12 BULLETIN 621, U. S. DEPARTMENT OF AGRICULTURE. 
cent). In the three months following a very uniform decrease is 
noted (46.98, 44.28, and 39.40), but even as late as September the 
animal portion constitutes nearly a third (32.32 per cent) of the 
food. Lower percentages from October to March, inclusive (14.29", 
18.74, 13.18, 14.94, 10.97, and 16.05), reflect the struggle for existence 
which is the lot of the crow during the colder months. With April, 
however, comes relief, and the animal food again becomes conspicuous 
(34.09 percent). 
INSECTS. 
In passing judgment on the economic value of most birds, nothing 
is of greater importance than a thorough understanding of their in- 
sect food. By this it is not meant merely that one should know the 
noxious forms eaten, the destruction of which is a benefit to man, but 
cognizance must also be taken of the complex relations between the 
various beneficial (predacious and parasitic) insects destroyed and 
the injurious ones upon which the bird commonly feeds. Some of 
this information is as yet unavailable, owing to the lack of knowledge 
of the interrelations between insect forms. Enough has been learned 
of the crow, however, by examination of 2,118 stomachs, 1,340 of 
which were of adults, and by reliable field observations to make 
possible the assertion that, for all practical purposes, sound judg- 
ment on the merits of the insect-feeding habits of the crow can be 
given. The series of stomachs available is sufficiently large and was 
collected under the varying environments of so many localities that 
the results obtained are probably close to a true average for the area 
in which the crow is common. 
Insect food was taken by adult crows in every month of the year, 
though in January it amounted to only 1.29 per cent. February was 
represented by 4.85 per cent; March, 4.58; April, 14.72; May, 39.77; 
June, 35.95; July, 33.85; August, 35.07; September, 27.64; October, 
11.51; November, 14.16; and December, 4.49. The insects identified 
belong to 12 orders, embracing no less than 455 specifically distinct 
forms. A discussion of this part of the crow's food will be taken up, 
order by order — Coleoptera (beetles), the order best represented in 
the crow's diet (7.58 per cent of the yearly food), being treated first. 
Coleoptera ( beetles ) . 
The crow is primarily a terrestrial feeder. Its quota of beetles, 
therefore, is made up almost exclusively of species found on or near 
the ground, or those which, by the turning over of sticks, clods of 
earth, or dung, are secured from beneath the surface. The latter 
is a common method of feeding employed diligently by the crow 
from early spring to the beginning of autumn, when the usual crop 
of grasshoppers furnishes a more accessible supply of food. 
