he not only tickled my ears with his rapid, reedy music, but amused my
mind as well with a pretty little problem in bird psychology. I could
sit within a few yards of his tangled haunt without hearing a note; but
if I jumped up and made a noise, or struck the branches with my stick,
he would incontinently burst into song. It is a very well-known habit of
the bird, and on account of it and of the very peculiar character of the
sounds emitted, his song is frequently described by ornithologists as
"mocking, defiant, scolding, angry," etc. It seems clear that at
different times the bird sings from different exciting causes. When,
undisturbed by a strange presence, he bursts spontaneously into singing,
the music, as in other species, is simply an expression of overflowing
gladness; at other times, the bird expressed such feelings as alarm,
suspicion, solicitude, perhaps anger, by singing the same song. How does
this come about?

I have stated, when speaking of the nightingale, that birds in which the
singing faculty is highly developed, sometimes make the mistake of
bursting into song when anxious or distressed or in pain, but that this
is not the case with the mocking-birds. Some species of these brilliant
songsters of the New World, in their passion for variety (to put it that
way), import every harsh and grating cry and sound they know into their
song; but, on the other hand, when anxious for the safety of their
young, or otherwise distressed, they emit only the harsh and grating
sounds--never a musical note. In the sedge-warbler, the harsh, scolding
sounds that express alarm, solicitude, and other painful emotions, have
also been made a part of the musical performance; but this differs from
the songs of most species, the mocking birds included, in the
extraordinary rapidity with which it is enunciated; once the song begins
it goes on swiftly to the finish, harsh and melodious notes seeming to
overlap and mingle, the sound forming, to speak in metaphor, a close