Least bittern | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Pelecaniformes |
Family: | Ardeidae |
Genus: | Botaurus |
Species: | B. exilis |
Binomial name | |
Botaurus exilis (Gmelin, JF, 1789) | |
Range of B. exilis Breeding range Year-round range Wintering range | |
Synonyms | |
Ardetta exilis Contents |
The least bittern (Botaurus exilis) is a small heron, the smallest member of the family Ardeidae found in the Americas. This species was formerly placed in the genus Ixobrychus.
The least bittern was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae . He placed it with the herons, cranes, storks, and bitterns in the genus Ardea and coined the binomial name Ardea exilis. [2] Gmelin based his description on the "minute bittern" from Jamaica that had been included by the English ornithologist John Latham in his multi-volume work A General Synopsis of Birds. Latham did not specify how he had obtained the specimen. [3] The least bittern was formerly placed in the genus Ixobrychus but when a molecular phylogenetic study of the heron family Ardeidae published in 2023 found that Ixobrychus was paraphyletic, Ixobrychus was merged into the genus Botaurus that had been introduced in 1819 by the English naturalist James Francis Stephens.. [4] [5] [6] The genus name Botaurus is Medieval Latin for a bittern. The specific epithet exilis is Latin meaning "little" or "slender". [7]
Six subspecies are recognised: [5]
North American birds were formerly divided into two subspecies, eastern (B. e. exilis) and western (B. e. hesperis), but this is no longer believed to be a valid distinction. [8] [9]
The least bittern forms a superspecies with the little bittern and yellow bittern. [10]
A dark rufous morph, B. e. neoxenus, termed "Cory's bittern" or "Cory's least bittern" was originally described by Charles Cory as a separate species in 1885 from a specimen collected on or near the Caloosahatchee River, near Lake Okeechobee, in southwest Florida. Cory stated that the specimen was "without doubt perfectly distinct from any other known species". [11] Further specimens followed over the next decades from Florida, [12] [13] Michigan, [14] Illinois, [15] [16] Wisconsin, [17] Ohio, [18] and Ontario. [19]
Initially, Cory's least bittern was accepted as a valid species, with Elliott Coues and Richard Bowdler Sharpe both including it in published species lists. [16] As early as 1892, however, doubts were raised about the validity of Cory's least bittern as a separate species. [13] Nonetheless, in 1896 Frank Chapman wrote a detailed paper supporting its retention as a valid species. [20] Outram Bangs later argued, in 1915, that this view was wrong and proposed that Cory's should become a junior synonym of least bittern. [21] This view eventually prevailed, with the American Ornithologists' Union removing the species from their list of North American birds in 1923, [22] although others held dissenting views until at least 1928. [23]
Cory's least bittern was once fairly common, but it is now exceptionally rare, with only five sightings since 1950. [24] More than 50% of the historical records are from the Toronto region of Ontario. [8] Initially known only from the North American subspecies exilis, it was first recorded in the South America subspecies erthyromelas in 1967. [25]
The least bittern is one of the smallest herons in the world, with perhaps only the dwarf bittern and the black-backed bittern averaging smaller in length. [10] It can measure from 28 to 36 cm (11 to 14 in) in length, and the wingspan ranges from 41 to 46 cm (16 to 18 in). Body mass is from 51 to 102 g (1.8 to 3.6 oz), with most least bitterns weighing between 73 and 95 g (2.6 and 3.4 oz), making this perhaps the lightest of all herons. [26] A recent manual of avian body masses cites another species in this genus, the stripe-backed bittern, as having a mean body mass slightly lower than the least bittern, which is credited with a mean mass of 86.3 g (3.04 oz). [27]
The bird's underparts and throat are white with light brown streaks. Its face and the sides of the neck are light brown; it has yellow eyes and a yellow bill. [28] The adult male is glossy greenish-black on the back and crown; [29] the adult female is glossy brown on these parts; both have white lines on their shoulders. They show light brown parts (covert feathers) on the wings in flight. [30]
These birds make cooing and clucking sounds, [28] [30] usually in the early morning or near dusk. [31]
The least bittern is an elusive bird. They spend much time straddling reeds. When alarmed, the least bittern freezes in place with its bill pointing up, turns its front and both eyes toward the source of alarm, and sometimes sways to resemble wind-blown marsh vegetation. This is perhaps a predator-avoidance behaviour, since its small size makes the bittern vulnerable to many potential predators. Thanks to its habit of perching among the reeds, the least bittern can feed from the surface of water that would be too deep for the wading strategy of other herons. The least bittern and much larger and different-looking American bittern often occupy the same wetlands but may have relatively little interaction because of differences in foraging habits, preferred prey, and timing of breeding cycles. The least bittern arrives on its breeding grounds about a month after the American bittern and leaves one or two months earlier. John James Audubon noted that a young captive least bittern was able to walk with ease between two books standing 4 cm (1.6 in) apart. When dead, the bird's body measured 5.7 cm (2.2 in) across, indicating that it could compress its breadth to an extraordinary degree.
