The American green kingfishers are the

kingfisher Kingfishers are a family, the Alcedinidae, of small to medium-sized, brightly coloured birds in the order Coraciiformes. They have a cosmopolitan distribution, with most species living in the tropical regions of Africa, Asia, and Oceania, ...

genus ''Chloroceryle'', which are native to tropical Central and

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 ...

, with one species extending north to south

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

Taxonomy and species

The genus ''Chloroceryle'' was introduced in 1848 by the German naturalist

Johann Jakob Kaup Johann Jakob von Kaup (10 April 1803 – 4 July 1873) was a German naturalist. A proponent of natural philosophy, he believed in an innate mathematical order in nature and he attempted biological classifications based on the Quinarian system. Kaup ...

. Kaup did not specify a

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 ...

but

Richard Bowdler Sharpe Richard Bowdler Sharpe (22 November 1847 – 25 December 1909) was an English people, English zoologist and ornithology, ornithologist who worked as curator of the bird collection at the British Museum of natural history. In the course of his car ...

designated the

American pygmy kingfisher The American pygmy kingfisher (''Chloroceryle aenea'') is a species of "water kingfisher" in subfamily Cerylinae of family Alcedinidae. It is found in the American tropics from southern Mexico south through Central America into every mainland So ...

in 1871. The genus name combines 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 ...

''khlōros'' meaning "green" with the genus '' Ceryle'' that was introduced by

Friedrich Boie Friedrich Boie (4 June 1789 – 3 March 1870) was a German entomologist, herpetologist, ornithologist, and lawyer.Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins Universi ...

in 1828. The genus contains four species:

Habits and appearance

The American green kingfishers breed by streams in forests or

mangrove A mangrove is a shrub or tree that grows mainly in coastal saline water, saline or brackish water. Mangroves grow in an equatorial climate, typically along coastlines and tidal rivers. They have particular adaptations to take in extra oxygen a ...

s, nesting in a long horizontal tunnel made in a river bank. These birds take

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

s and

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

caught by the usual kingfisher technique of a dive from a perch or brief hover, although the American pygmy kingfisher will hawk at

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 in flight. They have the typical kingfisher shape, with a short tail and long bill. All are plumaged oily green above, and the underpart colour shows an interesting pattern insofar as the smallest and second largest, American pygmy kingfisher and green-and-rufous kingfisher, have rufous underparts, whereas the largest and second smallest, Amazon kingfisher and green kingfisher, have white underparts with only the males also having a rufous breast band.

Evolutionary history

These water kingfishers are descended from a common ancestor which seems to have been closely related to a progenitor of the pied kingfisher (which at that stage had not yet lost the metallic plumage tone), and are similar in plumage and habits (Moyle, 2006). All four have overlapping ranges, and may fish the same waters; however the weight ratio of ''aenea'': ''americana'': ''inda'': ''amazona'' is almost exactly 1:2:4:8, which prevents direct competition for food. The ringed kingfisher, ''Megaceryle torquata'', a more distant relative, also occurs on the same rivers, but is twice as heavy as the Amazon kingfisher. Genetically, the largest species, ''C. amazona'', is the most distantly related, while the medium-sized (but differently colored) ''C. americana'' and ''C. inda'' are sister species. The differing coloration therefore does not indicate their evolutionary history, but rather seems to have evolved independently, to underscore the visual distinctness between taxa, thus helping to keep their

gene pool The gene pool is the set of all genes, or genetic information, in any population, usually of a particular species. Description A large gene pool indicates extensive genetic diversity, which is associated with robust populations that can survi ...

s separate (''see also''

Competitive exclusion principle In ecology, the competitive exclusion principle, sometimes referred to as Gause's law, is a proposition that two species which compete for the same limited resource cannot coexist at constant population values. When one species has even the slig ...

Taxonomy and species

Habits and appearance

Evolutionary history

References

Further reading