American Bittern
Kingdom
Phylum
Class
Subclass
Infraclass
Superorder
Family
Genus
SPECIES
Botaurus lentiginosus
Population size
3 Mlnlnn
Life Span
8.3 years
Weight
370-1072
13.1-37.8
goz
g oz 
Length
58-85
22.8-33.5
cminch
cm inch 
Wingspan
92-115
36.2-45.3
cminch
cm inch 

The American bittern (Botaurus lentiginosus) is a wading bird in the heron family that is best known for the unique, loud, guttural call made by the male, which has resulted in it being given several nicknames, including ‘water belcher’, ‘thunder pumper’, and ‘mire-drum’. These are well-camouflaged, solitary birds that stand motionless amongst tall marsh vegetation or patiently stalk their prey. American bitterns are fairly common over their wide range, however, their numbers are thought to be decreasing, especially in the south.

Appearance

The American bittern is a large, chunky, brown bird. Its 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 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.

Distribution

Geography

The American bittern occurs widely across Central and North America. In the summer it is found in the north as far as Alaska, and Newfoundland and central British Columbia in Canada. In winter, these birds migrate south to Central America and the northernmost Caribbean islands. They typically inhabit freshwater wetlands that have tall, emergent vegetation. During breeding, they prefer marshlands and ephemeral wetlands, but also forage in wet meadows and along shorelines, often preferring areas with much plant cover and open water.

American Bittern habitat map

Climate zones

American Bittern habitat map
American Bittern
Attribution-ShareAlike License

Habits and Lifestyle

An American bittern is a solitary forager, standing motionless or slowly walking with outspread toes as it searches for food. It hunts during the day, especially at dawn or dusk. Possibly its most famous behavior is its stance when it feels threatened. It points its bill to the sky, stretches out its body, and will even sway with the breeze, in order to blend in with the reedy surroundings. So ingrained is this pose that it will sometimes use it even when out in the open. These birds do not socialize much except when migrating in small groups, or during mating, or facing off over territories - and this can be dramatic. Males in competition with each other will crouch down and approach one another, displaying the white plumes that are between their shoulders. These moves can escalate into a chase in the air, the combatants spiraling upwards, while trying to stab their opponent with their bill.

Seasonal behavior
Bird's call

Diet and Nutrition

American bitterns are carnivores, they mainly eat insects, amphibians, crayfish, small fish and mammals.

Mating Habits

MATING BEHAVIOR
REPRODUCTION SEASON
early May
INCUBATION PERIOD
24-28 days
INDEPENDENT AGE
4 weeks
BABY NAME
chick
web.animal_clutch_size
2-7 eggs

America bitterns are polygynous breeders. Male and female do not really interact with each other except for copulation, though a female may site her nest close to a "booming" male in order to distract predators from her hatchlings. Pair formation takes place in early May when females arrive at the nesting area. The female chooses her nest site, usually amongst dense emergent vegetation above water of a depth of 4-5 cm. The female constructs the nest out of reeds, cattail, sedges, or other emergent vegetation. The female lays 2-7 eggs in one clutch, with incubation beginning before all the eggs are laid and lasting 24 to 28 days. Only the female carries out brooding and feeding duties. The hatchlings leave their nest in one to two weeks, but receive supplemental feeding for up to another four weeks after hatching.

Population

Population threats

This bird has an extremely large range. The population of American bitterns is undergoing a major decline due to degradation and loss of habitat. Eutrophication (where an ecosystem is enriched with chemical nutrients), chemical contamination, siltation, and human disturbance have greatly reduced habitat quality due to damage to the food supply. Habitat quality has also been eroded by stabilized water regimes and changes in wetland isolation. Acid rain also damages the wetlands.

Population number

According to the What Bird resource, the total population size of the American bittern is around 3 million individuals. Currently this species is classified as Least Concern (LC) on the IUCN Red List, but its numbers today are decreasing.

Fun Facts for Kids

  • American bitterns have a distinctive loud booming call, "unk-a-chunk, unk-a-chunk" sounding like a machine. This bird is, in fact, more often heard than it is seen.
  • This species uses resounding calls to communicate. They have earned many nicknames for their eerie calls: "mire-drum", "stake-driver", and "thunder-pumper".
  • A group of bitterns can be known by the following: a "dash", "freeze", "pint", “siege” or "pretense" of bitterns.
  • An American bittern can focus its eyes downward, giving its face a comically startled and cross-eyed appearance. Using its eyes in this way presumably increases its ability to detect and capture prey. Its yellow eyes turn orange during the breeding season.
  • This bird has a remarkable courtship display, which is rarely seen. The male will arch his back, shorten his neck, dip his breast forward, and "boom" at the female. Both of the birds perform complicated aerial displays.

Coloring Pages

References

1. American Bittern Wikipedia article - https://en.wikipedia.org/wiki/American_bittern
2. American Bittern on The IUCN Red List site - http://www.iucnredlist.org/details/22697340/0
3. Xeno-canto bird call - https://xeno-canto.org/601776

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