STATUS OF THE SIAMESE CROCODILE IN THE ...

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Ellen Trout Zoo. Jeremy Holden of the FFI ...... with assistance from Thap Sary, Pao Sea, and two porters, Trann and Soth, both from Thmar Baing. Both parties ...
STATUS OF THE SIAMESE CROCODILE IN THE

CENTRAL AND SOUTHERN

CARDAMOM MOUNTAINS, CAMBODIA

Findings of Recent ‘Kropeu Phnom’ Surveys Jenny C. Daltry, Chheang Dany, Em Phal, Poeung Mora, Sam Han, Sonn Pisith, Tan Thara and Boyd Simpson

2003

THE DESIGNATION OF GEOGRAPHICAL ENTITIES IN THIS DOCUMENT AND THE PRESENTATION OF THE MATERIAL DO NOT IMPLY ANY EXPRESSION ON THE PART OF THE AUTHORS, FAUNA & FLORA INTERNATIONAL OR THE DEPARTMENT OF FORESTRY AND WILDLIFE CONCERNING THE LEGAL STATUS OF ANY COUNTRY, TERRITORY OR AREA, OR ITS AUTHORITIES, OR CONCERNING THE DELINEATION OF ITS FRONTIERS AND BOUNDARIES.

THE OPINION OF THE INDIVIDUAL AUTHORS DOES NOT NECESSARILY REFLECT THE OPINION OF FAUNA & FLORA INTERNATIONAL OR THE DEPARTMENT OF FORESTRY AND WILDLIFE. THE AUTHORS, FAUNA & FLORA INTERNATIONAL AND THE DEPARTMENT OF FORESTRY AND WILDLIFE TAKE NO RESPONSIBILITY FOR ANY MISREPRESENTATION OF MATERIAL THAT MAY RESULT FROM THE TRANSLATION OF THIS DOCUMENT INTO ANY OTHER LANGUAGE. WE ALSO TAKE NO RESPONSIBILITY FOR ANY ATTEMPT TO USE THE MAPS OR GEOREFERENCES IN THIS DOCUMENT FOR NAVIGATIONAL PURPOSES.

PUBLISHED BY FAUNA & FLORA INTERNATIONAL: CAMBODIA PROGRAMME AND THE DEPARTMENT OF FORESTRY AND WILDLIFE

COPYRIGHT Copyright in text © 2003: Fauna & Flora International and Department of Forestry And Wildlife Copyright in photographs © 2003: With individual photographer

OWING TO THE SENSITIVITY OF SOME OF THE MATERIAL, NO REPRODUCTION OF ANY PART OF THIS PUBLICATION IS AUTHORISED WITHOUT WRITTEN PERMISSION FROM THE COPYRIGHT HOLDER.

Daltry, J.C., Chheang D., Em P., Poeung M., Sam H., Sonn P., Tan T. & Simpson, B. (2003) Status of the Siamese Crocodile in the Central and Southern Cardamom Mountains, Cambodia. Fauna & Flora International: Cambodia Programme, and Department of Forestry and Wildlife, Phnom Penh. (In English). SUGGESTED CITATION:

COVER PHOTOGRAPH: Siamese

crocodile (J. Holden/ FFI-DFW)

EXECUTIVE SUMMARY This reports describes the first surveys to assess the conservation status of the Siamese or mountain crocodile Crocodylus siamensis, in the Central and Southern Cardamom Mountains of South West Cambodia. The Siamese crocodile is one of the most threatened and poorly known of the world’s 23 species of crocodilian. Once common and widespread across mainland and island Southeast Asia, this animal has been extirpated from well over 95% of its original distribution range and is now classed as Critically Endangered. In the light of growing fears that this species might be effectively extinct in the wild, scientists from Fauna & Flora International (FFI) and the Department of Forestry and Wildlife (DFW) were delighted to discover relict populations of Siamese crocodiles in the Central Cardamom Mountains in 2000. Recognising that the crocodiles were far from secure even here, FFI and DFW formed the Cambodian Crocodile Conservation Programme to promote their survival by means of applied research, awareness raising, capacity building and both conventional and community-based protection. As part of this programme, FFI hosted a training workshop in crocodile biology and survey techniques for DFW staff in January 2002. Eight of the participants subsequently spent three months conducting field surveys along 12 major rivers and their associated tributaries, ponds and wetlands in the Central Cardamom Mountains. Many more people took part in the surveys, including local fishermen, military police and Cardamom Conservation Program rangers and volunteers. Training, equipment and fieldwork were kindly sponsored by Association for Cultural Exchange, Columbus Zoo and Aquarium, Disney Wildlife Conservation Fund, Fauna & Flora International, National Geographic Expeditions Council, The Cardamom Project and Wildlife Reserves Singapore. The main objectives of the 2002 surveys were to: • • • • • •

Survey the distribution of Siamese crocodiles in the Central and Southern Cardamom Mountains and provide estimates of population size Gather baseline data on diet, habitat use and reproductive behaviour Gather baseline data on threats to crocodiles in the Central and Southern Cardamom Mountains and recommend appropriate conservation actions Identify priority areas for protecting Siamese crocodiles Give Department of Forestry & Wildlife staff theoretical and practical training in crocodile survey techniques, from survey design to data collection and analysis, and report writing Devise and test straightforward methods for monitoring crocodile numbers in key areas

Approximately 357km of waterways were surveyed, or 25% of the watercourses draining the southern slopes of the Central and Southern Cardamom Mountains. The principle survey methods used were informal interviews with local people, spotlight surveys at night, and visual searches on foot for tracks, dung and other sign. In all areas where crocodiles were confirmed present, we endeavoured to calculate their minimum number, distinguishing different individuals according to their size. Below is a summary of the areas surveyed, with the minimum estimated population sizes shown in brackets: Veal Veng Marsh (40+): The 1,000-ha Veal Veng Marsh contains probably the largest breeding population of this species in the wild. In the dry season, the crocodiles are concentrated in only one or two small areas in the wettest part of the marsh, but are believed to disperse widely during the rainy season. There has been a long history of human settlement in this area and parts of the wetland have been modified for agriculture. Fortunately, the indigenous people in the nearby O’Som Commune traditionally revere the crocodiles and do not hunt them. -i-

Stoeng Krau and Stoeng Koi (4+): The Stoeng Krau drains Veal Veng Marsh and feeds into the Koi. Although there are suitable, deepwater areas along both rivers, crocodiles appear to be scarce and patchily distributed along the 24km surveyed. They have reportedly declined in the wake of the illegal yellow vine industry, which has polluted the rivers and has attracted migrant workers to this area. Stoeng Koi: Anlong L’Ang (10+): Anlong L’Ang is a deepwater section of the lower Stoeng Koi, approximately 1km long and reportedly more than 15m deep. This appears to be a very important site. Siamese crocodiles were frequently seen from vantage points in the forest, and included some of the largest adults seen this year. No juveniles were seen or reported here, however, and yellow vine collectors had recently moved into this area. Stoeng Russei Chrum (1+): Only 18km of this large river was surveyed owing to security threats. Dung from one crocodile was found, but local reports suggest that more crocodiles are present. Stoeng Kep (10+): Much of this beautiful river is remote and difficult to reach. 70km were surveyed, and three distinct sites confirmed to contain crocodiles, including a number of juveniles. Stoeng Tatai and Stoeng Touch (18+): 88km of the Stoeng Tatai and lesser tributaries, and 10km of the Touch were surveyed. Four distinct crocodiles sites were found, including a marshy floodplain near Chamkar Chray village, which could be an important breeding site. The survey team found crocodile dung and tracks at the highest elevation known thus far: 600m above sea level, at the headwaters of the Tatai. Stoeng Sala Munthun (0?): No crocodiles or signs were found during a short survey of a 23km stretch. Judging from the available habitat and according to local reports, the Sala Munthun used to contain crocodiles, but they are possibly rare or absent here now. This may be linked to the influx of people to this area during the past few years to collecting yellow vine and krasna wood (eaglewood). Stoeng Areng (30+): 53km of the river and a minor tributary was surveyed. The deeper parts of the Stoeng Areng between Prek Svay and Chumnoap villages, and its associated oxbow lakes, contain a resident population of juveniles, sub-adults and adults. The crocodiles often move between the river and the oxbow lakes using well-worn trails through the forest. The Ombot Touch oxbow lake is of special interest because it appears to serve as a nursery site for young crocodiles and is heavily used by local fisher people. Like the indigenous people of Veal Veng Marsh, most of the local villagers regard killing crocodiles as taboo, but young crocodile sometimes become caught in gill nets. Stoeng Trapeang Rung and Prek Yourn (0+): 27km of river were rapidly surveyed in just three days. No crocodiles, dung or tracks were seen, but the habitat appeared suitable and reports from local people were convincing. We found three holes in the riverbank on the Prek Yourn tributary that looked like crocodile burrows and were reportedly still in use. Closer to the sea, a recent report was received of a possible saltwater crocodile Crocodylus porosus. Prek Santung, Prek Tabeh Tes, and Stoeng Chi Phat (0+): 32km of these rivers was surveyed. Searches for crocodile sign were hampered by heavy rain, but interviewees reported some very recent sightings in several areas with suitable habitat. Following a phase of hunting during the early 1990s, our team concluded that crocodiles probably are still present, but much depleted. When combined, these results confirm the presence of at least 113 individuals. The numbers of crocodiles quoted here are a minimum, however, and are likely a gross underestimate of the actual - ii -

number present. The Central and Southern Cardamom Mountains are clearly a vital area for this critically endangered species, partly owing to their relative inaccessibility and partly because many of the indigenous people traditionally revere the crocodiles and consider hunting or harming them taboo. Even so, the wild populations appear to have been badly damaged by a wave of illegal poaching in the early-to-mid-1990s, allegedly involving people from other parts of Cambodia. Some of the most accessible colonies were eradicated at this time, and some, perhaps most, of the surviving groups may now be too small and isolated to persist without intervention. Siamese crocodiles take around 15 years to attain maturity, and appear slow to recover from even moderate hunting pressure. The threat from commercial hunting continues in the Central and Southern Cardamoms today, albeit at a lower levels. We also identified many other threats to crocodiles. In roughly decreasing order of importance, these are accidental capture or killing by fishermen, habitat modification (logging, clearance for farmland), killing of crocodiles for bush meat, pollution of waterways by yellow vine factories, and egg collection. Serious potential threats included proposed hydroelectric power schemes in the Cardamom Mountains. Further surveys will take place in 2003 to fill in the gaps and develop an even more thorough understanding of this rare and poorly known crocodilian. Based on the findings of the 2002 surveys, however, it already seems that without urgent, concerted action the Siamese crocodile could disappear from even the most remote parts of this mountain range within a few years. The following recommendations are presented and explained in more detail in this report: Summary of Conservation Recommendations (*** = First priority; ** = Second priority; *= Third priority) Law Enforcement • Clarify the specific roles and responsibilities of all agencies involved in protecting and managing crocodiles and the Cardamom Mountains, and promote full cooperation between them.** • Ensure that hunters, dealers and buyers involved in illegal trade in wild-caught crocodiles are seen to be prosecuted, and strictly enforce laws prohibiting civilians from possessing guns, explosives or other hazardous equipment for hunting and fishing. *** • Establish a visible protection presence in the Cardamom Mountains in areas where no such groups currently exist. ** • Identify and monitor the illegal trade in crocodiles. * • Raise awareness among people living and working within the Cardamom Mountains of the penalties for illegally hunting or trading crocodiles. *** • Cambodia should seek international co-operation, particularly with Thailand, Laos and Vietnam, to stamp out the illegal cross border trade in crocodiles. * Habitat Protection • Support active management of crocodile habitats in the existing wildlife sanctuaries and protection forests in the Cardamom Mountains. *** • Halt logging in critical parts of the Southern Cardamoms and establish a new ‘protection forest’ under MAFF administration. ** • Explore the possibility of establishing Veal Veng Marsh as a Wetland of International Importance. * • Halt additional inward migration to the Cardamom Mountains and reduce army presence to the minimum necessary for national security purposes. *** - iii -





