Turtles and Tortoises of Sri Lanka
Turtles and Tortoises of Sri Lanka
(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 infrequently).
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 the shell of the two species differ in the same manner.
photo licensed under CC BY 2.0 by Dallas KrentzelThe leathery turtle has thick leathery skin instead of a 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 the 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.
photo licensed under CC BY-NC-SA 2.0 by Kevin BryantThe 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 labors 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, helps 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.
photo licensed under CC BY-SA 3.0 by Bernard GagnonThe 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 lose much of their translucent luster. 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.
photo licensed under CC BY 2.0 by ukandaThe Department of Wildlife has decided recently to close all unauthorized 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 organization that is authorized 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 organizations 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 offense 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 authorize 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. 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.
photo licensed under CC BY-SA 2.0 by Amila KanchanaThe 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 undershell 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.
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.
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 softshell turtles, also called terrapins, live in stagnant and slow-flowing freshwater habitats. However softshell turtles have also been observed in brackish waters as well as frequenting lagoons. There are two subspecies of the hard-shelled turtles, the Sri Lanka Black Turtle and Parker’s Black Turtle. In Sinhala, they are called Gal Ibba (rock or hardshell 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 commonly found in all parts of the island except in the highest hills. It is also found in ditches in urban areas, paddy fields, etc.
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