UNITED STATES DEPARTMENT OF AGRICULTURE 
DEPARTMENT BULLETIN No. 1355 
Washington, D. C. 
November, 1925 
FOOD HABITS OF THE VIREOS: 
A Family of Insectivorous Birds 
By Edward A. Chapin, formerly Assistant Biologist, Division of Food Habiti 
Research, Bureau of Biological Survey 1 
CONTENTS 
Page 
Economic relations ... . 1 
Black-whiskered vireo 3 
Red-eyed vireo 4 
Philadelphia vireo 10 
The warbling vireos 13 
Yellow-throated vireo. 15 
Page 
The blue-headed vireos - 18 
The white-eyed vireos 21 
The Hutton vireos 23 
The Bell vireos. 25 
Gray vireo 27 
ECONOMIC RELATIONS 
During the summer almost anywhere in the United States at least 
one species of vireo, and usually more than one, is to be found flitting 
about in the trees or shrubbery. In the eastern and central parts of 
the country the common species is the red-eyed vireo, which is con- 
sidered the most abundant of all species of woodland birds. Others 
more or less common in the East are the white-eyed, warbling, and 
yellow- throated vireos, and in the far West there is another form of 
the warbling vireo that is abundant. The Philadelphia, the blue- 
headed, the Hutton, and the Bell vireos are found more or less 
locally. The black- whiskered vireo in the United States is found only 
in Florida, and the gray vireo is confined to the southwestern portion 
of the country where it is not at all common. One other species, the 
black-capped vireo {Vireo atricapillus), is very rare in the United 
States, and as no stomachs have reached the collection of the Bio- 
logical Survey nothing can be said concerning its food habits. 
Though in general the food items of all the vireos are very similar, 
their proportions vary in the diet of different species. For instance, 
the food of the red-eyed vireo is made up of about seven-eighths 
animal matter and one-eighth vegetable, whereas that of the yellow- 
throat contains vegetable matter only to the extent of one-fiftieth 
of the total, and that of the Bell vireos apparently to an even less 
extent. Caterpillars make up an eighth of the food of the Hutton and 
more than a third of the warbling vireos. Bugs are seldom eaten by 
the Philadelphia vireo and amount to but a tenth of the food, whereas 
1 Doctor Chapin has been transferred from the Biological Survey to the Zoological Division of the Bureau 
c> ; Animal Industry since preparing this report. 
50209— 25t 1 1 
