hearing is very remarkable, considering the smallness of the sound,
which, without being unpleasant, is somewhat similar to that produced by
the vibration of the brake of a train; it is not powerful enough to jar
the nerves, but appears to pervade the entire system. Lying still, with
eyes closed, and three or four of these birds singing near, so that
their strains overlap and leave no silent intervals, the listener can
imagine that the sound originates within himself; that the numberless
fine cords of his nervous network tremble responsively to it.

There are a number of natural sounds that resemble more or less closely
the most unbirdlike note of this warbler--cicada, rattlesnake, and some
batrachians. Some grasshoppers perhaps come nearest to it; but the most
sustained current of sound emitted by the insect is short compared to
the warbler's strain, also the vibrations are very much more rapid, and
not heard as vibrations, and the same effect is not produced.

The grasshopper warblers gave me so much pleasure that I was often at
the spot where they had their little colony of about half-a-dozen pairs,
and where I discovered they bred every year. At first I used to go to
any bush where I had caught sight of a bird and sit down within a few
yards of it and wait until the little hideling's shyness wore off, and
he would come out and start reeling. Afterwards I always went straight
to the same bush, because I thought the bird that used it as his
singing-place appeared less shy than the others. One day I spent a long
time listening to this favourite; delightedly watching him, perched on a
low twig on a level with my sight, and not more than five yards from me;
his body perfectly motionless, but the head and wide-open beak jerked
from side to side in a measured, mechanical way. I had a side view of
the bird, but every three seconds the head would be jerked towards me,
showing the bright yellow colour of the open mouth. The reeling would