OTHER USEFUL BIRDS. 



219 



accurate observation of their feeding habits is then difficult. 

 As warblers glean much of their food from the twigs and 

 foliage, it is highly probable that the mortality among the 

 small caterpillars is partly caused by these birds. 



Observations on the feedino- of the warblers were made 

 when the spring migrants had gone north and the sum- 

 mer residents were breeding. The warblers which breed in 

 the infested districts do not appear to feed habitually on the 

 gypsy moth. Both observations and dissections indicate that 

 most of them prefer the small, smooth, geometrid larvae. All 

 of them appear to have a particular fondness for the canker- 

 worms, and a few eat the tent caterpillar. Yet some of the ob- 

 servations made show that certain species of warblers destroy 

 many of the larger gypsy caterpillars. These species also 

 destroy moths, both male and female. Mr. Bailey saw a yel- 

 low warbler take two large gypsy moth larvae, tear them 

 open and eat out the body contents, leaving the skins upon 

 the tree. He saw a black-and-white creeping warbler just 

 from the nest capture and eat seventeen gypsy moth cater- 

 pillars. All of them were pecked open. 



Mr. I. C. Green, a former emploj^ee of the Board, consid- 

 ers the redstart the most useful of all birds in destroying the 

 gypsy moth, but does not give the details of his observations. 

 This species has been seen by other observers to feed espe- 

 cially on the male moth, which it often captures in flight. 



The oven bird is mentioned by several observers as feed- 

 ino- on larvee and moths. The other warblers in the list 

 have seldom been seen to take any form of the moth. 



Sparrows. — Though the towhee bunting or chewink was 

 not seen preying on the gypsy moth prior to 1895, the 

 observations of Mr. Mosher give ample proof of its useful- 

 ness in this respect, especially in woodland or in sprout- 

 land where it is a common bird. It eats readily all forms of 

 the moth excepting the eggs, and this habit has been fre- 

 quently observed. The rose-breasted grosbeak and indigo 

 bird occasionally eat the larvae. 



Flycatchers. — All the flycatchers which breed in the dis- 

 trict are given in the list of birds which destroy the moth. 

 Though most of them kill a great many moths, they proba- 

 bly are not as useful as most other birds on the list, as they 



