Kingfishers are a family, the Alcedinidae, of small to medium-sized, brightly colored birds in the order Coraciiformes. They have a cosmopolitan distribution, with most species found in the tropical regions of Africa, Asia, and Oceania, but also can be seen in Europe. They can be found in deep forests near calm ponds and small rivers. The family contains 116 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.
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.