|

Turtles and tortoises
Jayantha JAYAWARDENE
(Turtles are rarely seen because the sea is their habitat and only
the females come ashore and that too only after dark. The land turtles
and land tortoises are also seen in frequently).
DIFFERENT SPECIES: Today there are 250 species of turtles on earth.
Seven of these live in the ocean and are called sea turtles. The
remaining 243 species live on land or in freshwater ponds and marshes.
The terrestrial turtles, those that live solely on land, are called
tortoises.
Five of the seven species of sea turtles in the world visit the
shores of Sri Lanka to breed. They are the Green Turtle (Chelonia mydas),
Hawksbill Turtle (Eretmochelys imbricata), Olive Ridley (Lepidochelys
olivacea), Loggerhead (Caretta caretta) and Leatherback (Dermochelys
coriacea). The sea turtles are called Kesbawa in Sinhala and Amai in
Tamil.
There are three species of freshwater turtles and one terrestrial
tortoise in Sri Lanka. The freshwater turtles are Parker's Black Turtle
(Melanochelys trijuga pakeri) Sri Lanka Black Turtle (Melanochelys
trijuga thermalis) and the Soft or Flapshell turtle (Lissemys punctata
punctata). The terrestrial tortoise is the Star tortoise (Geochelone
elegans).
The shells of the turtles and tortoises differ. The Carapace or top
part of the shell of the turtles is streamlined and short making
swimming easy.
On the other hand the shell of the tortoise is thick and more useful
for their protection. The plastron or under shell of the two species
differ in the same manner.
The leathery turtle has a thick leathery skin instead of the bony
shell. Turtles have broad, flattened flippers whilst tortoises have
short cylindrical limbs. The flippers facilitate swimming greatly but
make it very difficult for females to move on the beaches where they
come back to nest.
The males once they get into the sea, as hatchlings never come ashore
though the females come back to the same beaches to lay their eggs.
Turtles take at least 20 years to mature sometimes even as much as 30
years. Mature females after mating at sea come ashore to lay their eggs.
They always come in after dark. The female moves as far up the beach
as possible to lay her eggs. This is to ensure that the water coming up
with the tide does not reach the eggs and spoil them.
Once ashore the female labours up the beach to a spot it chooses.
Then after turning and facing the sea, proceeds to dig a shallow
depression in the sand with its flippers. Once the pit is dug a
cylindrical egg chamber is dug, under her posterior end, also with its
flippers.
The egg chamber is about 18 to 20 inches depending on the length of
her flippers. Around 75 to 130 soft-shelled, ping-pong ball shaped eggs
are laid.
The number of eggs laid varies with the individuals and also with the
species of turtle. They are covered with mucous when laid. Once the eggs
are laid the nest chamber and the depression are covered with sand and
the female labours back to the sea, never to see her progeny.
Sometimes stray dogs and monitor lizards dig up the nests and eat the
eggs. The trail made by its flippers along the beach, which the turtle
leaves as it comes ashore and goes off, help the predators, including
humans, to trace the position of the nest.
The eggs take around 50 days to hatch and the hatchlings, as soon as
they are born, make their way to the sea. Crows, seagulls and other
seabirds eat some of the hatchlings, which are black, as they make their
way on the white sand.
Here again stray dogs and monitor lizards eat some hatchlings as they
move across the beach. The large fish that lurk in the shallows of the
sea also eat some of the young ones that just make it to the water. Only
a few of the hatchlings that come out of each nest survive to become
mature adults.
The main breeding season is from September to mid-April on the West
coast of the island and from February to June on the East coast. During
these periods there are no monsoon rains to dampen the eggs and also the
beaches are very broad and sandy.
It is at these times that both males and females gather off our
coastal waters in fairly large numbers to breed. Migrant fishermen also
operate off these coasts at the same times and unless vigilance is
exercised tend to catch excessive numbers of these reptiles for
commercial purposes.
In 1982 I wrote in the Tigerpaper, the Food and Agriculture
Organisation conservation magazine, "Turtle flesh is considered a
delicacy in certain coastal towns. The brown turtle is caught most
frequently in the seas off the coasts of the Jaffna Peninsula, which is
in the northernmost part of the island.
In Jaffna it is traditional for fishermen to capture turtles for the
sale of their flesh. Here only a few fishermen indulged in the capture
of turtles off the shores of Jaffna.
Turtles were also caught, but mostly by accident, by fishermen in
their nets along the Western and Southern coasts. Later however the
demand for turtle flesh in Jaffna became so great that even the
fishermen further South were persuaded to catch turtles to be sold in
Jaffna.
The middlemen or Mudalalis, who made great profits, did this. These
turtles were transported to the peninsula in lorries and vans".
Turtle flesh is sold in the most gruesome manner in those markets.
Since turtle flesh putrifies fast, the turtle is not killed but the
vendor cuts off portions of flesh, in quantities needed by the
customers. It is therefore not unusual to see, in these market places,
turtles with gaping holes in their bodies, still alive and weakly moving
their flippers about.
