The tree kingfishers, also called wood kingfishers or Halcyoninae, are the most numerous of the three subfamilies of birds in the kingfisher family, with around 70 species divided into 12 genera, including several species of kookaburras. The subfamily appears to have arisen in Indochina and Maritime Southeast Asia and then spread to many areas around the world. Tree kingfishers are widespread through Asia and Australasia, but also appear in Africa and the islands of the Pacific and Indian Oceans, using a range of habitats from tropical rainforest to open woodlands.
The tree kingfishers are short-tailed, large-headed, compact birds with long, pointed bills. Like other Coraciiformes, they are brightly coloured. Most are monogamous and territorial, nesting in holes in trees or termite nests. Both parents incubate the eggs and feed the chicks. Although some tree kingfishers frequent wetlands, none are specialist fish-eaters. Most species dive onto prey from a perch, mainly taking slow-moving invertebrates or small vertebrates.
Taxonomy
The tree kingfisher subfamily is often given the name Daceloninae introduce by Charles Lucien Bonaparte in 1841, but the name Halcyoninae introduced by Nicholas Aylward Vigors in 1825 is earlier and has priority.
The subfamily Halcyoninae is one of three subfamilies in the kingfisher family Alcedinidae. The other two are Alcedininae and Cerylinae. The subfamily contains around 70 species divided into 12 genera. A molecular study published in 2017 found that the genera Dacelo and Actenoides as currently defined are paraphyletic. The shovel-billed kookaburra in the monotypic genus Clytoceyx sits within Dacelo and the glittering kingfisher in the monotypic genus Caridonax lies within Actenoides.
