The green kingfisher (Chloroceryle americana) is a species of "water kingfisher" in the subfamily Cerylinae of the family Alcedinidae. It is found from southern Texas in the United States south through Central America, in every mainland South American country except Chile and Trinidad and Tobago.
Taxonomy and systematics
The green kingfisher was formally described in 1788 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it with the other kingfishers in the genus Alcedo and coined the binomial name Alcedo americana. Gmelin based his description on "Le martin-pêcheur vert et blanc" from Cayenne that had been described and illustrated in 1780 by the French polymath Comte de Buffon and also the "white and green kingfisher" that had been described in 1782 by the English ornithologist John Latham. The green kingfisher is now placed in the genus Chloroceryle that was introduced in 1848 by Johann Jakob Kaup.
A molecular phylogenetic study published in 2006 found that the green kingfisher is a sister species to the larger green-and-rufous kingfisher (C. inda).
Five subspecies are recognized: C. a. hachisukai (Laubmann, 1941) C. a. septentrionalis (Sharpe, 1892) C. a. americana (Gmelin, JF, 1788) C. a. mathewsii Laubmann, 1927 C. a. cabanisii (Tschudi, 1846)
Some populations of C. a. septentrionalis have in the past been separated as subspecies C. a. vanrossemi and C. a. isthmica. The population of Trinidad and Tobago, usually included with C. a. americana, has in the past been treated as subspecies C. a. croteta. Other populations of C. a. americana have been suggested to be split as C. a. hellmayri and C. a. bottomeana. None of these subspecies are currently (2022) recognized by major worldwide taxonomic systems.
Description
The green kingfisher is about long and weighs about ; females are larger and heavier than males. Birds in the northern and southern parts of its range, and those west of the Andes, are larger and heavier than the others, but the differences tend to be clinal. The species has the typical kingfisher shape with long heavy bill (heaviest in Trinidad and Tobago); in contrast to many other kingfishers, however, it does not have an obvious crest. The bill is black with some horn color at the base of the mandible and its legs and feet are dark gray. Both sexes have green upperparts with two or more rows of white spots on the flight feathers. Their underparts are mostly white with green spots on the sides and flanks. Their tail is green with much white on the outer feathers that shows best in flight. Adult males have a white collar and a rufous breast. Adult females have a white collar, a buffy throat and breast, and a band of green speckles across the breast and upper belly. Juveniles resemble females but are duller and have small buff spots on their crown and wing coverts.
One vocalization "resembles the striking of two pebbles together, usually single or double". Another is "a harsh, buzzy scold, described variously as tsheersh, tseelp or zchrrk". Authors differ on their interpretations of whether the vocalizations are calls or songs and if they are calls, what their purpose is.
The subspecies differ somewhat in the shade of the upperparts' green, the amount of white on the wings and tail, the amount and size of the flank markings, and the extent of the breast bands (complete or not). However, there is much individual variation within each subspecies and the differences are to some extent clinal, so the differences among the subspecies tend to be obscured.
Distribution and habitat
The subspecies of green kingfisher are distributed thus:
C. a. hachisukai, from extreme southern Arizona, southwestern New Mexico, and west central Texas in the USA into northwestern Mexico to Nayarit C. a. septentrionalis, from south central Texas and eastern Mexico south to northern Colombia and western Venezuela C. a. americana, South America east of the Andes from Venezuela east through the Guianas into northern and central Brazil and south to northeastern Bolivia; also Trinidad and Tobago C. a. mathewsii, from southern Brazil and southern Bolivia through Paraguay and Uruguay to central Argentina C. a. cabanisii, west of the Andes from Colombia through Ecuador to southernmost Peru; as a vagrant to Chile