BLUEBIRD (Sialia sialis) 
Length,* about 6% inches. 
Range: Breeds in the United States (west to 
Arizona, Colorado, Wyoming, and Montana), 
southern Canada, Mexico, and Guatemala; 
winters in the southern half of the eastern 
United States and south to Guatemala. 
Habits and economic status: The bluebird is 
one of the most familiar tenants of the farm 
and dooryard. Everywhere it is hailed as the 
harbinger of spring, and wherever it chooses 
to reside it is sure of a warm welcome. This 
bird, like the robin, phcebe, house wren, and 
some swallows, is very domestic in its habits. 
Its favorite nesting sites are crannies in the 
farm buildings or boxes made for its use or 
natural cavities in old apple trees. For rent 
the bird pays amply by destroying insects, and 
it takes no toll from the farm crop. The blue- 
bird’s diet consists of 68 per cent of insects to 
32 per cent of vegetable matter. The largest 
items of insect food are grasshoppers first and 
beetles next, while caterpillars stand third. 
All of these are harmful except a few of the 
beetles. The vegetable food consists chiefly of 
fruit pulp, only an insignificant portion of 
which is of cultivated varieties. Among wild 
fruits elderberries are the favorite. From the 
above it will be seen that the bluebird does no 
essential harm, but on the contrary eats many 
harmful and annoying insects. (See Farmers’ 
Bul. 54, pp. 46-48.) 
*Measured from tip of bill to tip of tail. 
RUSSET-BACKED THRUSH (Hylocichla 
ustulata) 
Length, 74% inches. Among thrushes having 
the top of head and tail nearly the same color 
as the back, this one is distinguished by its 
tawny eye-ring and cheeks. The Pacific coast 
subspecies is russet brown above, while the 
other subspecies is the olive-backed thrush. 
The remarks below apply to the species as a 
whole. 
Range: Breeds in the forested parts of 
Alaska and Canada and south to California, 
Colorado, Michigan, New York, West Virginia 
(mountains), and Maine; winters from Mex- 
ico to South America. 
Habits and economic status: This is one of 
a small group of thrushes the members of 
which are by many ranked first among Ameri- 
can song birds. The several members resemble 
one another in size, plumage, and_ habits. 
While this thrush is very fond of fruit, its 
partiality for the neighborhood of streams 
keeps it from frequenting orchards far from 
water. It is most troublesome during the 
cherry season, when the young are in the nest. 
From this it might be inferred that the young 
are fed on fruit, but such is not the case. The 
adults eat fruit, but the nestlings, as usual, are 
fed mostly upon insects. Beetles constitute the 
largest item of animal food, and ants come 
next. Many caterpillars also are eaten. The 
great bulk of vegetable food consists of fruit, 
of which two-fifths are of cultivated varieties. 
(See Biol. Surv. Bul. 30, pp. 86-92.) 
ROBIN (Planesticus migratorius) 
Length, 10 inches. 
Range: Breeds in the United States (except 
the Gulf States), Canada, Alaska, and Mexico; 
winters in most of the United States and south 
to Guatemala. 
Habits and economic status: In the North 
and some parts of the West the robin is among 
the most cherished of our native birds. Should 
it ever become rare where now common, its 
joyous summer song and familiar presence will 
be sadly missed in many a homestead. The 
robin is an omnivorous feeder, and its food 
includes many orders of insects, with no very 
pronounced preference for any. It is very 
fond of earthworms, but its real economic 
status is determined by the vegetable food, 
which amounts to about 58 per cent of all. 
The principal item is fruit, which forms more 
than 51 per cent of the total food. The fact 
that in the examination of over 1,200 stomachs 
the percentage of wild fruit was found to be 
five times that of the cultivated varieties sug- 
gests that berry-bearing shrubs, if planted near 
the orchard, will serve to protect more valuable 
fruits. In California in certain years it has 
been possible to save the olive crop from hun- 
gry robins only by the most strenuous exer- 
tions and considerable expense. The bird’s 
general usefulness is such, however, that all 
reasonable means of protecting orchard fruit 
should be tried before killing the birds. (See 
Farmers’ Bul. 54, pp. 44-46.) 
RUBY-CROWNED KINGLET (Regulus 
calendula) 
Length, about 4% inches. Olive green above, 
soiled whitish below, concealed feathers on 
head (crest) bright red. 
Range: Breeds in southern Canada, southern 
Alaska, and the higher mountains of the west- 
ern United States; winters in much of the 
United States and south to Guatemala. 
Habits and economic status: In habits and 
haunts this tiny sprite resembles a chickadee. 
It is an active, nervous little creature, flitting 
hither and yon in search of food, and in spring 
stopping only long enough to utter its beauti- 
ful song, surprisingly loud for the size of the 
musician. Three-fourths of its food consists 
of wasps, bugs, and flies. Beetles are the only 
other item of importance (12 per cent). The 
bugs eaten by the kinglet are mostly small, 
but, happily, they are the most harmful kinds. 
Tree-hoppers, leaf-hoppers, and jumping plant 
lice are pests and often do great harm to trees 
and smaller plants, while plant lice and scale 
insects are the worst scourges of the fruit 
grower; in fact, the prevalence of the latter 
has almost risen to the magnitude of a national 
peril. It is these small and seemingly insig- 
nificant birds that most successfully attack and 
hold in check these insidious foes of horticul- 
ture. The vegetable food consists of seeds of 
poison ivy, or poison oak, a few weed seeds, 
and a few small fruits, mostly elderberries. 
(See Biol. Surv. Bul. 30, pp. 81-84.) 