Outside of the existing wildlife sanctuaries and protection forest, commercial forestry operations should be conducted sustainably to the highest international standard and be compatible with preserving crocodile habitats. ** Major development activities in the Cardamom Mountains, such as roads, dams and resettlement schemes, should be subject to an independent, transparent and thorough Environmental and Social Impact Assessment. **

Crocodile Farms • Crocodile farms in Cambodia must be brought up to international standards and prevented from accepting and ‘laundering’ unsustainably collected wild-caught crocodiles or skins. Farms that are unable or unwilling to comply should be closed. *** Education and Awareness Raising • Ensure all local communities are fully aware of the laws protecting crocodiles and their habitats, and understand how and why it is necessary to conserve the crocodiles. *** • Raise the awareness of policy makers at district, provincial and central government levels of the relevant legislation and the special importance of conserving this species. ** • Promote cooperation between biodiversity conservation agencies and development agencies operating in the Cardamom Mountains. *** • To help raise national pride, Cambodia may choose a different common name for the Siamese crocodile. (‘Kropeu Phnom’ is already used locally). * • Develop an award system for individuals or groups who set a good example to others. * Essential Community Participation • Prioritise local communities in awareness-raising efforts, and as far as possible ensure that they see tangible benefits to conserving crocodiles and wetlands. ** • Work with local communities to develop local procedures for crocodile protection and a community-based enforcement system, and mitigate against human-crocodile conflict. *** Capacity Building • Train national and provincial government staff in crocodile biology, survey techniques and conservation management skills, and provide them with the necessary equipment and other resources to monitor and protect crocodiles effectively. *** • Encourage and enable Cambodian students to become involved in longer-term crocodile research projects as part of their degrees. * Strategy For Captured Crocodiles • Prepare guidelines and training on handling and temporary housing for crocodiles and a ‘decision making key’ for deciding what to do with confiscated and rescued individuals. ** Research Priorities • Conduct further baseline surveys of the status (distribution, numbers) and autecology of Siamese crocodiles in the Cardamom Mountains. *** • Develop and implement monitoring programmes for all known crocodile sites. ** • Conduct further consultations/ interviews with local communities to understand their attitudes towards, knowledge of, and impact on crocodiles, and monitor human numbers, distribution and impact in the Cardamom Mountains. * • Conduct rapid surveys of other parts of Cambodia to identify other remaining crocodile populations. ** - iv -

ACKNOWLEDGEMENTS We are grateful to Mr Ty Sokhun, Director of the Department of Forestry and Wildlife and Mr Men Phymean, Director of the Wildlife Protection Office, of the Ministry of Agriculture, Forestry and Fisheries for their active support and encouragement. We also thank the Governor of Koh Kong Province, the Governor of Pursat Province, the District Governor of Veal Veng District for their assistance and cooperation, and thank the many local people for their hospitality, helpfulness and participation in interviews. The survey was designed and implemented by the authors, with assistance from local fishermen and rangers and military police from the Cardamom Conservation Program. The Program also generously provided accommodation in Thmar Baing and use of a boat. Special thanks are due to David Mead, Peter Piggott, and volunteer Darren Cormack of Conservation International. Training, equipment and fieldwork were sponsored by (in alphabetical order): Association for Cultural Exchange, Columbus Zoo and Aquarium, Disney Wildlife Conservation Fund, Fauna & Flora International, National Geographic Expeditions Council, The Cardamom Project, The Ryklow Charitable Trust, Marjorie Coote Animal Charities Trust, and Wildlife Reserves Singapore (Singapore Zoological Gardens). Additional ‘in kind’ support was generously provided by National Geographic Explorer during the making of a documentary about the crocodiles in March 2002. Jenny Daltry thanks the ASEAN Regional Centre for Biodiversity Conservation for providing transport and loan of office equipment during the compilation of this report. Special thanks are owed to Mr Gordon Henley Jr, Director of Ellen Trout Zoo. Jeremy Holden of the FFI Sumatra Programme and FFI Communications, took the better photographs in this report and an active part in the Veal Veng survey. GIS support was ably provided by Ben Hammond, who produced the maps in this report and provided introductory training to Sam Han, Hor Leng and Chheang Dany. The FFI Cambodia team, especially Richard Paley (Country Director), Om Sony, Kan Sovanarid and Ouch Lee, helped with both the training workshop and field surveys. Our team also benefited greatly from the advice and assistance of Mike Appleton, David Ashwell, Ian Baird, Dr Brady Barr, Laurence Carvalho, Jeremy Ironside and Dr Steve Platt. The IUCN/SSC Crocodile Specialist Group has also been supportive in a number of ways, including providing technical guidance on survey methods. Special thanks are owed to Dr Grahame Webb, Dr Perran Ross, Dr Adam Britton and Sir Harry Messel for all their help. Finally, the editor thanks all of the authors for their hard work and patience in compiling this report, and the specialists who kindly gave up their time to review and comment on earlier drafts of chapters in this report. Any errors that remain are the responsibility of FFI.

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ACRONYMS AND ABBREVIATIONS a.s.l. c. o C CI CITES

DFW DoF DNCP FFI g GPS ha IUCN

above mean sea level circa degrees Celsius or Centigrade Conservation International Convention on International Trade in Endangered Species of Wild Fauna and Flora Department of Forestry and Wildlife Department of Fisheries Department of Nature Conservation and Protection Fauna & Flora International gram Global Positioning System hectare International Union for Conservation of Nature (the World Conservation Union)

kg km km2 L, l MAFF m mm NTFP SSC SVL SW UNDP WCS WWF

kilogram kilometre square kilometre litre Ministry of Agriculture, Forestry and Fisheries metre millimetre Non-Timber Forest Product Species Survival Commission Snout-Vent Length (measure of body length in reptiles) South West United Nations Development Programme Wildlife Conservation Society World Wide Fund for Nature

Note on place names and locations: Throughout this report, country names follow The Times Atlas of the World (1999), while local place names are largely as provided by the Cambodian survey personnel. Most names are phonetically similar to those shown on the commercially available 1:50,000 topographic maps. Khmer names for geographical features can be translated into English as follows: Phnom = Mountain or Mount; Phum = Village; Prek or O = Stream or River; Stoeng or Stung = River; Anlong = Deepwater section of river; Chay = Rapids. Georeferences in the text are intended for guidance only, and should not be relied on for navigational purposes. The survey personnel usually identified their position using UTM grids (read from the map or recorded using hand-held GPS). For the benefit of overseas readers, some of the most important localities have been converted into latitude and longitude in degrees, minutes and seconds using the UTM Converter at http://www.cellspark.com/UTM.html (© Colin Mummery). Cambodia is in UTM Grid Zone P48.

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CONTENTS EXECUTIVE SUMMARY…………………………………………………………………... i ACKNOWLEDGEMENTS………………………………………………………………….. v ACRONYMS AND ABBREVIATIONS……………………………………………………vii

1

GENERAL INTRODUCTION .......................................................................................1 1.1

BACKGROUND .................................................................................................................... 1

1.1.1 1.1.2 1.1.3 1.2

SURVEY OBJECTIVES ........................................................................................................ 3

1.3

GENERAL METHODS.......................................................................................................... 5

1.3.1 1.3.2 1.3.3 1.3.4 1.3.5 1.3.6

2

The Siamese Crocodile ................................................................................................... 1 The Cambodian Crocodile Conservation Programme .................................................... 2 The Cardamom Mountains.............................................................................................. 2

Participants and Training ................................................................................................ 5 Selection of Study Areas................................................................................................. 5 Surveying Distribution.................................................................................................... 5 Measuring Abundance: The Minimum Population Size ................................................. 6 Behavioural Ecology..................................................................................................... 11 Threats........................................................................................................................... 11

SURVEY AREA ACCOUNTS ......................................................................................12 2.1

VEAL VENG MARSH......................................................................................................... 12

2.1.1 2.1.2 2.1.3 2.1.4 2.2

STOENG KRAU AND STOENG KOI ................................................................................ 15

2.2.1 2.2.2 2.2.3 2.2.4 2.3

Introduction...................................................................................................................17 Methods......................................................................................................................... 17 Results........................................................................................................................... 18 Discussion ..................................................................................................................... 18

STOENG RUSSEI CHRUM ................................................................................................ 19

2.4.1 2.4.2 2.4.3 2.4.4 2.5

Introduction...................................................................................................................15 Methods......................................................................................................................... 16 Results........................................................................................................................... 16 Discussion ..................................................................................................................... 16

STOENG KOI: ANLONG L’ANG ...................................................................................... 17

2.3.1 2.3.2 2.3.3 2.3.4 2.4

Introduction...................................................................................................................12 Methods......................................................................................................................... 12 Results........................................................................................................................... 13 Discussion ..................................................................................................................... 14

Introduction...................................................................................................................19 Methods......................................................................................................................... 19 Results........................................................................................................................... 19 Discussion ..................................................................................................................... 19

STOENG KEP ...................................................................................................................... 20

2.5.1

Introduction...................................................................................................................20 - ix -

2.5.2 2.5.3 2.5.4 2.6

STOENG TATAI AND STOENG TOUCH......................................................................... 22

2.6.1 2.6.2 2.6.3 2.6.4 2.7

Introduction...................................................................................................................30 Methods......................................................................................................................... 30 Results........................................................................................................................... 31 Discussion ..................................................................................................................... 31

PREK SANTUNG, PREK TABEH TES, AND STOENG CHI PHAT ............................... 32

2.10.1 2.10.2 2.10.3 2.10.4

3

Introduction...................................................................................................................25 Methods......................................................................................................................... 26 Results........................................................................................................................... 27 Discussion ..................................................................................................................... 29

STOENG TRAPEANG RUNG AND PREK KUO YUON ................................................. 30

2.9.1 2.9.2 2.9.3 2.9.4 2.10

Introduction...................................................................................................................24 Methods......................................................................................................................... 25 Results........................................................................................................................... 25 Discussion ..................................................................................................................... 25

