84 FOOD HABITS OF THE GROSBEAKS. 
more than 13 times as much as the old birds take. So wide a dis- 
crepancy would seem to indicate that there is great difference between 
oid and young birds in the need for this material. 
YOUNG. 
Among the blue grosbeaks examined are 13 young collected in 
Kansas in July and August. Eight of these are nestlings, and 5 
are young just out of the nests, but still being fed by their parents. 
The percentage of animal food for the 13 young birds is 99.08; of 
vegetable, 0.92. 
Grasshoppers constitute 74.1 percent of the food. Among them 
are included the lesser migratory locust (Melanoplus atlantis) and a 
large coral-winged locust (Z/ppiscus, fig. 40). The remains of as 
many as 16 short-horned locusts were obtained from one stomach, 
while another contained 14. Caterpillars, among them the purslane 
sphinx, compose 10.7 percent of the subsistence of the nestlings, and 
Fig. 40.—Coral-winged locust (Hippiscus tuberculatus). (From Lugger, Minnesota Ex- 
periment Station.) 
snails 10. percent. The remainder of the animal food consists of a 
weevil, a long-horned beetle, a ground beetle, a robber fly, and the 
eggs of a tachina fly, which were on the purslane caterpillar. It is 
curious that so large a proportion of the beneficial insects consumed 
should be in the stomachs of nestlings, but it may be that these items, 
which ordinarily are rarely taken, are hurriedly gathered only be- 
cause of the insistent demands of the hungry young. 
The vegetable food consists of a few unidentified vegetable fila- 
ments and some slight remains of blackberries in two stomachs; this 
was the only fruit eaten by any of the birds, young or old. 
SuMMaRY. 
Present data shows that the food of the blue grosbeak is 67.6 per- 
cent animal and 32.4 vegetable. 
Grain constitutes 14.25 percent of the diet, a on account of the 
scattered distribution of the birds, no appreciable damage is done 
during most of the summer. Later, when they forage in flocks, they 
are said to do considerable injury. But, as noted above, the birds 
consume twice as much animal as vegetable matter, and even if all 
of the latter had been grain, instead of less than half, as is actually 
the case, it would have been paid for many times over. 
