The Asian openbill was described by the French polymath Georges-Louis Leclerc, Comte de Buffon in 1780 in his Histoire Naturelle des Oiseaux from a specimen collected in Pondichery, India.

[2] The bird was also illustrated in a hand-coloured plate engraved by François-Nicolas Martinet in the Planches Enluminées D'Histoire Naturelle which was produced under the supervision of Edme-Louis Daubenton to accompany Buffon's text.

[3] Neither the plate caption nor Buffon's description included a scientific name but in 1783 the Dutch naturalist Pieter Boddaert coined the binomial name Ardea oscitans in his catalogue of the Planches Enluminées.

The name is derived from the distinctive gap formed between the recurved lower and arched upper mandible of the beak in adult birds.

The cutting edges of the mandible have a fine brush like structure that is thought to give them better grip on the shells of snails.

Like other storks, the Asian openbill is a broad-winged soaring bird, which relies on moving between thermals of hot air for sustained flight.

[10] The species is very rare in the Sind and Punjab regions of Pakistan, but widespread and common in India, Sri Lanka, Nepal, Bangladesh, Myanmar, Thailand and Cambodia.

[16] In Thirunavaya Lotus Lake Wetland Malappuram district of Kerala state in India, they are mostly seen in the months of September–February season[17][18] Asian Openbills appear to be susceptible to dying during hailstorms.

[19] During the warmer part of the day, Asian openbills soar on thermals and have a habit of descending rapidly into their feeding areas.

Groups may forage together in close proximity in shallow water or marshy ground on which they may walk with a slow and steady gait.

The Asian openbill feeds mainly on large molluscs, especially Pila species, and they separate the shell from the body of the snail using the tip of the beak.

[20] Subsequent studies have dismissed this idea and the rough edge of the bill has been suggested as being an adaptation to help handle hard and slippery shells.

[8][21] They forage for prey by holding their bill tips slightly apart and make rapid vertical jabs in shallow water often with the head and neck partially submerged.

[22] At one location in Thailand, Asian Openbills discarded the male’s testes and female’s albumen glands of Pomacea canaliculata.

The Asian openbill breeds colonially, building a rough platform of sticks often on half-submerged trees (often Barringtonia, Avicennia and Acacia species), typically laying two to four eggs.

[25] Nesting colonies are sometimes in highly disturbed areas such as inside villages and on trees located in crop fields.