STOENG ARENG ................................................................................................................ 25

2.8.1 2.8.2 2.8.3 2.8.4 2.9

Introduction...................................................................................................................22 Methods......................................................................................................................... 22 Results........................................................................................................................... 23 Discussion ..................................................................................................................... 24

STOENG SALA MUNTHUN .............................................................................................. 24

2.7.1 2.7.2 2.7.3 2.7.4 2.8

Methods......................................................................................................................... 20 Results........................................................................................................................... 21 Discussion ..................................................................................................................... 21

Introduction...................................................................................................................32 Methods......................................................................................................................... 32 Results........................................................................................................................... 32 Discussion ..................................................................................................................... 33

GENERAL DISCUSSION .............................................................................................34 3.1

COMPLETENESS AND COVERAGE OF THE 2002 SURVEYS .................................... 34

3.2

STATUS OF THE SIAMESE CROCODILE....................................................................... 35

3.2.1 3.2.2 3.2.3 3.3

ECOLOGY ........................................................................................................................... 37

3.3.1 3.3.2 3.3.3 3.4

Distribution ...................................................................................................................35 Abundance .................................................................................................................... 36 Siamese Crocodile or Saltwater Crocodile?.................................................................. 36 Habitat........................................................................................................................... 37 Food and Feeding.......................................................................................................... 38 Reproduction................................................................................................................. 40

HUMAN ATTITUDES TOWARDS CROCODILES.......................................................... 41

3.4.1 3.4.2 3.4.3 3.4.4 3.4.5

People in the Central and Southern Cardamom Mountains .......................................... 41 Indigenous People ......................................................................................................... 41 New Settlers .................................................................................................................. 42 Parties of Non-Timber Forest Product (NTFP) Collectors ........................................... 42 Commercial Hunters and Traders ................................................................................. 42 -x-

3.5

THREATS............................................................................................................................. 43

3.5.1 3.5.2 3.5.3 3.5.4 3.5.5 3.5.6 3.5.7 3.6

4

5

Hunting ......................................................................................................................... 43 Fishing........................................................................................................................... 44 Egg Collection .............................................................................................................. 44 Habitat Loss .................................................................................................................. 44 Fragmented and Reduced Population............................................................................ 45 Pollution........................................................................................................................ 46 Human Disturbance....................................................................................................... 46

WHY CONSERVE CROCODILES IN THE CARDAMOM MOUNTAINS? ................... 46

CONSERVATION RECOMMENDATIONS..............................................................48 4.1

LAW ENFORCEMENT ....................................................................................................... 48

4.2

HABITAT PROTECTION ................................................................................................... 50

4.3

CROCODILE FARMS ......................................................................................................... 51

4.4

EDUCATION AND AWARENESS .................................................................................... 51

4.5

ESSENTIAL COMMUNITY PARTICIPATION ................................................................ 53

4.6

CAPACITY BUILDING ...................................................................................................... 54

4.7

STRATEGY FOR CAPTURED CROCODILES................................................................. 54

4.8

RESEARCH PRIORITIES ................................................................................................... 54

REFERENCES ...............................................................................................................56

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1

GENERAL INTRODUCTION

1.1

BACKGROUND

1.1.1

The Siamese Crocodile

The Siamese crocodile Crocodylus siamensis, is one of the most endangered of the world’s 23 species of crocodilian. Almost nothing is known of its ecology or behaviour in the wild (Ross, 1998). The Siamese crocodile is superficially similar to the larger saltwater or estuarine crocodile Crocodylus porosus, also native to Cambodia, as both are tan or pale gold in colour with dark spots. It is relatively small, however, perhaps only rarely exceeding three metres in total length. Siamese crocodiles have much broader snouts than saltwater crocodiles, and at least four enlarged scales on the nape of the neck (the saltwater crocodile typically has none). Unlike the saltwater species, Siamese crocodiles are considered relatively inoffensive, and no predatory attacks on people have been reliably documented. Siamese crocodiles were once common and widespread throughout the rivers, lakes and marshes of Southeast Asia, including Thailand, Cambodia, Vietnam, Laos, Malaysia, Indonesia and possibly also Brunei and Myanmar. Through the twentieth century, however, the species became greatly sought after for its valuable skin. Farms throughout Asia encouraged the collection of vast numbers of live Siamese crocodiles. Once in captivity, many of them were mated with the more aggressive saltwater crocodile or Cuban crocodile C. rombifer, to produce faster-growing young. Consequently, many of the so-called ‘Siamese crocodiles’ in farms and zoos today are hybrids of no conservation value. As well as over-hunting, Siamese crocodiles have also suffered from severe habitat loss and persecution from people living around rivers and wetlands. By the 1990’s, many scientists considered this species ‘effectively extinct in the wild’. The IUCN/SSC Crocodile Specialist Group placed the Siamese crocodile at the top of the world’s list of 23 crocodilians in terms of need for conservation (Messel et al., 1992). The Siamese crocodile is justifiably classed as Critically Endangered, the highest level of threat recognised by the World Conservation Union (Hilton-Taylor, 2000), and assigned to Appendix I of CITES (2002). Reports presented at the regional meeting of the IUCN/SSC Crocodile Specialist Group in Guangzhou, September 2001, indicated the current global status of the Siamese crocodile to be as follows: Indonesia: Java Extinct Kalimantan Extinct? (No recent sightings) Malaysia: West Extinct Sabah Extinct Sarawak Extinct Vietnam:

Extinct

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Laos:

‘Effectively extinct’- Possibly fewer than 10 adults, in scattered localities

Thailand:

‘Effectively extinct’- Fewer than five known, in scattered localities

Cambodia:

Unknown, but perhaps a few hundred, mostly in the Cardamom Mountains.

Scientists from Fauna & Flora International (FFI) and the Department of Forestry & Wildlife (DFW), first discovered Siamese crocodiles in Cambodia’s Cardamom Mountains in March 2000, during a biodiversity survey (Daltry & Momberg, 2000). The crocodiles were seen in several localities within the mountain range, including Veal Veng Marsh and the Kep and Koi rivers, where they are locally known as ‘Kropeu Phnom’ or ‘Mountain Crocodiles’. A further seven were examined at a private collection in Koh Kong Provincial Town on the Thailand– Cambodia border in 2000, which had reportedly come from four rivers in the Central and Southern Cardamom Mountains: the Kep, Tatai, Trapeang Rung and Russei Chrum. We also gathered convincing reports of crocodiles in the Chay Areng (the lower Stoeng Areng) and Atay drainages from hunters and wood collectors (Daltry & Chheang, 2000), but these still need confirmation.

1.1.2

The Cambodian Crocodile Conservation Programme

The Cambodian Crocodile Conservation Programme was established in 2001 by the DFW and FFI, under the name of the Siamese Crocodile Conservation Project. The goal of this programme is to ensure the long-term survival of the Siamese crocodile in the wild by means of integrated research and monitoring, awareness raising, capacity building and enhanced protection. The programme is currently focused on the Cardamom Mountain Range of South West Cambodia, which appears to be the last main stronghold of this species. The seven main objectives of this programme are to: 1.

Assess the status, ecology and distribution of the Siamese crocodiles in Cambodia.

2.

Raise awareness and understanding of the importance of conserving crocodiles among local communities, the general public, decision makers and the NGO community in Cambodia.

3.

Ensure that the Siamese crocodiles and their riparian and marsh habitats receive more effective legal protection throughout the Cardamom Mountains.

4.

Promote community-based conservation management of the Veal Veng Marsh and its resident population of Siamese crocodiles.

5.

Enhance the capacity of national conservation agencies to survey and conserve wild crocodiles.

6.

Establish a monitoring programme to evaluate whether conservation actions are proving effective and update and improve the conservation strategy where necessary.

7.

Share knowledge with other groups working to conserve and reintroduce Siamese crocodiles within Cambodia and neighbouring countries.

1.1.3

The Cardamom Mountains

Spanning more than one million hectares, the Cardamom Mountains of South West Cambodia comprise the Phnom Samkos massif, the Central Cardamom Mountains, the Phnom Aural massif and the land between them (Map 1). The highest point in this range is Mount Aural at 1,771m above sea level (a.s.l.). The Cardamom Mountains form one of the most pristine tropical forest ecosystems in mainland Southeast Asia. Much of this area is covered in primary-condition hill evergreen forest, with -2-

significant areas of dry dipterocarp forest, dry evergreen forest, hill evergreen forest, pine forest, marsh, montane evergreen forest, bamboo forest and moor land. The Cardamom Mountains cover only about 6% of Cambodia’s total land area, but support most of the nation’s known species of large mammal and at least half of the known resident birds, reptiles and amphibians (Daltry & Momberg, 2000; Daltry, 2002a). Rainfall is high, with some parts of the range receiving more than 4m (exceptionally more than 5m) of rain annually, especially the southwestern slopes that catch the saturated South West Monsoon from May to October. This high rainfall gives rise to numerous rivers, which in turn feed into the Gulf of Thailand to the South and the Mekong basin and the Tonle Sap to the north west. Temperatures are generally high (25–30oC), with little seasonal variation, but can drop below 15 oC at night at higher elevations. Until recently, there were only two protected areas here: the Phnom Samkos Wildlife Sanctuary (3,338km2) covering the western arm of the mountain range, and the Phnom Aural Wildlife Sanctuary (2,536km2) to the East (Map 1). Designated in 1993, their management and administration is chiefly the responsibility of the Ministry of the Environment (Ashwell, 1997). Between the wildlife sanctuaries, Central Cardamoms Protection Forest was gazetted in July 2002. This area is protected under the authority of Ministry of Agriculture, Fisheries and Forestry (MAFF) and covers approximately 4,200km2. Further south towards the Gulf of Thailand, the foothills of the Cardamom Mountains are currently under forest concession and many parts have been selectively logged.1 The human population of the Cardamom Mountains is relatively small, and most areas are uninhabited and rarely if ever visited by humans. The two wildlife sanctuaries together contain an estimated 13,000 people. There are only two main settlements in the Central Cardamoms – O’Som Commune (12o04’N, 103o13’E) and Thmar Baing Commune (11o41’N, 103o26’E) – each with up to 1,000 people. The people of this region include a number of ethnic minorities: for example, Highland Khmer comprise 70% of O’Som Commune (Hammond & Hor, 2002), and there are more than 1,000 Suoi in Phnom Aural Wildlife Sanctuary (Maxwell, 2000b). Relatively little on-the-ground biological survey work has occurred in the Cardamom Mountains to date, even within the wildlife sanctuaries and protection forest. This is largely due to their poor accessibility and significant health and security risks, especially between 1975 and the late 1990s, when much of South West Cambodia was under Khmer Rouge control. The first major biological and socio-economic surveys of the Cardamom Mountains was carried out by FFI, DFW and the Department of Nature Conservation and Protection (DNCP) in 1999 and 2000, focusing on Phnom Samkos Wildlife Sanctuary and selected parts of the Central Cardamom Mountains (Boonratana, 1999; Daltry & Momberg, 2000).

