8 
Conservation Bulletin 18 
which they were accustomed to feed. Under these circumstances what is more 
natural than for the birds to turn to cultivated fruit for their food. The 
remedy is obvious: Cultivated fruits can be protected by the simple expedient 
of planting the wild species which are preferred by tlie birds. Some experi¬ 
ments with catbirds in captivity show that the Russian mulberry is preferred 
to any cultivated fruit. 
The stomachs of 645 catbirds were examined and found to contain 44 per 
cent of animal (insect) and 56 per cent of vegetable food. Ants, beetles, cater¬ 
pillars, and grasshoppers constitute three-fourths of the animal food, the re¬ 
mainder being made up of bugs, miscellaneous insects, and spiders. One-tliird 
of the vegetable food consists of cultivated fruits, or those which may be 
cultivated, as strawberries, raspberries, and blackberries; but while we debit 
the bird with the whole of this, it is probable—and in the eastern and well- 
wooded part of the country almost certain—that a large part is obtained from 
wild vines. The rest of the vegetable matter is mostly wild fruit, as cherries, 
dogwood, sour gum, elderberries, greenbrier, spiceberries, black alder, sumac, 
and poison ivy. Although the catbird sometimes does considerable harm by 
destroying small fruit, it can not on the whole be considered injurious. On 
the contrary, in most parts of the 
country it does far more good than 
harm. 
THE SWALLOWS 
Seven common species of swal¬ 
lows are found within the limits of 
the United States, four of which 
have abandoned to some extent their 
primitive nesting habits and have 
attached themselves to the abodes 
of man. 
In the eastern part of the country 
the barn swallow 17 (fig. 7) now 
builds exclusively under roofs, hav¬ 
ing entirely abandoned the rock 
caves and cliffs in which it for¬ 
merly nested. More recently the 
cliff swallow 18 has found a better 
nesting site under the eaves of 
buildings than was afforded by the 
Pig. 7.—Barn swallow. Length, about 7 inches, overhanging cliffs of earth or stone 
which it once used and to which it 
still resorts occasionally in the East and habitually in the unsettled West. The 
martin 19 and the white-bellied, or tree, swallow 20 nest either in houses supplied 
for the purpose, in abandoned nests of woodpeckers, or in natural crannies 
in rocks. The northern violet-green swallow, 21 the rough-winged swallow, 22 and 
the’ bank swallow 23 still live in practically such places as their ancestors chose. 
Field observation convinces an ordinarily attentive person that the food of 
swallows must consist of the smaller insects captured in mid-air or picked from 
the tops of tall grass or weeds. This observation is borne out by an examina¬ 
tion of stomachs, which shows that the food is made up of many small species 
of beetles which are much on the wing; many species of flies, together with 
large quantities of flying ants; and a few insects of similar kinds. Most of 
these are either injurious or annoying, and the numbers destroyed by swallows 
are not only beyond calculation but almost beyond imagination. 
Unlike many other groups of birds, the six species of swallows found in the 
Eastern States extend in a practically unchanged form across the continent, 
where they are reinforced by the northern, or Pacific-coast, violet-green swallow. 
It is a mistake to tear down from the eaves of a barn the nests of a colony of 
cliff swallows, for so far from disfiguring a building they make a picturesque 
addition to it, and the presence of swallows should be encouraged by every 
17 Hirundo erythrogaster. 
18 Petrochelidon lunijrons. 
i» p r ogne subis. 
20 Jridoprocne bicolor. 
21 Tachycineta thalassina. 
22 Stelgidopteryx serripennis 
23 Riparia riparia. 
