Copyright by Gautam Sankar Surya 2018 The Dissertation Committee for Gautam Sankar Surya Certifies that this is the approved version of the following Dissertation: The Effects of Ecology and Climate Change on the Conservation of Eastern Himalayan Avifauna Committee: Tim Keitt, Supervisor Shalene Jha Mathew Leibold David Hillis Jennifer Miller The Effects of Ecology and Climate Change on the Conservation of Eastern Himalayan Avifauna by Gautam Sankar Surya Dissertation Presented to the Faculty of the Graduate School of The University of Texas at Austin in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy The University of Texas at Austin May 2018 Dedication To the village it took. ‘Into this wild Abyss the wary Fiend Stood on the brink of Hell and looked a while, Pondering his voyage; for no narrow frith, He had to cross’ Acknowledgements On the research side of things, I would like to thank my adviser, Tim Keitt, and the rest of my committee (Shalene Jha, Jennifer Miller, Mathew Leibold and David Hillis) for their guidance and mentorship. Shalene Jha deserves especial mention for her advice and mentorship. In addition, thanks are owed to Shalene Jha, Jennifer Miller, Rebecca Tarvin and Caroline Farrior for their advice and assistance in the preparation of these chapters. I have also received considerable assistance from labmates including Colin Addis, Andrew Tilker and Andria Salas. The third chapter in particular owes a lot to the efforts of Dylan Winkler, an undergraduate student working in my lab. None of my data could have been gathered without several people helping me in the field, most notably Binanda Hatibaruah as well as Kalu Tamang and Phurpa. On the personal side, I owe a great deal to several friends, foremost among whom are Andria Salas, Ashley Green and Erin Giglio, for their support and care. Finally, I have received a great deal of love and patience from my family, including my parents Drs. Shyamala Mani and Arjun Surya, my sister Sanjna Surya, and my wife Yun Luo, without whom none of this would have been possible. v Abstract The Effects of Ecology and Climate Change on the Conservation of Eastern Himalayan Avifauna Gautam Sankar Surya The University of Texas at Austin, 2018 Supervisor: Tim Keitt The existence of biodiversity is central to all biological sciences, and especially ecology. Without it, an entire branch of knowledge would cease to exist. Despite this centrality, there is considerable debate on the mechanisms that create and maintain diversity. This is especially true of high-diversity areas. There is also considerable debate on how we can best protect biodiversity, in order to allow the science of biology to flourish into the future. Here, I present an investigation of the processes that allow biodiversity to be maintained in the Eastern Himalayas, a critically understudied high-diversity region, as well as a systematic analysis of the conservation priorities there. I focus on birds as a charismatic, speciose and conspicuous set of taxa. I spent several months gathering fine- scale occurrence data for the breeding bird community in Arunachal Pradesh, a state in Northeast India that is at the heart of the Eastern Himalayan ecoregion. Using this data, I first show that bird species on the steep elevational gradient present in the region segregate into narrow elevational bands. I also show that this segregation can best be explained by evolutionary processes resulting from interspecies competition in the long term, and by continued interspecies competition in the short term. I then go on to demonstrate that these narrow ranges of climate tolerance will be greatly affected by climate change, with species’ ranges shifting and contracting over the next 50 years. Moreover, when interspecies competition is taken to account, these extent of these predicted changes is intensified. Finally, I use these predicted distributions to create a spatially explicit map of conservation priorities. I present alternatives based on different conservation goals, as well as different projections of the extent of global climate change. vi I also present an idealized map of areas most in need of protection, and compare that to the existing set of formally protected areas. Taken in their entirety, these studies present a cogent explanation for the existence of high biodiversity in one of the most special regions of the planet, as well as a roadmap toward protecting that diversity for future generations. vii Table of Contents List of Tables ................................................................................................................... xii List of Figures ................................................................................................................ xiii Introduction .........................................................................................................................1 Overarching questions ............................................................................................1 What allows diversity to exist? ...................................................................1 How can we ensure the continued existence of diversity? ....................5 Study system ............................................................................................................8 Chapter summaries ...............................................................................................11 Chapter 1 – Altitudinal limits of Eastern Himalayan birds are created by competition past and present .........................................12 Introduction .........................................................................................12 Hypothesis: .........................................................................................12 Methods: .............................................................................................13 Conclusions: .......................................................................................13 Chapter 2 – The effects of climate change and species interactions on ranges of Eastern Himalayan birds ........................13 Introduction .........................................................................................13 Hypothesis: .........................................................................................14 Methods: .............................................................................................14 Conclusions: .......................................................................................14 Chapter 3 – Systematic conservation planning for Eastern Himalayan birds ....................................................................................15 Introduction .........................................................................................15 Hypothesis: .........................................................................................15 viii Methods: .............................................................................................15 Conclusions: .......................................................................................15 Chapter 1 – Altitudinal limits of Eastern Himalayan birds are created by competition past and present ..................................................................................17 Abstract ....................................................................................................................17 Introduction .............................................................................................................18 Methods ...................................................................................................................22 Surveys: .......................................................................................................22 Modelling elevational ranges and range overlaps: ...............................22 Trait and phylogenetic data: .....................................................................24 Statistical and phylogenetic methods: ....................................................25 Software used: ............................................................................................26 Results .....................................................................................................................26 Discussion ...............................................................................................................28 Figures .....................................................................................................................31 Chapter 2 - The effects of climate change and species interactions on ranges of Eastern Himalayan birds .....................................................................................40 Abstract ....................................................................................................................40 Introduction .............................................................................................................41 Methods ...................................................................................................................43 Surveys: .......................................................................................................43 Modelling: ....................................................................................................44 Species interactions: ..................................................................................46 Software: ......................................................................................................47