1.2

SURVEY OBJECTIVES

This survey was intended to help meet several of the overall programme objectives listed in section 1.1.2: i)

Survey the distribution of Siamese crocodiles in the Central and Southern Cardamom Mountains and provide estimates of population size (Programme Objective 1).

1

When these surveys were conducted in 2002, the forest concessions in the ‘Southern Cardamoms’ were held by Silveroad Wood Products, Samling International and TPP Cambodia Timber Product Pty Ltd. The Voot Tee Peanich and GAT International concessions were cancelled on 8 May and 16 June 2002 respectively, however, and the fate of both concession areas has yet to be announced.

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ii)

Gather baseline data on diet, habitat use and reproductive behaviour (Programme Objective 1).

iii)

Gather baseline data on threats to crocodiles in the Central and Southern Cardamom Mountains and recommend appropriate conservation actions (Programme Objective 1).

iv)

Identify priority areas for protecting Siamese crocodiles (Programme Objective 3).

v)

Provide Department of Forestry & Wildlife staff with theoretical and practical training in crocodile survey techniques, from survey design to data analysis and report writing (Programme Objective 5).

vi)

Devise and test straightforward methods for monitoring crocodile numbers in key areas (Programme Objective 6).

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1.3

GENERAL METHODS

1.3.1

Participants and Training

Before conducting fieldwork, a classroom-based training workshop was held from 14 to 18 January 2002 inclusive (Appendix I). Training covered basic field skills such as navigation and field safety, and the biology and conservation of crocodilians. Films and slides were shown to illustrate crocodile behaviour. Towards the end of the week, the eight DFW participants applied what they had learned to design the field surveys and select suitable sites. Field surveys were carried out between 21 January to 4 April 2002, terminating at the start of the rainy season, when access to the mountains becomes more difficult and dangerous. A one-day training workshop on data analysis was conducted in April, followed by a session on report writing. The surveys were led by Dr Jenny Daltry (Senior Conservation Biologist, FFI) and the following staff from the DFW: Wildlife Protection Office

Koh Kong Provincial Forestry Department

Mr Chheang Dany

Mr Poeung Mora

Mr Sam Han

Mr Sonn Pisith

Mr Hor Leng

Forestry and Wildlife Research Institute

Mr Em Phal

1.3.2

Mr Tan Thara

Selection of Study Areas

Veal Veng Marsh and 12 named rivers were surveyed in the Central and Southern Cardamom Mountains (Table 1.1). Priority was given to areas within the Central Cardamoms Protection Forest and where crocodiles had been seen or reported previously, and fieldworkers could travel in relatively safety. A description of each river is given in Chapter 2. Most areas had never been subjected to a biological or any other type of survey before, and we therefore had little to go on other than the available 1:50,000 topographic maps. These are fairly accurate, but some of the rivers and settlements are shown with incorrect names, and minor water bodies are missing.

1.3.3

Surveying Distribution

Rapid surveys were conducted in as many drainage basins as possible to detect which areas contained crocodiles. Almost all of the searches were conducted by day and on foot. In the few instances where boats were available (a few sections of the Stoeng Areng and Stoeng Koi), we travelled slowly and disembarked at every sandbank to search for tracks and other sign. To confirm crocodile presence, we made intensive searches during the day for signs left by crocodiles, such as tracks, faeces and trails, along the banks, sandbars and islands of rivers and ponds. We also attempted to see the crocodiles during the day and, where possible, by night (see Box 1).

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Table 1.1

Summary of Survey Localities, Dates and Personnel

Area

Dates in 2002

Survey personnel

Veal Veng Marsh Stoeng Krau and Stoeng Koi (upper)

22–25 January, 13–25 February, 28 March. 27–29 January, 13–15 February

Chheang Dany, Sam Han, Em Phal, Sonn Pisith, Tan Thara, Jenny Daltry, Jeremy Holden. Sam Han, Hor Len, Poeung Mora, Tan Thara

Stoeng Koi (lower): Anlong L’Ang

26–30 January 10–14 February

Sam Han, Em Phal, Sonn Pisith, Jenny Daltry, Jeremy Holden.

Stoeng Russei Chrum

10–12 February

Sam Han, Tan Thara

Stoeng Kep

21 February to 3 March; 21–24 March

Em Phal, Tan Thara, Hor Leng

Stoeng Tatai and Stoeng Touch

21 February to 2 March

Poeung Mora, Sonn Pisith

Stoeng Sala Munthun

25–28 March

Hor Leng, Em Phal

Stoeng Areng

20 February to 2 March; 22–28 March

Sam Han, Chheang Dany, Jenny Daltry, Em Phal, Sonn Pisith, Tan Thara, Poeung Mora

Stoeng Trapeang Rung and Prek Yourn

30 March to 1 April

Sam Han, Poeung Mora, Sonn Pisith

Prek Santung, Prek Tabeh Tes, and Stoeng Chi Phat

2–4 April

Sam Han, Poeung Mora, Sonn Pisith

All sightings of crocodiles, dung, tracks and other sign were recorded as proof of crocodile presence. Dung was collected in bags, labelled, and brought back to Phnom Penh for analysis. Locations of crocodiles and their sign were accurately recorded using Garmin™ 12XL global positioning systems, crosschecked with 1:50,000 topographic maps. Locations were recorded in the field using UTM grid co-ordinates (read from the map or, more usually, recorded using the GPS). For the benefit of overseas readers, some of these have been converted into latitude and longitude in degrees, minutes and seconds. In addition, local communities were informally interviewed to gather information about crocodile distribution in the past, at other times of year or in areas that could not be surveyed adequately this year. Local people, especially fishermen, were frequently found to have a good knowledge of crocodile distribution. In this report, however, confirmed records (where crocodiles or their sign were found by our team) will be clearly distinguished from credible but unconfirmed verbal reports.

1.3.4

Measuring Abundance: The Minimum Population Size

It was alas not possible to apply a single, standardised method to surveying the absolute or relative abundance of crocodiles in all rivers. Considerable variation in accessibility (boat transport was rarely available), the substrate forming the banks, the ‘wariness’ of the resident crocodiles, and rainfall at the time of the visit, forced us to adapt our survey strategy to suit each river and circumstance. -6-

Box 1 Crocodile Sign and Sightings Sightings Crocodiles are sometimes seen in the water or basking on banks during the day, but are wary and quick to submerge. They can be more easily seen in the water at night by searching for their yellow or orange ‘eye-shine’. Our survey team used Petzl™ head torches and Q-Beam™ spotlights (500,000 and 1 million candlepower). The light source should be held close to the observer’s own eyes for the best results Eye-shine in torch-light Tracks Crocodiles leave footprints, and tail and belly drag marks on suitable substrates. The tracks commonly form a horseshoe shape on muddy or sandy riverbanks, where the crocodile has climbed out of the water, rested on the bank, and slithered or walked back into the river. The photographs shown here were all of tracks beside the Stoeng Areng (section 2.8) Tracks and dung on sand

Hand print in mud

Tracks on sand Faeces Crocodile faeces are pale grey with a chalky texture and musky smell. They turn almost white and brittle with age. The fresh example shown here, from Veal Veng Marsh, was approximately 15cm long.

Fresh dung

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Box 1 Crocodile Sign and Sightings (cont.) Trails In swampy areas, the movements of Siamese crocodiles create narrow, flooded channels through the emergent and marginal grasses and reeds, usually perpendicular to the river and several metres in length.. Crocodile trails through marshland are typically 40-50cm wide, and contain at least 15cm depth of water during the dry season (Daltry, 2002b). The example here was in Veal Veng Marsh.

Trail through marsh

Adult crocodiles also leave distinctive trails through forest beside rivers and ponds. These are characterised by their low height relative to their width (the air is clear of vegetation for only about 40cm above the ground). Mud is smeared on logs and tree roots, where the crocodile has scraped its belly. When the ground is wet (as shown here) sinuous tail drag-marks and footprints may be seen. Trail through forest

Nests Siamese crocodile nests are mounds of dead vegetation. Based on corroborating verbal reports, the nesting season begins in April or May.

Nest of (captive) crocodile Excavations We have discovered that Siamese crocodiles sometimes use burrows in the riverbank. The burrows tend to be larger than those made by otters or other riverside animals, and the entrances are often partially submerged even during the dry season. Because burrows may persist for many years, these cannot be accepted as proof of crocodile presence unless other fresh sign is found. Tracks were found inside the hole near Thmar Baing shown here.

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Crocodile burrow

To compare different rivers or monitoring changes over time, the field teams were asked to calculate the minimum number of crocodiles in each survey area. We defined this as the smallest number of different individuals that must be present to account for the crocodiles seen or sign found. (Many of the survey personnel lacked any previous experience of surveying crocodiles, and therefore could not be expected to estimate the actual number present from these initial surveys). Different individuals in each survey area were primarily distinguished according to their size. To determine the number of different-sized crocodiles in the survey area, the fieldworkers recorded the following (with reference to Box 1): •

Sightings: Estimate the total length of all crocodiles seen to the nearest 50cm.



Tracks: Measure the total length and width of all footprints to the nearest centimetre using a tape measure, and measure the step, stride and straddle of all ‘raised walk’1 tracks, to the nearest centimetre (Box 2).



Faeces: Measure the diameter of each faecal sample at its widest part using callipers, and assign the sample to one of the following size classes: 2.0-4.9mm, 5.0-8.9mm, 9.0-12.9mm, etc. 14 size classes were recognised, the largest being 53.0-56.9mm.

In each survey area, we selected one of the above methods to calculate the minimum number of crocodiles present. Our choice depended on which method was most appropriate for the local terrain. The grass-covered banks of Veal Veng Marsh, for example, were unsuitable for showing tracks, but the pale dung were clearly visible, so our analysis of abundance here was largely based on variation in faecal size (section 2.1). Conversely, dung was rarely seen on the white sandy banks of the Stoeng Areng (section 2.8), but the latter provided an excellent substrate for measuring and comparing tracks. The steep banks of Anlong L’Ang gorge (section 2.3), on the other hand, provided a poor surface for faeces or tracks, but the fieldworkers were more easily able to see and count the crocodiles from high vantage points in the forested banks. The most obvious drawback of this size-based approach is that crocodiles of the same or very similar size will tend to be counted as one individual unless they are seen at exactly the same time. In the Ombot Touch ox-bow lake, for example, 10 juvenile crocodiles were seen by spotlight on one night in February (section 2.8). Based on faeces and tracks alone, we were able to count only one of these. While fieldworkers were urged to be very careful in their measurements and not to try to measure broken faeces or other damaged sign, there was also some risk of one individual being perceived as two individuals. There was, however, a much greater likelihood of individuals being missed altogether because they had not been seen or no sign of them had been found! Small crocodiles in particular were prone to be overlooked. On balance, therefore, we believe that our counts are highly conservative.

1

Where the crocodile is walking with its belly lifted off the ground.

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Box 2 Measuring crocodile tracks TFW

THW

TFL

THL FRONT FOOT (RIGHT)

HIND FOOT (RIGHT)

Length and width are measured without including the claws. Total Hand Width (THW) From tip of thumb to tip of small finger. Total Hand Length (THL) The longest distance from the tip of the middle finger.

