A stocky and well-camouflaged heron of dense reed beds, the American Bittern is difficult to see. Its far-carrying booming call is distinctive, but the bittern itself likes to keep under cover. 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 bullrushes. 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. This makes it sometimes very tough to get great American Bittern pictures.
American Bitterns are almost always solitary and can be difficult to see. They often hide among wetland vegetation, walking slowly as they forage. American Bitterns typically hunt in low light, catching food with their bill and killing prey with biting or shaking movements. Flight is stiff and fairly clumsy with rapid wingbeats. Territorial males display at each other by approaching while hunkered down, head lowered to the level of its back, neck drawn in, and revealing white plumes at the shoulders.
Bitterns are thickset herons with bright, pale, buffy-brown plumage covered with dark streaks and bars. They are 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 (0.82–2.363 lb).
American Bitterns prey upon insect, fish, crustaceans, amphibians, reptiles, and small mammals. Preferred insects include dragonflies, water striders, water beetles, and grasshoppers; frequently consumed fish are eels, catfish, pickerel, sunfish, suckers, perch, killifish, and sticklebacks.
The nest of the American Bittern is made of a foundation of emergent vegetation like reeds, sedges, or cattails. It typically sits 3-8 inches above the water. The nest is lined with grasses and has an outside diameter of 10-16 inches. Nests on land are not as common but can occur in grasslands in locations with dense, tall herbaceous plants. Two or three eggs are incubated by the female for 29 days, and the chicks leave after 6–7 weeks.
American Bitterns summer throughout most of Canada and the United States, but move south into Central America and lower United States in the winter.
References: Wikipedia, Cornell Lab of Ornithology