Alcedinidae

Alcedinidae is a family of small to medium-sized birds in the order Coraciiformes, commonly known as kingfishers. The family comprises roughly 90 to 100 species distributed across Africa, Asia, Europe, and the Americas, typically near rivers, lakes, and coastal waters. It is usually divided into three subfamilies: Alcedininae (river kingfishers), Halcyoninae (tree kingfishers), and Cerylinae (water kingfishers). Some classifications place tree kingfishers in a separate family (Halcyonidae), but many authorities treat Halcyoninae within Alcedinidae.

Morphology and behavior: Members are compact with bright plumage and a stout bill for catching fish. They perch by water and dive feet-first to seize prey. Diet is mainly fish, but includes aquatic insects, crustaceans, and small vertebrates. They are generally territorial and vocal, with call notes that vary by species.

Habitat and reproduction: They inhabit watery environments from rivers and lakes to coastal areas. Nests are excavated in hollow trees, riverbanks, or termitaria, depending on species. Clutch sizes commonly range from four to seven eggs. Both parents incubate the eggs and feed the young, which fledge after a few weeks.

Distribution and conservation: Alcedinidae species are widespread, with many in tropical regions. Some are common and widely distributed, while others are restricted and threatened by habitat loss, water pollution, and overexploitation of fish. Conservation status varies widely among species.

Evolution and systematics: The group shows considerable ecological and morphological diversity, with adaptations for aquatic foraging. Molecular studies support the traditional subdivision into three subfamilies within the family. The fossil record for kingfishers extends to the Eocene, indicating an ancient and diverse lineage.