FOOD HABITS OF THE VIREOS 23 
they make up 13.25 per cent and in February 11.88 per cent of the 
food. In March the percentage drops to 4.79, in April to 0.52, and 
in May and June none are eaten. A few are taken in July and 
August, and by October as much as 20 per cent of the food may be 
from this source. 
Other insects. — Miscellaneous insects other than grasshoppers make 
up 3.74 per cent of the diet. The quantities eaten from month to 
month show no coordination, and the item appears to be greatly 
affected by chance. For instance, in January 5.68 per cent is to be 
referred here, in February none, in March 8.68 per cent. 
Other animal food. — Spiders are at no time very abundant in the 
food, although in August they form as much as 7.76 per cent of it. 
The yearly average is 3.59 per cent. Other animal food is composed 
mainly of snails, and in one stomach were bones of a small chameleon, 
the two together making up only 0.37 per cent of the|whole food. 
VEGETABLE MATTER 
In the spring and fall months foraging for suitable food compels 
the birds to turn to the berries and small fruits, which are usually 
to be had in almost any locality. In January 22.93 per cent of the 
entire food is vegetable, in February only 5.62, still less from March 
to July, in August 16.2, and in the next two months the percentage 
rises to 32.37. The vegetable food is composed of such berries as 
those of sumac, dogwood, wild grape, and wax myrtle, and has no 
economic importance. 
SUMMARY 
There is remarkably little in the food habits of the white-eyed 
vireos to condemn. The record of this species for the destruction of 
ladybird beetles is not bad and is more than offset by the destruction 
of many caterpillars, moths, plant bugs, and grasshoppers. These 
birds take very few beneficial hymenopterans and no valuable fruit. 
THE HUTTON VIREOS 
Vireo huttoni, subspp. 
The Hutton vireos, in their subspecies, range over the greater 
part of the Pacific coast and eastward into southern Arizona and 
western Texas. Throughout their range birds of this species are 
locally somewhat common in thickets along streams. There are in 
the collection of the Biological Survey 77 stomachs available for 
study, 70 of which contained sufficient food for use in the tabulations. 
Unfortunately, these stomachs were not collected in consecutive 
months, none in March, April, May, or November, and only a few 
in each of the other months. The data available show a preponder- 
ance of animal food (98.23 per cent), with but 1.77 per cent of vege- 
table origin. It is probable that an investigation of more stomachs 
will materially alter the conclusions reached at this time. (See 
%. 8.) 
ANIMAL FOOD 
The animal food is made up of insects and a few spiders, no trace 
of the few mollusks usual with other vireos being found. Caterpillars 
and other lepidopterous forms are not the dominating element of 
