Can Snow Skinks Survive Climate Change?
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Can Snow Skinks Survive Climate Change? The potential for behaviour, physiology and competition to mitigate and enhance climate change impacts on snow skink life history, distribution and persistence. Amanda Jane Caldwell, BSc Hons School of Biological Sciences, University of Tasmania A thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy May 2016 Declarations and Statements Declaration of originality This thesis contains no material which has been accepted for a degree or diploma by the University or any other institution, except by way of background information and duly acknowledged in the thesis, and to the best of my knowledge and belief no material previously published or written by another person except where due acknowledgement is made in the text of the thesis, nor does the thesis contain any material that infringes copyright. Amanda Jane Caldwell Date: 08/05/2016 Authority of access This thesis may be made available for loan and limited copying and communication in accordance with the Copyright Act 1968. Statement regarding published work contained in the thesis The publisher of the paper comprising Chapter 2 holds the copyright for that content, and access to the material should be sought from the respective journal. The remaining non published content of the thesis may be made available for loan and limited copying and communication in accordance with the Copyright Act 1968. Statement of ethical conduct The research associated with this thesis abides the Australian Code of Practice for the Care and Use of Animals for Scientific Purposes, 7th edition, 2004 and the University of Tasmanian Animal Ethics Guidelines. Amanda Jane Caldwell Date: 08/05/2016 ii Statement of Co-Authorship The following people and institutions contributed to the publication of work undertaken as part of this thesis: Amanda Jane Caldwell: School of Biological Sciences, University of Tasmania Erik Wapstra: School of Biological Sciences, University of Tasmania Geoffrey While: School of Biological Sciences, University of Tasmania Nicholas Beeton: School of Biological Sciences, University of Tasmania Michael Kearney: School of BioSciences, University of Melbourne Paper 1 (Chapter 2): Caldwell, A. J., While, G. M., Beeton, N. J., and Wapstra, E. 2015. Potential for thermal tolerance to mediate climate change effects on three members of a cool temperate lizard genus, Niveoscincus. Journal of Thermal Biology. 52: 14-23. Amanda Jane Caldwell (candidate and author 1) was the primary author and conceived of the idea, carried out its execution and was responsible for its presentation. Nicholas Beeton (author 3) carried out climate simulations. Geoffrey While (author 2) and Erik Wapstra (author 4) contributed to the formalization, development, refinement and presentation. Paper 2 (Chapter 3): Caldwell, A. J., While, G. M., and Wapstra, E. Plasticity of thermoregulatory behaviour in response to the thermal environment by widespread and highland reptile species. As submitted to Animal Behaviour. Amanda Jane Caldwell (candidate and author 1) was the primary author and conceived of the idea, carried out its execution and was responsible for its presentation. Geoffrey While (author 2) and Erik Wapstra (author 3) contributed to the formalization, development, refinement and presentation. Paper 3 (Chapter 4): Caldwell, A. J., Beeton, N. J., While, G. M., and Wapstra, E. Movin’ on up: an individual-based model predicts climate change will alter competition between species across a mountain gradient. In the final stages of preparation for submission to Ecography. iii Amanda Jane Caldwell (candidate and author 1) was the primary author and conceived of the idea, carried out its execution and was responsible for its presentation. Nicholas Beeton (author 2) carried out model simulations in collaboration with Amanda Jane Caldwell. Geoffrey While (author 3) and Erik Wapstra (author 4) contributed to the formalization, development, refinement and presentation. Paper 4 (Chapter 5): Caldwell, A. J., While, G. M., Wapstra, E., E., Kearney, M. R. Towards a mechanistic framework for interpreting climatic effects on widespread and highland temperate reptile species. In preparation for submission for publication in Functional Ecology. Amanda Jane Caldwell (candidate and author 1) was the primary author, conceived of the idea, carried out its execution and was responsible for its presentation. Geoffrey While (author 2) and Erik Wapstra (author 3) contributed to the formalization, development, refinement and presentation. Michael Kearney (author 4) assisted with parameterising the dynamic energy budget model component of the NicheMapR model. We the undersigned agree with the above stated “proportion of work undertaken” for each of the above published (or submitted) peer-reviewed manuscripts contributing to this thesis: Signed: Signed: Signed: Erik Wapstra Geoffrey While Anthony Koutoulis Candidate’s supervisor Candidate’s supervisor Head of School School