It is a large, chunky, brown bird, very similar to the Eurasian Great Bittern (Botaurus stellaris), though slightly smaller. It is 58–85 cm (23–33 in) in length, with a 92–115 cm (36–45 in) wingspan and a body mass of 370–1,072 g (0.82–2.36 lb).
Although common in much of its range, the American Bittern is usually well-hidden in bogs, marshes and wet meadows. Usually solitary, it walks stealthily among cattails or bulrushes. If it senses that it has been seen, the American Bittern becomes motionless, with its bill pointed upward, causing it to blend into the reeds. It is most active at dusk. More often heard than seen, this bittern has a call that resembles a congested pump.
This bird's underparts and throat are white with light brown streaks. Its face and the sides of the neck are light brown; it has yellow eyes and a yellow bill. The adult male is glossy greenish black on the back and crown; the adult female is glossy brown on these parts. They show light brown parts on the wings in flight.
