B. K. SHARATH
Department of Zoology, Vivekanada College, Nehru Nagar P.O., Puttur (D.K.) 574 203 India
Fax: +91 8251 22999 E-mail: sharath{at}}vcp.kar.nic.in
Introduction
India has one of the richest diversity of habitats, ranging from the cold Himalayan to dry deserts and mangroves to the tropical rainforests. The tropical forest, although degraded due to heavy human activity, supports a great variety of animal populations. The reptilian fauna here is well represented with 389 species among which 186 are endemic species' (Groombridge, 1994). The Ganges - Brahamaputra river basin in India and Bangladesh combined has the greatest species richness of turtle in the world (Iverson, 1992). Little has been published on the terrestrial chelonians of India especially of the two rare and endemic South Indian species, the Travancore tortoise (Indotestudo forstenii, Schlegel & Muller, 1844) and the cane turtle (Geoemyda siloatica, Henderson, 1907).
The Travancore turtle was first described by Boulenger in 1907. He described this tortoise as Geochelone travancorica, which happened to be the same species described earlier as Indotestudo forstenii by Schlegel and Muller in 1844, from Sulawesi (Hoogmoed and Crumly, 1984). Smith (1931) in his review made authentic comments on this tortoise too, while Auffenburg (1963 & 1964) published notes on the behaviour of these tortoises in captivity. Groombridge et al., (1983) published some notes on the occurrences of the tortoise. Moll (I989) and Das (1991) have reviewed the status of this chelonian. The Travancore tortoise has an entry in the IUCN Red Data Book (Groombridge, 1982). Based on the collections made by the author, Bhupathy (I995), Frazier (1994) and Sharath (I990a) reported the Travancore tortoise from Karnataka in South India.
The cane turtle was described by Henderson in 1912 as Heosemys situatica from Kavalai hills in Kerala. Moll et al. (1987) renamed this turtle as Geoemyda silvatica. After it's first description in 1912, this turtle was not reported at all for a long time, until Vijaya ( 1983) rediscovered it. However, this discovery was again from the same forests in Kerala. For the first time this endemic turtle was reported outside it's known restricted range in Kerala by Sharath (I990).
STATUS
The IUCN Red Data Book (Groombridge, 1982) lists the Travancore tortoise as "Insufficiently Known"'. Both the JUCN Red Data Book (I982) and the 1994 IUCN Red List of Threatened Animals (I 994) lists Travancore tortoises as "VULNERABLE"'. CITES puts it in the Appendix II whereas the Indian Wildlife (Protection) Act of 1972 includes it in the Schedule IV'. (The act is being revised). Das 1. ( 1985) rightly classifies this animal as "Vulnerable". The conservation priority ratings and Action plan Rating (APR) of this tortoise is "2" which means, species with restricted distribution and needs status investigation (Stubbs, 1991).
2) Red Data Book status categories: INSUFFICIENTLY KNOWN: Taxa that are suspected but not definitely known to belong to any of the categories of threat because of lack of imformation.
3) Red Data Book status categories: VULNERABLE: Likely to move into the "endangered" category in the near future if the causal factors continue operating.
4) Schedule IV of the Indian Wildlife (Protection) Act of 1972: This species is protected but may be exploited with a permit.
5) Schedule I of the Indian Wildlife (Protection) Act of 1972: Capture. trade or possession of an animal is prohibited.
The cane turtle is protected under Schedule 15 of the Indian Wildlife (protection) Act of 1972. This means capture, trade or posession of the animal is prohibited (Das, 1991). The IUCN Red Data Book (1982) and the 1994 IUCN red List of Threatened Animals (1993) lists cane turtle as vulnerable.The Action Plan Rating for this chelonian is "2".
KNOWN RANGE
Travancore tortoise
The tortoise was known to occur in the evergreen and semi evergreen forests of the Western Ghats up to an altitude of 450 m above sea level (Moll, 1989). This information was based on the observations and collections made in the Trichur district of the Kerala state. The small population of Travancore tortoises in Sulawesi and Indonesia are not native, instead introduced by travellers from South India (Hoogmoed and Crumly, 1984). Hence from the available literature one can summarize that the known range of the tortoise was Sulawesi (Celebes) and Halmahcra Islands in Indonesia and Kerala in India (Iverson, 1992).
However, Smith (1931) based on one single collection reported by Annandale (1915) describes the range of the Travancore tortoise in India to be as follows: "in the district of Trichur in Kerala and along the eastern slopes of Western Ghats in Coorg" (Coorg is a district of the Karnataka state). Annandale himself records that his report of the Travancore tortoise in Karnataka was based on one single collection (a shell). This shell was given to him by a British administrator, Mr. F. Hannyngt, ICS, presumably from the eastern slopes of the Western Ghats in Coorg. This location reported by Annandale must be inaccurate for two reasons. Firstly, currently the animal does not occur here (confirmed by this survey). Secondly, the climate, habitat and vegetation type of the eastern slope of the Western Ghats are quite different from the evergreen and semi evergreen vegetation of the western slopes. Hence it is most unlikely that the animal be found there.
