JAY FAMILY. 53 



are eaten so often, it is surprising that they do not form a larger 

 percentage of the food. 



A few miscellaneous creatures, such as raphidians, spiders, snails, 

 etc., form less than one-half of 1 percent of the food. 



The following is a list of insects identified in the stomachs of the 

 California jay: 



COLEOPTERA. 



Amara conflata. Diabrotica sp. 



Silpha ramosa. Coniontis robusta. 



Limonius fulvipes . Blapstinus rufipes. 



Perothops witticki. Sciopithes obscurus. 



Onthophagus sp. Balaninus sp. 



HEMIPTERA. 



Sinea diadema. Saissetia olese. 



HYMENOPTERA. 



LEPIDOPTERA. 



mellifera. 

 Carpocapsa pomonella. 



ORTHOPTERA. 



Melanoplus devastator. 



Besides the insects and other invertebrates already discussed, the 

 jay eats some vertebrates. The remains consisted of bones or feathers 

 of birds in 8 stomachs, eggshells in 38, bones of small mammals 

 (mice and shrews) in 11, and bones of reptiles and batrachians in 13 

 stomachs. In destroying small mammals the jay is conferring an 

 unmixed good, as practically all of them are injurious. His appetite 

 for reptiles and batrachians, however, is unfortunate. These crea- 

 tures, being mostly insectivorous, are very useful. Probably, how- 

 ever, their ranks are not seriously thinned by the jay. Of those eaten, 

 9 were lizards, one a snake, one a frog, and 2 others were batrachians, 

 but could not be further identified. The great interest in the jay's 

 vertebrate food, however, centers about the remains of birds and 

 eggs. Of the 46 stomachs containing these remains, 17 were taken 

 between the middle of May and the middle of July, and, as this period 

 practically covers the nesting season in California, all may be con- 

 sidered as from the nests of wild birds robbed by the jay. The others 

 represent either the eggs of domestic fowls or old eggshells. In the 

 above period 95 stomachs were collected, of which 17, or 18 percent, 

 contained eggs or remains of young birds. If we may infer, as seems 

 reasonable, that 18 percent of the California jays rob birds' nests 

 every day during the nesting season, then we must admit that the 

 jays are a tremendous factor in preventing the increase of our com- 

 mon birds. Mr. Joseph Grinell, of Pasadena, after careful observa- 

 tion, estimates the number of this species in California at about 



