Cambridge, Mass.
1913.
Feb. 13
[February 13, 1913]

Parus hudsonicus.

  Clear and cold with brisk N.W. [northwest] wind. Hudsonian Tit
appears at suet at 4.50 P.M. heralding his arrival by calling
thrice, this: - Pse - pse - dee. Pse - pse - dee - dee. Pse - pse - dee.
Stays 35 seconds. 

Feb. 14 [February 14, 1913]  Clear, cold, windless. Hudsonian Tit pays three visits to suet.
1 P.M. Stays 10 seconds and calls pse - psee; pse - psee once
without emphasis. 
2.07 P.M. stays 20 seconds. Calls pse - pse - psee on arriving, 
psip when about to depart.
3.35 P.M. stays 10 seconds. On arriving calls in sweet & liquid tones
t'swil - it, t'slwee - t'swee. This very like one of the common utterances of P. atricapillus [Parus atricapillus] for
which, indeed, I at first mistook it.

Feb. 16 [February 16, 1913]  Sunny, hazy, calm, warm. As Dr. William Simmons (of 
Bangor) and I stepped forth from the back door of our house at
1 P.M. to go to the museum our ears were greeted by what
seemed to be a song of the Hudsonian Tit. He was in the 
lilacs immediately behind the house and very tame, coming
within 8 feet of us to sing, and sing, and sing, always
uttering eight notes divided into two sets of four each by a
brief pause in the middle of the song. They may be rendered
thus: t'slee - t'slee - t'slee - t'slee, t'slee - t'slee - t'slee - t'slee.
All were essentially alike and given in the same key, 
in a loud, insistent, monotonous voice which seemed to
fill the whole garden and doubtless could have been heard
100 yards from the lilacs. The song reminded me more of
that of the Carolina Wren but were less melodious. In
intervals between its many utterances the bird sometimes
called tsip or ti-ti a few times.