the hen ostrich doubtless finds
more music in the thunderous note of her lord than in the faint melody
of such song-birds as her native Africa provides. The nightingale sings
to his mate while she is sitting on her olive-green eggs perching on a
low branch of the tree, at foot of which the slender nest is hidden in
the undergrowth. So much is known to every schoolboy who is too often
guided by the sound on his errand of plunder; and why the song of this
particular warbler should have been described by so many writers as one
of sadness, seeing that it is associated with the most joyous days in
the bird's year, passes comprehension. So obviously is its object to
hearten the female in her long and patient vigil that as soon as the
young are hatched the male's voice breaks like that of other choristers
to a guttural croak. It is said, indeed--though so cruel an experiment
would not appeal to many--that if the nest be destroyed just as the
young are hatched the bird recovers all his sweetness of voice and sings
anew while another home is built.

Although poetic licence has ascribed the song to the female, it is the
male nightingale only that sings, and for the purpose aforementioned.
The note of the nightjar, on the other hand, is equally uttered by both
sexes, and both also have the curious habit of repeatedly clapping the
wings for several minutes together. They moreover share the business of
incubation, taking day and night duty on the eggs, which, two in number,
are laid on the bare ground without any pretence of a nest, and
generally on open commons in the neighbourhood of patches of fern-brake.
Like the owls, these birds sleep during the day and are active only when
the sun goes down. It is this habit of seeking their insect food only in
the gloaming which makes nightjars among the most difficult of birds to
study from life, and all accounts of their feeding habits must therefore
be received with caution, particularly that which compares the bristles
on the mouth with baleen in whales, serving as a sort of strainer for
the capture of minute flying prey. This is an interesting suggestion,
and may even be sober fact; but its adoption would necessitate the bird
flying open-mouthed among the oaks and other trees beneath which it
finds the yellow underwings and cockchafers on which it feeds, and I
have more than once watched it hunting its victims with the beak closed.
I noticed this particularly when camping in the backwood