Perhaps the most important and interesting insect found was the black olive scale, which occurred in 24 stomachs and amounted to a little more than 18 per cent of the food. In addition, a number of the stomachs were more or less filled with another scale, which was not further identified. A number of small snout beetles (weevils) were eaten and some small caterpillars; there were also the remains of a spider.
The vegetable food of the species seemed to consist mostly of seeds, but they were so broken up as to defy recognition. A little fruit pulp and a little mast were also found.
Among the stomachs of the bush tits examined were those of one brood of eight nestlings about 10 days old. The vegetable matter in these stomachs was only three-fourths of 1 per cent and consisted of one seed and some rubbish. The animal matter was made up of beetles, wasps, bugs, caterpillars and pupæ, and spiders. The greatest interest lies in the fact that every one of these stomachs contained pupæ of the codling moth, on an average of over five to each. The oak tree in which these birds were found was in a belt of timber near a neglected orchard which the parent birds used as a foraging ground, and they did their best to remedy the neglect of the owner. As feeding and digestion in the case of nestling birds is almost continuous during the hours of daylight, the above record would be several times repeated during a day’s feeding. There were probably not less than a dozen nests of the bush tit along the border of this orchard, and these birds must have exerted a great restrictive influence upon the increase of the codling moth, as well as of other insects in that vicinity.
Fig. 4.—House wren. Length, about 4¾ inches.
The diminutive house wren[12] ([fig. 4]) frequents barns and gardens, and particularly old orchards in which the trees are partially decayed. He makes his nest in a hollow where perhaps a woodpecker had a domicile the year before, but he is a pugnacious character, and if he happens to fancy one of the boxes put up for bluebirds, he does not hesitate to take it He is usually not slow to avail himself of boxes, gourds, tin cans, or empty jars placed for his accommodation.