Note: Information is dated. Do not rely on it.Bittern. The name of several wading birds, family Ardeidae or herons, genus Botaurus. There are two British species, the common bittern, Botaurus stellaris, and the little bittern, Botaurus minutus, a native of the South, and only a summer visitor to Britain. Both, however, are becoming rare from the reclamation of the marshy grounds that form their favorite haunt. The American bittern, Botaurus lentiginosus, is about twenty-six inches in length, about forty five in expanse of wing; general color, yellowishbrown, with spots and bars of black or dark brown; feathers on the breast long and loose; tail short; bill about three inches long. It is remarkable for its curious booming or bellowing cry, from which come the provincial names of "stake-driver" and "thunder-pumper." The eggs, greenish-brown in color, are four or five in number. The little bittern, Ardetta exilis, is about a foot in length and more highly colored than its larger relative.