BIRDS IN RELATION TO THE ALFALFA WEEVIL. 13 



Three of a brood of five fully fledged young had divided the re- 

 mains of a small passerine bird. Another had been fed on what ap- 

 peared to be the remains of a young robin, while a third had eaten 

 eggs of the same species. The vegetable food was mainly rubbish. 



In June late broods of magpies (see PL I, fig. 1) were frequently 

 fed on the larvae of the weevil. Eighteen of twenty-five birds ex- 

 amined had eaten the insect at an average of 5.6 adults, 0.08 pupa, 

 and 29.24 larvae per bird, amounting to 6.6 per cent of the stomach 

 contents. The largest quantities of these insects occurred in this 

 series of stomachs. A brood of six nestlings, about four to five days 

 old, was observed in a cottonwood near the border of an alfalfa field. 

 This field had been cut one morning, and during the afternoon the 

 parent magpies were noticed making numerous visits, and judging 

 from the well-filled stomachs of the young birds, the old birds had 

 made good use of their time. This brood had consumed 36 adults, 

 2 pupae, and 677 larvae, an average of over 102 individuals per bird. 

 As the young had also eaten a varied assortment of other food, com- 

 prising at least 25 different items, the weevil formed only 18.7 per 

 cent of the contents. 



The remaining animal food for June was essentially the same as 

 for May, save that grasshoppers, taken in considerable numbers, 

 amounted to over 13 per cent. Three of a brood of five had divided 

 the remains of a sparrow, while one of another hatch had eaten the 

 eggs of. a robin. 



Adults. Being a resident the year round, the magpie was fre- 

 quently seen on cold, windy April days visiting alfalf a . fields. It 

 was at first thought that bits of carrion or field mice might be the 

 attraction, but analysis of stomachs showed that the birds were mak- 

 ing diligent search in the stubble and under clods of earth for the 

 adult weevils. Each of five birds examined had eaten weevils. 

 One had taken no less than 160 adults, while others had eaten 60, 55, 

 45, and 19 adults, respectively. These composed 26.2 per cent of the 

 magpie's food. 



The omnivorous nature of these birds is not revealed this early, 

 when comparatively few articles of food are available. Carrion 

 occurred in four stomachs, amounting to over 40 per cent. Bones 

 of a batrachian were found in another. Of the vegetable food, the 

 larger part ( 19 per cent) was waste grain. 



Eight magpies were collected in May, but the stomachs of three 

 were too nearly empty to be of use. However, two of these revealed 

 traces of adult weevils. Each of the other five had eaten this insect 

 in quantities varying from 2 to 50 per cent of the stomach contents, 

 while one especially remarkable stomach contained 181 adult weevils. 

 No grain had been eaten by these birds, but there was an increased 



