The Brewer blackbird[36] takes the place in the Western States of the
grackle, or crow blackbird, which lives in the Mississippi Valley and
farther east and is very similar in appearance and habits. It breeds east
to the Great Plains and north into Canada, and winters over most of its
breeding range in the United States and south to Guatemala. At home in
fields, meadows, and orchards, and about ranch buildings and cultivated
lands generally, it nests in bushes and weeds, sometimes in trees, and is
very gregarious, especially about barnyards and corrals. The bird feeds
freely in stockyards and in cultivated fields, and when fruit is ripe
does not hesitate to take a share During the cherry season in California
the birds are much in the orchards. In one case they were observed
feeding on cherries, but when a neighboring fruit grower began to plow
his orchard almost every blackbird in the vicinity was upon the newly
opened ground close after the plowman's heels in its eagerness to secure
the insects turned up.
[36] _Euphagus cyanocephalus_.
The laboratory investigation of this bird's food covered 312 stomachs,
collected in every month and representing especially the fruit and grain
sections of southern California. The animal portion of the food was 32
per cent and the vegetable 68 per cent.
Caterpillars and their pupæ amounted to 12 per cent of the whole food
and were eaten every month. They include many of those pests known as
cutworms. The cotton-boll worm, or corn-ear worm, was identified in at
least 10 stomachs, and in 11 were found pupæ of the codling moth. The
animal food also included other insects, and spiders, sow bugs, snails,
and eggshells.
The vegetable food may be divided into fruit, grain, and weed seeds.
Fruit was eaten in May, June, and July, not a trace appearing in any
other month, and was composed of cherries, or what was thought to be
such, strawberries, blackberries or raspberries, and fruit pulp or skins
not further identified. However, the amount, a little more than 4 per
cent for the year, was too small to make a bad showing, and if the bird
does no greater harm than is involved in its fruit eating it is well
worth protecting. Grain amounts to 54 per cent of the yearly food and
forms a considerable percentage in each month; oats are the favorite and
were the sole contents of 14 stomachs, and wheat of 2, but no stomach
was completely filled with any other grain. Weed seeds, eaten in every
month to the extent of 9 per cent of the food, were found in rather small
quantities and irregularly, and appear to have been merely a makeshift.
Stomachs of nestlings, varying in age from 24 hours to some that were
nearly fledged, were found to contain 89 per cent animal to 11 per cent
vegetable matter. The largest items in the former were caterpillars,
grasshoppers, and spiders. In the latter the largest items were fruit,
probably cherries; grain, mostly oats; and rubbish.