Friday, July 9, 2010

Asian Openbill/විවරතුඩුවා/බෙල්ලන් කොකා [Vivaratuduwa/Bellan koka] (Anastomus oscitans)

Smallest stork of Sri Lanka with a    characteristic bill which has a gap between mandibles when it is closed. Common breeding resident of marshes, tanks, paddy fields and lagoons. Much common in dry zone low lands where it met with singly or in small parties and flocks. However it has been observed that recently open bill had expanded its distribution range to the wet zone specially wetlands around Colombo such as Muthurajawela, Bellanwila and paddy fields of Western province. Its food  consists mainly of mollusks. Also eat crabs, frogs, fish and other small animals found in its swampy habitats
Its peculiar bill is obviously an adaptation to facilitate extraction of soft body of mollusks from the hard shell. Regularly soar on thermal currents on sunny days and can be seen flocks circling up to great height in sky. It is recorded that this stork brings bivalve mollusks to ashore and eat soft parts when valves open due to hot sun. Breeding season is from December to March and nest in colonies sometime up to hundreds or more in top of low trees by water.


  1. I've seen them around Kurunegala and Panadura. My attempts get a snap or a video of one has so far been hopeless.

  2. Hi Amila
    Yes...It is very common in paddy fields and tanks around Kurunagala and also Bolgoda lake and other marshy areas of Panadura. I have taken this picture at Anavilundawa wet land santuarly (One of the Ramsar site situated north of chilaw and south of Puththalam). A good place to watch/photograph nearly hundreds of bird species specially waders.

  3. විවරතුඩුවා or බෙල්ලන් කොකා