CHAP. 35.—BIRDS WHICH TAKE THEIR DEPARTURE FROM US, AND
WHITHER THEY GO; THE THRUSH, THE BLACKBIRD, AND THE
STARLING—BIRDS WHICH LOSE THEIR FEATHERS DURING THEIR
RETIREMENT—THE TURTLE-DOVE AND THE RING-DOVE—THE
FLIGHT OF STARLINGS AND SWALLOWS.
In a similar manner also, the blackbird, the thrush, and the
starling take their departure to neighbouring countries; but
they do not lose their feathers, nor yet conceal themselves, as
they are often to be seen in places where they seek their food
during the winter: hence it is that in winter, more especially,
the thrush is so often to be seen in Germany. It is, however,
a well-ascertained fact, that the turtle-dove conceals itself, and
loses its feathers. The ring-dove, also, takes its departure:
and with these too, it is a matter of doubt whither they go.
It is a peculiarity of the starling to fly in troops, as it were,
and then to wheel round in a globular mass like a ball, the
central troop acting as a pivot for the rest. Swallows are the
only birds that have a sinuous flight of remarkable velocity;
for which reason it is that they are not exposed to the attacks
of other birds of prey: these too, in fine, are the only birds that
take their food solely on the wing.