200 YEARBOOK OF THE U. 8. DEPARTMENT OF AGRICULTURE. 
To reconcile such contradictory evidence is certainly difficult, but it 
seems evident that these nest-robbing propensities are not as general 
as has been heretofore supposed. If this habit were as prevalent as 
some writers have asserted, and if it were true that eggs and young 
of smaller birds constitute the chief food of the blue jay during the 
breeding season, the small birds of any section where jays are fairly 
abundant would be in danger of extermination. 
The ease with which a bird’s actions may be misinterpreted is well 
illustrated by the case of a stomach which was received with the 
legend ‘‘Eating robins’ eggs,” but which, upon rigid examination, 
failed to reveal even a minute trace of an egg. It is of course possi- 
ble for a bird to eat an egg without swallowing any portion of the 
shell, in which case the soft contents would soon disappear from 
the stomach, but in view of the fact that such substances as dead 
leaves, bits of plant stems, and rotten wood, which ate evidently 
swallowed accidentally with insects or other food, are constantly found 
in birds’ stomachs, it does not seem probable that blue jays would 
discriminate against eggshells. To test this matter, four eggs of the 
English sparrow were offered to a jay in captivity. The bird at once 
seized the eggs and began to eat them, but when any piece of the 
shell, no matter how minute, was accidentally dropped it was at once 
picked up and swallowed, and several such picees that were thrown 
to the farther end of the eage were also caten, so that the shells with 
their membranes were entirely gone before the soft contents. 
Besides birds, remains of small vertebrates were found in twelve 
stomachs, as follows: Fish and salamanders in one stomach each, tree 
frogs in four, mice in five, and a shrew in one. It is perhaps worthy 
of note that Dr. B. I. Warren failed to find a trace of any vertebrate 
remains in examining twenty-three stomachs of the blue jay, fourteen 
of which were collected in May, one in June, three in September, and 
five in October, (Birds of Pennsylvania, pp. 200-201.) 
The jay kept in eaptivity by Mr, Judd showed a marked fond- 
ness for mice, and would devour them apparently with great: relish. 
Another bird ate only a portion of dead mice and refused to touch 
live mice, preferring insects when it had an opportunity for choice. 
INSECT FOOD, 
Insects are eaten by blue jays in every month in the year, but nat- 
urally only in small quantities during the winter. The great bulk of 
the insect food consists of beetles, grasshoppers, and caterpillars, with 
a few bugs, wasps, and flies, and an oceasional spider and myriapod. 
The average for the whole year is nearly 23 percent, varying from less 
than 1 per cent in January to over 66 per cent in August, and gradu- 
ally diminishing to 3.2 per cent in December, There is a remarkable 
increase in the quantities eaten in spring and summer, the percent- 
age increasing from 28 in May to 44 in June, and from 46 in July.to- 