Bennet stated in 1843 "Around 1843 hawksbill turtles nested so freely
along the south-eastern coasts of the island, especially at Amaduwa,
that the Government sold the right to capture the animals, to private
individuals.
Once captured, they were suspended over a fire and the heated scutes
were removed. These turtles were then released on account of a mistaken
impression that the scutes would regenerate and the animal could be
caught again.
In addition, there was a belief that if the scutes were stripped from
a dead turtle, they would loose much of their translucent lustre. The
scutes were used to make combs, cigar cases, fine boxes and other
ornaments known as 'tortoiseshell articles' and were exported both in a
raw and manufactured state.
The Department of Wildlife has decided recently to close all
unauthorised and substandard turtle hatcheries that have mushroomed
along the coastal belt, as lucrative tourist related businesses. There
were many before the 2004 tsunami washed them away but now quite a few
have sprung up again.
The Department has to issue guidelines on scientific hatchery
practices to hatchery owners. They will then have to take steps shortly
to close down hatcheries, which fail to adopt these guidelines.
As far as the Department is concerned the Turtle Conservation Project
(TCP) is the sole organisation that is authorised to run turtle
hatcheries in Sri Lanka.
However there are a number of private individuals who have taken up
this activity as a business venture. Some have the cooperation,
collaboration and funding from external organisations and various Non
Governmental Organisations. Most of them are located in the Kosgama,
Induruwa and Balapitiya areas.
Under the Fauna and Flora Protection Ordinance, it is an offence to
kill, wound, harm or keep a turtle in possession, sell or expose for
sale any part of a turtle, or to destroy or take turtle eggs.
On the other hand, the Director General of Wildlife can authorise
turtle hatcheries to be operated, under the existing legislation, for
the purpose of conservation and research.
However these hatcheries, if run scientifically, cannot make a
profit, since the hatchlings have to be allowed to get into the seas
soon after hatching and not kept back for exhibition purposes.
These hatcheries ensure the protection of the eggs that are laid on
the beaches close to the hatchery. In fact some of these hatcheries buy
turtle eggs from the local people who collect the eggs as soon as they
are laid. This is good in that it ensures that a maximum number of the
eggs that are laid hatch out.
Once they hatch out the hatchlings are taken and kept in cement ponds
or tanks so that they can be shown to the tourists as and when they
arrive.
In the natural process the hatchlings, as soon as they emerge through
the sand, head out directly to the sea, which will be their habitat for
the rest of their lives.
It is believed that in going straight to the sea from their nests the
location of the beach of their origin is implanted in their brain. This
helps them to come back to the same waters to breed and the females to
the same beaches to lay their eggs.
If the hatchlings are taken and put in tanks and prevented from going
directly to the sea, they will not have their origins implanted in their
memory since they would be disoriented.
In addition if the hatchlings are kept too long in the hatcheries,
they will not be able to find their food quickly enough once they get to
the sea.
Initially it takes time for a hatchling to find food and if this does
not happen their survival would be threatened. Ultimately this will not
help turtle conservation even though initially the eggs are rescued and
hatching ensured. Here only the hatchery owner benefits.
The IUCN- The World Conservation Union, Sri Lanka has come up with a
comprehensive Marine Turtle Conservation Strategy and Action Plan for
Sri Lanka, which has been done for the Department of Wildlife
Conservation.
It is now necessary that this action plan be converted to actual
action. Several adverse factors contribute to the threats to the
survival of these animals.
The deep-sea-going fishing trawlers find turtles inadvertently
trapped in their nets. They are brought ashore along with the rest of
the catch and are slaughtered and the flesh marketed illicitly because
the statute pertaining to its protection is given a low priority by the
law enforcement authorities.
Although turtle flesh is not considered a delicacy in Sri Lanka there
are specific localities, particularly along the western and northern
coast, where turtle flesh is readily marketable. Thus the large numbers
of turtles caught in fishing nets are ultimately killed.
Eggs unearthed from their nests are vulnerable and find a more ready
and safe market throughout the coastal beaches. The adverse impact of
destroying a nest, which generally contains over 100 eggs, would be a
major contributor to the threat to the survival of these species since
eggs are laid only on specific beaches and this habitat too is fast
being destroyed or not available for breeding turtles.
The star or starred tortoise (Geochelone elegans) is found in the
drier parts of the island and is common in the sand dunes, parklands and
scrub jungles of the north-western, north-central, eastern and northern
provinces.
It is seen mostly in the evenings, when it comes out of the shade,
and at daylight before it goes back into a shady place. It walks about
and searches for its food during this time. It is vegetarian and eats
grass and leaves that are within its reach.
Soft pods and fallen flowers are also eaten. Though it drinks water
when available, it can stay for long periods without water. It also gets
moisture from the vegetation that it consumes. This water is stored in a
sac in the dome of its carapace or shell.
This tortoise has a number of Sinhala names, the most common being
tharuka ibba (star tortoise) and Vetakeiya ibba (pandanus tortoise).
Vatekeiya because it resembles the leaves of the screw pine (pandanus)
that is found along the beaches.
