Ecology and Extinction of Southeast Asia's Megafauna

ECOLOGY AND EXTINCTION OF SOUTHEAST ASIA’S MEGAFAUNA JULIEN LOUYS Thesis submitted in fulfillment of the requirements for the degree of Doctor of Philosophy in the School of Biological, Earth and Environmental Sciences University of New South Wales Sydney, Australia December 2007 THE UNIVERSITY OF NEW SOUTH WALES Thesis/Dissertation Sheet Surname or Family name: Louys First name: Julien Other name/s: Claude Alexandre Abbreviation for degree as given in the University calendar: PhD School: Biological, Earth and Environmental Sciences Faculty: Science Title: Ecology and Extinction of Southeast Asia’s Megafauna Abstract 350 words maximum: (PLEASE TYPE) The Quaternary megafauna of Southeast Asia are among the world’s poorest known. Throughout the Pleistocene, continental collisions, active volcanic systems and fluctuations in sea level have had dramatic effects on the region’s geography, from southern China to Indonesia. Many Southeast Asian megafauna experienced geographical range reduction or complete extinction during that interval. This thesis explores the relative influence of environmental change and human interaction in these extinctions. There is currently no direct evidence to suggest that humans had a negative impact on Southeast Asian megafauna until the Holocene. Rather, extinctions and geographical range reduction experienced by megafauna are likely to have resulted from of loss of suitable habitats, in particular the loss of more open habitats. Environmental change throughout the Pleistocene of Southeast Asia is reconstructed on the basis of discriminant functions analysis of megafauna from twenty-seven Southeast Asian Quaternary sites, as well as Gongwangling, an early Pleistocene hominin site previously interpreted as paleoarctic. The discriminant functions were defined on the basis of species lists drawn from modern Asian nature reserves and national parks, and were analysed using both taxonomic and phylogeny-free variables. Biases present in these species lists were mitigated against using a range of mulitvariate techniques. The reconstructions show that Pleistocene environments in Southeast Asia varied from open (e.g. savannah), mixed (woodland) and closed (e.g. rainforest) habitats. Changes in habitats through time are likely to have been driven, at least in part, by changes in sea-level, in turn related to oscillations between glacial and interglacial conditions. The environmental changes associated with these oscillations are likely to have adversely affected many of Southeast Asia’s megafauna. The Toba super-eruption (~74kya) is unlikely to have been responsible for any of the megafauna extinctions of the Late Pleistocene. Declaration relating to disposition of project thesis/dissertation I hereby grant to the University of New South Wales or its agents the right to archive and to make available my thesis or dissertation in whole or in part in the University libraries in all forms of media, now or here after known, subject to the provisions of the Copyright Act 1968. I retain all property rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation. I also authorise University Microfilms to use the 350 word abstract of my thesis in Dissertation Abstracts International (this is applicable to doctoral theses only). …………………………………………………………… ……………………………………..……………… ……….……………………...…….… Signature Witness Date The University recognises that there may be exceptional circumstances requiring restrictions on copying or conditions on use. Requests for restriction for a period of up to 2 years must be made in writing. Requests for a longer period of restriction may be considered in exceptional circumstances and require the approval of the Dean of Graduate Research. FOR OFFICE USE ONLY Date of completion of requirements for Award: THIS SHEET IS TO BE GLUED TO THE INSIDE FRONT COVER OF THE THESIS ii ORIGINALITY STATEMENT ‘I hereby declare that this submission is my own work and to the best of my knowledge it contains no materials previously published or written by another person, or substantial proportions of material which have been accepted for the award of any other degree or diploma at UNSW or any other educational institution, except where due acknowledgement is made in the thesis. Any contribution made to the research by others, with whom I have worked at UNSW or elsewhere, is explicitly acknowledged in the thesis. I also declare that the intellectual content of this thesis is the product of my own work, except to the extent that assistance from others in the project's design and conception or in style, presentation and linguistic expression is acknowledged.’ Signed …………………………………………….............. Date …………………………………………….............. iii To my parents Pierre and Chantal Louys who provided boundless inspiration, moral and financial support iv Acknowledgments This thesis could not have been completed without the support and encouragement of many people. I would firstly like to thank my supervisors Mike Archer and Darren Curnoe, and my co-supervisor Sue Hand, who gave me the complete freedom to pursue whatever topic interested me, and to construct this thesis on my own terms. Many thanks to them for helpful discussions, critical readings and support provided from initial conception to finished product. A special thanks to Darren, who initially took me on, supported my move back to BEES, and helped finance my data collection trip. Many people have provided support, inspiration, helpful comments, reviews and discussions on the various ideas, papers and chapters produced throughout this thesis, including anonymous reviewers, Mina Bassarova, Robin Beck, Pip Brewer, Andy Coate, Darren Curnoe, Henk Godthelp, Yamila Gurovich, Sue Hand, Andy Herries, Scott Hocknull, Pierre Louys, Geoff Mulhearn, Gilbert Price, Jim Rose, Rachael Tomlins, Haowen Tong, Kenny Travouillon, John de Vos, Vera Weisbecker, Jolee West and Steve Wroe. Many thanks to Guillaume Louys and Kenny Travouillon for providing much needed assistance in generating the various figures; and to Diane Louys for her boundless enthusiasm in tackling all the tedious formatting chores I put to her. I thank the staff at the Museum of Natural History, Leiden (Naturalis), in particular John de Vos and Reiner van Zelst, for kindly hosting me, and making my trip to Holland so enjoyable. I also thank the staff at the Institute of Vertebrate Palaeontology and v Palaeoanthropology, Beijing for their kind hospitality, in particular Haowen Tong for his welcome and constant support during my time in China. The time spent working on this project would have been much duller had it not been for the students and friends in both the Biological Anthropology (Andy Coate, Hayley Green, Andy Herries, Diana Neuweger) and Vertebrate Palaeontology (Rick Arena, Mina Bassarova, Hayley Bates, Robin Beck, Karen Black, Pip Brewer, Kirstin Crosby, Anna Gillespie, Yamila Gurovich, Zac Kirkham, Karen Marino, Jackie Nguyen, Liz Price, Karen Roberts, Kenny Travouillon, Vera Weisbecker, Steve Wroe) Labs, in particular Robin and Kenny. Thanks guys. And finally, I wish to thank my family; my brothers Guillaume and Greg, my sister Diane, my sister-in-law Trinette and my parents Pierre and Chantal. If it wasn’t for their constant financial, moral, and emotional support throughout my many years of study, none of this would have been possible. vi Table of Contents 1. Introduction 1 1.1 Background 1 1.2 Aims 5 1.3 Specific objectives 5 1.4 Chapter outline 6 1.5 A note on the nature of the chapters 8 Part 1. Extinction 10 2. Characteristics of Pleistocene megafauna Extinctions in Southeast Asia 11 2.1 Abstract 11 2.2 Introduction 12 2.3 Methodology 13 2.4 Results and Discussion 15 2.4.1 Indochinese province 16 2.4.2 Sundaic Province 29 2.4.3 Taxa 37 2.4.4 Influence of humans in the region 46 2.4.5 Climate and vegetation 52 2.5 Conclusions 54 3. Southeast Asian Quaternary Extinctions: Position in the Debate and Further Analysis 56 3.1 Introduction 56 3.2 The Quaternary “megafauna” extinctions 57 3.2.1 What are megafauna? 57 3.2.2 The debate 58 3.2.3 Human-induced extinctions 59 3.2.4 Climate-induced extinctions 62 3.2.5 Towards a reconciliation 64 3.3 Quaternary extinctions in Southeast Asia 64 3.3.1 Geography of Southeast Asia 66 3.3.2 Southeast Asia’s megafauna 74 3.3.3 Human overhunting in Southeast Asia? 81 3.3.4 Climate change and megafauna 83 3.3.5 The modern extinction crisis 87 3.4 Summary 89 4. The Role of Volcanism in Extinctions: the Case of the Toba Eruption 90 4.1 Abstract 90 4.2. Introduction 90 4.3 Methods 92 4.4 Results 98 vii 4.4.1 Borneo 98 4.4.2 Vietnam 99 4.4.3 Sumatra 99 4.4.4 Java 100 4.4.5 Southern China 101 4.5 Discussion 102 4.5.1. General discussion 102 4.5.2 Volcanic winter 104 4.5.3 No volcanic winter 107 4.6 Conclusions 109 Part 2. Ecology 110 5. Palaeoecology Multivariate Methods: Examining Modern Habitat Biases and Application to Gongwangling Hominin Site, China 111 5.1 Abstract 111 5.2 Introduction 112 5.2.1 Geological context 115 5.2.2 Previous palaeoenvironmental analyses 115 5.3 Materials and Methods 116 5.3.1 Materials 116 5.3.2 Taphonomy 123 5.3.3 Zoogeographic identity 124 5.3.4 Palaeoecology 125 5.4 Results and Discussion 137 5.4.1 Taphonomy 137 5.4.2 Zoogeography 146 5.4.3 Palaeoecology 152 5.5 Summary 165 6. Palaeoecology of Quaternary Southeast Asian Sites Revealed Through Phylogeny-Free Discriminant Functions Analysis 167 6.1 Abstract 167 6.2 Introduction 168 6.3 Methods 171 6.4 Results 176 6.5 Discussion 191 6.5.1 Early Pleistocene sites 193 6.5.2 Middle Pleistocene sites 194 6.5.3 Late Pleistocene and Holocene sites 196 6.6 Conclusion 198 7.

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