The species winters in the southeastern and Gulf States and as far south as Central America and Cuba. Females choose the nest site in wetland areas, usually on the ground or raised slightly on a platform of thick vegetation. The female also builds the nest, usually out of reeds, sedges and similar plant material. Incubation begins when the first egg is laid and lasts for 24 to 29 days. The female is responsible for both incubation and tending the young.
Young bitterns differ in size.
They leave the nest after about two weeks but continue to be tended nearby. Their age of independence and first flight is unknown. The primary reason for the decline in American bittern populations is loss of habitat. The marshes and swamps upon which this species depends have been drained and filled for a variety of human uses including roadways, housing and commercial developments. The American bittern was common in Connecticut during the late 1800s and it was a regular, but not abundant, resident of freshwater wetlands in the early 1900s.