Concord, Mass.
1910.
May 8
(No 3)
[May 8, 1910]

  The discomfort of lying awake the greater part of
last night was compensated for in large measure by the
interest of hearing Swamp Sparrows singing almost incessantly
for two or three hours before daybreak. There were at least
two and I think three of them. During the period just
mentioned (probably from 1 to 3 A.M.) I heard one or
more of them every four or five minutes, and often there
would be two or three songs uttered within the minute.
Swamp Sparrows singing freely in middle of night
  Bitterns, also, were heard every five or ten minutes during
this same period. It is very unusual, according to my
experience, to hear them pumping in the middle of
the night or indeed at any time when there is not
at least some daylight.
Bitterns pumping in middle of night
  The stars were shining brightly all night but there
was no moonlight. The air was calm & warm.