American Bittern (Botaurus lentiginosus)

American Bittern

Ciconiiformes Ardeidae American Bittern (Botaurus lentiginosus)

[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

Physical charateristics

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.

wingspan min.: 125 cm wingspan max.: 135 cm
size min.: 80 cm size max.: 90 cm
incubation min.: 24 days incubation max.: 26 days
fledging min.: 7 days fledging max.: 14 days
broods: 1   eggs min.: 3  
      eggs max.: 7  

Distribution

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.

Listen to the sound of American Bittern



Copyright remark: Most sounds derived from xeno-canto

Habitat

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.

Foraging habits

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.


copyright Don DesJardin

Breeding habits

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.

Conservation

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. (source Birdlife.org)

Migration

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.

Distribution map breeding season

American Bittern range map summer

Literature

Title Geographical variation, sex and age in Great Bittern Botaurus stellaris using coloration and morphometrics
Author(s): MARINA DMITRENOK et al.
Abstract: Biometrics, plumage and bare-part colour of 87 Gre..[more]..
Source: Ibis(2007),149, 37-44

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Title HABITAT USE AND HOME RANGE OF AMERICAN BITTERNS (BOTAURUS LENTIGINOSUS) AND MONITORING OF INCONSPICUOUS MARSH BIRDS IN NORTHWEST MINNESOTA.
Author(s): SOCHEATA K. LOR
Abstract: An effective and efficient bird monitoring program..[more]..
Source: University of Missouri – Columbia

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Title Copulatory Behavior of the American Bittern
Author(s): PAUL A. JOHNSGARD
Abstract: There appears to be almost no detailed information..[more]..
Source: unknown

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Title Upland Nesting of American Bitterns, Marsh Hawks, and Short-Eared Owls
Author(s): Harold F. Duebbert and John T. Lokemoen
Abstract: Nests of American bitterns lentiginosus) marsh haw..[more]..
Source: U.S. Fish and Wildlife Service

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