[Illustration: THE ROOK (_Corvus frugilegus_).]
The ROOK, or FIELD CROW (_Corvus frugilegus_, or _Frugilegus segetum_),
is a most useful species, inhabiting all the plains of the south of
Europe and the southern portion of Siberia, even as far as Afghanistan
and Cashmere. These birds are distinguished by their slim appearance, the
decided elongation of their beaks, their long wings, abruptly rounded
tails, close, glossy plumage, and by the bareness of the face observable
in the old birds, occasioned, probably, by continually rubbing it upon
the ground when in search of food. Their length is from about eighteen
to nineteen inches, the breadth thirty-seven to thirty-nine inches,
the wing measures thirteen to fourteen inches, and the tail ten and
a half inches. The plumage of the adults of both sexes is an uniform
purplish black, and that of the young birds pale black; the faces of
the latter are covered with feathers. Unlike the members of the family
described above, the Rooks migrate regularly, and in enormous swarms,
towards Southern Europe and the north of Africa, everywhere preferring
well-wooded and fruitful plains, and never settling upon mountains except
whilst occupied in journeying from one country to another. Like their
congeners, they assemble in flocks, usually choosing a clump of trees
as a gathering point, from which they fly over the neighbourhood, and
upon these they build their nests. In their habits they are more social
than other Crows, freely associating with birds that are weaker than
themselves, but exhibiting such fear of the Raven that they will vacate
a favourite resort on its first appearance, even although they may be
so attached to the locality as to refuse to quit it when men attempt to
drive them from the spot. In bodily endowments and intelligence they are
inferior to none of their family, but are far more timid and harmless in
their disposition. Their voice is deep and hoarse, and though they are
capable of imitating sounds, they never attain the power of pronouncing
words. In spite of the comparative amiability of disposition exhibited
by the Rooks, they render themselves extremely troublesome in a variety
of ways, almost deafening their hearers by their incessant cawing, and
frequently doing considerable mischief by stealing fruit from the gardens
or seed from the fields, and even giving proof of still more voracious
propensities by strangling young hares or partridges. For the most part,
however, the food of this species consists of cockchafers and their
destructive larvæ or slugs; whilst in pursuit of these, their acute sense
of smell would seem to guide them to the exact spot under which they
lie concealed, and so enormous are the numbers they dig up, that, as we
have said, the hungry Rooks actually rub the feathers from their faces
by constantly burrowing in the ground with their beaks. In the breeding
season, numerous pairs build close together, quarrelling the whole time,
and robbing each other incessantly of the materials collected. The female
alone broods upon the eggs, which are usually four or five in number,
of a pale green, spotted with dark brown. During the time of incubation
comparative peace reigns in the colony; but no sooner are the nestlings
hatched than the uproar is redoubled tenfold, as the hungry little ones
clamour for food in most discordant tones from daybreak till the sun goes
down.
[Illustration: THE JACKDAW (_Monedula turrium_).]
Large numbers of Rooks are destroyed during their migrations, which are
made in flocks of incredible magnitude; whilst flying in this manner
from place to place they may sometimes be seen to delay their course
for half an hour at a time, merely to enjoy the pleasure of hovering or
performing a variety of evolutions on the wing, descending somewhat in
their flight as they pass over mountains, and soaring high into the air
when about to cross lowland districts; sometimes, as though again wishing
to alight, they plunge directly earthwards, falling like a lifeless mass
from two hundred feet above the ground, and then fly gently onwards for
a short distance before again ascending to continue their journey. In
the southern part of Europe, and in the north of Africa, the flocks are
seldom met with of the enormous size above described, as before reaching
so great a distance these large bodies have separated, and gone to spread
themselves in less destructive numbers over the countries they select
as winter quarters; despite this precaution, thousands perish from
starvation, and we ourselves have seen hundreds covering the ground near
Suez, the weary travellers not having found the food which they had come
so far to seek.