Cambridge, Mass.
1905
Nov. 10
  Clear and cool with strong N.W. wind.
  As I was writing in the Museum this evening
(about 9.30 P.M.) I heard twice apparently coming from
the garden the long even roll call which I heard
here so often last spring and which I believe to
be the love song of the Screech Owl. It was in
every respect identical with this spring call and
distinctly different from, although not wholly unlike,
the series of notes (not the wailing ones) that the bird
often utters in summer and autumn. When I described
(& imitated) this spring call to F. M. Chapman he assured
me that he had heard the Florida Screech Owl make
similar sounds at the approach of its breeding season.
Mr. E. H. Forbush also tells me that he has heard
the same call at Wareham in February and March
but not at other seasons.
  Without referring to the notes which I believe I 
made last spring I should describe the call that I
heard to-night as follows. It consisted of a number
(certainly more than a dozen) of low, hollow notes given
with exceeding rapidity and all on the same key without
special emphasis. The general effect may be imitated
by forcibly expelling the breath at the same time striking
the palm of the hand as rapidly as possible against the
lips a trick well known to & often practised by street
(?). The rolling call of the Owl, however, is less loud
than that made by the small boy. It is also more hollow
and the notes are given more quickly and smoothly. Furthermore
it has ventriloqual properties & it is often difficult to decide
as to the direction whence it comes.