be taken as the 
court of final appeal, and it is evident that a collection of stomachs 
covering every month in the year, and as nearly as may be all points 
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