222 THE GYPSY MOTH. 



the yellow-throat go from burlap to burlap, drawing out the 

 larvae from beneath. Yet Mr. Bailey reports that he has 

 seen individuals of these species search a tree over for hair- 

 less larvae before they would eat one of the caterpillars of 

 the gypsy moth, of which there were thousands on the tree. 

 I do not question the correctness of any of these observa- 

 tions. Certain fowls or flocks of fowls in the infested 

 region ate the caterpillars with avidity, while other individ- 

 uals or flocks would not touch them. The same individual 

 preference was noticed among toads. 



It appears that the presence of a great number of hair- 

 less larvae has the indirect effect of lessening the number of 

 gypsy moth caterpillars destroyed by birds. When canker- 

 worms are plentiful, the birds eat comparatively few of the 

 hairy caterpillars until the canker-worms have disappeared. 

 Although many gypsy moth caterpillars were eaten very 

 early in the season of 1895 by the orioles, vireos and other 

 birds, these caterpillars received very little attention later, 

 when the growing canker-worms became more noticeable. 

 Most of the birds then devoted their attention to the canker- 

 worms. About June 10, when the canker-worms had mostly 

 disappeared, the birds again attacked the gypsy moth larvae 

 and continued to feed upon them for some time. Their appe- 

 tites for these insects appeared finally to wane, having been 

 apparently cloyed by an excessive diet of hairy caterpillars. 

 It has been noticed that sometimes birds tire of a monotonous 

 diet, and that they will even cease to feed for a time upon a 

 favorite insect prey. This may partially account for the fact 

 mentioned by Grimm, that the birds forsook the Eussian 

 forest which had been devastated by the gypsy moth. Yet 

 this would not be a sufficient reason to account for a continued 

 absence, as birds often return to feast again after a change of 

 diet. But the lack of shade, water and green food, all of 

 which together make a region unfit for the habitation of wood 

 birds, may have driven them for a time from the devastated 

 forest. In the infested district in Massachusetts forest birds 

 will not remain constantly through the hot summer days in 

 woodland which has been stripped by the gypsy moth, but 

 will betake themselves to shaded glades and brooksides, mak- 

 ing frequent sallies into the bare, infested woods to feed on 

 the pest. 



