60 FOOD OF BOBOLINK, BLACKBIRDS, AND GRACKLES, 
Nearly 2,500 crow blackbird stomachs have been examined in the 
laboratory of the Biological Survey, of which 2,346 contained food; 
the remainder were empty. These stomachs were obtained from 
twenty-seven States, the District of Columbia, and Canada (see p. 75), 
Nebraska and Dakota are the most western States in which any were col- 
lected, and Florida and Texas the most southern. The stomachs were 
taken during every month in the year, but as the great body of the 
birds leaves the Northern States in October and does not return until 
Mareh, but few stomachs could be procured in November, December, 
January, and February. Great pains were taken to secure a large 
number during the breeding months of May and June, with the result 
that « little more than half of the whole collection was obtained at 
this time. Observation has shown that the food of young birds often 
differs materially from that of the adults, and in order to test this 
point +56 nestlings were collected in May and June. 
The food of the whole year, taking into account all the 2,346 stom- 
achs, young and adult, comprised 30.3 percent animal, and 69.7 per- 
cent vegetable matter. The animal food was found to be composed of 
insects, spiders, myriapods, crayfish, earthworms, sowbugs, hair snakes, 
snails, fish, tree toads, salamanders (newts), lizards, snakes, birds’ eggs, 
and mice. 
Insect food constitutes 27 per cent of the entire food for the year, 
and is the most interesting part of the bird’s diet from an economic 
point of view. 
When it is examined month by month, the smallest quantity appears 
in February (less than 3 per cent of the whole food), but as only 8 
stomachs were taken in this month the result can not be considered 
very reliable. In March it rises to one-sixth, and steadily increases 
till May, when it reaches its maximum of five-eighths of the whole; it 
then decreases to one-sixth in October, and appears to rise again in 
November, but the number of stomachs taken in: that month is too 
small to warrant any general conclusions. The great number of insects 
eaten in May and June is due in part to the fact that the young are fed 
largely on this kind of food. 
Analysis of the insect food presents many points of interest. Among 
the most important families of beetles are the scarabeeids, of which the 
common June hug or May-beetle and the rose bug are familiar exam- 
ples. These insects are eaten, either as beetles or grubs, in every 
month except January and November; in May they constitute more 
(han one-fifth, and in June one-seventh of the entire food. The babit 
grucklos have of following the plow to gather grubs is a matter of 
common observation which has been fully confirmed by stomach exam- 
inations, Many stomachs were found literally crammed with grubs, 
and jn many more, where other food predominated, the hard jaws 
showed that grubs had formed a goodly portion of a previous meal. 
