CHAP. 49. (33.)—THE INSTINCTIVE CLEVERNESS DISPLAYED BY
BIRDS IN THE CONSTRUCTION OF THEIR NESTS. THE WONDER-
FUL WORKS OF THE SWALLOW. THE BANK-SWALLOW.
The form of the nest built by the halcyon reminds me also
of the instinctive cleverness displayed by other birds; and, indeed, in no respect is the ingenuity of birds more deserving of
our admiration. The swallow builds its nest of mud, and
strengthens it with straws. If mud happens to fail, it soaks
itself with a quantity of water, which it then shakes from off
its feathers into the dust. It lines the inside of the nest with
soft feathers and wool, to keep the eggs warm, and in order
that the nest may not be hard and rough to its young when
hatched. It divides the food among its offspring with the
most rigid justice, giving it first to one and then to another.
With a remarkable notion of cleanliness, it throws out of the
nest the ordure of the young ones, and when they have grown
a little older, teaches them how to turn round, and let it fall
outside of the nest.
There is another1
kind of swallow, also, that frequents the
fields and the country; its nest is of a different shape, though
of the same materials, but it rarely builds it against houses.
The nest has its mouth turned straight upwards, and the entrance
to it is long and narrow, while the body is very capacious. It
is quite wonderful what skill is displayed in the formation of
it, for the purpose of concealing the young ones, and of presenting a soft surface for them to lie upon. At the Heracleotic
Mouth of the Nile in Egypt, the swallows present an insuperable obstacle to the inroads of that river, in the embankment which is formed by their nests in one continuous line,
nearly a stadium in length; a thing that could not possibly
have been effected by the agency of man. In Egypt, too,
near the city of Coptos, there is an island sacred to Isis. In
the early days of spring, the swallows strengthen the angular corner of this island with chaff and straw, thus fortifying it in order that the river may not sweep it away. This
work they persevere in for three days and nights together, with
such unremitting labour, that it is a well-known fact that
many of them die with their exertions. This, too, is a toil
which recurs regularly for them every year.
There is, again, a third kind2
of swallow, which makes holes
in the banks of rivers, to serve for its nest. The young of
these birds, reduced to ashes, are a good specific against mortal
maladies of the throat, and tend to cure many other diseases of
the human body. These birds do not build nests, and they take
care to migrate a good many days before, if it so happens that
the rise of the river is about to reach their holes.