THE INSTINCTIVE CLEVERNESS DISPLAYED BY BIRDS IN THE CONSTRUCTION OF
THEIR NESTS.
The form of the nest built by the halcyon reminds me also of the
instinctive cleverness displayed by other birds; and, 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.
There is a kind of swallow 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,
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 labor, that many of them die with
their exertions.
A third kind of swallow 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.