Step

Total Foot Width (TFW) Width across the three longest fingers Total Foot Length (TFL) The longest distance from the tip of the middle finger.

Step: This is a single step measurement or the distance from one track to the next (e.g., the tips of the toes on front left foot to tips of the toes on front right foot). Stride: This is a double step measurement, measured as the distance from one track (tip or base of one foot) to the same place on the next track on the same side of the body. On flat ground, this can give an approximate measure of the crocodile’s length from shoulder to hip.

Stride

Straddle: The distance from the outermost edges of tracks from opposite sides of the body (e.g., outer edges of front right foot to outer edges of front left. This measurement indicates the body width of the crocodile, when it is walking with its belly clear of the ground.

TRACKS OF A ‘HIGH WALKING’ CROCODILE Straddle

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1.3.5

Behavioural Ecology

1.3.5.1 Diet All intact crocodile dung was measured (length and diameter of bolus at its widest point) in the field and brought back to Phnom Penh for dietary analysis. Each faecal sample was carefully broken apart to locate and identify the non-digested remains of prey animals. Bone and soft tissues of the prey tend to be totally digested, but parts comprised of keratin (e.g., fur, feathers, scales and claws), chitin (arthropod exoskeletons) and enamel (mammalian teeth) pass down a crocodile’s gastro-intestinal tract largely intact. 1.3.5.2 Habitat use During the training workshop, the survey team discussed recording a variety of variables to describe areas where crocodiles were confirmed present and areas where crocodiles appeared to be absent. These included: • Depth of water body • Width of water body • Substrate on the banks • Submerged vegetation • Vegetation on the banks Techniques were discussed for recording environmental variable quantitatively. In practice, however, the measurements we used were largely qualitative, owing to lack of time and a forgivable reluctance to carry more measuring equipment (each team member hiked with up to 30kg of camping equipment, food, first aid kits and clothing). Classification of major vegetation types in this report follows Boyce et al. (2002). 1.3.5.3 Other Because of the rapid nature of this survey, information on reproductive behaviour, activity patterns and other behaviours were largely gleaned through informal interviews with local people. We were acutely aware that such second-hand information was inherently unreliable, and wherever possible we tried to corroborate verbal reports by posing the same questions to several people from different communities.

1.3.6

Threats

When assessing the areas where crocodiles were confirmed present and where they appeared to be rare or absent, we looked for hard evidence of human impact, such as poaching, use of explosives for fishing or habitat degradation. Local people were also interviewed at every opportunity to help clarify whether and how people were using these areas, and whether crocodile numbers had declined. The interviews were intentionally informal in nature, and usually did not commence until the interviewer and interviewee had become acquainted for several days. This relaxed approach went some way towards overcoming the interviewees’ fear of speaking out about illegal activities, even to DFW officers.

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2 2.1

SURVEY AREA ACCOUNTS VEAL VENG MARSH

By Jenny C. Daltry, Chheang Dany and Sam Han

2.1.1

Introduction

Siamese crocodiles were first reported in Veal Veng Marsh by Daltry & Chheang (2000). Since then, there have been several studies of the crocodiles and other wildlife, the hydrology of the marsh, and the people who live here (Carvalho, 2002; Daltry 2002b; Ironside et al. 2002). Veal Veng Marsh is a 1000ha freshwater marsh, 8km long and up to 3km wide, at 560m above sea level (a.s.l.) at 12o 2’N and 103o 16’E. At the core of the basin are permanently flooded beds of emergent plants and slow flowing rivers that cover about 50ha in the dry season, and there is also a mosaic of other small, permanently saturated mires scattered around the basin. This unusual marsh is part of the Stoeng Koi catchment. A network of black water rivers carries rainwater from the surrounding mountains through Veal Veng, where they are more than 5m deep in places. In some parts, especially towards the western end of Veal Veng, these slow-moving rivers flow beneath floating mats of grass. They eventually feed into the Stoeng Krau (= Chay Louk) (see section 2.2). The marsh climax vegetation is hyperseasonal savanna: a complex mosaic of emergents (reeds and sedges) in permanently flooded areas with trees (predominantly paper-bark tree Melaleuca sp., Myrtaceae) on seasonally flooded land. Surrounding Veal Veng is hill evergreen forest and the four villages of O’Som Commune: O’Som, Kandal, Chay Louk and Kien Chong Rouk. Parts of this area have been farmed, probably for a thousand years, and even within the marsh, trees have been felled in some of the drier parts and replaced with seasonally inundated open pasture. Farming is non-intensive, however, and less than 2% of the marsh was under arable cultivation at the start of 2002. The 2002 surveys were carried out when the surface water was at its lowest. During the rainy season (typically April to October), however, there are larger peripheral flood plains extending up to 200m either side of the rivers, causing much of the basin to become submerged to a depth of over one metre. At their full extent, the floods cover at least 500 hectares - a ten-fold increase over their dry season area.

2.1.2

Methods

Six staff from the DFW (Chheang D., Sam H., Hor L., Em P., Sonn P., Tan T.) and J. Daltry visited Veal Veng from 22-25 January 2002. FFI photographer Jeremy Holden remained in the marsh until 30 January. Further visits were made Sonn P. and J. Holden (15-17 February) and Chheang D. and J. Daltry (28 March). Hor L. conducted interviews with O’Som Commune villagers from 13-25 February (see below), and participated in a hydrological survey in June (Carvalho, 2002). To document the distribution of crocodiles in Veal Veng, the first group divided into two teams of three to four individuals, who rapidly surveyed accessible parts of the marsh for sign or sightings. It was already known from previous surveys in 2000 and 2001 (Daltry, 2002b) that the central part of - 12 -

the marsh remained flooded even during the dry season and was extremely difficult to survey safely or systematically. To assess the number of crocodiles in this core area, we therefore surveyed the accessible 800m-length of river from the bridge at 12o2’44”N, 103o16’15”E (0311770E, 1332184N) downstream to 12o2’37”N, 103o16’2”E (0311375E, 1331971N). Two teams walked slowly down each side of the river, looking for crocodile sign. The findings from this transect were extrapolated to estimate the total number of crocodiles in the core area of the marsh. We also informally interviewed local villagers about seasonal changes in the distribution of crocodiles in Veal Veng Marsh, how the villagers use the marsh and their attitude toward the crocodiles, and the possible threats to the crocodiles and their habitat. More detailed interviews in the Veal Veng area were carried out by DFW-FFI as part of a socio-economic study in 2001 (Hammond & Hor, 2002) and 2002 (Ironside et al., 2002).

2.1.3

Results

2.1.3.1 Central Veal Veng We confirmed the presence of crocodiles in the flooded core area of the marsh known as Romeas Ngorp and adjoining rivers during the dry season, with some fresh outlying sign to the West around UTM 03106E, 13314N. Within this area, we found large numbers of crocodile trails, plus dung and flattened basking areas on the drier banks. No crocodiles were seen here during the present survey, however, possibly due to disturbance by our large team or because of the unusually cold weather (air temperatures in the marsh dropped below 15 oC on several nights). In 2001, clear sightings of three adults were made on one day in March, all within a 10-m section of the main river at 03114E, 13319N. 45 faeces were found along our 800-metre transect (Table 2.1). They ranged in size from 6.8mm to 51.0mm maximum diameter, and represented 11 of our 14 pre-defined size classes. The results from Anlong L’Ang (section 2.3) are also included here for the sake of comparison. The Veal Veng Marsh dung was not evenly distributed, but tended to be in groups of similar size around flattened basking areas, which is suggestive of repeated use of each area by the same individual. Judging from the strikingly varied diameter of the faeces and the distribution of dung clusters, it appears there were at least 11 different and rather sedentary individuals living along the 800m transect. Simple extrapolation of these figures gives a tentative estimate of at least 40 individuals in the crocodiles’ total dry season distribution range in Central Veal Veng. 2.1.3.2 South West Veal Veng We also located a permanently flooded area centred on 12o1’55”N, 103o14’52”E (03093E, 13307N), where there was a large number of what appeared to be crocodile trails. Once an open lake (according to 1:50,000 topographic maps from the 1970s), this area has became overgrown with floating mats of grass and reeds. No faeces were found, but any dung would quickly decompose or fall through the flooded vegetation. A guide from O’Som Commune said that crocodiles occupy this area throughout the year, but are rarely seen because people do not visit very often. This area may form a second ‘dry season refuge’ for the marsh crocodiles. It is comparable in area to Central Veal Veng and contains water all year round. Without conclusive proof that crocodiles live here during the dry season, however, we have not attempted to estimate minimum population size here.

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Table 2.1

Crocodile dung found along 800m transects in two areas: Central Veal Veng and Anlong L’Ang (section 2.3). Number of faeces on an 800m transect

Diameter of dung at its widest point (mm)

Central Veal Veng (23–24 January)

Anlong L’Ang (27–28 January)

0 1 1 1 0 1 7 8 10 5 6 2 3 0

0 0 0 0 1 0 1 2 2 1 1 1 0 0

45

9

2.0 – 4.9 5.0 – 8.9 9.0 – 12.9 13.0 – 16.9 17.0 – 20.9 21.0 – 24.9 25.0 – 28.9 29.0 – 32.9 33.0 – 36.9 37.0 – 40.9 41.0 – 44.9 45.0 – 48.9 49.0 – 52.9 53.0 – 56.9 Total faecal samples 2.1.3.3 Elsewhere

A further 11 faecal samples were found along rivers throughout the marsh, even high up the main valley to the Southwest, but they were old and probably dated from the previous rainy season. This was consistent with reports from Kien Chung Roak villagers that the crocodiles in Central Veal Veng become widely dispersed throughout the marsh during the rainy season, but retreat to permanently flooded areas during the dry season. Sign found around shallow pools in the southern part of the wetland, from 12o2’13”N, 103o15’52”E (03111E, 13312N) westwards, appeared to be several months old, and thus dating from the 2001 rainy season. However, local villagers reported that several large crocodiles live here throughout the year. Further surveys are needed to confirm whether this is true, and the number of individuals concerned.

