The American Bittern is a smaller bird, but is probably a variety of the European species. It exhibits the same nocturnal habits, and has received at the South the name of _Dunkadoo_, from the resemblance of its common note to these syllables. This is a hollow-sounding noise, but not so loud as the voice of the Bittern to which Goldsmith alludes. I have heard it by day proceeding from the wooded swamps, and am at a loss to explain how so small a bird can produce so low and hollow a note. Among this family of birds are one or two other nocturnal species, including the Qua-Bird, which is common to both continents; but there is little to be said of it that would be interesting in this connection. The Herons, however, and their allied species, are birds of remarkable habits, the enumeration and account of which would occupy a considerable space. In an essay on the flight of birds in particular, the Herons would furnish a multitude of very interesting facts.
Let us now turn our attention to those diurnal birds that sing in the night as well as in the day, and which might be comprehended under the general appellation of Nightingales. These birds do not confine their singing to the night, like the true nocturnal birds, and are most vocal when inspired by the light of the moon. Europe has several of these minstrels of the night. Beside the true Philomel of poetry and romance, the Reed-Thrush and the Woodcock are of this character. In the United States, the Mocking-Bird enjoys the greatest reputation; the Rose-breasted Grosbeak and the New York Thrush are also nocturnal songsters.
The Mocking-Bird (_Turdus polyglottus_) is well known in the Middle and Southern States, but seldom passes a season in New England, except in the southern part of Rhode Island and Connecticut, which seem to be the northern limit of its migrations. Probably, like the Rose-breasted Grosbeak, which is constantly extending its limits in an eastern direction, the Mocking-Bird may be gradually making progress northwardly, so that fifty years hence both of these birds may be common in Massachusetts. The Mocking-Bird is familiar in his habits, frequenting gardens and orchards, and perching on the roofs of houses when singing, like the common Robin. Like the Robin, too, who sings at all hours excepting those of darkness, he is a persevering songster, and seems to be inspired by living in the vicinity of man. In his manners, however, he bears more resemblance to the Red Thrush, being distinguished by his vivacity, and the courage with which he repels the attacks of his enemies.