of Biological School of Biological School of Biological Sciences Sciences Sciences University of Tasmania University of Tasmania University of Tasmania Date: 08/5/2016 Date: 08/5/2016 Date: 25/10/2016 iv Acknowledgements I am extremely grateful to the many people who made this project possible and so enjoyable. First and foremost, it is my great pleasure to thank my supervisors Erik Wapstra and Geoff While. It has been an honour to undertake my doctorate with you both. Erik, I am sincerely grateful for all of your advice, encouragement and support through the years. You have taught me so much about science and the life that goes with it. Geoff, thank you for providing so much inspiration for my project and for the time you have spent reading and improving every piece of my writing. It has been a pleasure to work with you both. I am grateful to my collaborators, who have enriched my thesis with their involvement. Nick Beeton I am indebted to you for patiently explaining all things modelling and otherwise. Mike Kearney, I count myself very lucky to have had the opportunity to work with you. Elias Polymeropolous, though our work didn’t make it into the thesis, I am indebted to you for going above and beyond to help with my experiments. I would also like to express my gratitude to Alison Cree and Kelly Hare for your mentorship and guidance through the years, thank you for introducing me to the world of reptiles. Many thanks to everyone in the BEER group for being such a fun and supportive community, including Jo McEvoy, Luh Kasuma Yuni, Chloe Cadby, Laura Parsley, Matt Russell, George Cunningham, Hannah Cliff, Keisuke Itonaga, David Sinn, Sarah Tassell, and Hannah McGregor. You have all helped me in countless ways to overcome obstacles and made every visit to Hobart a happy time. Jos Kramer and Kirke Munch, thank you for the many idyllic hours we shared in the field. To the technical staff at the School of Biological Sciences, thank you for all your help through the years. My thanks also to all of the Postgraduates and academic staff at the School of Biological Sciences for your friendship and good times. I would like to express my sincere thanks to the funding bodies that made this work possible. Dr Holsworth, thank you for supporting three productive years of this project and for taking a personal interest. I am also grateful to have received support from the Ecological Society of Australia, the International Society of Behavioural Ecology, the Foundation for National Parks and Wildlife and the Kit Williams Grant. v Thank you to our Hobartian friends who treated Pete, William and I like family during our years in Hobart. Thanks especially to Dave and Shani, Chrystal and Mark, Laura and Rob, Amy, Jess, Kaylia, Natalie and Rob, Nat, Kate, Nathan, Dave and Judy, Erica, Hannah, and many others at Velocity. Special mention to Lydia, thank you for your kindness. Thanks to our kiwi friends too, especially Tahlia and Logan, Cathy, Aimee and Harry, Scott Jarvie and the fine folk at St Barnabas. To the Caldwell & Chamberlain extended families, thank you for your prayer and practical support. Joan, Roger and Ruth, you are each too good to be true. Grandmaggie, Nana and Grandad, thank you for all your kind words of encouragement. I hope I have made you proud. My heartfelt thanks to my brothers, Daniel, Jonathan, Matthew and David, for the adventures, hilarity and many distractions. I am grateful to have been born into your fine company. A very special thanks to my parents, Mark and Pip Chamberlain. Mum and Dad I couldn’t have finished without you. Thank you for your inexhaustible support, for giving us a home, for keeping abreast of developments, and especially for helping us raise William. There are no words that can adequately express my gratitude to you. I would like to dedicate my thesis to God, to the snow skinks and to my son William. God, thank you for starting me on the research path and helping me see it finished. To the lizards, may you live long and prosper in your cold mountain homes and warm seaside retreats. Dear William, I’ve loved every day with you. I look forward to exploring the world with you and seeing what our future brings. Finally, to my husband Pete. Thank you for helping me up and down my mountains. You have done a lot of carrying, caring and patient waiting over the last few years. I cherish the support that you have given me. vi SYNOPSIS 7 Abstract Shifting climates are affecting a diverse range of species, with many taxa predicted to become extinct. A great proportion of reptile species are at risk of extinction within the 21st century due to climate change, yet species-specific impacts of climate change are difficult to predict. This is partly due to inter-specific variance in the physiological and behavioural traits which mediate environmental temperature effects at the organismal level. A Tasmanian lizard genus, Niveoscincus, provides an excellent example of this, as variation in altitudinal distribution between species has led to divergent adaptations to local thermal conditions.