Kingfishers (locally known as Machhranga) are a group of compact-bodied birds usually with short tails, large heads and long, heavy, pointed bills, belonging to the families Alcedinidae, Halcyonidae and Cerylidae of the order Coraciiformes. They are generally shy birds. Physically small, the unmistakably bright blue and orange birds fly very low over the slow moving or still water, such as lakes, canals and rivers in lowland areas. They rapidly fly to hunt fish from riverside perches, occasionally hovering above the water’s surface.
About 94 species of kingfishers occur worldwide. The centre of abundance is Southeast Asia and New Guinea, but tropical Africa also has strong representation. In Bangladesh there are 12 species, two of which are threatened: one is endangered and the other one is vulnerable; three could not be evaluated due to paucity of data; seven do not have any immediate threats.
Kingfishers feed on a wide variety of prey. They are most famous for hunting and eating fish, and some species do specialise in catching fish, but other species take crustaceans, frogs and other amphibians, annelid worms, molluscs, insects, spiders, centipedes, reptiles (including snakes), and even birds and mammals. Individual species may specialise in a few items or take a wide variety of prey, and for species with large global distributions, different populations may have different diets.
Woodland and forest kingfishers take mainly insects, particularly grasshoppers, whereas the water kingfishers are more specialised in taking fish. The red-backed kingfisher has been observed hammering into the mud nests of fairy martins to feed on their nestlings. Kingfishers usually hunt from an exposed perch; when a prey item is observed, the kingfisher swoops down to snatch it, then returns to the perch. Kingfishers of all three families beat larger prey on a perch to kill the prey and to dislodge or break protective spines and bones. Having beaten the prey, it is manipulated and then swallowed. The shovel-billed kookaburra uses its massive, wide bill as a shovel to dig for worms in soft mud.
Kingfishers are vulnerable to hard winters and habitat degradation through pollution or unsympathetic management of watercourses. A number of species are considered threatened by human activities and are in danger of extinction. The majority of these are forest species with limited distribution, particularly insular species. They are threatened by habitat loss caused by forest clearance or degradation and in some cases by introduced species.