Socioecology of Cat Ba Langurs (Trachypithecus poliocephalus): Implications for Conservation Rebecca Lynne Hendershott A thesis submitted for the degree of Doctor of Philosophy of The Australian National University SUBMITTED FEB 2017 © Copyright by Rebecca Lynne Hendershott 2017 All Rights Reserved ii Statement of originality The work presented in this thesis is, to the best of my knowledge and belief, original and my own work except where otherwise acknowledged. This material has not been submitted either in whole or in part, for a degree at this or any other university. Rebecca Lynne Hendershott Word count: 106,237 (all inclusive) iii Acknowledgments This work would not have been possible without the collaboration of Australian National University (ANU), the Cat Ba Langur Conservation Project (CBLCP), Cat Ba National Park (CBNP), and Fauna & Flora International. Funding was generously provided by ANU, the Australian government (Australian Government Research Training Program Scholarship), and Primate Action Fund (Conservation International). My supervisors – Alison Behie, Colin Groves, and Benjamin Rawson – have been so helpful, patient, and supportive during this intense journey. Ben was key to setting up the field site. Alison had excellent advice in the field, while applying for grants, and writing chapters, as well as for what comes next. Colin’s career in academia and the contributions he’s made to the field serve as an inspiration (as do his socks!). Thank you, Colin, for teaching me that there is no such thing as being ‘overly impressed’ by a library. Dr Ben Rawson, Prof Colin Groves, and Dr Alison Behie in the field, Cat Ba Island Photo taken Aug 2014 by R Hendershott I am extremely grateful to Teresa Newman in the Statistical Consulting Unit (ANU) for our hours and hours of chats, learning SPSS (and figuring out which boxes to tick), and discussions about statistical theory (and politics!). It took a lot of go’s, but we got there! Mr Neahga Leonard, Ms Le Thi Ngoc Han, and Ms Dalma Zsalako (CBLCP) were critical to on-the-ground support and translations as well as visas, research ideas, and mental health. Thank you to Mr Nguyen Cam, my CBNP ranger and boat driver, who always met me with a smile and enthusiasm (even at 4am!) – he worked hard every single day to protect the langurs in between learning English and teaching me Vietnamese. iv Mr Nguyen Cam and myself on our boat Photo taken Jan 2015 by B Kimitsuka I am incredibly grateful to so many people who all nodded and understood what I meant when I said I was ‘thesising’. Thank you to my parents – Sue and Jon Evans, Ron Hendershott and Jasna Kuvacich-Hendershott – who always told me I could do anything I wanted to do. I still blame them for not mentioning that I had to earn money in that process, but I am so grateful that they never held me back when I told them I was off to go do monkey business. I am especially grateful to my mother, Sue, for responding to every freaked-out email, every I’m-going-to-fail phone call, and taking every opportunity to tell me how proud of me she is. Being able to get together and chat (groom?) is key to primate mental health. It was chats with Sue and Jim Michael, Carmina Eliason, Jennifer Muranjan, Alice Yeates, and Nicole Henderson that kept me sane. I am so grateful to have met Kirrily Apthorp, Kayla Ruskins, Felicity Gilbert, and Megan O’Donnell, all of whom I baby-stepped through this doctorate process with. My brother, Justin Hendershott, has always been there for a laugh as I call to update him on my progress, and lack therein. The arguments we got into about Euclidean geometry, the curve of the earth, and how to measure north were key to me realising that I had a larger support network on which to rely. My partner, Ben Kimitsuka has been there with me every step of the way. From moving to Australia, staying in Australia while I moved to Vietnam, listening to my I-want- to-talk-about-this-thing-I-learnt-today-about-primates spiel, taking care of the dogs, the garden, the house; hugging me when that was the whole world, to laughing in my face v when I told him I was quite sure I could not do it: support from Ben has been critical to this dissertation happening. I am so, so, so grateful for his encouragement, time, energy, patience, and love. Our dogs, Sir Toki Wartooth and Mr Erignathus Barbouts, have kept me grounded. They remind me, on a daily basis, that there is more to life than staring at my computer. Watching them turns the theory of animal behaviour into something relevant and tangible. Thank you to Ben, Toki, and EB for not giving up on me. Finally, thank you to Jane Goodall, for being the original and sustaining inspiration for this life path. vi Abstract Cat Ba langurs (Trachypithecus poliocephalus), endemic