2.1.4

Discussion

Veal Veng Marsh contains a resident population of juveniles, sub-adults and adults. This may be the single largest breeding colony of this species left in the wild. Our findings have indicated there are at least 40 individuals in the permanently flooded central part of the wetland around Romeas Ngorp (= ‘Dead Rhino’). It seems likely that there are additional individuals in the south and south west of the marsh, notably in the swampy area south of Bak Angroute. During the dry season, the crocodiles are rather sedentary and concentrated in these wettest parts of Veal Veng, which total an area of approximately 50ha. According to local intelligence and the distribution of old dung, the crocodiles

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disperse during the rainy season across an area of up to 500ha. Villagers from Kien Chong Rouk village reported seeing nests at the start of the rainy season, in April and May. The Veal Veng crocodile population is unusual in that it has evidently survived living alongside humans for many hundreds of years. The O’Som Commune is largely comprised of Highland Khmer or Khmer Leu (Hammond & Hor, 2002), who regard killing of crocodiles as taboo. They reported that the crocodiles were unafraid of people in the past, but Khmer Rouge soldiers shot many of them during the 1970’s. Their numbers have apparently largely recovered from this cull, but the Veal Veng crocodiles have learned to be wary of people. The immediate threat to the crocodiles of Veal Veng is loss of habitat due to agricultural practices. The O’Som Commune’s apparent intention to ‘improve’ drainage and plant larger areas with lowland rice could be disastrous (see Daltry, 2002b). Habitat destruction is also being caused by the new herd of buffalo: these large animals have a great capacity for changing natural wetland habitats by grazing, trampling and defecating in watercourses, causing erosion, eutrophication, and altering drainage patterns.1 The villagers have begun burning large tracts of the marsh every dry season. In 2002, such burning extended right up to the edge of rivers occupied by crocodiles. This practice undoubtedly disturbs the crocodiles, reduces their food supply and probably exposes young crocodiles to predators. Hunting is another serious concern. Veal Veng Marsh is now accessible by truck from Pursat and Koh Kong for much of the year, and many migrant workers have come to the area since 2000 in search of yellow vine and other valuable resources. Even though many of the older, more traditional members of O’Som Commune appear to have a genuine respect for crocodiles and believe that they must never be hunted, the younger generations and newcomers to this area unfortunately cannot be counted upon to share these views. Young individuals sometimes become accidentally caught on fishhooks or in nets, with at least three crocodile deaths reported in 2000 (Daltry, 2002b) and another two in 2002 (Ben Hammond pers. comm.).

2.2

STOENG KRAU AND STOENG KOI

By Sam Han, Tan Thara, Hor Leng and Poeung Mora

2.2.1

Introduction

The Stoeng Krau (or Chay Louk) leads out of the Veal Veng Marsh (see previous section) and appears to provide good Siamese crocodile habitat. Water is present throughout the year, and is 1-3m deep in many parts, even during the dry season. People living beside the river use the water to irrigate their crops.2 The river drops from 560 to 490m a.s.l. and is surrounded by lower hill evergreen forest. The Stoeng Krau feeds into the Stoeng Koi, which also appears favourable for crocodiles because there are deepwater pools where the water is 7-10m deep. Both sides of the banks have plenty of 1

In some parts of Australia’s Northern Territory, for example, trampling and grazing by feral buffalo have significantly reduced the floating rafts of grass on which crocodiles nest from 30% to 5% (Webb & Manolis, 1998). 2 Few people live beside the Krau. Most belong to Chay Louk village (O’Som Commune), which had a total population of 212 in 2001 (Hammond & Hor, 2002).

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grasses, sand, and suitable areas for the crocodile to bask and nest, and the surrounding vegetation type is mainly lower hill evergreen forest. Unfortunately, however, yellow vine factories were established in this area in 2001, which discard waste acid into the river. Around this river, there appear to be fewer wild animals than expected because people come to collect yellow vine and other natural resources from the forest. The animals have become very shy. The lower part of Stoeng Koi, at around 440m a.s.l, contains Anlong L’Ang, which will be discussed in section 2.3.

2.2.2

Methods

Surveys of a 16km length of the Stoeng Koi and 8km of the lower Stoeng Krau were carried out by Sam Han, Tan Thara, Hor Leng and Poeung Mora, accompanied by a local porter (Gnem Kong). The Krau and Koi rivers were surveyed by boat and on foot from 27–29 January 2002. In addition, the Koi was surveyed on foot from 13–15 February 2002, and an upper part of the Krau, where it exits Veal Veng Marsh, was visited briefly by Sam Han, Hor Leng and Jenny Daltry in June. We visually surveyed both sides of the rivers and searched for faeces and tracks. Faeces were collected when found, and the tracks were measured to determine the size of the crocodile. We also searched for possible nesting areas.

2.2.3

Results

2.2.3.1 Upper Koi We found crocodile tracks along the upper Stoeng Koi on 26 January 2002. In spite of being downstream of and close to a yellow vine factory, faeces were found 2.5km downstream on 27 January 2002. Both areas were at approximately 490m a.s.l. 2.2.3.2 Krau No sign was found during the January survey. A fisherman from Chum Rum hamlet accidentally netted a young crocodile in May 2002, however, at the point where the Stoeng Krau leaves Veal Veng Marsh. Unsure what to do with it, but not wanting to kill it, the fisherman kept it in a small pen by his house and fed it fish. The crocodile was photographed and released unharmed by our team in the same river in June.

2.2.4

Discussion

Siamese crocodiles were confirmed present in the upper Stoeng Koi in January 2002, but appeared to be scarce. Human disturbance and environmental pollution from the yellow vine factories may be a problem here. We observed that the water was black and ‘smelled bad’ in some areas, and local people observed that crocodiles had been more common in the past. No sign were found in the Stoeng Krau during January, but one live crocodile was found here in June. We suspect human disturbance may explain why crocodiles are scarce here, and they might be threatened by hunting (the main road from Koh Kong to O’Som crosses the Krau). - 16 -

Based on the tracks and dung found and the one crocodile seen, there is an absolute minimum of four crocodiles in the 24km length of Stoeng Koi and Stoeng Krau surveyed. We recommend that the local authority and NGOs should take action to help restore these rivers and make them cleaner and safer areas for crocodiles to live.

2.3

STOENG KOI: ANLONG L’ANG

By Sam Han, Em Phal, Sonn Pisith and Jenny Daltry

2.3.1

Introduction

Anlong L’Ang (‘natural well’) is in O’Som Commune, Veal Veng District, Pursat Province at 11o58’48”N, 103o8’24”E (02975E, 13250N) and 440m a.s.l. This deepwater section of the Stoeng Koi is 25-35m wide and 800-1,000m long. According to a local guide, the river is 15-20m deep here. The riverbank on the north side is steeply sloping in most parts. There are a few small sandy beaches with clumps of treng, where crocodile can rest and bask. On the south bank is a vertical rock wall, extending up to 10m above the water level (dry season). The river is dark and slow flowing here, with few aquatic plants. Trarv (a species of arum) grows at the water’s edge in some places. There were many fallen leaves and old logs in the water when this area was visited in January. Many species of fish and snakes live in Anlong L’Ang.1 It is by far the deepest part of the Stoeng Koi. Further upstream and downstream, the river is generally less than 1m deep and faster flowing. The upper Stoeng Koi has also been surveyed and is described in section 2.2. Downstream of Anlong L’Ang is a major waterfall, with a sheer 30-m drop. It would not be possible for a crocodile to pass up or down the waterfall at any time of year without making a substantial detour through the forest, perhaps for several kilometres. A few kilometres upstream of Anlong L’Ang is a second, smaller waterfall. This fall is only 4-6m high, but would be difficult for a crocodile to cross during the dry season. We therefore believe that crocodiles are effectively confined to Anlong L’Ang during the dry season, but they may be able to disperse upstream when the river rises during the rainy season. Crocodiles were first confirmed in Anlong L’Ang in February 2001 (Daltry, 2002b). At least three different individuals, ranging from 2.5-3.0m in total length, were seen during the daytime. Eye-shine from two crocodiles - one well over 3m in length - was seen at night. Thirteen faecal samples were collected, most on the north bank.

2.3.2

Methods

Three staff from DFW (Sam H., Em P., Sonn P.) and one from FFI (J. Daltry) visited Anlong L’Ang from 26–30 January 2002. Following a preliminary survey on 26 January, we spent 27 January slowly walking along the northern bank of Anlong L’Ang, counting all crocodiles seen and measuring all sign found. The next day, we repeated this procedure along the south bank.

1

Villagers from O’Som Commune often walk the 14km distance to Anlong L’Ang to fish. The fish are said to be particularly large and abundant here - a factor that might help explain the number of large crocodiles.

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Several large crocodiles were seen during these searches. To gain a more accurate count of the number of crocodiles within this area, on 28 January, we spread out along the southern side, and each member sat quietly watching the river from 15:30 to 17:30, and recorded the precise time and location that each crocodile was seen. To determine the extent of the crocodiles’ distribution, the survey team also walked downstream 1.5km to the 30-m waterfall, and 2.5km upstream to the 4-6m waterfall, searching for sign on both sides of the river.

2.3.3

Results

Along the 800-m long banks of Anlong L’Ang, we found 11 pieces of crocodile dung, in seven size classes (see Table 2.1). Twelve sightings of crocodiles were made in this section, ranging in size from 2m to over 3m in total length (estimated by eye). These include six different individuals seen during a standard count on 28 January. Four of these were in very close proximity, on and near two large boulders between 16:20 and 16:35. No signs or sighting were recorded along the river surveyed downstream or upstream of this deepwater section. Based on the dung and sightings of whole animals, the consensus of the field team was that Anlong L’Ang contained at least 10 crocodiles, all of which appeared to be adults. Local people reported that there are 30 to 40 crocodiles in Anlong L’Ang.

2.3.4

Discussion

Anlong L’Ang appears to be an important site for Siamese crocodiles, containing at least 10 individuals during the dry season. These included some of the largest individuals seen during the 2002 surveys, and all appeared to be adults. An old O’Som villager who has been coming here for many years to fish said that he had never seen nests or juveniles here (Daltry, 2002b). It is possible, however, that the Anlong L’Ang adults move elsewhere during the rainy season to breed. They are almost certainly unable to move downstream to the Stoeng Atay owing to the very large waterfall, but might be able to migrate upstream to join other crocodiles in the Koi and its tributaries (section 2.2). It is probably feasible for crocodiles in Anlong L’Ang to bypass several small waterfalls and travel 20km upstream to the known nesting areas in Veal Veng Marsh (section 2.1). Our local guide said that crocodiles had decreased in number in Anlong L’Ang in recent years. Threats to crocodiles in the Stoeng Koi, including Anlong L’Ang, include: • • •

Fishing with nets and hooks. Poisonous waste from yellow wine factories on the Koi (section 2.2). Temporary camps of people along this stream in every season. People visit this area to fish, hunt and collect non-timber forest products. Signs of camps and well-worn trails were found on both sides of the river.

Our guide also reported that although there are no crocodiles immediately below the 30m waterfall, he has seen crocodiles below an ‘even bigger’ waterfall further downstream on the Stoeng Koi, shortly before its confluence with the Stoeng Atay at around 11o58’46”N, 103o6’35”E and 300m a.s.l. This area should be surveyed, but is very remote and will be very difficult to reach.

