Plumage compact; size generally small; bill small, much depressed, very
wide at base, and suddenly compressed to the tip, giving it a somewhat
triangular shape; wings long; tail various, frequently forked; legs and
feet short and weak.
These birds form a peculiar and easily-recognized family, species of
which inhabit all parts of the world, and in civilized countries are
generally regarded with favor. The Swallows are eminently social and
gregarious, being almost constantly seen in companies even in the
breeding season, and are amongst the comparatively few birds whose
numbers are not diminished by the progress of the settlement and
cultivation of countries. They subsist exclusively on insects captured
on the wing, in the pursuit of which they exhibit extraordinary powers
of flight.