Effectively the range of the Travancore tortoise is known to be confined only to the hills of Anamalai and Chalakudy in Kerala (Figure 2). It is noteworthy that this range of the tortoise is to the south of the Paighat only (Figure 2). The Paighat gap is a 30 km gap between the otherwise uninterrupted hill ranges of the Western Ghats. The habitat in the Paighat area is drier and quite different from the hill ranges. Hence, this gap offers a natural barrier to most animals. The author reported the occurrence of the Travancore tortoise north of this barrier (Sharath, 1990).
Cane turtle
The cane turtle (Geoemyda silvatica) was thought to be an endemic species, restricted only to the forests of Kavalai which are in the hills of Chalakudy, in Kerala, until Sharath (1990) reported it from the forests of Karnataka. This location in Kerala is also the type locality of the species. The turtle was rediscovered from the same area (Chalakudy) later by Vijaya (1982). All the live specimens that were kept captive at the Madras Crocodile park were all collected from the same (Chalakudy) locality (R. Whiteker, pers. comm.). Hence the cane turtle is known to occur only in Chalakudy hill above an elevation of around 450 m above sea level.
Study Area
The Western Ghats are a chain of mountains (I 800 km long) running north to south in south western India. It stretches through the Indian states of Gujrai, Maharashira, Goa, Karnatake, Kerala and Tamil Nadu. In Karnataka these mountains ranges run close and parallel to the coastline . The average altitude of this mountain range is around 900 m. However, the range is studded with abruptly arising mountain peaks ranging from 1200 m to more than 1900 m above sea level. The mountain slopes on the west support rich tropical rain forests. These forests are classified as evergreen and semi evergreen type forests (Champion and Seth, 1968). The rich forest is due to the heavy rainfall it receives from the south west monsoon winds (annual average more than 4000 mm), while the eastern slopes are not very steep and this face leads into a plateau (the Deccan plateau) which receives less rainfall. The forests in this region are mainly moist deciduous or dry deciduous type.
Methods
This study involved extensive survey of the forests in seven districts of Karnataka state, The forests in this area are given different levels of protection. Some are reserved forests, some are sanctuaries, while others are National Parks. There is very little human activity within these forests. Surveys were conducted during the post monsoon (November to February) and summer (March to May) months as the forests becomes impregnable during monsoon. All the searches for the tortoises in the forest used trained dogs and local people which proved to be the best way to find the animal. However, many of these searches became impractical in forests infested with leeches and ticks and with temperatures ranging from 27 to 33 degrees Celsius during the day. The harsh terrain denies easy access to the researcher, as the sites are often six to seven hours trek from the nearest road access. Hence, in order to reduce the efforts with optimum results the following method was followed:
Sampling was done along transacts, cutting across the Ghats from east to west. Nine transacts spaced approximately 50 km distance between two consectutive transacts were marked in the study area. These transacts were one km wide and 40 km long (Figure 3). These transacts were run three times during the survey period, the details of the activity conducted during these runs are given below:
- A presence absence survey based on interviews of knowledgeable persons living within the marked area was conducted. This involved collecting information in a formatted questionnaire and showing people photographs and sometimes a live specimen. Areas of possible occurrence of the tortoises were identified in this run. This reduces the unfruitful searches in sites where the animal is unlikely to be seen.
- During the second run a team of students with educational materials visited. and camped in the regions which were identified in the previous run. This was more educative than explorative. During this visit a brief educational talk was organized to educate the locals of the need for chelonian conservation. A preliminary survey of the area was conducted and sites were marked for an all out search.
- Based on the above information a detailed 'all out search' was planned for the third run. These searches were organized using trained dogs and trackers (local experts in tracking tortoises). Searches were conducted in sites identified in the second run. Once an animal was located, the search was abandoned in that area, and then continued 2 km further along the transact. After recording the morphometric details of the tortoise they were marked and released wherever they had been found. No collections of specimens were made for reasons of conservation.
The data collected was recorded and plotted on a map of the district. Later all these maps were compiled together and a distribution map for the state was made .The exercise takes around a week per run or on average of little over a month per transect.
Results
Nine transacts were surveyed for the two terrestrial turtles namely the Travancore tortoise (Indotestudo fortenni) and the cane turtle (Geoemyda silvatica). A total of 79 sites were sampled in the seven districts of the state of Karnataka. Out of the sites sampled Travancore tortoises were sighted in 21 sites. Whereas the cane turtle was rarer and found in only 4 sites. The Travancore tortoise seems to be more abundant than the cane turtle Both these chelonians were found only in the western slopes from an altitude of around 100 m above sea level to 686 m. The locations of sightings of the tortoises were recorded and used to produce the distribution map. The survey is complete in the state of Karnaka only, a complete distribution map will be available once the ongoing study is over .The Travancore tortoise was seen to occur along a stretch of about 200 km in Karnataka.