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2.4

STOENG RUSSEI CHRUM

By Sam Han and Tan Thara

2.4.1

Introduction

The Stoeng Russei Chrum is one of the largest rivers in the Cardamom Mountains. The segment described in this report was 12km south of Veal Veng Marsh (measured in a straight line), near to the border of Pursat and Koh Kong Provinces. This river here is just over 300m a.s.l. The survey began where the road from Koh Kong provincial town crosses the Russei Chrum (11o55’42”N, 103o13’51”E; 03073E, 13192N), approximately 12km upstream of its confluence with the Stoeng Koi. This road was constructed by the You Ry Saco logging company in 1999, and continues north to O’Som Commune, Veal Veng District, Pursat Province. The dominant vegetation type is lower hill evergreen forest, but illegal logging activity took place in this area between 1990 and 1999. A few kilometres upstream of this bridge, along the Stoeng Russei Chrum (to 03240E, 13245N) are the abandoned hamlets and farms of Russei Chrum village, which were last occupied in the 1970’s. During the dry season the river is at its lowest, and in some areas, the water flows underground or over rocks, for example. There are some deepwater sections, however, where the water is 1–6m deep even during the dry season. These include: Anlong Teuk Klang (‘well with strong water’), Anlong Teuk Reark and Anlong Ta Leung. During the rainy season, the river becomes much deeper and fast flowing throughout.

2.4.2

Methods

Two DFW staff (Sam H. and Tan T.) surveyed an 18km section of the Russei Chrum on foot from 10 to 12 February. The survey was unfortunately cut short owing to security problems.

2.4.3

Results

The guide indicated a deep 7km stretch of the river where he had seen crocodiles during the 1970s. During this very short survey, we collected one piece of dung to confirm that crocodiles were present here, at 350m a.s.l. Local people from O’Som Commune, some of whom used to live in the Russei Chrum village asserted that crocodiles had often been seen in the river during the 1970s, before the Russei Chrum settlement was abandoned.1 The Russei Chrum village used to be a series of tiny hamlets, stretched out along the floodplain from 6 to 17km upstream of the area we surveyed.

2.4.4

Discussion

Crocodiles were confirmed present in the Stoeng Russei Chrum, but their status is unknown. Further surveys are needed to ascertain which parts of the river the crocodiles occupy. Probable threats

1

More recently, visitors to O’Som Commune have reported seeing crocodiles in the Stoeng Russei Chrum near the road crossing. These include the drivers hired by the DFW-FFI team in 2000 and 2001.

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include people fishing with nets along the river, and the temporary camps of people harvesting nontimber forest products, such as yellow vine.1

2.5

STOENG KEP

By Em Phal and Hor Leng

2.5.1

Introduction

Daltry & Chheang (2000) first confirmed the presence of crocodiles in the Stoeng Kep on 29 February 2000, when one young individual and tracks of an adult were seen on a small sandbank at 320m a.s.l. A juvenile was seen in the river nearby. The 2002 survey of the Stoeng Kep began at Thmar Baing district town, Koh Kong Province (11o41’N, 103o26’33”E; 03302E, 12920N). This area still has a rich dry evergreen and lower hill evergreen forests, mixed with bamboo forest. The river has many sandy beaches and sand banks, with shrubby marginal plants. In some parts of the river are emerged boulders, which provide crocodiles with good basking sites. About two-fifths of the river is shallow (less than 1m deep) and sluggish during the dry season, and some parts are very rocky. There are a number of deepwater areas that are 2–7m deep and 30–40m wide during the dry season, however, probably becoming more than 10m deep and 40–50m wide in the wet season. The Stoeng Kep flows in a southwesterly direction towards the Stoeng Tatai, and meanders between the mountains. There is a rich and diverse wildlife in this area, including wild pig, gaur, deer, bear, common and water monitor lizards, primates, egrets, wreathed hornbills and eagles. There are many fish and soft-shell turtles in the water, and numerous invertebrates such as bees, ‘prout’, ‘mroum’ and leeches. Stoeng Kep gives attractive views, with the high mountain range around it and the various types of fresh, green forest cover. There are waterfalls along the river that have potential tourism and aesthetic value.

2.5.2

Methods

Two surveys were carried out, covering a total of 70km. The first was from 21 February to 3 March 2002 and led by Em Phal and Tan Thara, with assistance from Thap Sary (a teacher at Thmar Baing), Usophea (a armed ranger from the DFW-CI Cardamom Conservation Program at Thmar Baing), Pao Sea and Dy Chann (hunters from Thmar Baing district centre). The second survey was conducted from 21–24 March 2002 and was led by Hor Leng and Em Phal, with assistance from Thap Sary, Pao Sea, and two porters, Trann and Soth, both from Thmar Baing. Both parties searched for crocodile faeces, which were measured and collected for analysis, and tracks, which were measured to estimate the size of the crocodile. Most of the survey was carried out on foot, but we constructed a bamboo raft to survey some parts where the river was deep enough. 1

The long history of human settlement along this part of the river might account for the species’ apparent scarcity here. The Russei Chrum community was part of the O’Som Commune, however, and the people traditionally shared the same cultural respect for crocodiles. If crocodiles have been killed here, it is most likely by newcomers to the area, such as soldiers or yellow vine harvesters.

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In addition, during their survey of the Stoeng Tatai (section 2.6), Sonn Pisith and Poeung Mora travelled along part of the Stoeng Kep, downstream of where it is joined by the Stoeng Tatai.

2.5.3

Results

Through this research, we identified three possible crocodile areas, two of which were confirmed: 2.5.3.1 Upper Kep We obtained proof of crocodiles along a deep part of the upper river, spanning 11km from approximately 11o46’58”N, 103o25’41”E (03287E, 13030N) to 11o45’05”N, 103o23’34”E (03249E, 12996N). 11 dung samples were collected (maximum diameter 20mm, 25mm, 30mm, 20mm and 48mm), indicating that large crocodiles were present. One set of tracks was measured on 21 March (total hand width 12.5cm; total foot width 9.6cm; total foot length 16cm). An adult crocodile (head length approximately 40cm) was seen at 13:15. A second crocodile of approximately 2.5m total length was seen ‘floating’ in the river at 15:20. This area includes the site identified by J. Daltry and Chheang D. in 2000. 2.5.3.2 Middle Kep Em Phal and Hor Leng identified a deep part of the lower river spanning 2km from approximately 11o41’23”N, 103o19’02”E (03166E, 12928N) to 11o40’49”N, 103o18’54”E (03163E, 12917N) where crocodiles may be present. Local inhabitants reported seeing crocodiles here in 2001 (but these verbal records are not shown on our maps). 2.5.3.3 Lower Kep Sonn Pisith and Poeung Mora discovered two large tracks (one forefoot print was 11cm x 13cm) on patches of sand among rocks.

2.5.4

Discussion

Even reaching the Stoeng Kep survey area is difficult. Motorbike transport could be used from Thmar Baing along roads made by logging concessionaires, but only for part of the way. Other problems faced by the survey team - and any potential poachers - in working here included the dense forest understory full of thorny plants, lack of space to walk along the high and steep riverbank, lack of a boat, and many annoying insects. According to the findings of this survey and the geography of this area, Stoeng Kep appears highly suitable for supporting large numbers of crocodiles. Of particular interest was a deepwater area in the Upper Kep where crocodiles have reportedly lived for many years and could increase if not threatened by hunting or other human activities. We recommend that DFW should collaborate with FFI and other agencies to formulate a mutual strategic conservation plan for Stoeng Kep as a priority area for crocodiles. It is important to ensure the information in this report does not fall into crocodile traders’ hands. We also ask other concerned

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countries to contribute grants to the Cambodian Crocodile Conservation Programme. This species is now seriously threatened by human beings.

2.6

STOENG TATAI AND STOENG TOUCH

By Poeung Mora and Sonn Pisith

2.6.1

Introduction

The Stoeng Tatai is another major river through the hill evergreen forests of the Central and Southern Cardamom Mountains, descending from over 600m a.s.l. to below 200m a.s.l., where it joins the Stoeng Kep. The Stoeng Tatai flows through two districts: Thmar Baing District and Koh Kong District, Koh Kong Province, located east of Koh Kong provincial town. This river has a number of tributaries, and passes through dense forest. Along the riverbank is exposed granite interspersed with stretches of sandy silt. In the wet season, the Stoeng Tatai becomes 5-15m deep. In the dry season, the level drops considerably, although in some deepwater parts the water maintains a depth of 1-8m. This includes at least one deepwater area similar to Anlong L’Ang (section 2.3), where the river is 20-25m across. The Stoeng Tatai also includes an area of marshland on the floodplain. The Stoeng Touch is an important tributary to this river. Much of it is shallow and rocky during the dry season, but we discovered one area that was over 2m deep. Many species of wildlife are found here, owing to the rich forest growth along the riverbank. Twenty years ago, Koh Kong was known as one of the most richly forested provinces with abundant wildlife, but unfortunately, humans are invading it now. This invasion is causing a remarkable decrease in natural resources in the province year by year.

2.6.2

Methods

88km of the Tatai and lesser tributaries, and 10km of the Stoeng Touch were surveyed, largely on foot, between 21 February to 2 March by Poeung Mora, Sonn Pisith and the staff members of the Cardamom Conservation Program, together with the close cooperation with the local communities. Through interviews and field study, our task force observed and studied the geography of the Stoeng Tatai, and other tributaries along the river as follows: •

Upper Stoeng Tatai/ Stoeng Dach): On February 22, 2002, from UTM 03411E, 13076N to 03460E, 13120N at an altitude of 490–664m. The river here varies in width from 15–50m and in depth from 2–5m. There is dense forest and sandy silt on the riverbank.



Middle Stoeng Tatai/ Stoeng Puoch: On February 23–25, 2002, from 03386E, 13060N to 03291E, 12923N, at an altitude of 360-430m. The river width here varies from 15-50m, and depth from 1–6m. There is semi-dense forest, inundated forest and sparse forest, alluvial soil, sandy silt, and part of the riverbank is exposed to sunlight.



Stoeng Touch: On February 26, 2002, from 03306E, 12940N to 03351E, 12963N, at an altitude of 400–430m. The river varies in width from 15–20m and depth from 1–3m. There is semi-dense forest with a lot of dead wood and tree branches falling into the river, reeds, rattan, sandy soil, alluvial silt, and many wildlife for prey (including fish, snakes and mice) and insects.

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Lower Stoeng Tatai: On February 27, 2002, from 03018E, 12818N to 03198E, 12728N, at an altitude of 35-220m. Deeper parts of the river here are 1-10m deep and 10-40m wide in the dry season (50-100m in the wet season). In the middle of the river, there are many large stones. There is dense forest on the riverbank. Particularly, at an altitude of 200-220m, some parts of the river are 5-8m, and 30-40m wide, with alluvial soil, sands, ‘salty soil’, exposure to sunlight, and a lot of wildlife for prey, including fish, snakes and other creatures. These areas are difficult for humans to reach.

