CALIFORNIA SHRIKE. 37 



collected in July. In one stomach remains of robber-flies (Asilida?) 

 were detected. This is a family of large predaceous flies, some species 

 of which are said to prey upon honey-bees. These two orders and a 

 few other odd insects constituted 5 percent of the food. 



Spiders and several other kindred creatures form less than 2 per- 

 cent of the food, but though not eaten in great numbers they appear 

 in a good many stomachs. In one stomach was found one of those 

 bristly and uncanny monstrosities of the order of jointed spiders 

 (Solpugida). It is wonderful that any bird should attack one, still 

 more that it should eat it, as it would seem to be about as palatable 

 as a paper of pins. The lingual ribbon, or tongue, of a snail was 

 found in one stomach, and bits of what appeared to be the limbs of 

 small crustaceans in several. They did not amount to a noticeable 

 percentage. 



Vertebrates. — The vertebrate part of the shrike's food amounts to 

 a little more than 12 percent, and consists of the remains of small 

 mammals, birds, and lizards. Mammals were found in 4 stomachs, 

 birds in 2, and lizards in 12. Neither of the birds could be identified 

 further than that both were small song birds. Of the mammals, 

 one was a pocket mouse (Perognathus), one a young field mouse 

 (Microtus), and one a shrew (Sorex). The fourth mammal could 

 not be identified, as there was little left except hair. The lizards 

 were not recognizable either generically or specifically, as the remains 

 consisted only of bones and scales. From an economic standpoint, 

 lizards are useful animals, as they subsist on insects. The same is 

 true of birds, so that in destroying birds and lizards the shrike is 

 doing harm. Fortunately, it does not eat many birds. The destruc- 

 tion of the mammals is an unmixed blessing, except, perhaps, in the 

 case of the shrew (Sorex), which is largely insectivorous. Even if 

 all the above vertebrates were useful the score against the shrike 

 would not be a very heavy one and would not outweigh the 

 value of its services in destroying grasshoppers. In the writer's field 

 experience with the shrike only one attempt to capture a vertebrate 

 animal was observed. In this case the shrike was seen to plunge 

 into a thicket of weeds in pursuit of a brood of tiny quail, but a 

 few seconds later it emerged in a great hurry, closely followed by 

 the irate cock quail. As a matter of fact, the noxious mammals 

 eaten both by the eastern and western shrikes far outnumber the 

 birds, and when to the former are added harmful insects the balance 

 is very largely on the credit side. 



FOOD OF YOUNG. 



No nestlings of shrikes were at hand for investigation, but the 

 stomachs of two young just out of the nest were examined. Both 



