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 wore 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 {Hemipiera) were not 

 detected during our laboratorj^ investigations, though a cicada sup- 

 posed to have been impaled by a shrike was found by Mrs. Musick, at 

 Mount Oarmel, 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 y<mng 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 fmin 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 i)ests. 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; and 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. 



HIKl>S KATKN BY THE LOGUKRHKAl). 



Only 7 birds were found in the 88 loggerhead stomachs examined. 

 One of these was an English sparrow, another a tree sjjarrow, and 

 most of the others, which were not specifically identified, were also 

 seed eating birds. 