2.6.3

Results

Four key crocodile areas were found: 2.6.3.1 Lower Stoeng Tatai Approximately 12km upstream (East) of the confluence with the Stoeng Kep. Five dung piles and tracks were found on sandy banks and beaches. After observing and studying the condition and location of the footprints and faeces in the above locations, the task force concludes that there are approximately five crocodiles here. Further west (downstream) towards the Kep, the river is too shallow for crocodiles. 2.6.3.2 Middle Stoeng Tatai Parts of the river here pass due south through a marshy floodplain at c. 400m a.s.l. which could provide good nesting habitat. We gathered six reports of crocodiles here, including a crocodile caught on a hook in 2001, and another seen in January 2002. In 1993, there were crocodile holes dug 4–5m in length with an internal floor area of 1 x 4m. The river here is 3–4m deep and 15–20m wide. 2.5km downstream, a track was found on sand, near where the Tatai is joined by the Stoeng Touch, where the water was 3-3.5m deep, and 25-30m wide. The people of Chamkar Chrey reported seeing crocs in two places near this ancient village, but during the rainy season only (the water here drops below 1m deep in the dry season). The last time a crocodile was seen near that village was the 2000 rainy season. A short distance downstream of the Stoeng Tatai/ Touch confluence, near Thmar Baing district town, a crocodile hole was found in the riverbank. Local people reported that two crocodiles live here, but one was killed in 2001 (the skin and skull of this animal was examined and found to be an sub-adult Siamese crocodile of 1m snoutvent length). The hole was 80cm high, 50cm wide and 3m deep. The entrance was slightly submerged even during the dry season, but the burrow floor was dry inside. After observing and studying the footprints, faeces and condition of the crocodile holes at the above location, the task force concludes that there are approximately four crocodiles in the middle Tatai area, but it was rumoured that there were from 30 to 50 crocodiles here in 1990. 2.6.3.3 Stoeng Touch Even though we spent only one day here, four piles of dung and four tracks were found, and a 2-m crocodile was seen nearby. A crocodile was reportedly seen eating a wild pig in the same area. Based on our evidence in the field, we conclude that there are at least seven crocodiles in this area.

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According to information from people living in this area, baby crocodiles gather here during the breeding season. 2.6.3.4 Upper Tatai - Stoeng Dach This is one of the higher tributaries. A crocodile track and one pile of dung were found on sand around the deepwater area of the Stoeng Touch. The recorded elevation was 600m a.s.l. and the river was 3-4m deep at this point. This area is upstream of the Tatai Leu village. The track and dung appeared to be from two different crocodiles. A crocodile was reportedly killed in a faster flowing section of the river nearby in 2000 (the interviewee said that ‘the three people who killed the crocodile all died two days later’!).

2.6.4

Discussion

We covered almost 100km in 10 days, so were not able to spend much time in each place. Nevertheless, we found definite proof of crocodiles in four main areas. Interviewees in Chamkar Chray estimated that there are around 25 crocodiles in whole Tatai/ Touch system. Based on the hard evidence of tracks and signs, we infer there are at least 18 present, including 7 in the Stoeng Touch and 11 in the Stoeng Tatai. We found crocodiles at the highest elevation known thus far: 600m a.s.l. in the Doch headwaters of the Stoeng Tatai. The Stoeng Touch site is also of interest as a possible breeding site, because juveniles were reported here. It is very close to the village of Chamkar Chray. Threats to crocodiles in this area include: • • • •

2.7

Anarchic deforestation is causing negative effects to the ecological system and loss of forest cover. This will pose problems for human society as well as wildlife. Illegal trafficking in wildlife, particularly crocodiles, use of explosive materials and electrocution, and forest encroachment. Wildlife trafficking to meet the demand in foreign countries and domestically. High market price for crocodiles.

STOENG SALA MUNTHUN

By Hor Leng and Em Phal

2.7.1

Introduction

We travelled to the Stoeng Sala Munthun via Thmar Baing district centre, Koh Kong province. There are dense evergreen forests along both sides of the river, and a road follows the river valley between the mountains. According to interviews and our own observations, the river can become 15–20m wide during the wet season and flows very fast. In the dry season, on the other hand, the river is only 7– 12m wide and generally 1.5–3m deep. In some places, the water moves very slowly between rocks. The Stoeng Sala Munthun flows into Stoeng Tatai, and onwards to the sea.

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2.7.2

Methods

The survey was led by Hor Leng and Em Phal, with assistance from Khouk Siphan, Khouk Sophea (Cardamom Conservation Project, Thmar Baing), Pao Sea (a hunter from Thmar Baing village), and two porters, Tren and Soth. We interviewed villagers at Daung who fish, harvest vine and hunt along the river, and surveyed the Stoeng Sala Munthun on foot to find crocodile signs. 23km of the river were surveyed. We classed the status of the river as follows: • • • • • •

From 03129E, 13029N to 03126E, 13028N the river is 0.8-3m deep. From 03126E, 13028N to 03120E, 13016N is a deepwater area called Anlong Vil. From 03120E, 13016N to 030111E, 13000N is a road for transporting timber across the river (area called Chay Khie), but this was abandoned last year. From 030111E, 13000N to 03110E, 12997N are rapids (‘chay’). From 03110E, 12997N to 03097E, 12985N the water is 1–2. 5m deep. From 03097E, 12985N to 02999E, 12934N the water is shallow, with exposed rocks.

2.7.3

Results

During the four-day survey, our team did not see any tracks, paths or other signs of crocodiles.

2.7.4

Discussion

According to local reports and the available habitat, we are sure that crocodiles used to live in this area. None were seen during this survey, however, and they appear to be either rare or absent here. We suspect this may be linked to people collecting yellow vine and krasna (eaglewood: Aquilaria crassna) in this area in the past few years. The upper Stoeng Sala Munthun is easily reached by the road connecting Koh Kong town to O’Som Commune, Pursat province: the road follows the river for some distance. People may also be fishing with explosives here, and a new yellow vine factory was established in 2001 on the upper river at 03120E, 13015N, which may have poured poisonous waste into the river. Thick, thorny forest on its banks made it difficult to investigate the bank thoroughly for signs of crocodiles, however. Survey work was also affected by heavy rain, which may have washed crocodile tracks or faeces away. It is therefore possible that some crocodiles were overlooked. We wish that other countries in the world and donors who are concerned about wildlife conservation would contribute grants to this survey programme for crocodile protection and conservation, because crocodiles are seriously threatened by human beings.

2.8

STOENG ARENG

By Sam Han, Chheang Dany and Jenny C. Daltry

2.8.1

Introduction

Siamese crocodiles were first confirmed in Stoeng Areng by Darren Cormack, a volunteer with Conservation International. During a survey for large mammals, three adult crocodiles were phototrapped on a forest trail beside the river in January and February 2002. - 25 -

The Areng is one of the largest rivers in the Cardamom Mountains. This survey covered the upper Stoeng Areng from 11o46’15”N, 103o38’13”E (03515E, 13016N) at 200m a.s.l. downstream to 11o35’35”N, 103o28’39”E (03340E, 12820N), at 110m a.s.l. Fed by tributaries in the eastern Central Cardamom Mountains, this river is relatively slow flowing. Much of the river examined in this survey meanders through a wide, sandy floodplain. Of particular interest is the 10km stretch between the newly established Prek Svay or Areng village (11o37’39”N, 103o32’7”E; 03403E, 12858N) and the Chumnoap village crossing (03477E, 12880N). Here, the river is generally 2–3m deep during the dry season, with sandy beaches and sandbars that appear ideal for basking. The banks are well vegetated with grasses and forest. Upstream of the Chumnoap village crossing (to Chamna village), the river is much more shallow; generally less than 1m. There are several small oxbow lakes close to the river, including Ombot Thom at 11o37’57”N, 103o33’44”E (03433E, 12863N), Ombot Touch (03450E, 12874N), and Dombok (03441E, 12865N). Ombot Touch is an S-shaped lake approximately 40m long, 10m wide and 1.5m deep at its deepest point during the dry season. Further upstream is the Chamna wetland, where there is an abandoned village (Sra Khonh), large areas of abandoned paddy fields, and the Bung Yus or Chay Areng lake at 11o46’53”N, 103o39’20”E (03535E, 13027N). When this wetland was visited at the height of the dry season, only a few hectares of this marsh were flooded and the lake had become heavily silted up. We established a base camp at the Prek Svay village, which is situated in Thmar Baing District, Koh Kong Province, about 90km from Koh Kong provincial town. There are two overland routes to the village: (1) via a partially paved road from Koh Kong town to Thmar Baing district ‘town’, east of Areng, then a 25km track from Thmar Baing town to Prek Svay village, which can be travelled by motorbike or buffalo cart; (2) via a dirt road from Chi Phat town, south of Areng, also in Thmar Baing District. Although Prek Svay village is a new settlement (since the late 1990s), people have lived around this part of the Stoeng Areng for centuries. Stretched along the floodplain to the west of the river are the villages of Triet, Chumnoap, Chrak Russei, Pralay, Samraong, Tangel and Chamna. There are large expanses of ancient farmland around the villages, and much of the forest near the river has been selectively logged, but retains a dense canopy. Most of the inhabitants of Prek Svay were from these older villagers or the abandoned village of Russei Chrum (section 2.4). Together, these Areng villages constitute the Thma Doen Poa Commune.

2.8.2

Methods

A total of 53km of the Stoeng Areng and the Prek Spean Kaa tributary was surveyed. Most of the work in this report was carried out by Jenny Daltry and Sam Han from 20 February to 2 March 2002, assisted by Ven Savouen (Cardamom Conservation Program). We found that Fisherman Lum, a Vietnamese resident of the new Prek Svay village, had developed an in-depth knowledge of the crocodiles’ distribution during the dry season. To validate his reports, however, we travelled by boat and on foot along the river several times by day and night, documenting all sightings and sign. Even during the dry season, the river was navigable by boat from Prek Svay Village to the Chumnoap crossing.

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As well as surveying the main river, we travelled on foot to survey the oxbow lakes Ombot Thom, Ombot Touch and Dombok. We also visited an unnamed lake east of the river at 11o41’04”N, 103o37’42”E (03357E, 12921N) with guide Sok Mom from Samraong village, and surveyed the Chay Areng lake in Chamna wetland on 1 March. We also travelled downstream of Prek Svay village, to survey the deepwater part of the Stoeng Areng known as Anlong Kbal Touk (03349E, 12823N), a small pond near the ford (03357E, 12830N), and the Spean Kaa tributary up to a deepwater area called Teuk Noeung (‘Still Water’) at 11o35’58”N, 103o28’48”E (03343E, 12827N). Our guide, Pik Khom, claimed to have seen crocodiles in all these areas during the 2001 wet season while he was hunting for dragonfish. Between 22 and 28 March 2002, Jenny Daltry, Chheang Dany, Sonn Pisith, Sam Han and Brady Barr made additional visits to this area during filming for a National Geographic programme.

2.8.3

Results

2.8.3.1 Upper Stoeng Areng This survey confirmed the presence of crocodiles in the deeper (>1.5m) sections of the river during the dry season, between Prek Svay village and the Chumnoap crossing. Within this area, we found large numbers of crocodile trails on the sandy banks. Three different crocodiles were seen at night, but were extremely wary and could not be approached by boat. Further upstream, the river appeared to be too shallow to support crocodiles during the dry season. Because the sandy banks of the Stoeng Areng provided an excellent substrate for preserving tracks, these sign were used as the basis for calculating minimum population size. 34 clear tracks were found along the Stoeng Areng (Table 2.2). Forefoot tracks ranged in width (THW) from