The very cry of the Bittern adds to this atmosphere of desolation. By day the bird is silent, but after the sun has gone down it utters its strange wild cry, a sound which exactly suits the localities in which it loves to make its habitation. During part of the year it only emits a sharp, harsh cry as it rises on the wing, but during the breeding season it utters the cry by which it summons its mate, one of the strangest love-calls that can be imagined. It is something between the neighing of a horse, the bellow of a bull, and a shriek of savage laughter. It is very loud and deep, so that it seems to shake the loose and marshy ground. There was formerly an idea that, when the Bittern uttered this booming cry, it thrust its bill into the soft ground, and so caused it to shake. In reality, the cry is uttered on the wing, the bird wheeling in a spiral flight, and modulating its voice in accordance with the curves which it describes in the air. This strange sound is only uttered by the male bird.
In every country inhabited by the Bittern we find that its deep sepulchral cry, booming out through the darkness, and heard at an immense distance, has been dreaded as the prophecy of some evil to come. In some parts both of England and Ireland it is known as the Night-raven, and under that title is held in the greatest fear. Allusion is made to this belief in the well-known passage from Middleton's "Witch":—
"At the Night-raven's dismal voice,
When others tremble, we rejoice;
And nimbly, nimbly, dance we still
To the echoes of a hollow hill."
Under the same title Goldsmith writes of it in his "Animated Nature." "I remember, in the place where I was a boy, with what terror the bird's note affected the whole village,—they considered it as the presage of some sad event, and generally found or made one to succeed it. I do not speak ludicrously, but if any person in the neighbourhood died, they supposed it could not be otherwise, for the night-raven had foretold it; but if nobody happened to die, the death of a cow or a sheep gave completion of the prophecy."
In some parts of England the Bittern is known by the odd title of Butter-bump, a fact which was mentioned in the Zoologist many years ago:—
"There'll either be rain, or else summat waur,
When Butter-bump sings upo' Potterie car."