The Distribution of Elephants, Tigers and Tiger Prey in Thailand’s Western Forest Complex A Dissertation SUBMITTED TO THE FACULTY OF UNIVERSITY OF MINNESOTA BY Pornkamol Jornburom IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY James L. David Smith, Adviser December 2016 © Pornkamol Jornburom, 2016 Acknowledgements This study is a part of collaborative work among Thailand’s Department of National Parks, Plant, and the Wildlife Conservation (DNP), the Wildlife Conservation Society (WCS, Thailand) and the World Wildlife Fund (WWF, Thailand) to conduct occupancy suveys in the western forest complex of Thailand. I am grateful with supports from DNP to conduct this research. I owe much to field crew who came from several organizations. I am particularly thankful for Mr. Somphot Duanchatrasiri, Mr. Krearkpon Wongchoo, and staff members at Khao Nang Rum Wildlife Research Station. I especially would like to thank WCS survey team: Sitthichai Jinamoy, Wittaya Teaktao, Don Roman, Kamol Faengbhupha, and Kwanchai Waitanyakan and WWF team: Rungnapa Phunchampa, Utai Dechyotdee, Worrapan Phumanee for their excellent jobs in the field despite resource and many challenges. Funding support for this project and my study were received from, the Rhino and Tiger Conservation Fund of the U.S. Fish and Wildlife Service, Liz Claiborne and Art Ortenberg Foundation (LCAOF), WCS graduate scholarship program, Hatch funding, ConsBio summer fellowship- the Conservation Biology Program at the University of Minnesota – Twin Cities, and Richard & Judi Huempfner Ruffed Grouse Fellowship. I am grateful with Professor James L. David Smith who served as an excellent adviser and fully supported my academic and research undertaking. I cannot thank you enough for accepting me into Conservation Biology Graduate Program at University of Minnesota. I am also deeply thankful to him for being patient reviewing and made constructive comments for my dissertation. I feel so gratified to have Professor Todd W. i Arnold, Assistant Professor John Fieberg, and James E. Hines as committee members. I appreciate their guidance regarding data analysis and all consistent support. I am sincerely grateful to all my committees for suggestions and insightful comments which improve my manuscripts and dissertation. In addition, I appreciate Professor Francesca J. Cuthbert for valuable comments for bringing this manuscript in this shape. I consider myself fortunate to have met, studied and worked with Dr. Anak Pattanavibool the Director of Wildlife Conservation Society-Thailand Program, who has supported me from the beginning of my career. I would like to thank him for believing in me, I cannot put into words how grateful I am to cover half of his supports. I benefited greatly from the friendship of my colleague graduate students: Fabiola Iannarilli, Lorraine Scotson, Josh Egan, Diele Lobo, Dr. Worata Klinsawat, Dr, Andrea Claassen, and Hannah Spcth, for their encouragement and suggestion on preliminary exams and data analysis. Also, I am grateful to all Thai friends in Minnesota and in Thailand for always being there for me. Finally, I thank my amazing family, especially my parents, sister, brothers and my grandmother for their love and supports. Anything I have accomplished could not have been possible without them. My deepest appreciation goes to Shaurav Raj Adhikai who helped me throughout the process which was, at times, difficult and frustrating. I am glad to have you as my partner in crime through all the good and the bad times. My greatest appreciation and admiration goes to His Majesty King Bhumibol Adulyadej (Rama IX) as a role model of moral merit and perseverance to sustain and protect the nation’s environment and natural resources. His Majesty will live in my heart eternally. ii Dedication For wildlife And those who cannot live without wild things iii Abstract Conservation of large mammals such as Asian elephants (Elephas maximus), tigers (Panthera tigris) and their main prey, gaur (Bos gaurus), banteng (Bos javanicus), and sambar (Cervus unicolor) requires a systematic and statistically rigorous monitoring system that accounts for imperfect detection. Despite conservation efforts, these large mammals are highly threatened and declining across their entire range. In Thailand, large viable populations of these large mammals remain in the Western Forest Complex (WEFCOM), an approximately 19,000 km2 landscape of 17 contiguous protected areas. To determine species distribution and factors that affect distribution patterns, a government/NGO team conducted occupancy surveys throughout the WEFCOM landscape from 2010-1012. I analyzed these data at both a landscape scale (256 km2 for elephants, 64 km2 for tigers and their prey) and a local scale (1 