Cambridge, Mass.
1910.
March 26 [March 26, 1910]
  A Northern Shrike in the garden most of the latter
half of the afternoon - an old [male], apparently the same
which I noted on the 19th. As on that occasion he
was in full song much of the time to-day. At first (for 10
minutes) in the top of a little tree by the pond in front of the museum,
next (for 5 minutes) in the upper branches of the big
catalpa tree, finally in the Parkman's apple. His
song was quite as loud as on the 19th but less musical
and very much less varied, the same note being repeated
over and over, sometimes as many as six or eight times
in succession. Thrice when this happened the bird
crouched low on the branch with lowered and extended
head and neck, quivering his half-opened wings as if quite
carried away by emotional feeling. It seemed as if there
must be a [female] near at hand to account for this unusual
display (quite new to me) of feeling on the part of a
Northern Shrike in the Garden
His Song 
He quivers his wings while singing.