Temporal range: Late Miocene to Recent
|Marabou stork at Brevard Zoo, Florida, United States|
These are huge birds, typically 110–150 cm tall with a 210–250 cm wingspan. The three species each have a black upper body and wings, and white belly and undertail. The head and neck are bare like those of a vulture. The huge bill is long and thick. Juveniles are a duller, browner version of the adult.
Leptoptilos storks are gregarious colonial breeders in wetlands, building large stick nests in trees. They feed on frogs, insects, young birds, lizards and rodents. They are frequent scavengers, and the naked head and neck are adaptations to this, as are those of the vultures with which they often feed. A feathered head would become rapidly clotted with blood and other substances when a scavenging bird's head was inside a large corpse, and the bare head is easier to keep clean.
Most storks fly with neck outstretched, but the three Leptoptilos storks retract their necks in flight like a heron.
- Lesser adjutant, Leptoptilos javanicus
- Greater adjutant, Leptoptilos dubius
- Marabou stork, Leptoptilos crumenifer
There is an ample fossil record of this genus. L. titan, which was hunted by prehistoric humans, was truly gigantic, and L. falconeri possibly was one of the most widespread storks worldwide during the Pliocene:
- †Leptoptilos falconeri (Early to Late Pliocene of south Asia and east Africa)
- †Leptoptilos indicus (Late Pliocene of Siwalik, India) – formerly Cryptociconia indica, may be the same as L. falconeri (Louchart et al. 2005)
- †Leptoptilus patagonicus (Puerto Madryn Late Miocene of Valdés Peninsula, Argentina)
- †Leptoptilos pliocenicus (Early Pliocene of Odessa, Ukraine and Urugus, Ethiopia to Late Pliocene of Koro Toro, Chad and Olduvai, Tanzania) – includes L. cf. falconeri, may be the same as L. falconeri
- †Leptoptilos richae (Beglia Late Miocene of Bled ed Douarah, Tunisia, and Wadi Moghara, Egypt?)
- †Leptoptilos robustus (Pleistocene, Flores, Indonesia)
- †Leptoptilos titan (Notopuro Middle/Late Pleistocene of Watualang, Java, Indonesia)
- †Leptoptilos sp. (Ngorora Late Miocene of Baringo District, Kenya: Louchart et al. 2005)
- Louchart, Antoine; Vignaud, Patrick; Likius, Andossa; Brunet, Michel & and White, Tim D. (2005). "A large extinct marabou stork in African Pliocene hominid sites, and a review of the fossil species of Leptoptilos". Acta Palaeontologica Polonica 50 (3): 549–563.
- Meijer HJM & R A Due (2010). "A new species of giant marabou stork (Aves: Ciconiiformes) from the Pleistocene of Liang Bua, Flores (Indonesia)". Zoological Journal of the Linnean Society 160: 707–724. doi:10.1111/j.1096-3642.2010.00616.x.