This electronic thesis or dissertation has been downloaded from Explore Bristol Research, http://research-information.bristol.ac.uk Author: Riley, Joanna L Title: Spatial ecology and conservation management of the endangered sandhill dunnart, Sminthopsis psammophila General rights Access to the thesis is subject to the Creative Commons Attribution - NonCommercial-No Derivatives 4.0 International Public License. A copy of this may be found at https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode This license sets out your rights and the restrictions that apply to your access to the thesis so it is important you read this before proceeding. Take down policy Some pages of this thesis may have been removed for copyright restrictions prior to having it been deposited in Explore Bristol Research. However, if you have discovered material within the thesis that you consider to be unlawful e.g. breaches of copyright (either yours or that of a third party) or any other law, including but not limited to those relating to patent, trademark, confidentiality, data protection, obscenity, defamation, libel, then please contact [email protected] and include the following information in your message: •Your contact details •Bibliographic details for the item, including a URL •An outline nature of the complaint Your claim will be investigated and, where appropriate, the item in question will be removed from public view as soon as possible. Spatial ecology and conservation management of the endangered sandhill dunnart, Sminthopsis psammophila Joanna Louise Riley A dissertation submitted to the University of Bristol in accordance with the requirements for award of the degree of PhD in the Faculty of Life Sciences. School of Biological Sciences March 2020 Word count: 50,930 Abstract We are experiencing a global biodiversity and climate crisis that is rapidly causing the extinction of species. Mammal species have been disproportionately affected; however, this trend is considerably worse in Australia. Since Australia’s occupation by Europeans, 34 mammal species have been declared extinct. Australian mammals in deserts are particularly at risk of extinction. Many arid zone mammals have specialised adaptations to their hostile, unpredictable ecosystems. For example, they use thermally insulative refuges, prefer habitats that reduce predation risk, or have large home ranges and broad diets to maximise energy intake. Understanding these adaptations is essential for informed conservation management. However, little ecological data is known for the sandhill dunnart, Sminthopsis psammophila, an endangered and charismatic marsupial that now remains within just a few natural refugial habitats in Australia’s southern deserts. To address conservation biology knowledge gaps, an integrated, evidence-based approach (i) quantified the diurnal and nocturnal ecology of S. psammophila in the Western Australian Great Victoria Desert (WAGVD), (ii) estimated the past, present and future distributions of S. psammophila throughout Australia, (iii) examined the key threats to S. psammophila - particularly wildfires and anthropogenic climate change - and (iv) proposed conservation management solutions for a) S. psammophila and b) sympatric arid zone species. Between 2015 and 2019, radio tracking and global positioning system (GPS) technologies examined the sheltering, foraging, dietary and habitat preferences of S. psammophila in the WAGVD. In contrast to its previously reported habitat preferences, S. psammophila preferred burrowing within long unburned (32+ years since a wildfire) spinifex (Triodia spp.) grassland habitats. Dense lower stratum swale, sand plain and dune slope habitats were preferred, whereas habitats lacking spinifex and open dune crest habitats were rarely used. Hence, wildfires were identified as a significant threat to the species. i The sheltering preferences of S. psammophila agreed with the premise that small desert mammals often use shelters with thermal advantages and anti-predation benefits, such as burrows, Lepidobolus deserti hummocks and logs. Conversely, spinifex hummocks were not found to be insulative against extreme temperatures and were not preferred. The foraging adaptations of S. psammophila agreed with the premise that arid zone species often have large home ranges to exploit resource patches or islands. The 100 % home ranges of S. psammophila [mean: 70 ha; range: 6-274 ha; minimum convex polygon (MCP)] were influenced by sex and reproductive status. In addition, a Formicine-rich diet indicated that ants are an important dietary resource for S. psammophila. Species distribution models (SDMs) predicted the past, present, and future distributions of S. psammophila, evaluated the environmental parameters that