THIS REPORT HAS BEEN PRODUCED IN 100% COLLABORATION Status of Tigers in Sundarban Biosphere Reserve RECYCLED WITH: ® 24-Parganas (South) Forest Division, West Bengal, India WWF STATUS OF TIGERS IN REPORT IND 2013 982.56 sq km SUNDARBAN BIOSPHERE RESERVE, 24-PARGANAS (SOUTH) FOREST DIVISION +20 STUDY AREA TIGERS Status of Tigers in Sundarban Biosphere Reserve 24-Parganas (South) Forest Division, West Bengal, India , WEST BENGAL, INDIA +1080 1682 sq km WORK DAYS TO COMPLETE AREA OF 24-PARGANAS (SOUTH) THE STUDY FOREST DIVISION I N D This report was printed on 100% recycled paper, in order to reduce the ecological impact and minimise paper wastage. w w f i Why we are here. n To stop the degradation of the planet’s natural environment and d i to build a future in which humans live in harmony with nature. a . www.wwfindia.org o r g WWF-India, 172 B Lodhi Estate, New Delhi 110 003, India Tel. +91 11 4361 6248 Fax. +91 11 4150 4779. For contact details and further information, please visit our website at www.wwfindia.org SUBHRO SEN Status of Tigers in Sundarban Biosphere Reserve 24-Parganas (South) Forest Division, West Bengal, India Authors Sunit Kumar Das, Pankaj Kumar Sarkar, Ratul Saha, Pradeep Vyas, A. Anurag Danda and Joseph Vattakavan Citation Das, S. K., Sarkar, P. K., Saha, R., Vyas, P., Danda, A. A., and Vattakavan, J. (2012). Status of Tigers in Sundarban Biosphere Reserve, 24-Parganas (South) Forest Division, West Bengal, India. World Wide Fund for Nature-India, New Delhi. Cover Photo Pradeep Vyas Maps Abhijit Choudhury Illustrations Arnab Roy Processing & Printing YES Revised Edition, February 2013 © WWF-India, 2013 Status of Tigers in Sundarban Biosphere Reserve 24-Parganas (South) Forest Division, West Bengal, India PREFACE Despite multiple challenges and demands on its resources, India's efforts to preserve its wildlife and its tigers are exemplary; yet, tigers remain in a precarious existence in India. Faced with threats of habitat loss and organised poaching, tiger populations need scientific monitoring, protection and trans-boundary cooperation among other things to ensure their long term survival. In this context, 'Status of Tigers in Sundarban Biosphere Reserve: 24-Parganas (South) Forest Division' is an important publication that looks into the development of a landscape specific tiger monitoring protocol. It is the first such publication from the Sundarbans. Sundarbans is an important biodiversity area that spans across India and Bangladesh, well known for its unique and rich variety of flora and fauna as well as the scenic landscapes. Parts of Sundarbans in the two countries are listed as World Heritage Sites by UNESCO, underlining their importance as conservation landscapes. The Sundarbans is also the only mangrove habitat in the world to be home to tigers. This report provides an overview of the first tiger monitoring study undertaken outside the Sundarban Tiger Reserve using camera traps and the resultant tiger population estimate. Besides tigers, the study has also highlighted the presence of other felids such as fishing cat, jungle cat, leopard cat, and possibly the first reported melanisitic leopard cat. It also looks at the challenges facing the Sundarbans. I hope that this report will highlight the critical importance of scientific monitoring for better management of our wildlife. The efforts of the Sundarban Biosphere Reserve Directorate in putting in place the framework of cooperation between state and other partner entities are to be highly commended. Their success, as evidenced by this report’s contents and progress in the field, I hope will spur trans-boundary cooperative efforts, between India and Bangladesh. For it is only through such concerted efforts that our Protected Areas and the incredible diversity of flora and fauna they harbour, will find a safe and secure future and continue to thrive in the years to come. Our thanks go out to all those who have helped put this study together; to those who care and support the cause of the tiger and its habitat. Ravi Singh Secretary General and CEO WWF-India ii PRADEEP VYAS iii ACKNOWLEDGEMENTS This exercise is supported by WWF-Sweden. We are grateful to Mr. S.B. Mondal, PCCF & Chief Wildlife Warden, West Bengal, Mr. Samir Chandra Pal, ADFO and Mr. Ashis Mondal, RFO: 24 Parganas (South) Forest Division for the collaboration and logistic support. Despite time constraints Dr. Somenath Bhattacharyya and Dr. Kakoli Sen Sarma, Institute of Environmental Studies and Wetland Management (IESWM) extended technical support in terms of chemical analysis of soil and water samples from all the camera trap stations as a contribution to this project. We are also grateful to the Director of IESWM, Mr. Arijit Banerjee for the whole hearted cooperation extended to the project. We would like to thank the following Forest Department personnel in carrying out the study successfully. Ramganga Range: Arup