The impacts of urbanisation on the ecology and evolution of dragonflies and damselflies (Insecta: Odonata) Giovanna de Jesús Villalobos Jiménez Submitted in accordance with the requirements for the degree of Doctor of Philosophy (Ph.D.) The University of Leeds School of Biology September 2017 The candidate confirms that the work submitted is her own, except where work which has formed part of jointly-authored publications has been included. The contribution of the candidate and the other authors to this work has been explicitly indicated below. The candidate confirms that appropriate credit has been given within the thesis where reference has been made to the work of others. The work in Chapter 1 of the thesis has appeared in publication as follows: Villalobos-Jiménez, G., Dunn, A.M. & Hassall, C., 2016. Dragonflies and damselflies (Odonata) in urban ecosystems: a review. Eur J Entomol, 113(1): 217–232. I was responsible for the collection and analysis of the data with advice from co- authors, and was solely responsible for the literature review, interpretation of the results, and for writing the manuscript. All co-authors provided comments on draft manuscripts. The work in Chapter 2 of the thesis has appeared in publication as follows: Villalobos-Jiménez, G. & Hassall, C., 2017. Effects of the urban heat island on the phenology of Odonata in London, UK. International Journal of Biometeorology, 61(7): 1337–1346. I was responsible for the data analysis, interpretation of results, and for writing and structuring the manuscript. Data was provided by the British Dragonfly Society (BDS). The co-author provided advice on the data analysis, and also provided comments on draft manuscripts. This copy has been supplied on the understanding that it is copyright material and that no quotation from the thesis may be published without proper acknowledgement. The right of Giovanna de Jesús Villalobos Jiménez to be identified as Author of this work has been asserted by her in accordance with the Copyright, Designs and Patents Act 1988. © 2017 The University of Leeds and Giovanna de Jesús Villalobos Jiménez ii Acknowledgements Firstly, I would like to thank everyone who gave me the opportunity to embark on this crazy, challenging journey called PhD. Thank you Chris Hassall for allowing me to work with you, for being such an amazing supervisor, for believing in me and for all the patience you had every time I had a panic attack! I realise how fortunate I am of having such a cool and supportive supervisor. I would also like to thank my co-supervisor Alison Dunn for the support, guidance and for always being so energetic. Thanks to my sponsor, CONACYT, without their funding I would most certainly not be able to do my PhD. Thank you Laura Petteway, Stuart Richardson, Rochelle Meah, and Emily Pepper for helping me collect data, and also thank you Steve Sait and Marianne Mugabo for letting me use your incubators for my experiments. Thanks to my wonderful boyfriend Héctor for always supporting me, for making time to help me with my project, either by doing field work, pointing landmarks on damselfly wings, or analysing the data. Thank you for listening and for being with me through highs and lows. Thanks to my beautifully quirky family for always supporting me, even from the other side of the pond. To my mother for being my role model and for staying strong despite all the difficulties, my sisters Anel and Erika for being like my second and third mothers, my brother-in-law Victor for being such an amazing dad for my nephews and for always being there for my family, I’ll never forget everything you’ve done for us. I’d also like to thank my friends back home, especially David, Lorena, Cristina, Alex, and Cecy for all the good times we’ve had which have motivated me iii even more to return, and thanks to all the friends I’ve made here, Corinne, Ekbal, Emma, Raul, Hope, Shifa, Fabio, Chris, Luke, Laura, Myrna, Jens, Aliya, Brigitte and Marianne. Thank you all for the laughs, the movie nights, the fun times playing Catan, the tea/coffee breaks, the pub Fridays and the parties, all those moments made those rough times in my PhD easier to cope. I’m so glad I met you all, and now it will be hard to say goodbye, but you’ll always be a part of me regardless of the distance. Besides, you are always welcome to visit me in Mexico. Now, on to the next adventure! iv The impacts of urbanisation on the ecology and evolution of dragonflies and damselflies (Insecta: Odonata) Abstract Urbanisation is one of the main drivers of ecosystem change. The impacts of urban land use on biodiversity have been investigated, but other aspects of ecology have been overlooked, as well as the effects of urban stressors. Understanding the effects of specific urban stressors is crucial in order to appropriately manage urban areas and conserve their biodiversity. Dragonflies and damselflies (the Odonata) are a suitable taxon for evaluating the impacts of urbanisation on both terrestrial and aquatic ecosystems. Here, using a combination of field and laboratory data, I study the ecological impacts of urban stressors on odonates. I found that the urban heat island has negligible impacts on the phenology of odonates compared to climate change. Moreover, noise disturbance reduces significantly the feeding rate of the damselfly Ischnura elegans, although anthropogenic noise has no significant impact. Regarding the impacts of polarised light pollution (PLP), the strength of polarotaxis increased significantly with age in laboratory-reared specimens, but there was no significant differentiation between urban and rural populations. However, field-caught urban specimens showed less preference to polarised light compared to rural populations, suggesting strong selective pressures are acting upon urban populations, but no adaptation has occurred. Flight-related traits v showed no significant differentiation among urban and rural populations of I. elegans. Lastly, biodiversity patterns did not differ among urban and rural areas, although aquatic vegetation and presence of fish were the main drivers of community composition. These results show odonates can tolerate a wide range of urban stressors, notably I. elegans. However, PLP, fish, and absence of aquatic vegetation in urban ponds can have a negative impact on odonate biodiversity, which has important implications on conservation and management of urban areas. Urban ecosystems are complex, thus an integrative approach is necessary in order to understand in depth the impacts of urbanisation on biodiversity. vi Contents Acknowledgements ...................................................................................................... iii Abstract ......................................................................................................................... v Contents ....................................................................................................................... vii Figures ........................................................................................................................... x Tables ......................................................................................................................... xiii Equations ..................................................................................................................... xv Chapter 1: Dragonflies and damselflies (Odonata) in urban ecosystems: a review . 1 Abstract ......................................................................................................................... 2 Introduction ................................................................................................................... 3 The effects of urban stressors on terrestrial and freshwater ecosystems .................. 4 Dragonflies and damselflies as a model system ........................................................ 6 Literature review ........................................................................................................... 7 The effects of urban stressors on odonates ................................................................ 9 Odonates as bioindicators in urban environments .................................................. 16 Ecological traps in cities ......................................................................................... 18 The conservation value of urban water bodies for odonates ................................... 19 Adapting to urbanisation ......................................................................................... 22 Research needed .......................................................................................................... 23 Thesis outline .............................................................................................................. 29 Chapter 2: Effects of the urban heat island on the phenology of Odonata in London, UK ................................................................................................................... 31 Abstract ....................................................................................................................... 32 Introduction ................................................................................................................. 33 Methods ....................................................................................................................... 35 vii Results ........................................................................................................................