6 
Conservation Bulletin IS 
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 pup®, 
and spiders. The greatest interest lies in the fact that every one of these stom¬ 
achs contained pupre 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. 
THE WRENS 
The diminutive house wren 13 
(fig. 4) frequents barns and gar¬ 
dens, and particularly old orchards 
in which the trees are partially 
decayed. He makes his nest in a 
hollow where perhaps a wood¬ 
pecker had a domicile the year 
before, but he is a pugnacious char¬ 
acter, and if he happens to fancy 
one of the boxes put up for blue¬ 
birds, 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. 
In food habits the house wren is entirely beneficial. He may be said to 
live upon animal food alone, for an examination of 88 stomachs showed that 
98 per cent of the contents was made up of insects or their allies, and only 2 
per cent was vegetable food, including bits of grass and similar matter, evi¬ 
dently taken by accident with the insects. Half of this food consisted of 
grasshoppers and beetles; the remainder of caterpillars, bugs, and spiders. 
As the wren is a prolific breeder, frequently rearing in a season from 12 to 16 
young, a family of these birds must cause considerable reduction in the number 
of insects in a garden. Wrens are industrious foragers, searching every tree, 
shrub, and vine for caterpillars, and examining every post and rail of the fence 
and every cranny in the wall for insects or spiders. 
The house wren is only one of a numerous group of small birds of similar 
habits. There are within the limits of the United States 28 species and sub¬ 
species of wrens, occupying more or less completely the whole country from 
the Atlantic to the Pacific. With the exception of the marsh wrens, 14 they all 
appear to prefer some cosy nook for a nesting site, and, as it happens, the 
farm buildings afford just the place desired. This has led several of the wrens 
to seek out the habitations of man, and he is benefited by their destruction of 
noxious insects. Wrens have rarely been accused of harm, and their presence 
should be encouraged except when undue interference with the nests of other 
birds is noted. 
14 Telmatodytes palustris and Cistothorus stellaris. 
13 Troglodytes aedon. 
