FEEDING ECOLOGY OF AN INVASIVE PREDATOR ACROSS AN URBAN LAND USE GRADIENT Submitted by Ben Stepkovitch BSc (Advanced Science - Zoology) A thesis submitted in requirement for the degree of Master of Research Hawkesbury Institute for the Environment Western Sydney University September 2017 Supervisory panel: Dr. Justin Welbergen, Hawkesbury Institute for the Environment, Western Sydney University (Principal Supervisor) Dr. John Martin, Royal Botanic Garden & Domain Trust, Sydney (Principal Supervisor) Professor Christopher Dickman, School of Biological Sciences, University of Sydney (Associate Supervisor) ACKNOWLEDGEMENTS The work undertaken for this study would not be possible without the contributions of many people and organisations. First and foremost, I must thank my supervisors Justin Welbergen, John Martin and Chris Dickman for all their help, support and expertise over the course of this project; and for going above and beyond to help explain concepts that I was unfamiliar with prior to this project. I must acknowledge the Hawkesbury Institute for the Environment for supporting the costs involved with this study and for allowing me to attend conferences to present my research where I had valuable opportunities to network with other people in the field of vertebrate pest management and wildlife research. I would not have been able to put the time and effort into this project without the support of my parents, who kept a constant supply of leftovers in the fridge for me for when I would return home late from the lab or training. I must also thank my partner for putting up with me over the course of this project, even when I stunk out the car with roadkill foxes. Big thanks must also go out to my Australian team mates for understanding my commitments for this project but also pushing me to find time to train in preparation for our competition this year. To my employers, thank you for your understanding of my commitments towards field work (in other aspects of this project) and allowing me to be flexible with my work hours when necessary. The amount of foxes obtained for this study would not have been possible without the assistance of National Parks and Wildlife Services (NPWS) Metro North-East and the Desert Ecology Research Group (DERG) at the University of Sydney, for their donation of old chest freezers that enabled me to set up fox carcass drop off points across Sydney. Thanks as well to David Phalen for providing freezer space at his clinic for carcasses to be dropped off there. I must thank the staff at the DERG again for taking me under their wing during this project, not only providing me with lab space but office space as well. Fundamentally, this research could not have been carried out if it weren’t for the numerous pest controllers, land managers and numerous others who went out of their way to provide carcasses (or at least keep them fresh for me) for this project or alerted me to the presence of dead foxes that could be collected. Thanks to all of you, we can now shed some light on the potential impacts of foxes on native species in Sydney. Especially, I must thank Jared McNaught (NPWS Metro North East), Alison Towerton (Greater Sydney Local Land Services), Jason Dimmuno (Stealth Pest Control) and the team at Australian Feral Management (AFM) for their significant contribution of carcasses and local knowledge about foxes in Sydney. There were many people who helped me out in the lab, whether that be providing advice on different techniques or helping me to process carcasses. Juliana Brailey, Steph Yip, Josh Phillips and Bobby Tamayo thank you so much for all your assistance over the course of this project. To Justin Welbergen, Glen Shea, and Jan Slapeta, thank you for taking the time to identify various prey or parasite remains and allowing me to bring smelly prey remains into your offices. Also thank you to Jessica Meade and Vanya Jha for their assistance with mapping and extracting human population density data to be used for analysis. There were a few aspects of this project that haven’t got off the ground yet, such as camera collars for foxes, but thank you to all that helped with the initial development of a prototype (yet to be tested). To Calmsley Hill City Farm, thank you for allowing me to try out prototypes on your captive red foxes; to Hugh McGregor, thank you for your time in explaining the ins and outs of developing a similar design to what you used on feral cats; and thank you to Cam-Do Solutions, Ragecams and Outdoor Cameras Australia for all your advice on the technical aspects of developing camera collar. Lastly, thank you to Heather Crawford, Malcolm Kennedy, Joe Porter, Stephen Sarre and Anna MacDonald for your various insights into different aspects of the project. This research has been conducted under Animal Research Authority no. A11254 issued by Western Sydney University, approved 22/3/2016. TABLE OF CONTENTS TABLE OF CONTENTS ................................................................................................................................. I LIST OF TABLES .......................................................................................................................................... III LIST OF FIGURES ........................................................................................................................................ IV LIST OF APPENDICES ............................................................................................................................... VI LIST OF ABBREVIATIONS ..................................................................................................................... VII SUMMARY ................................................................................................................................................... VIII CHAPTER 1: INTRODUCTION & THESIS OVERVIEW .................................................................... 9 1.1 General Introduction ...................................................................................................................... 9 1.2 Red fox diet across environments .......................................................................................... 14 1.3 Red fox morphology and condition across environments ........................................... 20 1.4 Study Aims ....................................................................................................................................... 22 1.5 Study Area ........................................................................................................................................ 23 1.6 Thesis Overview ............................................................................................................................ 27 CHAPTER 2: DIET COMPOSITION OF AN INVASIVE PREDATOR ACROSS AN URBAN TO NATURAL LAND USE GRADIENT ................................................................................................. 28 2.1 Abstract ............................................................................................................................................. 28 2.2. Introduction ................................................................................................................................... 30 2.3 Methods ............................................................................................................................................. 33 2.3.1 Study area ................................................................................................................................ 33 2.3.2 Carcass collection, measurement and dissection .................................................... 33 2.3.3 Diet assessment ..................................................................................................................... 34 2.3.4 Land use categories ............................................................................................................. 35 2.3.4 Statistical analysis ................................................................................................................ 37 2.4 Results ............................................................................................................................................... 38 2.4.1 Diet across the Greater Sydney region ........................................................................ 38 2.4.2 Diet composition across a land use gradient ............................................................ 43 2.4.2.1 Non-urban vs. Urban superclass ............................................................................ 46 2.5 Discussion ........................................................................................................................................ 47 2.5.1 Variation in diet composition among land use categories ................................... 48 2.5.2 Variation in diet composition across the land use gradient ............................... 49 2.5.2.1 Exploiting anthropogenic food ............................................................................... 50 2.5.2.2 Native and introduced mammals .......................................................................... 52 2.5.3 Implications for fox management in urban areas of Australia .......................... 52 I 2.6 Conclusion ........................................................................................................................................ 56 CHAPTER 3: MORPHOMETRICS AND BODY CONDITION OF AN INVASIVE PREDATOR ACROSS AN URBAN