to Cat Ba Island (Vietnam), are a member of the limestone langur group (francoisi species-group) found in Laos, Vietnam, and China. With less than 75 individuals in the world, these Cat Ba langurs are Critically Endangered. This dissertation represents the first long-term behavioural study of the species (549 contact hours across 11 months), and provides socioecological information for two groups (n=17-20) living on the Cua Dong fjord, which can be used in conservation management. Like most other colobines, the majority of the Cat Ba langur diet is leaves (84% of their dietary budget). This may explain their activity budget, which is primarily inactivity (55% of their activity budget), followed by foraging (19%) and social behaviour and locomotion (12% each). Activity and dietary budgets vary seasonally, with animals spending more time in social behaviours in the wet season, when they eat more fruit, and more time in foraging in the dry season, when leaves are ingested more, suggesting they are energy maximisers. In addition, age differences were found, with adults spending the most time in social behaviours and resting. Social behaviour primarily includes grooming and playing with others - play is more common in younger animals, while older animals tend to groom more. Overall, they spend 58% of their days not in proximity to any other langurs. Adult males spend the most time alone, and seem to avoid young langurs. Disputes tend to be between adult females, and two females only tend to come together if there is a young langur acting as a ‘social glue’. Home ranges varied between groups with the larger group’s range being 50ha compared to just 22ha for the smaller group. In both areas, rocks and sparsely covered areas are used most often, which is due to the shrubby, discontinuous vegetation. Most of the langurs’ observable time is spent on exposed slopes (47%), followed by steep cliffs (38%), summits (11%), valleys (3%), and the ground (1%); this varied seasonally, likely to balance foraging needs with thermoregulation. The langurs used 22 sleeping sites, including ledges (61%) and caves (17%). When newborn, Cat Ba langurs are bright orange. They start to lose this natal coat as an infant, and become much darker during the young juvenile stage. As individuals age, they also become more independent and start to forage and locomote more on their own. These reported behaviours can be used to create a baseline for activity budgets, home range size, and habitat use, and development and maturation that can be used for comparative purposes in vii future studies. Results find that animals are behaviourally similar to other related species and their biggest threat is likely their small, fragmented population structure. To combat this, I support habitat protection, patrols, and enforcement; education and training; habitat corridors; and limiting the human population, as these support an entire ecosystem while teaching locals the importance of biodiversity, reducing resource competition, and fragmentation from infrastructure, and providing a means for the langurs themselves to disperse. viii Table of Contents Acknowledgments iv Abstract vii Table of Contents ix List of Figures xiii List of Tables xv Abbreviations xvi Chapter 1: Introduction 1 1.1 Introduction 1 1.2 Research Aims 3 1.3 Research Limitations 4 1.4 Permissions Obtained 5 1.5 Thesis Outline 5 1.6 Species Overview 9 1.6.1 Taxonomy 9 1.6.1.1 Colobines 10 1.6.1.2 Asian Colobines 10 1.6.1.3 Trachypithecus 11 1.6.1.4 Trachypithecus poliocephalus and T. leucocephalus 12 1.6.2 Distribution 13 1.6.2.1 Vietnamese Primates 13 1.6.2.2 Asian Colobines 14 1.6.2.3 Trachypithecus 15 1.6.2.4 Trachypithecus poliocephalus 16 1.6.3 Anatomy 18 1.6.3.1 External Morphology 18 1.6.3.2 Specialised Digestion 23 1.6.4 Diet and Activity 24 1.6.5 Home Range 29 1.6.6 Life History and Reproduction 30 1.6.7 Social Structure 33 1.7 Conservation Issues of Limestone Langurs 35 Chapter 2: Methods 39 2.1 Study Site 39 2.1.1 Geography of Cat Ba Island 39 2.1.2 Plants on Cat Ba Island 40 2.1.3 Nonhuman Animals on Cat Ba Island 41 2.1.4 Human Population on Cat Ba Island 43 2.2 Study Groups Home Range - Cua Dong 45 2.3 Cat Ba Langur Conservation Project and Cat Ba National Park 49 2.4 Weather on Cat Ba Island 49 2.5 Data Collection 51 2.6 Behavioural Observations 55 2.6.1 Study Animals 55 2.6.2 Behavioural Data Collection 59 2.6.3 Ethogram 61 ix 2.6.4 Habitat 63 Chapter 3: Activity and Dietary Budgets 65 3.1 Introduction 65 3.2 Methods 68 3.2.1 Behavioural Data Collection 68 3.2.2 Data Analysis 69 3.3 Results 71 3.3.1 Activity Budget 71 3.3.1.1 Time Differences in Activity Budgets 72 3.3.1.2 Seasonal Differences in Activity Budgets 74 3.3.1.3 Group Differences in Activity Budgets 74 3.3.1.4