26 FOOD OF BOBOLINK, BLACKBIRDS, AND GRACKLES, 
Beetles form 5.3 percent of the year’s food. The predaceous ones, 
or those that prey to a greater or less extent on other insects (Cara- 
bide and a few Cicindelide), although living on the ground and 
often found by cowbirds, are rarely eaten, the aggregate for the year 
being about three-fourths of one percent of the whole food. Of the 
eight families of beetles represented in the food, only one group, the 
snout-beetles or weevils (Rhynchophora), are eaten to any noticeable 
extent, and these amount to little more than 2 percent of the food of 
the year, although in June they rise to more than 9 percent. They 
belong mostly to the families of scarred snout-beetles (Otiorhynchide), 
curculios (Curculionide), and ‘bill bugs’ (Calandride), and as they 
are all potentially harmful and most of them actual pests, their 
destruction is a benefit to agriculture. The rest of the beetle food, 
comprising species that are all more or less injurious, amounts toa 
little more than 2 percent, and is taken chiefly in April, May, and 
June. 
Grasshoppers appear to be the cowbirds’ favorite animal food, and 
compose almost half of the insect food, or 11 percent of the whole. 
They are first taken in March, when the birds return from their winter 
home, reach a maximum of 45.1 percent in August, and decrease to 
6.2 percent in November. This is a large record, compared with 
those of most other birds whose food has been accurately determined. 
It is much greater than those of the crow, crow blackbird, or red- 
winged blackbird, all noted ground feeders, and is exceeded only by 
those of the meadowlark and a few of other families. 
Caterpillars are eaten to some extent in every month of the cow- 
birds’ stay in the North, but do not constitute a very important element 
of the food, averaging only a little more than 2 percent of the whole. 
The greatest number, amounting to a little more than 10 percent, are 
eaten in May. The notorious army worm (Leucania wnipuncta) was 
identified in four stomachs, and was probably contained in many more, 
but not in a condition to be recognized. One small moth and one 
ephemerid were also found. 
Spiders were found in many stomachs, but not in large numbers. 
They seem to be eaten wherever they are found, but probably only ter- 
restrial species are taken. Snails were found in a number of stomachs. 
Eggshells occurred in several stomachs, but in such small quantities 
as to preclude the probubility that they were taken from the nests of 
other birds. When young birds are hatched the parents remove the 
eggshells and drop them at some distance from the nest, where, 
doubtless, they are found and eaten by other birds, for bits of eggshell 
appear more or less frequently in the stomachs of nearly every species 
examined. 
The vegetable food of the cowbird exceeds the animal food, both in 
quantity and variety. When searching the ground about barnyards 
or roads the bird is evidently looking for scattered seeds rather than 
insects, though the latter are probably taken whenever found. Various 