These birds nest in large marshes with dense vegetation from southern Canada to northern Argentina. Nest of strips of rushes woven together to form a platform and fastened to saw grass growing on the bank of a stream. [32] The nest is a well-concealed platform built from cattails and other marsh vegetation. The female lays four or five eggs, in extreme cases from two to seven. The eggs are pale blue or green. Both parents feed the young by regurgitating food. A second brood is often produced in a season.
These birds migrate from the northern parts of their range in winter to the southernmost coasts of the United States and areas further south, travelling at night.[ citation needed ]
They mainly eat fish, frogs, crustaceans, insects and small mammals, [28] which they capture with quick jabs of their bill while climbing through marsh plants. [33]
The numbers of these birds have declined in some areas due to loss of habitat. They are still fairly common but are more often heard than seen. As the species has a large range and a large total population, the International Union for Conservation of Nature has assessed its conservation status as being of "Least Concern". The least bittern is protected under the Migratory Bird Treaty Act of 1918. [34]
The boat-billed heron, colloquially known as the boatbill, is an atypical member of the heron family. It is the only member of the genus Cochlearius and was formerly placed in a monotypic family, the Cochleariidae. It lives in mangrove swamps from Mexico south to Peru and Brazil. It is a nocturnal bird, and breeds semicolonially in mangrove trees, laying two to four bluish-white eggs in a twig nest.
The American bittern 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.
The Eurasian bittern or great bittern is a wading bird in the bittern subfamily (Botaurinae) of the heron family Ardeidae. There are two subspecies, the northern race breeding in parts of Europe and across the Palearctic, as well as on the northern coast of Africa, while the southern race is endemic to parts of southern Africa. It is a secretive bird, seldom seen in the open as it prefers to skulk in reed beds and thick vegetation near water bodies. Its presence is apparent in the spring, when the booming call of the male during the breeding season can be heard. It feeds on fish, small mammals, fledgling birds, amphibians, crustaceans and insects.
Herons are long-legged, long-necked, freshwater and coastal birds in the family Ardeidae, with 74 recognised species, some of which are referred to as egrets or bitterns rather than herons. Members of the genus Botaurus are referred to as bitterns, and, together with the zigzag heron, or zigzag bittern, in the monotypic genus Zebrilus, form a monophyletic group within the Ardeidae. Egrets do not form a biologically distinct group from herons, and tend to be named differently because they are mainly white or have decorative plumes in breeding plumage. Herons, by evolutionary adaptation, have long beaks.
The little bittern is a wading bird in the heron family, Ardeidae. This species was formerly placed in the genus Ixobrychus.
The white-faced heron also known as the white-fronted heron, and incorrectly as the grey heron, or blue crane, is a common bird throughout most of Australasia, including New Guinea, the islands of Torres Strait, Indonesia, New Zealand, and all but the driest areas of Australia.
The cinnamon bittern or chestnut bittern is a small Old World bittern, breeding in tropical and subtropical Asia from India east to China and Indonesia. It is mainly resident, but some northern birds migrate short distances. This species was formerly placed in the genus Ixobrychus.
