Within the thick vegetation of its habitat, the American Bittern uses resounding calls to communicate. The eerie calls for which it known has won the species many nicknames: stake-driver, thunder-pumper, and mire-drum. The species remains relatively unstudied due to its secretive nature and inaccessible habitats.
Perception Channels: visual ; tactile ; acoustic ; chemical
The American Bittern population is undergoing a substantial decline due to loss and degredation of habitat. The species was listed as a Nongame Species of Management Concern by the United States Fish and Wildlife Service in 1982 and 1987. It is listed as a species of special concern in the state of Michigan. Eutrophication, siltation, chemical contamination, and human disturbance have significantly reduced habitat quality by damaging the food supply. Changes in wetland isolation and stabilized water regimes are also eroding habitat quality. Acid rain is also another significant threat to the species due to its damaging effects on wetlands.
US Migratory Bird Act: protected
US Federal List: no special status
CITES: no special status
State of Michigan List: special concern
IUCN Red List of Threatened Species: least concern
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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.
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.
Biogeographic Regions: nearctic (Native )
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.
Terrestrial Biomes: forest ; rainforest
Range lifespan
Status: wild: 8.3 (high) years.
Average lifespan
Status: wild: 100 months.
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.
Other Physical Features: endothermic ; bilateral symmetry
Average mass: 600 g.
Average basal metabolic rate: 2.7412 W.
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.
Key Reproductive Features: iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Average time to hatching: 34 days.
Average eggs per season: 4.
Although not particularly small (around 23 inches), the American Bittern’s mottled brown plumage and short, thick build provide it with excellent camouflage in its heavily vegetated habitat. This heron may be best identified by its coloration, short yellow legs, white throat, and black neck stripes. Male and female American Bitterns are similar to one another in all seasons. The American Bittern breeds widely across the northern United States and the southern half of Canada. In winter, American Bitterns migrate to coastal areas of the United States south to Mexico, Central America, and the West Indies. This species may be found all year along the Pacific coast as well as in the Mid-Atlantic Region. American Bitterns breed primarily in shallow, heavily-vegetated freshwater wetlands. In winter, this species utilizes many of the same habitat types as in summer, but some bitterns wintering close to the coast may be found in brackish water. American Bitterns primarily eat animal matter, both invertebrates (mainly insects) and vertebrates (including fish, amphibians, and small mammals). Due to its short stature and the nature of its habitat, American Bitterns are difficult to observe while feeding or standing still. Bitterns may be more visible in the air, undertaking short flights above the top of the marsh grass. This species is primarily active during the day.
Although not particularly small (around 23 inches), the American Bittern’s mottled brown plumage and short, thick build provide it with excellent camouflage in its heavily vegetated habitat. This heron may be best identified by its coloration, short yellow legs, white throat, and black neck stripes. Male and female American Bitterns are similar to one another in all seasons. The American Bittern breeds widely across the northern United States and the southern half of Canada. In winter, American Bitterns migrate to coastal areas of the United States south to Mexico, Central America, and the West Indies. This species may be found all year along the Pacific coast as well as in the Mid-Atlantic Region. American Bitterns breed primarily in shallow, heavily-vegetated freshwater wetlands. In winter, this species utilizes many of the same habitat types as in summer, but some bitterns wintering close to the coast may be found in brackish water. American Bitterns primarily eat animal matter, both invertebrates (mainly insects) and vertebrates (including fish, amphibians, and small mammals). Due to its short stature and the nature of its habitat, American Bitterns are difficult to observe while feeding or standing still. Bitterns may be more visible in the air, undertaking short flights above the top of the marsh grass. This species is primarily active during the day.
The American bittern (Botaurus lentiginosus) is a species of wading bird in the heron family. It has a Nearctic distribution, breeding in Canada and the northern and central parts of the United States, and wintering in the U.S. Gulf Coast states, all of Florida into the Everglades, the Caribbean islands and parts of Central America.
It is a well-camouflaged, solitary brown bird that unobtrusively inhabits marshes and the coarse vegetation at the edge of lakes and ponds. In the breeding season it is chiefly noticeable by the loud, booming call of the male. The nest is built just above the water, usually among bulrushes and cattails, where the female incubates the clutch of olive-colored eggs for about four weeks. The young leave the nest after two weeks and are fully fledged at six or seven weeks.
The American bittern feeds mostly on fish but also eats other small vertebrates as well as crustaceans and insects. It is fairly common over its wide range, but its numbers are thought to be decreasing, especially in the south, because of habitat degradation. However the total population is large, and the International Union for Conservation of Nature has assessed its conservation status as being of "Least Concern".
