206 USEFUL BIRDS. 



Moths and butterflies of many kinds are eaten ; also assassin 

 bugs, tree hoppers, and bugs that eat plants and fruit. Many 

 beetles, among them boring beetles, bark beetles, and weevils, 

 grasshoppers, katydids, locusts, all are eaten. This bird at 

 times becomes an expert flycatcher, taking horseflies, mos- 

 quitoes, and other gnats, and many gall flies. It appears to 

 take a larger proportion of fruit than the other Vireos. In 

 summer I have found many seeds of berries in the stomachs 

 of these birds, and sometimes a stomach will be found nearly 

 filled with blueberries. Raspberries, blackberries, and mul- 

 berries are commonly eaten. Professor King has found dog- 

 wood berries, berries of the prickly ash, and sheep berries in 

 their stomachs ; Dr. Fisher says they are fond of the fruits 

 of the benzoin bush, the sassafras, and magnolia ; and Dr. 

 Warren asserts that they feed on poke berries and wild 

 grapes. 



Warbling Vireo. 

 Vireo gilvus. 



Length. About five and three-fourths inches. 



Adult. Upper parts generally brownish-gray, tinged more or less with olive- 

 green ; sides of head lighter, with a rather light line above the eye, but no 

 dark line through it ; below, dull white, passing into yellowish on the belly 

 and pale buff or olive on sides. 



Nest and Eggs. Much like those of the preceding species, but a trifle smaller; 

 usually in a shade tree, from fifteen to fifty feet up. 



Season. May to September. 



In appearance the Warbling Vireo is much like the Red- 

 eye, but it is smaller and less distinctly marked. In the 

 breeding season it is usually seen 

 at no great distance from the 

 large elms and other great shade 

 trees that line country roads and 

 village streets. It was found com- 

 monly in city shade trees until the intro- 

 duced House Sparrow drove it out. The 

 Warbling Vireo, like its closely related 

 Pig. 72. -warbimg congeners, moves about amid the branches 



Vireo, natural size. /. a . 11 j.i 



of trees, flying only occasionally to the 

 ground, or moving from tree to tree in short flights. Its 

 ordinary notes are similar to those of the Red-eye, but are 



