94 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 



months mentioned, 71 stomachs remain, from which a fairly reliable 

 idea of the winter food of the robin in California may be obtained. 



In the first examination we find 40 percent of animal food to 60 

 of vegetable. The food of eastern robins for the whole year con- 

 tains 42 percent of animal matter to 58 percent of vegetable, and 

 during the six months beginning on November 1 the amounts are: 

 Animal 35 percent and vegetable 65 percent. If, however, our study 

 is restricted to the three winter months, we find that the eastern robin 

 eats 18 percent of animal food and 82 percent of vegetable, while 

 for the same period the western one consumes 22 percent animal 

 and 78 percent vegetable. These comparisons do not indicate essen- 

 tial differences in the food of the two birds. The western bird eats 

 more insects during the winter months because on the west coast 

 insects are more abundant and more easily obtained at that season 

 than in the East. Confining attention, however, to the six months 

 beginning with November, the eastern bird eats a greater percentage 

 of insects. It is almost certain that if the material were at hand to 

 illustrate the food of the western robin during the remainder of 

 the year, the bird would be found to eat a nuich larger percentage 

 of insects than in the six months covered by this investigation. 



'Animal food. — Beetles of various families are the largest item of 

 animal food. The greater number were eaten in April, when they 

 amount to over 54 percent of the whole food for the montli. They 

 were distributed among several families, but the most conspicuous 

 were t'he snout-beetles, or Aveevils, Avhich aggregated 25 percent. 

 This is a favorable showing for the robin, for these beetles are among 

 the most harmful insects with which the fruit growers and farmers 

 have to contend. The average percentage of beetles for the whole 

 six months is about 13 percent of the food. Caterpillars are next in 

 order of abundance and amount to over 4 percent. The remainder of 

 the animal food is made up of various insects, of which no order 

 claims preeminence, and of a few angleworms. 



Vegetable food.— The bulk of the vegetable food from November 

 onward is cultivated fruit. After this month it gradually falls off, 

 and very little was found in stomachs collected in March and April. 

 With the exception of olives, the bird can obtain no fruit of value 

 after the 1st of November, and as olives were not identified in any of 

 the stomachs it is probable that most of the fruit consumed was 

 worthless, having been left after the crop was gathered. The follow- 

 ing fruits were identified : Grapes in 5 stomachs, figs in 3, prunes in 

 2, pear, apple, and blackberries in 1 each. Of wild fruit, pepper ber- 

 ries were found in 17 stomachs, mistletoe berries in 2, and fruit not 

 positively identified in 11. Pepper berries evidently are the favorite, 

 since not only were they found in the greater number of stomachs, 

 but 1 stomach contained 24 and another 28 of these berries. Two 



