316 BOARD OF AGRICULTURE. [Pub. Doc. 



BIRDS AS DESTROYERS OF HAIRY CATERPILLARS. 



BY E. H. F0RBU8H, ORNITHOLOGIST TO THE BOARD. 



One spring day, long years ago, a vireo sang in a sunny, 

 swampy thicket. Suddenly the bird ceased its song, leaned 

 forward, ran along the limb, picked a large caterpillar from 

 a twig, pecked it a little, swallowed it and resumed its song. 

 A small boy, a witness of the act, followed the bird closely, 

 and saw that during each intermission of the song it was 

 occupied either in catching caterpillars or other insects on 

 the twigs and leaves, or in pursuing flying insects through 

 the air. 



Previous to that day birds had interested the writer princi- 

 pally because of their beauty and song, but this incident 

 opened a new field for study, the pursuit of which has since 

 convinced him that birds as a class excel all other animals as 

 destroyers of those insects which feed upon vegetation, and 

 that the species of plant-feeding insects which escape deci- 

 mation by birds, at one time or another, are very few as com- 

 pared to the total number of such species in existence. 



In such research as the writer has been able to make in 

 agricultural, ornithological and entomological literature it 

 has become noticeable that certain insects are supposed by 

 many writers to be protected by prickly hairs or spines from 

 the attacks of birds. This astonishing error, for which there 

 is really very little excuse, has been repeated, in one form or 

 another, by writer after writer during the present century, 

 and is still persisted in. No less an authority than the late 

 Prof. C. V. Rile}^ for many years entomologist to the United 

 States Department of Agriculture, has assisted in the promul- 

 gation of this belief. The most positive statements have 

 been made to the efiect that birds do not eat hairy cater- 

 pillars, although here and there an exception to the rule is 

 named. 



