Migration of Asian Openbills is seasonal
and spectacular, says Arunayan Sharma
The Raiganj Wildlife Sanctuary alias Kulik
Bird Sanctuary is located in a confined pocketed area in West
Bengal. The sanctuary is home to 164 bird species. The Kulik
Heronry actually is a mixed breeding colony 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.
A large number of Asian Openbill Anastomus oscitans are 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 began in the 1970s with tree
species are Kadam Anthocephalus cadamba, Jarul lagerstroemia
flosreginae, Sisoo Dalbergia sisoo and Eucalyptus and classified
as Tropical Dry Deciduous Forest. The shape of the sanctuary
is “U” shaped with a network of artificial canals
connected with the river Kulik. There is also a small island
in the core area of the sanctuary, planted by Eucalyptus trees
and surrounded by artificial canals is the main breeding ground
for Asian Openbills. During monsoon the river water enters
the sanctuary, which provides a wide variety of food for the
birds, particularly for the Asian Openbill, whose main diet
is Apple Snail Pila globosa.
The Asian Openbill Anastomus Oscitans belongs to stork family,
one of the common bird species widely distributed in Asian
countries. This species is native and breeds in Bangladesh,
India, Bhutan, Cambodia, Thailand, Vietnam, Laos, Myanmar,
Nepal, Pakistan and Sri Lanka. It is medium sized dull white
stork with blackish or grayish wings and tail. The bill of
this species is heavy with a gap between the mandibles (upper
& lower beak) and it got its name as Asian Openbill. On
an average its height is 70cm. In West Bengal commonly it
is known as Samukh Khol (snail eater), because it mainly feeds
on Mollusks (the main diet is Apple Snail). Sometimes it feeds
on frogs, lizards and fishes. It is a common resident bird
of India, particularly in West Bengal. They are found in the
agricultural fields, marshy wetlands, near waterbodies, ditches,
riversides and paddy fields. When they breed they assemble
in a place known as Heronry with some other waterbird species.
The Kulik Heronry of North Dinajpur district is one of such
important heronry.
The Asian Openbills visits 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 group of Asian Openbill
arrives and starts their nest building activities in various
selected trees. Competition for selection of nesting trees
and nest building are high in this heronry. Individuals those
who are not able to get some nesting trees prefer to build
nests in the trees 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 are as
close as one to two meters from each nest. At least six species
of water birds found building nests in close proximity of
each other. In this heronry, it has been observed that a pair
of Asian Openbill lays three to five eggs in which approximately
four eggs hatches and 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 to 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 meters to four
meters and sighting of tamed Asian Openbills roaming in the
floor of sanctuary are common sight. In the month of October
parents starts flight training to their juveniles. At this
time sighting of parents protecting their chicks from scorching
sun is a beautiful sight. During this period a large number
of juveniles fall from the nest and killed by straying dogs,
jackals, jungle cats and monitor lizards. Although the respective
parents try to feed them for first few days but at last hope
abandons them. A large number of Asian Openbills dies for
such reasons only.
Sometimes a healthy population of Asian Openbills breeds outside
the sanctuary. However, people often objected about the foul
smell of the dropping of the eggs in their garden and backyard
and are found unwilling to protect them. The total breeding
population of Asian Openbills in the South Asia is more than
1,25,000. As per the breeding population data of Asian Openbills
of the Kulik Bird Sanctuary, the small Kulik Bird Sanctuary
regularly supports 32-40 per cent existing population of Asian
Openbills of South Asia.
Since agricultural fields are over contaminated by use of
synthetic and artificial pesticides and fertilizers, which
destroy their food. The so called developmental works all
over the India, 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 killed by the farmers
by inserting poison in the shell of apple snail in agricultural
fields to protect their newly sworn paddy saplings, because
while foraging these birds destroying their crops. Asian Openbills
are trapped, poached and killed for their flesh, which is
a substitute of meat for a section of the society.
Some birds are just being killed for feathers for some ornamental
purposes to be used as a musical instrument known as Dhak
(Drum). The major threat is their habitat loss and increasing
amount of contaminated food resources. But, hopes are still
alive to protect the species from extinction in near future
and may provide them some roosting sites as well.
(The author is director Centre for
Ecological Engineering, Malda )
Courtesy: The Statesman |
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