The yellow bittern is a small bittern. It is of Old World origins, breeding in the northern Indian Subcontinent, east to the Russian Far East, Japan and Indonesia. It is mainly resident, but some northern birds migrate short distances. It has been recorded as a vagrant in Alaska and there is a single sighting in Great Britain, from Radipole Lake, Dorset on November 23, 1962 – however, the British Ornithologists' Union has always considered this occurrence to be of uncertain provenance and currently it is not accepted onto the official British List. This species was formerly placed in the genus Ixobrychus.
The black bittern is a bittern of Old World origin, breeding in tropical Asia from Pakistan, India, Bangladesh and Sri Lanka east to China, Indonesia, and Australia. It is mainly resident, but some northern birds migrate short distances. This species was formerly placed in the genus Ixobrychus.
Botaurus is a genus of bitterns, a group of wading birds in the heron family Ardeidae. The genus includes species that were previously placed in the genus Ixobrychus.
Carl Eduard Hellmayr was an Austrian ornithologist.
The Chinese pond heron is an East Asian freshwater bird of the heron family, (Ardeidae). It is one of six species of birds known as "pond herons". It is parapatric with the Indian pond heron to the west and the Javan pond heron to the south, and these three are presumed to form a superspecies. As a group they are variously affiliated with the squacco heron or the Malagasy pond heron. As of mid-2011 there are no published molecular analyses of pond heron interrelationships and osteological data is likewise not analyzed for all relevant comparison taxa.
Von Schrenck's bittern or Schrenck's bittern is a small bittern named after Leopold von Schrenck, the 19th-century Russian zoologist. It breeds in southeast Siberia, east China, the Korean Peninsula and Japan. It winters from the Malay Peninsula to the Greater Sunda Islands, Sulawesi and the Philippines. This species was formerly placed in the genus Ixobrychus.
The Antillean crested hummingbird is a species of hummingbird in the family Trochilidae. Found across Anguilla, Antigua and Barbuda, Barbados, Dominica, Grenada, Guadeloupe, Martinique, Montserrat, north-east Puerto Rico, Saba, Saint-Barthélemy, Saint Kitts and Nevis, Saint Lucia, Saint Martin, Saint Vincent and the Grenadines, Sint Eustatius, the British Virgin Islands, the U.S. Virgin Islands, and the Lesser Antilles, while it has also been recorded as a vagrant in Florida, USA.
The stripe-backed bittern is a South American bird species belonging to the family Ardeidae, which includes Herons, Egrets and Bitterns. It was formerly placed in the genus Ixobrychus. Commonly found near freshwater swamps, marshes, lake shores and streams, stripe-backed bitterns span over a wide distribution that divides into the northern and southern populations, spanning on both sides of the Andes. Although increasingly recognized and researched worldwide, much life history details are lacking concerning this species, which remains understudied compared to its similar looking sister clade, including the least bittern.
The New Zealand bittern is an extinct and enigmatic species of heron in the family Ardeidae. It was endemic to New Zealand and was last recorded alive in the 1890s.
The dwarf bittern is a species of heron in the family Ardeidae that is widely distributed across Sub-Saharan Africa avoiding only the very arid regions. This species was formerly placed in the genus Ixobrychus.
The black-backed bittern, also known as the black-backed least bittern or Australian little bittern, is a little-known species of heron in the family Ardeidae found in Australia and vagrant to southern New Guinea. Formerly lumped with the little bittern, it is one of the smallest herons in the world. This species was formerly placed in the genus Ixobrychus.
Viktor von Tschusi zu Schmidhoffen was an Austrian ornithologist.
The western cattle egret is a species of heron found in the tropics, subtropics and warm temperate zones. Formerly, most taxonomic authorities lumped this species and the eastern cattle egret together, but the two cattle egrets are now treated as separate species. Despite the similarities in plumage to the egrets of the genus Egretta, it is more closely related to the herons of Ardea. Originally native to parts of Asia, Africa and Europe, it has undergone a rapid expansion in its distribution and successfully colonised much of the rest of the world in the last century.