Continued from
The ubiquitous Brahminy Kites
Point Calimere has been one of those places where, one is
supposed to see waders, big and small, lots and lots of them. I think I saw larger colonies of waders in
Pallikaranai than I did in Point Calimere, this season. So, what is wrong?
The paper focuses
on Chilika, Pt Calimere, Gulf of Mannar and Pulicat. Here is an extract from the paper about Point
Calimere:
The Point Calimere Wildlife Sanctuary
(10°18’N, 79°51’E) is situated on a low promontory on the Coromandel Coast (southern
Deccan Plateau) in the Bay of Bengal (Fig. 1). The adjoining Great Vedaranyam
Swamp stretches parallel to the
Palk Strait for about 48 km, and is
separated from it by a sandbank. Its north-south dimensions vary from about 10
km at its broadest in the east, to about 8 km in the central part and about 6
km in its western portion. Five freshwater channels connected to the Cauvery
River empty into the swamp. There is a gradual slope from north to south. The
total area is about 349 sq. km.
In about two-thirds of the swamp, the
habitat varies seasonally. During the monsoon and periods of south-westerly
winds, there is a continuous expanse of fresh, brackish or saline water extending
to the northern tip of the swamp. At other times, the area of open water
gradually dries up from north to south. During
the drying stage, there are exposed flats and shallow pools. The extreme
eastern promontory of the swamp,
comprising Kodikkarai and Kodikkadu
Reserve Forest, has been declared a wildlife sanctuary. This sanctuary, the
Point Calimere Wildlife Sanctuary, supports both littoral and terrestrial life zones
(Ali 1980, Manakadan 1992). It comprises 26 sq. km of tropical dry evergreen
forest intermingled with scrub jungle and mangrove vegetation, and intersected
by numerous tidal inlets and creeks. Exploitation of the Great Vedaranyam Swamp
for salt extraction and other marine-based industries is fast growing.
Two private chemical firms have been
operating in the leased swamp areas adjoining the wildlife sanctuary. The
manufacture of salt involves three stages. Sea water is pumped into reservoirs and
then condensed before it is finally allowed to flow into salt-pans, where the
salt crystallizes. The reservoirs alter the ecosystem to some extent since they
are, in the absence of tidal fluctuation, more or less stagnant. The
composition of the littoral communities and microfauna is drastically altered
under
such conditions. The condensers have a
relatively high salinity and temperature which create an ecological barrier for
most marine organisms from April to October. Only the monsoon makes this
environment temporarily habitable for marine organisms.
Point Calimere and Great Vedaranyam
Swamp are an important wintering and staging area for over 1 000 000 waders and
other waterbirds, and are the only site that has been intermittently monitored
by bird ringing studies for the last three
decades. The swamp is of great
importance as a staging area for migrants on their way to and from Sri Lanka
and other wintering grounds.
So, Pt Calimere is on the
“South Asian Flyway” – the little chappies breed in the Arctic in the summer,
and then fly all the way down for the winter.
Again quoting from the paper
–
Most waders migrate to India during early
autumn, mainly through the north and north-west. From here, some birds continue
on south-west to wintering areas in Africa (as confirmed in the Ruff), while
others move south-east to the east coast of India, as demonstrated by a Curlew
Sandpiper that was ringed at Bharatpur (north-west India) and recovered in the
same winter at Point Calimere (south-east India). A similar migratory divide
between birds wintering in India and those wintering in south-west Asia and
Africa may also occur in Kazakhstan, as most of the recoveries during autumn
passage of birds ringed in India have been from Kazakhstan. The spring passage
of waders along the east coast of India is relatively well known (Ali 1981,
Balachandran 1998, Hussain 1991).
Now here is the alarming and
worrying bit –
The decline in waterbird populations at
Point Calimere is very conspicuous not only to ornithologists, but also to
laymen in the area. Any local villager, especially anyone over 40 years of age,
can recall the drastic changes that have occurred in the numbers of waders and
other waterbirds in the Great Vedaranyam Swamp.
