''Butorides'' is a genus of small

heron Herons are long-legged, long-necked, freshwater and coastal birds in the family Ardeidae, with 75 recognised species, some of which are referred to as egrets or bitterns rather than herons. Members of the genus ''Botaurus'' are referred to as bi ...

s. It contains four similar species, the striated heron ''Butorides striatus'', the lava heron ''Butorides sundevalli'', the green heron ''Butorides virescens'' and the little heron ''Butorides atricapilla''. They are closely related, and some authorities have considered them all to be subspecies of just one species; when treated so, the merged species is called green-backed heron. The name ''Butorides'' derives from

Middle English Middle English (abbreviated to ME) is a form of the English language that was spoken after the Norman Conquest of 1066, until the late 15th century. The English language underwent distinct variations and developments following the Old English pe ...

''Butor'' (" bittern") and the

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

suffix ''-oides'', "resembling". Adults of the extant species are among the smallest herons, ranging in length from , and have a dark grey to blackish back and wings (sometimes with greenish or bluish

iridescence Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear gradually to change colour as the angle of view or the angle of illumination changes. Iridescence is caused by wave interference of light in microstru ...

), a black cap, and short legs; the legs are yellow most of the year, but flush bright orange-red during pre-breeding courtship. The species have different underpart colours; white to grey or orange-buff in striated heron, and very dark grey in lava heron, and red-brown in green heron; in all, there is a line of white streaks running down the front of the throat and breast. The juveniles are browner above and extensively streaked below, and have greenish-yellow legs. ''Butorides'' herons breed in small wetlands, building a nest from platform of sticks, often in shrubs or trees, sometimes on the ground. The female lays three to five

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the ...

s. Both parents incubate for about 20 days until hatching, and feed the young birds, which take a further three weeks to

fledge Fledging is the stage in a flying animal's life between egg, hatching or birth and becoming capable of flight. This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnera ...

. They stand still at the water's edge and wait to ambush prey. They mainly eat small fish,

frog A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...

s and aquatic

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s. They are known to drop lures on the water surface to attract fish. A

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

species, ''Butorides validipes'', is known from the

Early Pleistocene The Early Pleistocene is an unofficial epoch (geology), sub-epoch in the international geologic timescale in chronostratigraphy, representing the earliest division of the Pleistocene Epoch within the ongoing Quaternary Period. It is currently esti ...

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

in the United States.

Taxonomy

The genus ''Butorides'' was introduced in 1852 by the English zoologist

Edward Blyth Edward Blyth (23 December 1810 – 27 December 1873) was an English zoologist who worked for most of his life in India as a curator of zoology at the Asiatic Society, Royal Asiatic Society of Bengal in Calcutta. He set about updating the museum ...

to accommodate a single species, ''Ardea javanica'' Horsfield, which is therefore becomes the

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

. ''Ardea javanica'' is now considered to be a subspecies of the little heron (''Butorides atricapill''). The genus name is combines the genus ''Butor'' introduced by Thomas Forster in 1827 for the bitterns with the

-οιδης/''-oidēs'' meaning "resembling". ''Butor'' is the

word for a bittern. Within the heron family Ardeidae, ''Butorides'' is most closely related to the genus '' Ardeola'' (pond herons). The ''Butorides'' herons were formerly considered a single species, the green-backed heron, but are now normally split, with the green heron breeding in eastern

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

Central America Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...

, the

West Indies The West Indies is an island subregion of the Americas, surrounded by the Atlantic Ocean, North Atlantic Ocean and the Caribbean Sea, which comprises 13 independent island country, island countries and 19 dependent territory, dependencies in thr ...

and the

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the cont ...

coast of

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

and the United States, the striated heron in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

, and the little heron in the

Old World The "Old World" () is a term for Afro-Eurasia coined by Europeans after 1493, when they became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia in the Eastern Hemisphere, previously ...

tropics and warm temperate regions from west

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

. A

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

study of the genus ''Butorides'', submitted as a master's thesis in 2023, found that the striated heron was

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

. To resolve the paraphyly, twenty

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

of the striated heron were moved to a new species, the little heron, making the striated heron a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

species restricted to South America. The following cladogram shows the phylogenetic relationships between the species: The genus contains four species:

References

{{Authority control Bird genera Herons Extant Pleistocene first appearances Taxa named by Edward Blyth