Concord, Mass.
1907.
April 8
  Snowing hard all day - big flakes, most of them melting
as they struck but the ground white by noon and covered to
a depth of nearly two inches by nightfall. Wind N.E., very
strong at times.
  Only 7 or 8 Fox Sparrows came about the cabin to-day.
They sang freely in the early morning and late afternoon.
I started several of them from their roosts in the Pine
Park plantation as early as 5 P.M. and saw others
flying to the pines behind Ball's Hill at 6 P.M. but when,
some fifteen minutes later, I got back to the cabin
there were still two or three feeding there.
The chucking call of Passerella similar to if not identical with that of Junco
  I had a chance this evening to directly compare the
clucking note of the Fox Sparrow with that of the Junco
when a bird of each species perched on either side of
me, in plain view and less than twenty yards away
uttered it fifteen or twenty times. They did not cluck
together but alternately, as if answering one another.
Until I saw them distinctly and made sure that each
was uttering the sounds that seemed to come from
it I supposed that they belonged to the same
species for their calls were to my ears identical in form
and tone. Once or twice I thought that the Fox Sparrow
had the stronger voice but of this, even, I was not
quite certain. After closely studying the call which
both gave I decided that it could be best rendered
by the word tuck. The fact that these particular
birds called so very nearly (if not exactly) alike does
not necessarily invalidate the correctness of the observations
that I made on the evening of the 7th. It is true
that I did not then hear both species at once but