Asian Openbill Stork
Anastomus oscitans
About the Asian Openbill Stork
The Asian openbill is a medium-sized stork named for the distinctive gap between its upper and lower mandibles when the bill is closed. This unique adaptation is an evolutionary specialization for feeding on apple snails — the openbill can hold the round shell between its mandibles and crush it with the tips. They are grey-white with black flight feathers and pinkish legs. During the breeding season, they develop subtle pinkish tones on their body feathers.
Wilpattu Significance
Openbills are common at Wilpattu's villus, especially when water levels are receding and apple snails become concentrated. They are often seen in small flocks, wading methodically through shallow water. Their feeding technique is fascinating to watch — they pick up a snail, crush the shell, tip the head back to swallow, and move on to the next. They nest in mixed colonies with painted storks and cormorants.
Conservation Status
Least Concern. Healthy population across Sri Lanka's wetland ecosystems.
Best Season to See
Year-round, but most visible during the dry season (May-September) when snails concentrate in shrinking water bodies.
Best Locations in Wilpattu
- Kokkare Villu
- Lunuwewa Villu
- Mahaweva Villu
- shallow margins of all villus
Viewing Tips
- 1Watch them feed in shallow water — the snail-crushing technique is fascinating
- 2They are less shy than painted storks, allowing closer approach
- 3Small flocks of 5-15 are common at productive feeding areas
- 4Breeding season (July-October) brings nesting activity in colony trees
Photography Tips
- A feeding sequence (picking up snail, crushing, swallowing) makes an excellent series
- Side profile shows the distinctive open bill most clearly
- Flocks in flight against a dramatic sky create strong environmental images
Did You Know?
The gap in the openbill's beak is not a deformity or injury — the upper and lower mandibles never touch except at the tips. This gap is precisely the right width to hold an apple snail shell while the tips crush it, like a pair of wire cutters.
Ready to see the Asian Openbill Stork in the wild? Book a Wilpattu safari with expert naturalists who know exactly where and when to find them.