Asian Openbill at Kambala

It has been a month since famous Kadri Kambala (Buffaloe Race) had taken place at Mangalore. I was driving past the Kadri Kambala fields on that afternoon I saw this Asian Openbill catching snails in the Kambala fields. Kadri Kambala is one of the famous and the first Kambala to occur in a Kambala season. To know more about Kambala have a look at my blog on Moodabidri Kambala here. Soon after the Buffaloe race, paddy is sown in these fields. The luscious paddy field with plenty of water is a nice breeding ground for Land snails which are favorite food source of these Asian Openbill. I captured this lonely Asian openbill along with huge number of cattle egrets (Bubulcus ibis) surrounding it using my Canon EOS 5D Mark III fitted with Canon EF 300mm f/2.8L II IS USM & Canon EF 2X III Extender. There was a nice late afternoon sun light seeping from the surrounding coconut trees and flooding the green paddy field.

The Asian Openbill or Asian Openbill Stork (Anastomus oscitans) is a large wading bird in the stork family Ciconiidae. Asian Openbill has a conspicuous gap in its bill, allowing the bird to catch its preferred food, the freshwater snails. 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.

Asian Openbill is the most common Asian stork, and populations are not threatened. 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. They feed in rice-fields and marshes in freshwater. Asian Openbill breeds near inland wetlands. They live in shallow marshes and flooded areas. They are resident in tropical southern Asia, from India and Sri Lanka, east to south-eastern Asia. Asian Openbill populations are resident in their range. Some groups may move after breeding season, but most of them are sedentary. Breeding season depends on the location. Northern populations breed from July to September, and southern birds breed from November to March. They are very social birds.

Asian Openbill feeds mainly on molluscs, and particularly freshwater snails, Apple Snails, (genus Pila – Ampullariidae), living in rice-fields and swamps. Prey is located by touch and sight. The gap in the bill allows good grasp of the snail’s shell. Asian Openbill walks slowly in shallow water, searching for prey. It extracts snail from the shell, with pointed lower mandible. The usual foraging habitats are inland wetlands and are only rarely seen along river banks and tidal flats. Birds may move widely in response to habitat conditions. Young birds also disperse widely after fledgling. Individuals ringed at Bharatpur in India have been recovered 800 km east and a bird ringed in Thailand has been recovered 1500 km west in Bangladesh. Storks are regularly disoriented by lighthouses along the southeast coast of India on overcast nights between August and September. The species is very rare in the Sind and Punjab regions of Pakistan, but widespread and common in India, Sri Lanka, Burma and Thailand.

They nests in colonies, with numerous nests in the same tree, up to 40 and more. Long courtship displays occur at the beginning of breeding season. In threat displays, Asian Openbill has open wings and neck outstretched. Usually, rivals threaten each other, but rarely fight. Asian Openbill uses warm air stream for rising in the air, and flies high in the sky. Then, it glides to destination. Landing is spectacular. Asian Openbill drops from the air as a parachute, with dangling legs, and lands. Asian Openbill nests in colonies with other species, such as Ardeidae and acacia. Nest is located in trees or bamboos. It is made with sticks, and interior is lined with green leaves. Female usually lays 2 to 4 white eggs. Incubation lasts about 27 to 30 days, and young fledge at 35 to 36 days after hatching. Young birds are greyish, with dark bill. They stand and wait for adults. Parents approach the nest cautiously, and regurgitate the food. Adults shade their young in the nest, to protect them from sun. One of the parents stands in the nest with semi-open wings above the chicks. Asian Openbill is usually monogamous, but polygamy exists. In this case, all members of polygamous nest raise the young, and brood success is more important than in monogamous nests.