The disappearance of the fabulous clouds
of waterbirds (waders, ducks, terns, flamingos, egrets) that passed through the
villages on their way between feeding and roosting sites up until the late 1980s
is a visible indicator of the decline. The appearance of large mounds of salt
on the mudflats, which were once thronged
by thousands of waders, ducks and
flamingos, is an indication of the habitat loss and degradation.
The ringing and census data from Point
Calimere indicatethat there has been a decline of over 70% in certain species
of waders since the 1980s.
The most affected species are the two Arctic-breeding
Calidris sandpipers, Little
Stint and Curlew Sandpiper, which were formerly the most abundant winter
visitors at Point Calimere. The reservoirs, inter-tidal zone and other brackish
areas at Point
Calimere provided enormous feeding areas
for these species, with numbers of Little Stint in the 1980s exceeding 200 000
and those of Curlew Sandpiper, 150 000. During the last four years, however, neither
of these species has been recorded in numbers exceeding 25 000. It appears that
these two species formerly benefited from the shallow water levels in the
reservoirs which carried many littoral organisms (crustaceans, polychaetes)
into the environment. The plentiful rains also helped to increase the
productivity of these habitats during the wet season. The extension of
salt-based industries, the diminishing rainfall and disturbances caused by
fishermen have now altered these habitats.
But for those who had visited even in the '80s, the salt pans and the swamps were bare.
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The white dots in the distance were gulls and a few egrets. |
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These looked like little stints but were too far away. Every now and then, they would take off in unison, and treat us to this lovely sight of a spontaneous, synchronised air show! |
At the salt pans and pump house -
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Black-winged stilts - I think the only ones I saw. Supposedly found in large numbers in Calimere earlier. Are they all stopping over at Pallikaranai, then? |
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Egrets in plenty |
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A mixed flock of little terns, brown-headed gulls and gull-billed terns |
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Empty expanses, with some pelicans sometimes |
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Brown-headed gulls were in abundance, flashing their wing "mirrors" at us! |
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Two of the gulls at the pump house. They had a long conversation - mostly one squawked and the other listened, like a much-married couple. |
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The gull-billed terns were also in plenty, tirelessly fishing. |
There were several types of terns, including Caspian, we saw when we went to the beaches, but more of that later.
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This ringed plover was busy on the edges of the salt pans. |
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A females sparrow looked curiously up at Sekar, at the pumphouse. |
We made several forays into the salt pans, enjoyed the wide open spaces and the strong winds which kind of dissipated the heat form the sun. We would be out close to midday, only returning when we were summoned for lunch at Ramar's mess!
The children went squelching in the mud, and looked like they had indulged in mud-bath therapy at the end of it. There were shells of a multitude of types that I had never seen, some beautiful butterflies and even dragonflies, but the waders were not that many, and ofcourse I did not see a flamingo.
We also walked the grasslands and the swamps.
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A kestrel sat and stared at us - and then flew off in disgust. |
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This was the extent of birds in the swamp, a small flock here and there. |
There were a lot of
wood sandpipers here
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This was one large mixed flock we came across - egrets, spoonbills, painted storks, ibises and even a heron |
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As the heat rose, the painted storks took to the air, and after a while we could see them, high up, riding the thermals, along with a whole bunch of pelicans. |
The grasslands had bulbuls, pipits, starlings and babblers in plenty, and every now and then a kingfisher would swoop by. Lapwings would call out as also francolins. Its the wader migrants that seem to be of concern.
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A rosy starling poses |
I had a strong sense of disquiet on reading Dr Balachandran's paper. Could it also be that there are issues causing falling numbers in their breeding grounds, in the north?
As he recommends, a better understanding means studies across countries in the South Asian flyway. And studies to understand the role of the salt industry and what measures are needed to mitigate their effect?
Up next, beaches and lighthouses