20 CUCKOOS AND SHRIKES IN RELATION TO AGRICULTURE. 
pillars were contained in one-fifth of the stomachs examined, and during 
the months of January and February amount to 8 percent of the vol- 
ume of the stomach contents. Dr. A. K. Fisher collected in March 
two stomachs that were full of caterpillars. Even the bristly Isabella 
caterpillar is eaten, an object apparently as edible as a chestnut bur. 
Cutworms were found in several instances, but moths were seldom met 
with. Ants, wasps, flies, and thousand legs are sometimes eaten, and 
spiders constitute 3 percent of the food; but bugs (Hemiptera) were not 
detected during our laboratory investigations, though a cicada sup- 
posed to have been impaled by a shrike was found by Mrs. Musick, at 
Mount Carmel, Mo. 
Important as is the study of the food of nestlings, it must, for 
lack of material, rest on the work of other writers. Audubon states 
that caterpillars, other insects and spiders, together with small fruits, 
form the first food of young butcherbirds. It seems odd that a bird 
which eats no fruit itself should feed its young on berries. The log- 
gerhead shrike, as far as my investigation shows, neither takes vege- 
table food nor gives it to its young; and furthermore, our fruit-eating 
birds, so far as known, never begin by feeding their young on fruit. 
The present investigation shows that beneficial birds torm less than 
one-fourth of the food of the butcherbird. It also shows that the 
butcherbird, in addition to being an enemy of mice, is a potent check 
on the English sparrow, and on several insect pests. One-fourth of 
its food is mice; another fourth grasshoppers; a third fourth consists 
of native sparrows and predaceous beetles and spiders, while the 
remainder is made up of English sparrows and species of insects, most 
of which are noxious. 
THE LOGGERHEAD SHRIKE. 
The geographic races of the loggerhead shrike have almost identi- 
cal habits, and consequently will be considered together. During 
the breeding season the loggerhead, the southern representative of the 
butcherbird, inhabits the United States, northern Mexico, and the 
southern part of the interior of Canada. It is smaller and differs in 
minor details of color: the lower mandible is black, while that of the 
butcherbird is yellowish; aud the black bars on the side of the head 
meet across the forehead, but fail to do so in the butcherbird. In fall 
the loggerheads wander southward, but in spring they return to their 
breeding grounds and nest in thorny shrubs. 
BIRDS EATEN BY THE LOGGERHLEAD, 
Only 7 birds were found in the 88 loggerhead stomachs examined. 
One of these was an English Sparrow, another a tree sparrow, and 
most of the others, which were not specifically identified, were also 
seed-eating birds, 
