Source : The Statesman, India, 07 Aug '07
By : Arunayan Sharma
  

The Asian Openbill has a large range, with an estimated global extent of occurrence of 1,000,000-10,000,000 sq km. Their global population is estimated to be 1,30,000 by Wetlands International and the species is not believed to approach the thresholds for population decline criterion of the IUCN Red List (ie declining more than 30 per cent in 10 years or three generations). For these reasons, Birdlife International evaluates the species as of "Least Concern". This species is native to Asia and breeds in Bangladesh, India, Bhutan, Cambodia, Thailand, Vietnam, Laos, Myanmar, Nepal, Pakistan and Sri Lanka.

Although this species is evaluated as least concerned, but now its breeding heronries needs protection from external threats like natural calamities, human greed for flesh, habitat destruction and overuse of artificial pesticides and fertilizers in the agricultural fields. This species is known to breed in a colony, but there are very few established breeding colonies present in India and hardly now protected from such threats. Still it is also not known which heronry of India is the highest Asian Openbill breeding colony, particularly in Asia. I am about to explore on a largest breeding colony of this species in India named as Kulik Bird Sanctuary. Even before the sanctuary upgraded from social forestry sector to as a wildlife sanctuary, Asian Openbills started assembling here for breeding purposes. And it is one of the reasons that to give protection to those innocent birds it is declared as Raiganj Wildlife Sanctuary.

The Raiganj Wildlife Sanctuary alias Kulik Bird Sanctuary is located in a confined area in West Bengal. Ornithologically it is a very important heronry. The sanctuary is also home to 164 species of birds. The Kulik Bird Sanctuary is located in the North Dinajpur district of West Bengal which is officially designated as the "Raiganj Wildlife Sanctuary" in the year 1985, lies just 4km North from the district center Raiganj town. This wildlife sanctuary also popularly known as Kulik Bird Sanctuary as because the river Kulik flows beside the sanctuary and acts as the boundary in its Eastern and Southern parts.

The Kulik Heronry actually a mixed breeding of various species of waterbirds mainly Little Cormorant Phalacrocorax niger, Indian Shag Phalacrocorax fuscicillis, Black Crowned Night Heron Nycticorax nycticorax, Cattle Egret Bubulcus ibis, Little Egret Egretta garzetta, Large Egret Casmerodius albus, Median Egret Mesophoyx intermedia and Pond Heron Aedeola grayii. Along with them a large number of Asian Openbill Anastomus oscitans breeding here since 1984.

The habitat of this heronry is an artificial planted forest under the social forestry programme of West Bengal forest department which had began in 1970 with main tree species like Kadam Anthocephalus cadamba, Jarul lagerstroemia flosreginae, Sisoo Dalbergia sisoo and Eucalyptus which were classified as tropical dry deciduous forest. The area of the sanctuary is c. 1.30 sq km in which Core Area c. 0.14 Sq km and Buffer Area c. 1.16 Sq km. The shape of the sanctuary is that of the English alphabet "U" with a network of artificial canals connected with the river Kulik. There is also a small island in the core area of the sanctuary, mainly surrounded by the Eucalyptus trees and surrounded by artificial canals is the main breeding ground for Asian Openbills. There are 656 nesting trees are so far found within the protected area where birds are breeding with out any disturbances. During monsoon the river water enters the sanctuary, which supports a wide variety of food for the birds, particularly for the Asian Openbill, whose main diet is Apple Snail Pila globosa.

The Asian Openbills started flocking in this heronry from the month of July or the arrival of monsoon and stayed up to the month of January of next year. In the first phase, a group of birds arrives and inspects the area and selected the nesting trees. At the end of July or first of August the whole group of Asian Openbill arrives and starts their nest building activities in various selected trees. Competition for selection of nesting trees and nest building is high in this heronry. Individuals those who are not able to get some nesting trees they prefer to build nests outside the protected areas along the National Highway 34 and sometimes in the garden or backyard trees of adjacent human settlements. Sometimes Asian Openbills build nests with other species of water birds. Their nests sometimes are close to two meters apart from each nest.

At least six species of water birds found building nests in close proximity of each other. In this heronry, it was observed that a pair of Asian Openbill lays three to five eggs in which averagely four egg hatches and at last two chicks survives. During this time egg lifting is a common feature by the Large-billed Crows Corvus macrorhynchos. The average hatching duration is between 30 and 40 days. Watching nest building and breeding activities of birds in this sanctuary is very easy observation. Someone can watch their activities as close as two metres to four metres and sighting of tamed Asian Openbills roaming in the floor of sanctuary are common sight. The nest building concentration so dense that in a single tree 517 with c. 2,000 individuals was recorded. In the month ofOctober parents starts flight training to their juveniles. At this time sighting of parents protecting their chicks from scorching sun is a beautiful sight. At the morning juveniles are found dying their wings by spreading them towards the sun. During this phase of time a large number of juveniles fall down from the nest and killed by straying dogs, jackals, jungle cats and monitor lizards. Some juveniles who are fall down from the nests due to small space in the nests or by competition never returns to nests. Although in such cases the respective parents try to feed them for first few days and at last hope abandons them. A large number of Asian Openbills also died from such cause. At the end of December most of the birds left the sanctuary, few thousands stay within the sanctuary and left the place in the month of January of the next year.

