Concord, Mass.
1901.
July 14
(No 3)
(Chaetura pelagica) the chimney soon after daybreak and
did not once return to it until nearly dark. On the
evening of the 13th one of them came in at 7.40, the
other at 7.50; on that of the 14th they returned
practically together at 7.50.
  This manner of entering and leaving the chimney varied.
Sometimes the bird would descend to the nest or ascend
from it by one continuous flight during which it kept
its body nearly horizontal and restarted the downward or
accomplished the upward movement by rapidly beating
its fully extended wings the tops of which nearly touched
the opposite sides of the narrow flue. Not infrequently,
however, it would first alight just inside the mouth
of the chimney and after clinging there for a moment
begin descending by a succession of short flights while
its ascent was often performed in the same manner.
During some of these shorter flights the bird used not
only its wings but its feet, running, as it were, either
up or down the vertical surface, within foot-reach
of which it maintained its body but constantly vibrating
its wings. Every such movement of the wings, whether of
long or short countenance, was accompanied by the
hollow (or rather ruffled) rumbling sound which
one always hears so frequently in summer in
chimneys where Swifts are breeding. From some
observations which I made when we were passing the
summer of 1892 in the Tolman Cottage in Concord
I concluded that this sound was sometimes produced
intentionally rather than incidentally; or, to be more precise,
that the birds sometimes extended and beat their
wings for the express purpose of making the sound.
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