Alcedinidae Kingfishers
Version: 1.0 — Published March 4, 2020
Introduction
Ranging in size from tiny dwarf and pygmy kingfishers to the crow-sized kookaburras, kingfishers occupy waterside or wooded habitats around the world. Although some eat no fish, all kingfishers are adept hunters on land or water, seizing prey in their large bills. Most nest in tree holes or in burrows in banks or termite nests. Burrow excavation begins by the pair taking turns diving right into the wall, beak-first, to dislodge the first body-length or so of earth. Aquatic species have an off-axis camshaped lens that allows them to switch instantly between focus points on their retinas as soon as their head is underwater capturing prey.
Habitat
Many kingfishers live near water, but the terrestrial kingfishers of the Old World occupy a variety of woodland and forest habitats.
Diet and Foraging
As with their habitats, kingfishers have a varied diet, although all are entirely carnivorous. Most kingfishers are sit-and-wait predators, either perching or hovering over water or the forest floor. Small terrestrial kingfishers feed primarily on large insects, whereas larger terrestrial kingfishers such as Halcyon and Dacelo also eat lizards, amphibians, mammals, and birds. The many aquatic kingfishers feed primarily on fish, which they capture by plungediving into the water. Clytoceyx uses its short, heavy bill to push through soft dirt in search of earthworms and other subterranean prey.
Breeding
Most kingfishers are monogamous with biparental care. In diverse species across the family, cooperative breeding sometimes occurs, with either retained offspring or unrelated helpers. Serial polyandry has also been reported in some. All kingfishers are cavity-or burrow-nesters, though they use a variety of substrates. Many excavate their own burrows in earthen banks, using their semi-fused front toes to help shovel out dirt and sand. Others nest in tree cavities, utilizing old woodpecker cavities when available, or excavating their own nest hole in soft or rotted wood or in arboreal termite nests. Kingfishers generally lay 2 to 10 eggs, with fewer eggs laid in tropical species. Both members of the pair involve themselves in all aspects of parental care, from nest construction on. The chicks hatch naked with eyes closed, and some use a hook on their bill tip to kill siblings if food deliveries from the parents are sparse. Incubation takes two weeks to a month (longer in larger species) and chicks are in the nest for three to six weeks. Most are fed for only a few days after leaving the nest, and they become independent fairly rapidly.
Conservation Status
At least 42 kingfisher species (35%) are of conservation concern (25 NT, 10 VU, 2 EN, 4 CR, 1 EW). The Guam Kingfisher Todiramphus cinnamominus is considered extinct in the wild, but a captive breeding program appears to be producing enough offspring that a reintroduction to its limited island range would be feasible if the habitat could be restored and introduced brown tree snakes Boiga irregularis could be eradicated. Many of the other endangered kingfishers have very small island ranges, and they are all vulnerable to habitat alteration and introduced predators. Intensive logging has also led to widespread destruction of habitat for forest kingfishers in Southeast Asia.
Systematics History
The most robust recent studies strongly support placing Alcedinidae as sister to Momotidae within Coraciiformes (Ericson et al. 2006a, Hackett et al. 2008). Despite some contrary morphological characters (Johansson et al. 2001, Livezey & Zusi 2007), it seems most likely that Todidae is sister to this clade of two (Ericson et al. 2006a, Hackett et al. 2008). There are three main groups within the Alcedinidae, each recognized as a subfamily (Moyle 2006). Alcedininae occurs throughout the Old World and includes many small to tiny jewel-colored species. Most species in the small subfamily Cerylinae specialize on diving for fish, and the subfamily contains all the kingfishers of the Western Hemisphere. The most speciose subfamily, Halcyoninae, includes the kookaburras and most of the other woodland-dwelling kingfishers, which have little or no association with watercourses.
Conservation Status
Least Concern |
63.2%
|
---|---|
Near Threatened |
17.1%
|
Vulnerable |
4.3%
|
Endangered |
0%
|
Critically Endangered |
3.4%
|
Extinct in the Wild |
0.85%
|
Extinct |
0%
|
Not Evaluated |
0%
|
Data Deficient |
0.85%
|
Unknown |
10.3%
|
Data provided by IUCN (2023) Red List. More information