86 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 



preference for any -particular kind is indicated. The only decidedly 

 useful insects in any of the stomachs were 2 ladybird beetles {Coc- 

 cinella t. calif orniea), which had been eaten by P. calif ornica. As 

 this beetle is very abundant in California it is not surprising that 

 birds should eat a few of them. Caterpillars amount to about 5 

 percent of the diet of the gnatcatchers. Apparently they are not a 

 favorite food. Other insects, such as a few flies and grasshoppers, 

 with some spiders, aggregate 6 percent, and probably are makeshifts, 

 eaten when nothing more palatable is at hand. 



SUM jM ART. 



^Miile the foregoing discussion of the foocl of the gnatcatchers is 

 based upon a small amount of material, the agreement of the evidence 

 renders it probable that a much larger quantity Avould not greatly 

 change the results. This evidence confirms what *has long been sus- 

 pected, that the gnatcatchers are doing a useful work and should be 

 carefully protected. 



RUSSET-BACK THRUSH. 



{Hylocichla ustulatu. ) 



The russet-back thrush abounds in the region about San Francisco 

 Bay and other parts of the humid coast belt. It remains in this part 

 of the State from April to November, inclusive, and then moves 

 farther south for the winter. Its favorite haunts are the bushes and 

 trees bordering streams, and in these it nests and rears its young. 



While the thrush is very fond of fruit its partiality for banks of 

 streams keeps it from frequenting orchards when they are far from 

 water. It is most troublesome during the cherry season, at the time 

 Avhen the young are in the nest. It might be inferred from this that 

 the nestlings are fed on fruit, but such is not the case to any notice- 

 able extent. The parent birds eat the fruit themselves, while the 

 young, as is usual with nestlings, are fed mostly upon insects. The 

 old birds eat some fruit throughout the season, but do not seem to 

 attract much attention by their depredations on prunes and the later 

 fruits. As the thrush, unlike the linnet, is one of the so-called ' soft- 

 billed ' birds, its attacks on fruit are limited to the thin-skinned varie- 

 ties. Probably it can peck holes in ripe cherries; still it is as often 

 seen on the ground pecking at fallen fruit as attacking the fruit on 

 the trees. It thus probably confines its depredations upon the later 

 fruits to such as have already been broken into by linnets or other 

 stout-billed birds. 



Be this as it may, the thrush is an efficient destroyer of insects, 

 and during the eight months of its sojourn in the fruit region a 

 little more than half of its food consists of harmful insects. In the 