The other Sinhala names for it are maivara ibba (marked tortoise)
vairan ibba (striped tortoise), mukalan ibba (forest tortoise). Hooniam
ibba (black magic tortoise) and makaral ibba (bean tortoise). In Tamil
it is called katu amai (forest tortoise) and katu petti amai (forest box
tortoise).
The upper shell or carapace has small knob-like protrusions or scutes
distributed symmetrically over its surface. They are in three distinct
lateral rows running from the front to the back.
Each of these scutes, there are thirteen in number, has yellow
streaks flowing from its dome, giving a starry effect that gives its
name.
The markings on the young tortoises are very bright but with age the
luster fades. In their natural surroundings, especially during times of
drought, they look very drab due to the dust and dirt collected on their
shells.
In some of the older animals the shell wears down by it creeping and
crawling among rocks and stones. The under shell or plastron is yellow
with a few black markings.
The face, neck and both pairs of legs have fairly thick scales. This
enables it to move freely amongst thorns, cactus and strong twigs etc.
The head has no scales but is covered with a thick layer of skin.
It has no teeth but has strong jaws, which have grooves where the
teeth should be. The head and club-shaped limbs are retractable and are
withdrawn into the shell the moment it senses danger.
This method of protection is very essential because the tortoise is
very slow in its movements and cannot get away quickly from danger.
Once within its shell it is comparatively safe. If a tortoise is
turned on its shell - on its back as it were - it has great difficulty
in getting back on its feet. Tortoises are quite adept at walking over
rocky and uneven ground without taking a tumble.
Very sure footed though slow, they are instinctively capable of
taking cover fairly quickly.
The female lays eggs twice or thrice a year. Two to six eggs, which
are almost spherical, are laid each time. They are about an inch in
diameter and weigh approximately three quarters of an ounce. The eggs
are laid in a hole in the ground excavated by the female.
If the ground is hard, she urinates on the surface to moisten and
loosen the soil and then proceeds to dig. The back limbs are used to dig
the soil similar to the female turtles. Once the eggs are laid the hole
is covered with the same earth.
Then the female stands with her feet well extended on top of the hole
and drops down hard on the earth. This is done to stamp down the earth
and is repeated a few times. The incubation period can vary from nine to
fifteen weeks.
Once the eggs are laid the female goes away and does not see her
young ones at all except for a chance encounter. Does she recognize her
progeny when she chances on them in later years? No one knows.
The young when they are hatched are about an inch in diameter. Their
shells are soft but harden as they grow older. As soon as they are born,
they crawl under cover and wait for sometime. They use up food material,
which is in a small yolk sac attached to the undershell of their bodies.
Soon after they eat worms caterpillars etc. that are found where they
initially hide. They soon leave this place and get onto a vegetarian
diet for the rest of their lives.
The numbers of the star tortoise are reducing, mainly because its
forest habitats are being cleared for development. In some parts of the
country its flesh is consumed. There is also a demand for this tortoise
for the pet trade abroad. The shell of the star tortoise being
attractive also has a demand.
The Fauna and Flora Protection Ordinance affords the star tortoise
complete protection. However the law alone is not enough. The law has to
be applied and administered.
Of the three terrestrial turtles found in Sri Lanka one is the Soft
or Flapshell turtle known in Sinhala as Kiri Ibba and Paal Amai in
Tamil.
In both languages it means milk turtle. The soft shell turtles, also
called terrapins, live in stagnant and slow flowing freshwater habitats.
However soft shell turtles have also been observed in brackish waters as
well as frequenting lagoons.
There are two sub species of the hard shelled turtles, the Sri Lanka
Black Turtle and Parker's Black Turtle. In Sinhala they are called Gal
Ibba (rock or hard shell turtle) and in Tamil Karuppu Amai (Black
turtle).
The Sri Lanka Black turtle is endemic to this country in that it is
found only here. Parker's Black turtle is very rare with only a few
specimens seen. This terrapin differs from the other black turtle in
size and shape of carapace.
On the other hand the Hard Shelled Turtle is quite common found in
all parts of the island except in the highest hills. It is also found in
ditches in urban areas, paddy fields etc.
Soft-shelled turtles unlike other turtles have a leather skin
covering their near circular backs as opposed to horned, hard plates.
Their heads draw into a snout that shares some similarity with the snout
of a pig, with a snorkel like nostrils.
The jaws are covered by soft, fleshy lips. Soft-shelled turtles are
predominantly aquatic and are good swimmers. They spend a great amount
of time underwater, stretching their long necks so their snouts are just
above the waterline.
They have webbed feet. They are fairly inactive yet are capable of
sudden bursts of energy. They feed mainly on fish. Both hard shell
species inhabit stagnant and slow flowing freshwater habitats.
Of these freshwater terrapins, The Sri Lanka Black turtle is common
and widely distributed from the plains up to 1500 m above mean sea
level. These two species live in harmony with the Hard shelled turtle.
The females lay their eggs on land in small depressions under moist leaf
litter.
The flesh is widely eaten and considered a delicacy. However, it is
necessary to conduct further systematic surveys to ascertain more
definitely the status of the different species of turtles in Sri Lanka.
Pix: Ruchira SOMAWEERA |