Both these tortoises are diurnal and are active during the day. It was observed during the study that the Travancore tortoises begin their activity at dawn (06.00) and were found to be actively foraging on the forest floor until dusk (18.00). They rest for a couple of hours during the midday under short shrubs. Most of the time they were found feeding on fallen fruits and grass, occasionally they were found to feed on mushrooms too. When they rest they do so adjacent to a rock or fallen tree. These tortoises were conspicuously absent in large openings in the forests due to felling of trees. Many of them were found near water sources as there are numerous perennial hill streams flowing in the study area.
Discussion
As a result of the present study it is evident that the range of the Travoncore tortoise (Indotestudo forstenii) is more extensive than previously known. Hence, reporting an extension of the known range of the two chelonian species, this study establishes the present range for the species.
The Travancore tortoise generally ranges along the western slopes of the Western Ghats in Karnataka (Figure 1). The northern limits of this range can now be extended by 600 km outside it's previously known range. The animal was found from the Waynad region in North Kerala to the Uttara Kannada (earlier known as North Kanara) District of Karnataka. The animal was recorded from the forests at the base of the Western Ghats, which is at about I 00 m from the mean sea level, up to an altitude of 650 m up the Ghats. Hence, it can be said that the animal is found to occur in the forests, all along the western slopes. The map in Figure 1 shows the results of this survey. Therefore, the present range of the tortoise in Karnataka is continuous all along its western slopes (480 kms) and seems to be well defined.
The distribution of cane turtle seems more complicated. Their densities in Karnataka are extremely low, much less than their counterpart population in Kerala. The secretive living and feeding habits of the animal makes it difficult to find them in the forests. The distribution of cane turtles in the study area is not constant, it seems the range is patchy and fragmented. Although it is tempting to conclude and draw a distribution map, more distribution data are needed in order to understand the actual range of these animals. However, it is evident that this survey extends the range 300 kms north of the previously known range of the animal . Wherever it occurs, the Travancore tortoise is abundant. Although, it would be befitting to conduct a quantitative estimation of the densities and abundance of this tortoise, it was out of scope of this study. Meanwhile the animal is hunted for its meat and is considered a delicacy among tribal people. However, the meat is consumed locally and no export of the meat is recorded.
The population of the cane turtle is much lower than those populations found in Kerala. Due to the scanty population the secretive nature of the animal and its crepuscular habit it became out of the scope of this study to assess the status of the animal.
Suggested Conservation Measures
The main threats to these animals seems to be habitat destruction and overhunting. The Karnataka State Government has notified protected areas in addition to those which had already been brought under protection. New areas should be identified and added to those notified areas with specific intention of protecting these chelonians.
The staff of the forest department have to be educated about these chelonians and their ecology. Many of them are not able to differentiate these tortoises from the other common chelonians like the black pond turtle (Melanochelys tryuga). The people living close to forests are ignorant of the need to conserve these chelonians and are presently hunting them for food. Hence, public awareness has to be created through school and village administrations. The public need to be educated of the role these animals play as a component of the forest floor ecosystem. They must also be informed of the endemic character of the tortoises, which are not found elsewhere and thus need protection to ensure future survival of the species.
There are not many non-government organizations (NGO) engaged in wildlife conservation activities within the study area. It is therefore essential to promote the functioning of healthy NGO's in the area which will take care of the survival of the chelonians in the future.
Recommendations for future research
There is little information literature, on the ecology of these tortoises. Ecological information such as home range, feeding and breeding habits and activity patterns are essential to recommend positive conservation measures. With this in mind the following research activity in the Western Ghats region is suggested for the future.
- A comprehensive survey of the Western Ghats in India, including the states of Maharashtrsa, Kerala and Tamil Nadu including more study sites.
- Radio telemetry based field work leading to the information on home range and activity pattern of these terrestrial tortoises.
- Quantitive estimations of the population densities and population structure to be carried out using methods such as capture, recapture or line transect.
- Preliminary research trials leading to development of semicaptive breeding of these chelonians with a view to reintroduce the species in protected areas with suitable habitat. The monitoring of the reintroduced animals for a long term project is essential to ensure that it is successful.
Acknowledgements
This project was partly funded by the British Chelonia Group conservation grant. It was also supported by the Wildlife Conservation Society, The Mangalore University, and The Neria Estates Pvt. Ltd. The author expresses his profound gratitude to Dr. John G. Frazier, CRC, Front Royal, Virginia, USA for his motivation. Thanks are due to Prof. Ian R. Swingland, DICE, University of Kent at Canterbury, UK, for his recommendations and guidance. Wg. Cdr. R. P. Langton, British Chelonia Group and Mr. R. 1. Vane-Wright of the Natural History Museum, London who encouraged the author to take up this work. Thanks to Dr. Ullas Karanth and Prof. S. N. Hedge of Mangalore University for the support in the field.
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Testudo Volume Four Number Five 1998
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