University of Reading Unintended Consequences: How Human Intervention Affects the Ecology of Urban Birds Hugh James Hanmer School of Biological Sciences A thesis submitted for the degree of Doctor of Philosophy August 2017 2 Acknowledgements I would first like to thank my supervisors Professor Mark Fellowes and Dr Becky Thomas, without whom this thesis would not have been possible. I am sincerely grateful for all their guidance and support throughout my research at Reading. I am very grateful to the Keith Duckworth scholarship and Keith Cowieson at Songbird Survival for generously funding my PhD. I would like to thank all the volunteer garden and cat owners who facilitated the majority of my fieldwork, allowing most of this research to take place. Thank you to the various undergraduate students who contributed to parts of my research both successful and unsuccessful; Bradley Collins, Gareth Beswick, Arron Watson, Alex Rozek, Imogen Brown, Ayesha Carew, Reuben Clarke, Toby Elliott, Lauren Vallance and Ben Dorgan. To Rob Jackson, Deepa Paliwal, Chris Foster, Marco Kreuzer, Sandro Leidi, Alejandra Perotti and Deepa Senapathi for lending their specialist expertise when called upon. To Colin Prescott for providing me with bird rings throughout my time at Reading. To my fellow postgrads and researchers of the People and Wildlife (PAW) Research Group and the University of Reading Biological Sciences more generally for their friendship and support. To Ana Wass, Tara Pirie, Yati Ngah, Sam Bedry, Peter Hanmer, the members and associates of Reading Knights and St Andrews University Canoe Clubs, and in particular to my partner Susan Jones for helping keep me sane through the highs and lows along this journey. Lastly, I wish to dedicate this thesis to my parents, Alison and Philip Hanmer as my passion for birds, wildlife, ecology and conservation largely originates from them! 3 The following people must be acknowledged for their practical assistance during the following chapters of this thesis: Chapter 2: Imogen Brown, Ayesha Carew, Reuben Clarke and Toby Elliott provided assistance with the collection of the data as part of their third year dissertations. This chapter is under review as: Hanmer, H. J., Thomas, R. L. and Fellowes, M. D. E. Been caught stealing: Introduced Grey Squirrels subvert supplementary feeding of suburban wild birds. Submitted to Landscape and Urban Planning. Each author contributed to writing the manuscript. Chapter 3 This chapter is published as: Hanmer, H. J., Thomas, R. L. and Fellowes, M. D. E., 2017. Provision of supplementary food for wild birds may increase the risk of local nest predation. Ibis. 159(1): 158-167. Each author contributed to writing the manuscript. Chapter 4: Ben Drogan assisted with the collection of the bacteria samples from bird feeders and initial cell processing before DNA extraction. Deepa Paliwal undertook the DNA extractions prior to Next Generation Sequencing and the initial data processing following it. Richard Ellis at the Animal Health and Veterinary Laboratories Agency coordinated the Next Generation Sequencing of the DNA samples. Rob Jackson provided important general guidance and expertise to the project. This chapter is in preparation for submission as: Hanmer, H. J., Paliwal, D., Jackson, R. W., Thomas, R. L. and Fellowes, M. D. E. Structure of bacterial communities on bird feeders determined by feeder design rather than animal visitors. In preparation for submission to Applied and Environmental Microbiology. Each author contributed to writing the manuscript. Chapter 5: Bradley Collins and Gareth Beswick provided assistance with the processing of nest material and invertebrate data as part of their third year dissertations. Chris Foster provided assistance 4 with the identification of invertebrates and generally helped supervise the students along with Tara Pirie. Alejandra Perotti provided specialist expertise for the identification of the mites. Colin Prescott provided bird rings and the locations of large proportion of the nest boxes used in the project. Arron Watson assisted with some of the nest box monitoring. Dave Coles, Tim Alexander and Tim Ball provided additional monitored nest samples from Beale Park, Lavell’s Lake NR and Hosehill Lake NR respectively. This chapter is published as: Hanmer, H. J., Thomas, R. L., Beswick, G.J.F., Collins, B.P. and Fellowes, M. D. E. 2017. Use of anthropogenic material affects bird nest arthropod community structure: influence of urbanisation, and consequences for ectoparasites and fledging success. Journal of Ornithology. DOI: 10.1007/s10336-017-1462-7. Each author contributed to writing the manuscript. Chapter 6 This chapter is under review as: Hanmer, H. J., Thomas, R. L. and Fellowes, M. D. E. Urbanisation affects range size of the domestic cat (Felis catus): consequences for conservation. Submitted to the Journal of Urban Ecology. Each author contributed to writing the manuscript. Declaration of original authorship: Declaration: I confirm that this is my own work and the use of all material from other sources has been properly and fully acknowledged. Hugh J. Hanmer. University of Reading. August 2017. 5 6 Contents Acknowledgements ................................................................................................................................. 3 List of figures ........................................................................................................................................ 11 List of tables.......................................................................................................................................... 15 Abstract ................................................................................................................................................. 17 Chapter 1: Introduction ......................................................................................................................... 19 1.1. Urbanisation .............................................................................................................................. 21 1.2. Urban green spaces ................................................................................................................... 21 1.3. Urban birds ................................................................................................................................ 22 1.4. Supplementary Feeding............................................................................................................. 25 1.4.1. Scale and extent ................................................................................................................ 25 1.4.2. Adult body condition and survival .................................................................................... 26 1.4.3. Density and distribution .................................................................................................... 27 1.4.4. Productivity ....................................................................................................................... 28 1.4.5. Predation ........................................................................................................................... 29 1.4.6. Pathogen transmission....................................................................................................... 31 1.5. Nest boxes ................................................................................................................................. 32 1.5.1. Nest boxes as a resource ................................................................................................... 32 1.5.2. Nest construction and parasitism ...................................................................................... 32 1.6. Competition and predation ........................................................................................................ 33 1.6.1. Invasive birds .................................................................................................................... 33 1.6.2. Grey Squirrels ................................................................................................................... 34 1.6.3. Domestic Cats ................................................................................................................... 34 1.7. Thesis rational, aims and objectives ......................................................................................... 35 Chapter 2: Been caught stealing: Introduced Grey Squirrels subvert supplementary feeding of suburban wild birds ............................................................................................................................... 39 2.1. Abstract ..................................................................................................................................... 41 2.2. Introduction ............................................................................................................................... 43 2.3. Materials and Methods .............................................................................................................. 45 2.3.1. Study Area ........................................................................................................................ 45 2.3.2. Individual Site Selection ................................................................................................... 45 2.3.3. Study Design ..................................................................................................................... 46 2.3.4.