American green kingfisher
Encyclopedia
The American green kingfishers are the Chloroceryle genus of kingfisher
s, which are native to tropical Central
and South America
, with one species extending north to south Texas
.
They comprise four species:
The American green kingfishers breed by streams in forests or mangrove
s, nesting in a long horizontal tunnel made in a river bank.
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.
These birds take crustacean
s and fish
caught by the usual kingfisher technique of a dive from a perch or brief hover, although the American Pygmy Kingfisher will hawk at insect
s in flight.
s 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
s separate (see also Competitive exclusion principle
).
Kingfisher
Kingfishers are a group of small to medium sized brightly coloured birds in the order Coraciiformes. They have a cosmopolitan distribution, with most species being found in the Old World and Australia...
s, which are native to tropical Central
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, with one species extending north to south Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
.
They comprise four species:
- Amazon KingfisherAmazon KingfisherThe Amazon Kingfisher, Chloroceryle amazona, is a resident breeding bird in the lowlands of the American tropics from southern Mexico south through Central America to northern Argentina, with at least one bird having strayed north to Texas. Records from Trinidad are thought to be erroneous.This...
, Chloroceryle amazona - Green KingfisherGreen KingfisherThe Green Kingfisher, Chloroceryle americana, is a resident breeding bird which occurs from southern Texas in the USA south through Central and South Americal to central Argentina....
, Chloroceryle americana - Green-and-rufous KingfisherGreen-and-rufous KingfisherThe Green-and-rufous Kingfisher, Chloroceryle inda, is a resident breeding bird in the lowlands of the American tropics from southeastern Nicaragua south to southern Brazil.-Description:...
, Chloroceryle inda - American Pygmy KingfisherAmerican Pygmy KingfisherThe American Pygmy Kingfisher, Chloroceryle aenea, is a resident breeding bird which occurs in the American tropics from southern Mexico south through Central America to western Ecuador, and then around the northern Andes cordillera in the east to central Bolivia and central Brazil...
, Chloroceryle aenea
The American green kingfishers breed by streams in forests or mangrove
Mangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
s, nesting in a long horizontal tunnel made in a river bank.
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.
These birds take crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s and fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
caught by the usual kingfisher technique of a dive from a perch or brief hover, although the American Pygmy Kingfisher will hawk at insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s in flight.
Evolutionary history
These water kingfisherWater Kingfisher
The water kingfishers or Cerylidae are one of the three families of kingfishers, and are also known as the cerylid kingfishers. All six American species are in this family....
s are descended from a common ancestor which seems to have been closely related to a progenitor of the Pied Kingfisher
Pied Kingfisher
The Pied Kingfisher is a water kingfisher and is found widely distributed across Africa and Asia. Their black and white plumage, crest and the habit of hovering over clear lakes and rivers before diving for fish makes it distinctive. Males have a double band across the breast while females have a...
(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
Ringed Kingfisher
The Ringed Kingfisher is a large, conspicuous and noisy kingfisher, commonly found along the lower Rio Grande River valley in southeasternmost Texas in the United States through Central America to Tierra del Fuego in South America....
, 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
Gene pool
In population genetics, a gene pool is the complete set of unique alleles in a species or population.- Description :A large gene pool indicates extensive genetic diversity, which is associated with robust populations that can survive bouts of intense selection...
s separate (see also Competitive exclusion principle
Competitive exclusion principle
In ecology, the competitive exclusion principle, sometimes referred to as Gause's law of competitive exclusion or just Gause's law, is a proposition which states that two species competing for the same resources cannot coexist if other ecological factors are constant...
).