64 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 



adult moths arid some pupae, aggregate 33 percent, which is three 

 times as many as were eaten by the old birds. They were found in 

 22 of the 29 stomachs. The most interesting part of this item is 15 

 codling moth pupae that were contained in 7 stomachs. Four adult 

 stomachs also contained one each of these pupae, but they seem to 

 be mostly reserved as tidbits for the young. Grasshoppers and 

 crickets were found in 21 stomachs, and aggregate 30 percent of the 

 food, more than eight times as much as was eaten by the adults, so 

 these insects also are evidently reserved for the nestlings. Spiders 

 amount to 11 percent of the food of the young, although less than 1 

 percent of the parents' food. Various other insects and a few snails 

 make up the rest of the animal food. 



The vegetable food consists of fruit, grain, and rubbish. Fruit, 

 probably cherries, was found in 4 stomachs of one brood. The 

 average for each stomach was 43 percent. This was the oldest 

 brood taken, and the birds were nearly ready to fly, which probably 

 accounts for the large proportion of vegetable food. Oats, found in 

 the stomach of one bird about a week old, amounted to about 45 

 percent of the contents, and seemed unusual food for so young a 

 bird. The other two of the same brood had grass and other rubbish 

 in their stomachs. Rubbish is the best term to describe the vegeta- 

 ble matter in most of these stomachs. The fruit and grain were all 

 that should be called food. 



One can not fail to notice the very pronounced difference in diet 

 between these nestlings and the adults. Not only is the animal 

 food of the young greatly in excess, but it is practically made up of 

 spiders, caterpillars, and grasshoppers. All of these are compara- 

 tively soft-bodied creatures, and probably on that account are 

 selected for the young. 



SUMMARY. 



. In so far as its animal food is concerned, but little fault can be 

 found with the Brewer blackbird. The insects eaten are fairly well 

 distributed among the various orders, and include only a compara- 

 tively small number that are useful. As to fruit, no more is eaten 

 than may be considered a fair return for the destruction of insects. 

 The weed seed eaten must be set down to the bird's credit. All 

 question, then, in regard to its economic position must rest upon the 

 grain it eats. Most of the grain is taken in the months from August 

 to February, inclusive. The average amount consumed in those 

 seven months is over 75 percent of the food, while the average for* 

 the other five months is less than 24 percent, yet this last period 

 covers the time from sowing to the end of harvest. As matters 

 stand at present, probably the bird is doing no harm by eating grain, 

 except perhaps under exceptional circumstances. It has a decided 



