The Cormorants

           
	   Kalpakkam township has many attractive, features to
develop  into a mini bird sanctuary for resident and migratory
birds.  The backwards providing a large lagoon, a green canopy
in the township, and fresh water Edayur lake inside our campus
provides a natural haven for winged visitors. This fresh water
lake,  having  sufficient water all through the year,  is  not
affected  by drought. Apart from this lake, the adjacent  back
waters  endowed with rocky outcrops, offer resting  place  for
birds  like  Egrets, Herons and Cormorants. Birds  throng  the
lake  in  their  thousands, feed and breed  from  November  to
April.  Roughly  5,500  birds of 60  species  were  identified
around  the lake. According to a population study made,  since
1982, the number of birds of each species visit every year has
been  generally on the rise due to the reasons unknown. Though
the  flora  of Kalpakkam is by no means large, the predominant
visitors are Ducks, painted Storks, grey Herons, black  winged
Stilts and Cormorants.
	   
	   The Edayur lake together with its privacy, provides
the  acrobatic  display  of  black  dotted  Kingfisher  diving
vertically  for  its  prey,  is mostly  seen  along  with  its
partner.  While in its flight, the nectar drawing swift  honey
eater, Humming bird with iridescent feathers seen occasionally
by  the  side CDO floral bush. Surprisingly, the Humming  bird
got  its  name  not by its melodious voice, but  from  humming
sound  heard  when  it beat the wings more  than  60  times  a
second.  Wandering with territorial right, beautifully crested
Hoopoe with its long downcurved narrow bill, is known form its
peculiar cry from the foliage enclaving Officers  Hostel., and
powerful  flock  of Cormorants are some of ;the  displays  one
cannot miss. The Cormorants can be seen most part of the  year
in  Kalpakkam  both  at  Edayur lake  and  at  the  lagoon  in
township.

	   Cormorants or Shag is along necked, web footed bird
that  catches fish by diving underwater. More than 30  species
of  cormorants are found throughout the world, except for  the
polar  regions. Most of them live on sea coasts, but they  are
often   seen  on  large  rivers  and  lakes  Duck  like  birds
Cormorants  may  be  from 48 to 100 cm long.  All  have  long,
strong  bills with a hook on the end. Its tail feathers spread
out  like a partly opened fan. Their plumage is usually glossy
blackish and often has a metallic sheen. Some Cormorants  have
white  under parts and brightly coloured eyes. The  sexes  are
almost identical. The Japanese Cormorants are smaller, trained
for   fishing.   The  most  important  are,  guano()excrement)
producers, the Peruvian Cormorants. There is so much guano  it
is collected and exported as a fertiliser.

	  Cormorants can stay underwater a long time when they
dive  for  fish,  but some dive to depths of 36  meters.  They
propel themselves underwater with their webbed feet, which are
set for back on their bodies, are streamlined. These birds fly
close  to the water, looking for fish, or they perch in trees,
on rocks and on the ledges of sea cliffs. Cormorants in groups
with  their feathered bodies, long necks and flat heads,  look
like rows of bottles sitting on the cliffs.

	   They  wait  for fish to appear; hunt by diving  and
picking  up  their  prey underwater. When  a  cormorant  meets
resistance from its victim it beats it on the water, submerges
it,  shakes it, and somehow manages to keep it away  from  the
unwanted interest of its comrades brought to the spot  by  the
commotion.  After diving, the Cormorant always  seeks  out  an
elevated spot, where it perches, with wings outspread.  It  is
commonly supposed that this is to dry the feathers, which  are
not as  water Proof  as those of other aquatic birds.

	  One of the enigmas of ornithology is that Cormorants
and Darters get water logged easily. This can be explained  by
the  fact that their wings lack oil. In other aspect they  are
very  well adapted to an aquatic life. but after emerging from
the  water  they  hold  their wings out  to  dry-  an  unusual
practice in water birds. This habit exists even among  captive
species in zoos, who do not have to dive for food.

	   Cormorants are trained to catch fish for fishermen.
Cormorant fishing dates back to the 12th century in China  and
Japan  and  it  was once practised in England.  The  fishermen
usually  have small flock of Cormorants which may be  tethered
with  a  long  cord or free ring. Each bird has a  metal  ring
around  its neck so that it cannot swallow large fish. On  its
return to the boat, the cormorant is relieved of its fish  and
rewarded with a small piece of fish!

	    During   the  early  stages  of  courtship,   male
Cormorants  give  the female presents- in  the  form  of  nest
material.  Later,  this becomes part of the greeting  ceremony
and  a stick may be removed from the nest and proffered as one
bird  arrives to relieve the other on the eggs while hatching.
The   pair  bond  once  established,  is  reinforced  by  such
activities as joint nest building and defence, and preening of
one  bird  by the other. During the nesting season  it  has  a
crest  of  white  curved  feathers  behind  each  eye.  Mating
frequently  occurs with the same partner in successive  years,
and  in  many  populations the same nest site may be  occupied
repeatedly.

	   The Cormorants are choosy, they dive underwater and
come  up with wet twigs to make their nests softer. Since most
species nest colonial, fighting over nest site is common.  The
nests  are  built  of  twigs or sea seed  and  are  set  close
together  on  the flat ground in crowded colonial  sites,  and
sometimes  in trees or on rocks. Female normally lay  2  to  4
pale  blue  or  green eggs, that have a chalky  covering.  The
sexes  share  parental duties. Incubation takes from  3  to  5
weeks.

	  The guano or excrement of sea birds ins an important
organic  fertiliser.  There were estimated  18  million  guano
birds on the coast of Peru early in the 1960s. Of these, about
15 Million were guano Cormorants. The harvest of guano at that
time  amounted  to  bout 1.8 million toms  per  year.  Milling
Cormorants throng Peruvian rockery islands. One island held an
estimated  peak  population  of  5  million  seabirds,   which
devoured 1,00 tons of anchovies a day.

	   The  guano,  that the birds deposit on their  rocky
nesting islands along the coast of Peru, is one of the richest
natural   fertilisers  in  the  world.  In  Southwest  Africa,
artificial platforms have been constructed in coastal  lagoons
and  on  an offshore reef, greatly facilitating the collection
of  guano.  At  Vedanthangal, according to  a  study  made  in
detail,  the  droppings of the birds make the  water,  a  rich
source  of  nutrients, and crops raised using this water  have
shown  significantly higher yields, with known improvement  in
quality.

	   Energy  from sunlight, and phosphorus from mineral-
laden  deepwater, support the dense population  of  plant  and
animal plankton. The plankton, in turn, feed great numbers  of
anchovies.  Millions of sea birds- Cormorants,  Pelicans,  and
Boobies-  prey  on  the anchovies. The guano  that  the  birds
deposit  is a useful fertiliser to man. This is self ;renewing
natural  cycle of life in Humboldt current off Peru. Now  that
the fish is directly exploited on a large scale, there is some
competition  between the birds, and fishing  industry.  Sadly,
the guano has been treated like coal, and oil- as a mineral to
be mined rather than as a renewable natural resource. When too
many anchovies are taken, the cycle is disrupted, and the bird
population declines.

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