km2). At the landscape scale, I estimated the proportion of sites occupied by each species. At a finer scale, I identified the key variables that influence site-use and developed predictive distribution maps. At both scales, I examined key ecological and anthropogenic factors that help explain distribution and preferred habitat use. Occupancy models revealed that elephant, gaur and sambar avoided villages and elephants, banteng and sambar prefered lower slopes near streams. Gaur, in contrast, preferred steep slopes at higher elevation. I estimated that elephants occupied 82% of the the landscape. Other species occupied much smaller portions of WEFCOM (tigers = 37%, gaur = 48%, sambar 53% and banteng 13%). Tiger occupancy was largely influenced by the three large prey species. Additionally, presence of villages has a consistent negative impact on occupancy and iv site-use by all these large mammals; therefore, reducing the impact of human activities near villages is the key conservation recommendation from this study. By modeling occupancy while accounting for probability of detection, I established reliable benchmark data on distribution of these endangered species. The results of this study underlined the need for further conservation and management to maintain wildlife distribution and populations in WEFCOM and other sites in Thailand and Southeast Asia. v Table of Contents List of Tables……………………………………………………………………………viii List of Figures……………………………………………………………………………x Chapter 1 - Two-scale Occupancy models for Conserving Asian Elephant in Thailand’s Western Forest complex Introduction………………………………………………………………………..1 Methods……………………………………………………………………………5 Results……………………………………………………………………….…...17 Discussion…...…………………………………………………………………...27 Conservation and Management Implications……………….…………………....30 Chapter 2 - Occupancy and Site Use of Tiger Prey in Thailand’s Western Forest Complex Introduction……………………………………………………………………....32 Methods…………………………………………………………………………..39 Results…………………………………………………………………………....50 Discussion…...…………………………………………………………………...69 Methodological issues……………………...……………….…………………....72 Chapter 3 - Impact of Prey Occupancy and Other Ecological and Anthropogenic Factors on Tiger Distribution in Thailand’s Western Forest Complex Introduction……………………………………………………………………....75 Methods…………………………………………………………………………..83 Results………………………………………………………………………........94 vi Discussion…...………………………………………………….……………....105 Conservation and Management Implications……………….…………………..108 Bibliography…………………………………………………………………………123 Appendix……………………………………………………………………………..141 vii List of Tables Table 1.1 Summary of the field occupancy survey effort for each protected area in the Western Forest Complex (WEFCOM), Thailand. October 2010 - December 2012……..7 Table 1.2 List of factors hypothesized to influence patterns of occupancy (256 km2), use (1 km2) and detection probability of elephant in Western Forest Complex (WEFCOM), Thailand………………………………………………………………………………..13 2 Table 1.3. Model selection results of occupancy estimates at 256 km -scale (휓256) and 1 2 km -scale (휓1) for elephant based on ΔAIC <2 and estimates of untransformed 훽 coefficient values (standard errors, SE)………………………………………………….20 Table 2.1 Summary of the field occupancy survey effort for each protected area in the Western Forest Complex (WEFCOM), Thailand, Octoer 2010 - December 2012……...37 Table 2.2 List of factors hypothesized to influence patterns of occupancy (64 km2), use (1 km2) and detection probability at both scales of tiger prey in Western Forest Complex (WEFCOM), Thailand…………………………………………………………...………56 Table 2.3. Model-averaged estimates of tiger prey occupancy at 64 km2 and 1 km2 scale based on Hines et al. (2010) model, which incorporates spatial auto-correlation of sign detections (WEFCOM, Thailand, 2010-2012)…………………………...………………51 Table 2.4 Predictor variables used to include in all models for adequately describing variation in occupancy probability (휓) so that variation in 휓 would not be incorrectly interpreted as variation in detection probability (푝) at 64-km2 -scale…………………...52 viii 2 Table 2.5 Model selection results of occupancy estimates at 64 km -scale (휓64) for tiger prey based on ΔAIC <2 and estimates of untransformed 훽 coefficient values (standard errors, SE). Occupancy survey data conducted in WEFCOM, Thailand, 2010-2012 …..55 Table 2.6 Predictor variables used as a global occupancy model to evaluate covariates influencing detection for each species at 1-km2 scale…………………………………...63 Table 2.7 Most predictive models of site occupancy estimates (휓1) for focal tiger prey species as determined by Akaike’s Information Criterion (ΔAIC) <2 and estimates of untransformed 훽 coefficient values (standard errors, SE) based on occupancy survey