The hind neck is olive, and the mantle and scapulars are dark chestnut-brown, barred and speckled with black, some feathers being edged with buff.

The back, rump, and upper tail-coverts are similar in color but more finely speckled with black and with grey bases to the feathers.

[6] However, fossils found in the Ichetucknee River in Florida, and originally described as a new form of heron (Palaeophoyx columbiana McCoy, 1963)[7] were later recognized to be a smaller, prehistoric subspecies of the American bittern which lived during the Late Pleistocene (Olson, 1974)[8] and would thus be called B. l. columbianus.

[11] In his book on the common names of American birds, Ernest Choate lists "bog bumper" and "stake driver".

It breeds in southern Canada as far north as British Columbia, the Great Slave Lake and Hudson Bay, and in much of the United States and possibly central Mexico.

It migrates southward in the fall and overwinters in the southern United States of the Gulf Coast region, most notably in the marshy Everglades of Florida, the Caribbean Islands and Mexico, with past records also coming from Panama and Costa Rica.

It is an aquatic bird and frequents bogs, marshes and the thickly-vegetated verges of shallow-water lakes and ponds, both with fresh and brackish or saline water.

More often heard than seen, the male bittern has a loud, booming call that resembles a congested pump and which has been rendered as "oong, kach, oonk".

It has been suggested that the bird gradually puffs out its neck by inflating its esophagus with air accompanied by a mild clicking or hiccuping sound.

[15] Like other members of the heron family, the American bittern feeds in marshes and shallow ponds, preying mainly on fish but also consuming amphibians, reptiles, small mammals, crustaceans and insects.

It is a territorial bird and has a threat display which involves slowly erecting long, white, previously-concealed, plumes on its shoulders, to form wing-like extensions that nearly meet across its back, resembling a ruff.

The nest is usually about 15 cm (6 in) above the water surface and consists of a rough platform of dead stalks and rushes, sometimes with a few twigs mixed in, and lined with bits of coarse grass.