determine the species’ distribution and identified habitats of high conservation value. The past model supported evidence that S. psammophila was widespread but has recently contracted to more climatically favourable areas of its geographic range. Ground-validation of the present model’s predictions discovered a population 150 km north of the species’ known range. Future models identified that climate change is a potential catastrophic threat for S. psammophila. By 2050, under Representative Concentration Pathway (RCP) 8.5 (our current pathway) there is a predicted 95 % reduction in suitable habitat for S. psammophila in the WAGVD. By 2070 (RCP 8.5), only the Eyre Peninsula population may remain viable and the continental distribution of S. psammophila may contract by up to 80 %. However, this contraction is predicted to be halved if global greenhouse gas emissions peak in 2040 then reduce (RCP 4.5). Due to specific habitat preferences for long unburned habitats, S. psammophila is further restricted within its climatically and geographically suitable range. As a semi-arid specialist, it is also vulnerable to drought-related population crashes. Hence, S. psammophila should remain listed as endangered at the state and federal level, and its status should be revised by the International Union for Conservation of Nature. ii Acknowledgements I wish to especially thank my partner, Jeff Turpin, for awakening my love for the Great Victoria Desert and sandhill dunnarts. You are a brilliant scientist, conservationist, and person - and your dedication for our natural world is inspiring. Thank you and I love you always. I also especially thank my mum, dad, and brother (Ramona, Chris and David Riley) for all of our adventures while growing up, your academic encouragement and for being such wonderful, caring people. Many thanks to my incredibly supportive aunts, uncles, cousins, family and friends back home in the UK, and for all the love and laughter (there are too many of you to name, but I hope that you know who you are!) I would like to dedicate my PhD to Matt Treadgold, who I miss and will remember always, not only as a brilliant scientist but also as someone who would play table tennis with me in the back of statistics classes. You inspired me to use science to better the world. Many thanks to my Australian family and friends for adopting me and sharing your knowledge, homes, and lives with me. You are all so passionate about the Australian environment and culture, and such a lovely family to be a part of. I sincerely thank my supervisors, Professor Gareth Jones and Dr Matt Zeale, at the University of Bristol for teaching me how to be a scientist! Thank you for all of your encouragement and expert advice during the project. The dunnarts (although they are not bats) greatly appreciate your help. Special thanks to my first year co- supervisor, Dr Orly Razgour, for her modelling expertise and to Dr Jeremy Froidevaux for his coding wizardry. I am incredibly grateful to all members of our research group and thank Dr Parvathy Venugopal, Penelope Fialas, James Goldsmith, Dr Lia Gilmour, and Sarah Richdon for helping me throughout the process, and for being such knowledgeable and friendly Bristolians. Many thanks to Zoe Bertucci and Gerardo Arias who welcomed us into their Bristol lives with open hearts. I wish to thank Professor Malcolm Burrows, Dr Greg Sutton, Dr Steve iii Rogers, and Dr Judy Dunlop for providing mentorship during my time at the University of Cambridge and in Australia. I am incredibly grateful to Dr Brian Heterick and Dr Alex Baynes at the Western Australian Museum for their expertise and friendship over the years. Your knowledge has undoubtedly made this PhD more interesting! Thank you to the sandhill dunnart experts, Sue Churchill, Glen Gaikhorst and Dr Amanda McLean, for your assistance and advice. I hope that our research will protect this beautiful and iconic species. Many thanks to Donell Hole at Sirtrack for providing expert radio and GPS advice and support - it worked! This research was independently funded and only possible due to collaborations with industry and conservation management bodies. Enormous thanks to our fellow Golden Gecko Award winner, Brynne Jayatilaka at APA Group (APA), whose environmental dedication continues to make threatened species conservation possible throughout Australia. With special thanks to Rose Lane (rights for dunnarts!) at Tropicana Gold Mine (TGM), for her unwavering support of the project over the years. This PhD would not have been possible without you both. Special thanks to everyone at APA and TGM who came out tracking and trap checking and for the financial and logistical support. Special thanks to the Goldfields Environmental Management Group (GEMG),