Kumar Maity (Forest Guard), Phonibhusan Maity (Forest Guard), Tapas Kumar Maity (Forest Guard), and Bhagirath Singh (Forest Guard) Raidighi Range: Uttam Biswas (Deputy Ranger), Braja Nath Halder (Forest Guard), Subal Mondal (Boatman), Dilip Kumar Ganguli (Forest Guard), Dulal Mondal (Banshramik), Dibakar Das (Majhi), Madan Mohan Das (Forest Guard), Prithvi Raj Maity (Forest Guard) Baruipur Range: Abu Jafar Molla (Forest Guard), Mujibar Rahaman Molla (Forest Guard), Joydeb Adhikari (Forest Guard) Matla Range: Kajal Biswas (Beat Officer), Paresh Kulu (Banshramik), Monu Patra (Banshramik) We would also like to thank the boat crew of MB Sundari, Sreedham Gayen, Ishwar Chandra Shaw, Dinanath Mondal and Ananta Mondal for their excellent services and on board hospitality. Abishek Harihar and Dr. Jimmy Borah reviewed the report at very short notice for which we are grateful. Their comments have strengthened this report. Special thanks are due to Dr. Bivash Pandav for his initial encouragement and guidance to undertake tiger monitoring study in the Sundarbans. Last but not the least, we remain grateful to Mr. Ravi Singh, SG & CEO, WWF-India; Dr. Sejal Worah, Programme Director, WWF-India; and Dr. Dipankar Ghose, Director, Species and Landscapes Programme, WWF-India for their inputs. iv CONTENTS Preface ii Acknowledgements iv Executive Summary vi Executive Summary in Bangla vii 1. INTRODUCTION 1 1.1 Indian Sundarbans 1 1.2 Tiger estimation in Sundarbans 2 2. STUDY AREA 5 2.1 Location 5 2.2 Physical features 6 2.3 Flora 8 2.4 Fauna 9 2.5 Human population 9 3. METHOD 10 3.1 Pre-field work 10 3.2 Reconnaissance survey 10 3.3 Data collection 13 3.4 Analytical details 14 3.4.1 Mark-Recapture approach 14 3.4.2 Method for density estimation 14 4. RESULTS 17 4.1 Capture dynamics 17 4.2 New capture saturation 19 4.3 CloseTest and model selection 20 4.4 Tiger population (N-hat) 21 4.5 Tiger density (D-hat) 21 4.6 Activity pattern of tigers 22 4.7 Anthropogenic pressures 23 5. MANAGEMENT IMPLICATIONS 24 REFERENCES 25 ANNEXURES 27 A. List of birds sighted 27 B. Captures of tigers 29 C. Captures of other felids 34 D. Captures of other mammals 35 E. Captures of birds 36 F. Fringe villages adjoining the study area 37 EXECUTIVE SUMMARY The Sundarbans is the only mangrove forest in the world where the tiger is at the apex of the food chain. The Sundarbans ecosystem is subjected to variable salinity, periodic high tides and tidal inundations, occasional tidal surges and frequent flooding. The terrestrial fauna inhabiting this ecosystem is significantly different from their counterparts inhabiting other ecosystems. The tiger being an umbrella species, effective tiger conservation enhances survival prospects for other forms of biodiversity. Earlier tiger estimates in Sundarbans were based on pugmark methods, attacks on humans, interviews with local community, and radio telemetry based extrapolation. This study presents the findings of the first attempt to estimate the tiger population in the 24-Parganas (South) Forest Division of the Sundarban Biosphere Reserve using photographic capture-recapture analysis. As part of Phase-IV monitoring protocol to obtain minimum tiger numbers in the Indian Sundarbans, WWF-India in collaboration with the Sundarban Biosphere Reserve Directorate carried out the camera trapping study. This study used remotely triggered camera traps and the capture-recapture framework to estimate the minimum population and density of tigers in two ranges of 24-Parganas (South) Forest Division. A total of 41 camera trap pairs were used in two ranges to cover about 982.56 sq km area. A total sampling effort of 600 trap days (20 camera trap stations, each operating for 30 occasions) at Ramganga range yielded 28 photographs (both flanks) of tigers. In Raidighi range, a total sampling effort of 714 trap days (21 camera trap stations, each operating for 34 occasions) yielded 71 photographs (both flanks) of tigers. Population is estimated to be 8.0±0.2 (N-hat±SE) individuals for Ramganga range and 13±3.5 (N-hat±SE) individuals for Raidighi range. Tiger density is estimated as 4.3 individuals/100 sq km at Ramganga range with an effective trapping area of 184.5 sq km and 7.08 individuals/100 sq km at Raidighi range with an effective trapping area of 141.3 sq km. In MLSECR (Maximum Likelihood Spatially Explicit Capture Recapture) analysis, estimated tiger density was 3.8 (±SE 1.5) individuals/100 sq km for Ramganga range and 5.2 (±SE 1.7) individuals/100 sq km for Raidighi range. In addition to tigers, the study also photo captured cats viz. fishing cat, jungle cat and leopard cat, as well as prey and other species. Apart from this, melanistic leopard cat was also photo captured. It is the first photographic evidence of its presence in the Sundarbans. These results provide insights into the richness and diversity which imply that the 24-Parganas (South) Forest Division is a rich landscape.