The American bittern is a large, chunky, brown bird, very similar to the Eurasian bittern (Botaurus stellaris), though slightly smaller, and the plumage is speckled rather than being barred. 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 (0.816–2.363 lb).[3][4]
The crown is chestnut brown with the centers of the feathers being black. The side of the neck has a bluish-black elongated patch which is larger in the male than in the female. The hind neck is olive, and the mantle and scapulars are dark chestnut-brown, barred and speckled with black, some feathers being edged with buff. The back, rump, and upper tail-coverts are similar in color but more finely speckled with black and with grey bases to the feathers. The tail feathers are chestnut brown with speckled edges, and the primaries and secondaries are blackish-brown with buff or chestnut tips. The cheeks are brown with a buff superciliary stripe and a similarly colored mustachial stripe. The chin is creamy-white with a chestnut central stripe, and the feathers of the throat, breast, and upper belly are buff and rust-colored, finely outlined with black, giving a striped effect to the underparts. The eyes are surrounded by yellowish skin, and the iris is pale yellow. The long, robust bill is yellowish-green, the upper mandible being darker than the lower, and the legs and feet are yellowish-green. Juveniles resemble adults, but the sides of their necks are less olive.[5]
The American bittern was first described in 1813 by the English clergyman Thomas Rackett from a vagrant individual he examined in Dorset, England.[6] No extant subspecies are accepted.[6] However, fossils found in the Ichetucknee River in Florida, and originally described as a new form of heron (Palaeophoyx columbiana McCoy, 1963)[7] were later recognized to be a smaller, prehistoric subspecies of the American bittern which lived during the Late Pleistocene (Olson, 1974)[8] and would thus be called B. l. columbianus. Its closest living relative is the pinnated bittern (Botaurus pinnatus) from Central and South America.[6]
The generic name Botaurus was given by English naturalist James Francis Stephens, and is derived from Medieval Latin butaurus, "bittern", constructed from the Middle English name for the Eurasian bittern, botor.[9] Pliny gave a fanciful derivation from Bos (ox) and taurus (bull), because the bittern's call resembles the bellowing of a bull.[10] The species name lentiginosus is Latin for "freckled", from lentigo (freckle), and refers to the speckled plumage.[9]
Many folk names are given for its distinctive call.[11] In his book on the common names of American birds, Ernest Choate lists "bog bumper" and "stake driver".[12] Other vernacular names include "thunder pumper", "bog bull",[13] "bog thumper", "mire drum", and "water belcher".[14]
Its range includes much of North America. It breeds in southern Canada as far north as British Columbia, the Great Slave Lake and Hudson Bay, and in much of the United States and possibly central Mexico. It migrates southward in the fall and overwinters in the southern United States of the Gulf Coast region, most notably in the marshy Everglades of Florida, the Caribbean Islands and Mexico, with past records also coming from Panama and Costa Rica. As a long-distance migrant, it is a very rare vagrant in Europe, including Great Britain and Ireland. It is an aquatic bird and frequents bogs, marshes and the thickly-vegetated verges of shallow-water lakes and ponds, both with fresh and brackish or saline water. It sometimes feeds out in the open in wet meadows and pastures.[5][6]
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The American bittern is a solitary bird and usually keeps itself well-hidden and is difficult to observe. It usually hunts by walking stealthily in shallow water and among the vegetation, stalking its prey, but sometimes it stands still in ambush. If it senses that it has been seen, it remains motionless, with its bill pointed upward, its cryptic coloration causing it to blend into the surrounding foliage. It is mainly nocturnal and is most active at dusk. More often heard than seen, the male bittern has a loud, booming call that resembles a congested pump and which has been rendered as "oong, kach, oonk".[6] While uttering this sound, the bird's head is thrown convulsively upward and then forward, and the sound is repeated up to seven times.[5]
The process by which the bittern produces its distinctive sound is not fully understood. It has been suggested that the bird gradually puffs out its neck by inflating its esophagus with air accompanied by a mild clicking or hiccuping sound. The esophagus is kept inflated by means of flaps beside the tongue. Once this action is completed and the esophagus is fully inflated, the distinctive gulping sound is made in the syrinx. When the sound is finished, the bird deflates its esophagus.[15]
Like other members of the heron family, the American bittern feeds in marshes and shallow ponds, preying mainly on fish but also consuming amphibians, reptiles, small mammals, crustaceans and insects. It is a territorial bird and has a threat display which involves slowly erecting long, white, previously-concealed, plumes on its shoulders, to form wing-like extensions that nearly meet across its back, resembling a ruff. The bird then stands still in a threatening posture, or stalks the intruder in a crouching position, with its head retracted and a gliding gait.[5]
This bird nests solitarily in marshes among coarse vegetation such as bulrushes and cattails, with the female building the nest and the male guarding it. The nest is usually about 15 cm (6 in) above the water surface and consists of a rough platform of dead stalks and rushes, sometimes with a few twigs mixed in, and lined with bits of coarse grass. Up to about six eggs are laid and are incubated by the female for twenty-nine days. The eggs are bluntly ovoid in shape, olive-buff and unspeckled, averaging 49 by 37 mm (1.93 by 1.46 in) in size. The chicks are fed individually, each in turn pulling down the female's beak and receiving regurgitated food directly into its beak. They leave the nest at about two weeks and are fully-fledged at six to seven weeks.[5]
The bird's numbers are declining in many parts of its range because of habitat loss. This is particularly noticeable in the southern part where chemical contamination and human development are reducing the area of suitable habitat.[13] However, the bird has an extremely large range and a large total population, and the International Union for Conservation of Nature has assessed its conservation status as being of "least concern".[1] The American bittern is protected under the United States Migratory Bird Treaty Act of 1918.[16] It is also protected under the Canadian Migratory Birds Convention Act of 1994 to which both Canada and the United States are signatories.[17]
The American bittern (Botaurus lentiginosus) is a species of wading bird in the heron family. It has a Nearctic distribution, breeding in Canada and the northern and central parts of the United States, and wintering in the U.S. Gulf Coast states, all of Florida into the Everglades, the Caribbean islands and parts of Central America.
It is a well-camouflaged, solitary brown bird that unobtrusively inhabits marshes and the coarse vegetation at the edge of lakes and ponds. In the breeding season it is chiefly noticeable by the loud, booming call of the male. The nest is built just above the water, usually among bulrushes and cattails, where the female incubates the clutch of olive-colored eggs for about four weeks. The young leave the nest after two weeks and are fully fledged at six or seven weeks.
The American bittern feeds mostly on fish but also eats other small vertebrates as well as crustaceans and insects. It is fairly common over its wide range, but its numbers are thought to be decreasing, especially in the south, because of habitat degradation. However the total population is large, and the International Union for Conservation of Nature has assessed its conservation status as being of "Least Concern".
