[order] Ciconiiformes | [family] Ardeidae | [latin] Botaurus lentiginosus | [UK] American Bittern | [FR] Butor d'Amérique | [DE] Nordamerikanische Rohrdommel | [ES] Avetoro Lentiginoso | [IT] Tarabuso americano | [NL] Amerikaanse Roerdomp

Amerikaanse Roerdomp determination

copyright: Don DesJardin

The American Bittern is a medium-sized heron with a stout body and a neck, short legs, and a white neck. The upperside of the bird is brown finely speckled with black. The undersides are heavily streaked with brown and white. There is a long black patch that extends from below the eye down the side of the neck.

In the breeding range, the American Bittern inhabits areas of freshwater wetlands with tall emergent vegetation, shorelines, and vegetative fringes. The bird prefers beaver-created wetlands to those of glacial origin.

During the breeding season, the American Bittern ranges from the Mid-United States to northern Canada. Its wintering range stretches from the south Atlantic coast across the Gulf coast and west to southern California.

The basic diet of the American Bittern includes insects, amphibians, crayfish, and small fish and mammals. When foraging, it relies mostly on stealth, waiting motionless for its prey to pass by. Its coloration adds to its ability to go undetected by prey. When its prey is in reach, the bird darts forward and seizes the prey in its bill. The prey is then killed by biting or shaking and is swallowed head first. Microhabitats for foraging include vegetation fringes and shorelines. Even-aged stands of older, dense or dry vegetation are avoided.

This species has a large range, with an estimated global Extent of Occurrence of 8,800,000 km². It has a large global population estimated to be 3,000,000 individuals (Wetlands International 2002). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern. [conservation status from birdlife.org]

The American Bittern is considered monogamous; however, it is possibly polygynous under some circumstances. Pair formation occurs in early May when the female arrives at the nesting site. The female then chooses the nest site, which is usually in dense emergent vegetation over water that is 4-5 cm in depth. The nest is built by the female and is constructed of reeds, sedges, cattail, or other emergent vegetation. Egg laying is performed daily with one egg laid in the in the morning. Incubation begins before the full clutch is laid and lasts 24 to 28 days. Brooding and feeding duties are performed solely by the female. The hatchlings leave the nest after one to two weeks, but they receive supplemental feedings by the adults up to four weeks after hatching.

Extensive post-breeding dispersal from Jul; in Sep-Nov birds migrate S, returning Feb-Mar or may in extreme N; migration basically at night. Fairly sedentary more temperate parts in S and W of breeding range. During migration occasional anywhere from s Alaska to Panama; accidental to Greenland, Bermuda; S America and several times in W Europe, S to Canary Is.