12 BULLETIN 107, U. S. DEPARTMENT OF AGRICULTURE. 



flanked both sides of the stream, whatever was learned here concern- 

 ing the magpie as a weevil enemy must be regarded as having been 

 obtained under most favorable conditions. 



Nestlings. A series of 134 stomachs of nestlings was secured in 

 May, and in 79 the weevil was found. It usually occurred in small 

 numbers, the average for the lot being 4.8 weevils per bird, which 

 amounted to 2.42 per cent of the food. Some, however, had eaten 

 considerable numbers of the breeding adults. A half -fledged young 

 had been fed 74 of the insects, and 5 others had eaten, respectively, 

 62, 55. 33, 26, and 24. 



Examination of these stomachs shows how omnivorous are these 

 birds, no less than 85 different items being recognized, besides large 

 quantities of carrion and rubbish. In the material identified were 

 six orders of insects, spiders, a shrimp, mollusks, a reptile, batra- 

 chians, earthworms, three species of birds, four of mammals, and 

 seeds of eight species of plants. As each of these items has a differ- 

 ent economic significance, the problem of the value of the magpie is 

 complicated. 



The largest animal food item was caterpillars (22.1 per cent), 

 which occurred in 104 stomachs. Many of these were cutworms, 

 gleaned from alfalfa fields along with the weevil. The remains of 

 small mammals and carrion of many forms amounted to 14.75 and 

 11.86 per cent, respectively. Among the mammal remains were 

 recognized meadow mice (Microtus), ground squirrels (Citellus 

 mottis), a gopher (Thomomys], and a shrew (Sorex leucogenys}. 

 Associated with the carrion were large numbers of muscid pupae and 

 larvae, which comprised 16.34 per cent of the stomach contents. It 

 appeared from some of the material that parent birds visited a car- 

 cass of a beef or horse and removed only dipterous Iarva3 and pupae, 

 leaving the putrid animal matter as a breeding ground for more of 

 the same. The stomachs of many young birds were nearly filled 

 with the dipterous remains, only a few black or brown hairs indi- 

 cating the source of the food. Ground beetles formed 5.15 per cent 

 of the food, and miscellaneous Coleoptera, members of the genera 

 NeoropJiorus and SilpJia predominating, 4.05 per cent. Other insect 

 food was divided in small quantities under several heads. 



Other components of the animal food economically highly impor- 

 tant were the remains of chickens and wild birds and their eggs. The 

 feathers of what appeared to be a young chicken were found in 

 the stomachs of two young birds of the same brood while fragments 

 of eggshell occurred in 22 of the 134 collected. The entire stomach 

 contents of one young magpie consisted of eggshell and what ap- 

 peared to be its partially incubated contents. Another stomach was 

 about four-fifths full of similar material. 



