Scientific Name: Anastomus oscitans
Name: Asian Openbill
Asian Openbill is a small stork with conspicuous gap in its bill, allowing the bird to catch its preferred food, the freshwater snails.
Size in cm:
Adult has white plumage in breeding season, and pale grey for rest of the year. Scapulars, flight feathers and tail are black.
Head is white or grey. The open bill is formed by a hollow in the lower mandible. Both mandibles meet at tip. Large, strong bill is pale pinkish-grey. Eyes are dark brown. Lores are greyish to pinkish. Long legs and feet are pinkish to red.
Both sexes are similar.
Juvenile have brown tinge, instead white or pale grey. Bill is dark grey with lower mandible almost straight. Gap forms later.
Size in Inch
white (Bird may have more colors)
Asian Openbill feeds mainly on Apple Snails, but it also consumes frogs, crabs and large insects, and other small aquatic animals.
Habit and habited:
Asian Openbill feeds in rice-fields and marshes in freshwater. It breeds near inland wetlands. It lives in shallow marshes and flooded areas.
Asian Openbills are very noisy while flying in flocks. We can hear a continual hubbub, as the gabbling of hundreds of ducks. Call is a mournful hoo-hoo.
The Asian openbill or Asian openbill stork (Anastomus oscitans) is a large wading bird in the stork family Ciconiidae. This distinctive stork is found mainly in the Indian subcontinent and Southeast Asia. It is greyish or white with glossy black wings and tail and the adults have a gap between the arched upper mandible and recurved lower mandible. Young birds are born without this gap which is thought to be an adaptation that aids in the handling of snails, their main prey. Although resident within their range, they make long distance movements in response to weather and food availability.
The Asian openbill stork is predominantly greyish (non-breeding season) or white (breeding season) with glossy black wings and tail that have a green or purple sheen. The name is derived from the distinctive gap formed between the recurved lower and arched upper mandible of the beak in adult birds. Young birds do not have this gap. 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. The tail consists of twelve feathers and the preen gland has a tuft. The mantle is black and the bill is horn-grey. At a distance, they can appear somewhat like a white stork or Oriental stork. The short legs are pinkish to grey, reddish prior to breeding. Non-breeding birds have a smoky grey wings and back instead of white. Young birds are brownish-grey and have a brownish mantle. Like other storks, the Asian openbill is a broad-winged soaring bird, which relies on moving between thermals of hot air for sustained flight. They are usually found in flocks but single birds are not uncommon. Like all storks, it flies with its neck outstretched. It is relatively small for a stork and stands at 68 cm height (81 cm long).