Kingfishers are a family, the Alcedinidae, of small to medium-sized, brightly coloured birds in the order Coraciiformes. They have a cosmopolitan distribution: most species live in the tropical regions of Africa, Asia, and Oceania, but they can also be found in Europe and the Americas. They can be found in deep forests near calm ponds and small rivers. The family contains 118 species and is divided into three subfamilies and 19 genera. All kingfishers have large heads, long, sharp, pointed bills, short legs, and stubby tails. Most species have bright plumage with only small differences between the sexes. Most species are tropical in distribution, and a slight majority are found only in forests. They consume a wide range of prey, usually caught by swooping down from a perch. While kingfishers are usually thought to live near rivers and eat fish, many species live away from water and eat small invertebrates. Like other members of their order, they nest in cavities, usually tunnels dug into the natural or artificial banks in the ground. Some kingfishers nest in arboreal termite nests. A few species, principally insular forms, are threatened with extinction. In Britain, the word "kingfisher" normally refers to the common kingfisher.
Taxonomy, systematics and evolution The kingfisher family Alcedinidae is in the order Coraciiformes, which also includes the motmots, bee-eaters, todies, rollers, and ground-rollers. The name of the family was introduced (as Alcedia) by the French polymath Constantine Samuel Rafinesque in 1815. It is divided into three subfamilies, the tree kingfishers (Halcyoninae), the river kingfishers (Alcedininae), and the water kingfishers (Cerylinae). The name Daceloninae is sometimes used for the tree kingfisher subfamily but it was introduced by Charles Lucien Bonaparte in 1841 while Halcyoninae introduced by Nicholas Aylward Vigors in 1825 is earlier and has priority. A few taxonomists elevate the three subfamilies to family status. In spite of the word "kingfisher" in their English vernacular names, many of these birds are not specialist fish-eaters; none of the species in Halcyoninae are. The scientific name is derived from Greek mythology and the ancient belief that the birds nested in the open sea: the Greeks called them halkyons (Latin halcyon) from hals (sea) and kyon (born). In Greek mythology the gods gave the halkyons the ability to calm the waters when nesting. In Greek mythology, one of the Pleiades named Alcyone (Alcedo in Latin) married Ceyx who was killed in a shipwreck. Alcyone drowned herself in grief and the gods revived them both as kingfishers. The phylogenetic relationship between the kingfishers and the other five families that make up the order Coraciiformes is shown in the cladogram below. The number of species in each family is taken from the list maintained by Frank Gill, Pamela C. Rasmussen and David Donsker on behalf of the International Ornithological Committee (IOC).
The centre of kingfisher diversity is the Australasian realm, but the group originated in the Indomalayan region around 27 million years ago (Mya) and invaded the Australasian realm a number of times. Fossil kingfishers have been described from Lower Eocene rocks in Wyoming and Middle Eocene rocks in Germany, around 30–40 Mya. More recent fossil kingfishers have been described in the Miocene rocks of Australia (5–25 Mya). Several fossil birds have been erroneously ascribed to the kingfishers, including Halcyornis, from the Lower Eocene rocks in Kent, which has also been considered a gull, but is now thought to have been a member of an extinct family. Amongst the three subfamilies, the Alcedininae are basal to the other two subfamilies. The few species found in the Americas, all from the subfamily Cerylinae, suggest that the sparse representation in the Western Hemisphere resulted from just two original colonising events. The subfamily is a comparatively recent split from the Halcyoninae, diversifying in the Old World as recently as the Miocene or Pliocene. The following cladogram is based on a molecular phylogenetic study published in 2017.
Description The smallest species of kingfisher is the African dwarf kingfisher (Ispidina lecontei), which averages 10 cm (3.9 in) in length and between 9 and 12 g (0.32 and 0.42 oz) in weight. The largest kingfisher in Africa is the giant kingfisher (Megaceryle maxima), which is 42 to 46 cm (17 to 18 in) in length and 255–426 g (9.0–15.0 oz) in weight. The common Australian kingfisher, known as the laughing kookaburra (Dacelo novaeguineae), is the heaviest species, with females reaching nearly 500 g (18 oz) in weight. The plumage of most kingfishers is bright, with green and blue being the most common colours. The brightness of the colours is neither the product of iridescence (except in the American kingfishers) or pigments but is instead caused by the structure of the feathers, which causes scattering of blue light (the Tyndall effect). In most species, sexual dimorphism is limited. When clear distinctions do occur, size differences between the sexes generally remain minimal. The kingfishers have long, dagger-like bills. The bill is usually longer and more compressed in species that hunt fish, and shorter and more broad in species that hunt prey off the ground. The largest and most atypical bill is that of the shovel-billed kookaburra, which is used to dig through the forest floor in search of prey. They generally have short legs, although species that feed on the ground have longer tarsi. Most species have four toes, three of which are forward-pointing and fused towards the base ("syndactyl") to some extent. The irises of most species are dark brown. The kingfishers have excellent vision; they are capable of binocular vision and are thought in particular to have good colour vision. They have restricted movement of their eyes within the eye sockets, instead using head movements to track prey. In addition, they are capable of compensating for the refraction of water and reflection when hunting prey underwater, and are able to judge depth under water accurately. They also have nictitating membranes that cover the eyes to protect them when they hit the water; the pied kingfisher has a bony plate, which slides across the eye when it hits the water.
Distribution and habitat
… excerpt ends here. Continue reading the full article.
