92 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 



be the only kind eaten to any considerable extent, and in the later 

 summer wild fruit forms a large part of its vegetable diet. This 

 thrush does not aid in the destruction of the seeds of noxious weeds. 

 In its insect diet the russet-back thrush is almost wholly beneficial, 

 as it eats but few predaceous beetles or other useful insects. As 

 young thrushes are fed almost exclusively upon insects, and as they 

 eat almost continuously from morning till night, they must destroy 

 an enormous number of these harmful creatures. From our present 

 knowledge of its food and general habits, the russet -back thrush must 

 be considered as one of our positively beneficial birds. 



HERMIT THRUSH. 



(Hylocichla guttata.) 



The hermit thrush occurs in the valley and foothill parts of Cali- 

 fornia only as a winter visitant. Thus it can destroy no fruit, except 

 perhaps olives, and thus far no complaints have been made against 

 the species in this respect. Although the bird has not yet attracted 

 attention b} 7 depredations upon fruit, it may be well, nevertheless, 

 to glance at its food habits as indicated by the contents of 68 stomachs. 

 These were mostly taken in or about the Bay region, while a few 

 came from the southern part of the State. Examination of the con- 

 tents of these stomachs shows animal matter to the extent of 56 

 percent and vegetable 44 percent. The proportion of the two 

 elements varies little in the different months. 



Animal food. — Hymenoptera, mostly ants, constitute the largest 

 item of the insect food. They amount to 24 percent, and appear to 

 be eaten regularly in every month. This record is better than that 

 of the russet-back. Caterpillars come next in importance, and form 

 10 percent of the food. They seem to be eaten rather more freely 

 in February and March than in other months, though they are taken 

 at all times of year. Predatory beetles (Carabidse) are noticeable by 

 their absence, as only a few remains of them appear. Beetles of other 

 families, all harmful species, form 11 percent of the food. Weevils, 

 or snout-beetles (Shynchophora), constitute more than two-thirds 

 of these, which would seem to indicate that they are a favorite food. 

 When we consider that the carabids live on the ground, and are the 

 most abundant and most easily obtained of any of the common 

 beetles, and note how few of them the hermit thrush eats, while on 

 the other hand it eats many snout-beetles, which, living to a great 

 extent on trees, are generally much more difficult to find, we are 

 forced to the conclusion that the latter are a preferred food, and that 

 the} 7 are purposely sought for. Other insects, with some spiders and 

 a few miscellaneous articles of diet (Oniscus), amount to about 12 