It is not the Asian Openbills always breed inside the protected area. A healthy population also breeds outside the sanctuary. Large number of Asian Openbills also breeds on 24 trees outside the sanctuary, which are not protected by the forest authorities and subject to threat from the poaching, egg lifting, killing and disturbances caused by the National Highway 34, which runs beside the sanctuary. People objected about the foul smell of the dropping of the birds in their garden and backyard and unwilling to protect them. A large number of Asian Openbills also killed or died out of some natural calamities like flood, rain and storm.

The account of Asian Openbills of Kulik Bird Sanctuary is available from the year 1984. The very next year 1985 it was notified as a wildlife sanctuary. At the beginning of the year 1984 there were 22,364 birds were counted. Up to the year 1992 there was a steady rise in the breeding population which was more than two times of the existing initial breeding population. In the very next year in 1993 the breeding population of Asian Openbills reduced to fifty per cent because of the heavy rain, storm and flood in the sanctuary.

Slowly over the year the breeding population regained in-between 30,000 and 40,000. Such rise and fall in the population of Asian Openbills in the Kulik Bird Sanctuary is a common phenomenon. Due to conservation efforts between the years 2000 and 2006 the population of Asian Openbills in the Kulik Bird Sanctuary rises and established between 40,000 and 50,000. Out of the population 40,160 survived and in the year 2005 the breeding population was 51,488 individuals. Over the last 23 years 56,148 individuals were recorded in the year 2001 which is the highest breeding population ever recorded and 21,646 individuals were recorded in the year 1993 which was the lowest population ever recorded in the heronry.

It is still not known why a large number of Asian Openbills flocking in the small area of the Kulik Bird Sanctuary where there are lots of human and artificial interferences are occurring during their breeding period. It may be the same batch of birds that hatched and raised from this heronry returns year after year. Probably the birds are behaviorally accepted and habituated in such artificial conditions since their hatch. This behavior of Asian Openbills needs further research and investigation. Another factor could be that the region is a flood plain area and main rice growing area of the region dotted with many large water bodies, river beds and marshy areas which are full of their main food diet Apple Snail Pila globosa.

The total breeding population of Asian Openbills in the South Asia is more than 1,25,000 and the 1 per cent threshold population is 1,250 individuals by Wetlands International. As per the breeding population data of Asian Openbills Sanctuary reveals that the small Kulik Bird Sanctuary regularly supports 32 - 40 per cent existing population of Asian Openbills of South Asia. A heronry, which supports such large number Asian Openbills in South Asia, is not only a nationally important heronry but also an Internationally important heronry. The breeding colony of Asian Openbills of Kulik Bird Sanctuary is estimated among top heronries of India and now an important bird area of India. It could be that the Kulik Bird Sanctuary of North Dinajpur district, West Bengal, India is the highest Asian Openbill breeding Heronry not only in India but also in whole South Asia, which supports more or less than fifty per cent of the global population.

In 1970s, within the mature trees in forest birds started assembling. The Raiganj Social Forestry Division gave protection and later in 1985 it was designated as a Wildlife Sanctuary. In the beginning of conservation efforts, which started from the year 1984, the population of Asian Openbills in Kulik Bird Sanctuary rose rapidly. Although in between sue to some natural calamities there were little ups and down in the breeding of this species. Slowly over last 23 years it is now established as a one of the largest Asian Openbill breeding heronry in India. With some more conservation efforts the heronry may be developed as a largest Asian heronry.

The Asian Openbill being the least concerned species may not face any serious threat of extinction, but by some external and artificial factors it is now facing some threats. The species do not have any natural prey except egg lifting by large-billed Crows and Monitor Lizards. Naturally some population also destroyed by hailstorm, strong wind and flood which destroy their food base.

The main foraging grounds of Asian Openbills are the agricultural fields, mainly in the rice fields where they look for apple snail. Now it is well known that these agricultural fields are now contaminated by over use of synthetic and artificial pesticides and fertilizers. In future it could be that their food resources may affect and destroyed by such chemicals. The so called developmental works all over the country, particularly in these regions now engulfing the agricultural lands for conversion of housing and industrial projects, reducing their foraging grounds. It is also found that in this region Asian Openbills are found killed by farmers by inserting poison (pesticides) in the shell of apple snail in agricultural fields to protect their newly sworn paddy saplings, because while foraging these birds destroying their crops. Apart from these factors Asian Openbills are also trapped, poached and killed for their flesh, which is a substitute of meat for the poor section of the society. Eggs are found sold in the market for the same purpose. For some the innocent birds are just being killed for feathers for some ornamental purposes in a musical instrument known as Dhak (Drum). The droppings of Asian Openbills are very toxic and have strong foul smell. For this reason people do not allow them to settle and breed within the garden, backyard or agricultural trees. To get rid of them people sometimes killed them just for no reason.

There were some hue and cry over the killing of Asian Openbills by Bird Flu in the sanctuary. But no symptoms of Bird Flu were found not a single bird. The main threat is their habitat loss and threat to their food resources. But still there are some hopes we can protect this species from extinction in near future and can provide them some roosting sites. As this species known to nest colonially, their nesting colonies even a small one which at least supports one per cent biographic population of this species. Out of these threats there are some hope that still to some arrival of this species in the region is a sign of good monsoon which is after a summer is not only essentials for all the living beings but also important for good harvest. Hope in this year arrival of Asian Openbills will bring good monsoon and joy for us.