A severe drought which continued
for almost three years in the North Central Province has come to an end with
the monsoon rains this year - 2018. A land that flourishes a unique hydraulic
civilization and a network of water storing tanks or ponds called “Wewa” in
native Sinhala are full to capacity. The paddies below the tanks are tilled and
sown giving a lush hue of fading green. A pleasing site at dawn, with the night’s
mist clearing in the morning streaks.
Typical layout of a cascading tank irrigation system
Our night stay in Rambawewa within
the watershed of a medium sized tank was full of water and the extended spread
of water leading into a growth of shrub and vegetation thriving on the once rich
silty tank bed.
Up early morning with binoculars,
camera and the bird activity in the water spread skirting right up to the
benches placed on the periphery of the property to sit and enjoy the aquatic environment
was very pleasing. From the behind came the high pitched honking of a peacock
on a “Mango tree” Mangifera indica …. it’s night peach waiting for the sun to come up.
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| Purple Heron |
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| Large Egret |
Five Spot-billed Pelicans are feeding
among the reeds and short shrubs in the shallow stagnant water. It is amazing
to note that all five pelicans are feeding individually and their success rate
is very high. Generally the pelican hunts as a team cornering the fish and
attacking them in unison. It was different over here in the very shallow water.
The shape in the shrilled shadow through its pouch membrane against the
sunlight shows them to be fairly large catfish.
These man-made water-bodies are
used to store rainwater for a six month season of cultivation and the water is
released to a pre-planned schedule. The tank water level decreases with the water
issue and the last waters are held close to the bund which is the deepest location
in this water systems. Likewise the aquatic life too gets into a cycle where
the nutritious vegetation in the outer spread gets attracted by the carps, tilapia
and the catfish that feed on them. Gradually with the water being drained for irrigation
the fish get a limited feeding area and finally gets confined in the puddles
and pools and become prey to many water birds, otters and small wild cats.
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| Intermediate Egrets in flight. |
However catfish being air
breathers they bury themselves in the mud pools keeping their skin moist and
survive the interim period until the next rains are in filling the tank for
another season with a fresh aquatic cycle. In the case of the tilapia; its eggs
survive and are even transferred from one water body to another by travelling
over land stuck in the feet of most water birds. This being the secret for fish
to occur in any new water-body.
Getting back to our pelicans ……
it is these catfish that had buried themselves in the mud and are now active in
the outer reaches of the tank feeding on the grasses in the shallow waters that
turn out as prey to the pelicans. The water being shallow and the catfish being
a slow mover is easy prey to the pelican not needing teamwork?
It’s fascinating to see the sequence
of the pelican spotting the fish and attacking which was almost always successful.
No sooner it spots the fish the head is pushed right back with the pouch and
the bill tightly sunk in the stooping frontal part of its body until the stabbing
attack with a high-speed leap takes place securing the prey in its pouch with
the head swung in an upward movement.
Birdwatching is much more fun and
engrossing when you study their behavior and understand the reason for such
behavior.