THE SMALLER BIRDS
“Almost all the smaller birds are helpful to us in protecting the
fruits of the earth from the ravages of insects. Their services deserve
to be recorded in a long and detailed history, but time for that is
lacking and we must confine ourselves to brief mention of a few of
these valiant caterpillar-destroyers.
“The titmouse, or tomtit, is a small bird full of life and showing a
petulant humor. Always in action, it flits from tree to tree, examines
the branches with minute particularity, perches on the swaying end of
the frailest twig, where it clings persistently even though hanging
head downward, accommodating itself to the oscillations of its flexible
support without once relaxing its clutch or ceasing its scrutiny of the
worm-infested buds, which it tears open in order to get at the enclosed
vermin and insect-eggs.
“It is calculated that a tomtit rids us of three hundred thousand of
these eggs every year. It has to supply the needs of a family seldom
equalled in size; but the support of twenty young ones, or even more,
is not too heavy a burden for this active bird to bear. With this
infant brood on its hands, it must give constant and careful inspection
to buds and to fissures in the bark, in order to catch larvæ, spiders,
caterpillars, little worms of all kinds, and thus find food for twenty
beaks incessantly agape with hunger at the bottom of the nest.
“Let us suppose the mother bird to arrive with a caterpillar. The nest
is immediately all in a tumult: twenty beaks are stretched wide open,
but only a single one receives the morsel, while nineteen are kept
waiting. The indefatigable mother flies off again, and when the
twentieth beak has at last been fed, the first has long since begun
again its importunate demands. What a multitude of worms such a brood
must consume!
“Whole families of birds devote themselves, as does the titmouse, to
this patient quest for insect eggs in the crevices of tree-trunks or
concealed in rolled-up leaves, for larvæ between the scales of buds and
in worm-holes in wood, and for insects hidden in cracks and crannies.
In this kind of hunt the bird does not have to chase its game and catch
it by superior swiftness of flight; it must simply know how to find it
in its lair. To this end it needs a keen eye and a slender beak; wings
play but a secondary part.
“But other species spend their energies in the free open-air chase:
they pursue their game on the wing, hunting for gnats, moths,
mosquitoes, and flying beetles. They must have a short beak, but one
that opens wide and snaps up unerringly insects on the wing, despite
the uncertainties of aërial flight; a beak in which the victim is
caught and held without any retardation of the bird’s swift course; in
short, a beak with a sticky lining which a tiny butterfly cannot so
much as graze with its wing and not become entangled. Above all, an
untiring and swift wing is necessary, one that does not flag in the
pursuit of game desperately putting forth its utmost efforts to escape,
and one that is not baffled by the tortuous course of a moth driven to
bay. A beak inordinately cleft and wings of extraordinary power—such,
in a word, should be the equipment of the bird whose hunting ground is
the vast expanse of the open air.
“These conditions are fulfilled in the highest degree in the swallow
and the martin, both of which hunt flying insects, pursuing them this
way and that, back and forth, ceaselessly and with a thousand subtle
tricks. They catch them in their wide-open and viscous gullet, and
continue their course without a moment’s pause.
“The bird that lives on grain and seeds, the granivorous bird, as it is
called, has a beak that is very wide at the base and adapted by its
strength to the opening of the hardest seeds. In this class are the
chaffinch, the greenfinch, the linnet, the goldfinch, and the swallow.
The bird that lives on insects, or the insectivorous bird, has a beak
that is fine and slender, in delicacy proportioned to the softness of
its prey. To this number belong the nightingale, the warbler, the
fallow-finch, and the wagtail. Agriculture has no better defenders
against the ravages of worms than these little birds with slender
beaks, voracious devourers as they are of larvæ and insects.
“But the granivorous birds have certain grave faults: some of them are
addicted to pilfering in the grain-fields and know how to get the wheat
out of the ear, and some even come boldly to the poultry-yard to share
with its inmates the oats thrown to them by the farmer’s wife. Others
prefer the juicy flesh of fruit, and know sooner than we when the
cherries are ripe and the pears mellow. Such failings, however, are
amply atoned for by services rendered. The granivores pick up in the
fields an infinite number of seeds of all sorts which, if left to
germinate, would infest our crops with weeds.
“To this rôle of weeder they add a second not less meritorious. Grain
and seeds are, it is true, their regular diet; but insects are to few
of them so despicable as to be refused when sufficiently plentiful and
easy to catch. Indeed, we can go still further in our commendation of
these birds: in their early days when, feeble and featherless, they
receive their nourishment by the beakful from their parents, many of
them are fed on insects.
“Let us take for example the house-sparrow. Here we have, it must be
admitted, an inveterate devourer of grain. He robs our dove-cotes and
poultry-yards, steals their food from the pigeons and the hens, and
anticipates the farmer in reaping the grain-crops near his house. Many
other misdeeds are to be reckoned against him. He plunders the
cherry-trees, commits petty larceny in the garden, plucks up sprouting
seeds, and regales himself on young lettuce and the first leaves of
green peas. But as soon as the season of insect-eggs opens, this
shameless pilferer becomes one of our most valuable helpers. Twenty
times an hour, at least, the mother and the father take turns in
bringing the beakful of food to their little ones; and each time the
bill of fare consists of a caterpillar, or an insect large enough to be
divided into quarters, or perhaps a fat larva, or it may be a
grasshopper, or some other kind of small game.
“In one week the young brood consumes about three thousand insects,
larvæ, caterpillars and worms of all species. There have been counted
in the immediate vicinity of a single nest of sparrows the remains of
seven hundred June-bugs, besides those of innumerable smaller insects.
That is the supply of food required for rearing only one brood. Let us
then, my children, wish well to all the little birds that deliver us
from that formidable ravager, the insect.”