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. californica), which had been eaten by P. californica. 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. . 
SUMMARY. 
While the foregoing discussion of the food of the gnatcatchers is 
based upon a small amount of material, the agreement of the evidence 
renders it probable that a much larger quantity would 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 ustulata.) 
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 
when 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 
