Response of Australian Boobooks (Ninox boobook) to threatening processes across urban, agricultural, and woodland ecosystems Michael T. Lohr B.S. The Pennsylvania State University M.S. The University of Delaware Thesis Submitted for the degree of Doctor of Philosophy in the School of Science Edith Cowan University November 2019 “One of the penalties of an ecological education is that one lives alone in a world of wounds. Much of the damage inflicted on land is quite invisible to laymen. An ecologist must either harden his shell and make believe that the consequences of science are none of his business, or he must be the doctor who sees the marks of death in a community that believes itself well and does not want to be told otherwise.” - Aldo Leopold, “A Sand County Almanac” ii Abstract The effects of habitat fragmentation on native wildlife can vary depending on the type of land use occurring in the matrix between remaining habitat fragments. I used Australian boobooks (Ninox boobook) in Western Australia to investigate interactions between matrix type and four different potential threatening processes: secondary poisoning by anticoagulant rodenticides (ARs); limitation of juvenile dispersal and impacts on spatial genetic structure; breeding site availability; and infection by the parasite Toxoplasma gondii. I also conducted a literature review on the use and regulation of ARs in Australia and published accounts of non-target impacts in order to contextualise exposure patterns observed in boobooks. The review revealed records of confirmed or suspected poisoning across 37 vertebrate species in Australia. World literature relating to AR exposure in reptiles suggests that they may be less susceptible to AR poisoning than birds and mammals. This relative resistance may create unevaluated risks for wildlife and humans in Australia where reptiles are more abundant than in cooler regions where AR exposure has been studied in greater depth. I analysed AR residues in boobook livers across multiple habitat types. Second generation anticoagulant rodenticides were detected in 72.6% of individuals sampled. Total AR concentration correlated positively with the proportion of urban land use within an area approximately the size of a boobook’s home range centred on the point where the sample was collected. ARs originating in urban habitat probably pose a substantial threat to boobooks and other predatory wildlife species. No spatial genetic structure was evident in boobooks across habitat types. I observed one individual dispersing at least 26km from its natal home range across urban habitat. The apparent permeability of anthropogenically altered landscapes probably explains the lack of spatial genetic structure and is likely related to the observed ability of boobooks to use resources in both urban and agricultural matrices. Boobooks did not appear to be limited by the availability of suitable nesting sites in urban or agricultural landscapes. Occupancy did not change significantly over the duration of the study in remnants provided with artificial nest boxes in either landscape type. iii However, in one instance, boobooks successfully used a nest box located in an urban bushland. Nest boxes may be a useful management tool in highly-altered areas where natural hollows are unavailable. Toxoplasma gondii seropositivity in boobooks did not vary significantly by landscape type but was more prevalent in individuals sampled during cooler wetter times of year. Risk of exposure due to greater cat abundance in urban and agricultural landscapes may be offset by creation of environmental conditions less favourable to the survival of T. gondii oocysts in soil. Taken together, this body of research demonstrates variation in relationships between different types of habitat fragmentation and threatening processes related to fragmentation. This research also raises questions about how habitat fragmentation is discussed and studied in the context of species which are capable of making extensive use of matrix habitat. I recommend greater consideration of the concept of “usable space” when studying fragmentation impacts in habitat generalists. iv Declaration I certify that this thesis does not, to the best of my knowledge and belief: i. incorporate without acknowledgment any material previously submitted for a degree or diploma in any institution of higher education; ii. contain any material previously published or written by another person except where due reference is made in the text; or iii. contain any defamatory material. iv. I also grant permission for the Library at Edith Cowan University to make duplicate copies of my thesis as required. Michael T. Lohr 06/11/2019 v Acknowledgments I would first like to thank my supervisors Dr. Rob Davis and Dr. Allan Burbidge. Their insights into navigating the complex ecosystem that is conservation research in Western Australia are greatly appreciated. I sincerely appreciate the free rein they gave me in exploring a series of sometimes unconventional side projects. These opportunities have proved invaluable. Rob’s willingness to meet at length to discuss new opportunities and troubleshoot occasional difficulties made the entire PhD experience easier and more enjoyable. Cheryl, your accommodation of my bizarre nocturnal field schedule, financial support, tolerance for endless monologues about anticoagulant rodenticides, and R code are what made this whole thing actually work. Thank you. I look forward to having our life back in the near future. Many thanks to the large number of people and organisations willing to hold their collective noses and accumulate dead owls for me. This PhD would not have been possible without your efforts. I hope to continue to do my part to convert the smelly data you collected into meaningful conservation actions. Samples were contributed by Kanyana Wildlife Rehabilitation, Native Animal Rescue, Native ARC, Nature Conservation Margaret River Region, Eagles Heritage Wildlife Centre, and many individual volunteers especially Steve Castan, Simon Cherriman, Angela Febey, Warren Goodwin, Amanda Payne, Stuart Payne, and Boyd Wykes. Many people provided help on long nights of owl surveys and nest box checks including: Casper Avenant, Rachele Bernasconi, Jakeb Cumming, Angela Febey, Sian Glazier, Melissa Hetherington, Tyson Isles, Michael Just, Candice Le Roux, Gabe Mach, Paul Radley, Calan Rance, Geoffrey Schoonakker, Nakisa Shahrestani, Lia Smith, Steven Spragg, Paula Strickland, and Mitch Wright. I am particularly grateful to Simon Cherriman, whose enthusiastic assistance in preliminary field work helped me build confidence in working with these amazing birds. His subsequent nest box design, construction, and installation and advice on interpretation were critical to the nest box chapter. The inclusion of Simon’s photo in the title page of this vi dissertation is a testament to the quality of his photography and the mileage I have gotten out of his photos of my work. I sincerely hope I can repay my debt as he continues his PhD and I look forward to future and ongoing collaborations. I wish to express my sincere thanks to Dr. Jamie Tedeschi for her patience and expertise in introducing me to the world of genetic analysis and to Louise Pallant and A/Prof. Annette Koenders for their advice and assistance on serological testing. Training a field ecologist to do lab work is surely a painful experience and I am grateful that they attempted it. I particularly appreciate Jerry Olsen contributing data from his boobook banding projects as well as helpful advice and friendly correspondence throughout my PhD. I also thank Ben Jones and Yvonne Sitko for helping me to communicate the results of my work to the public. Without their efforts, much of my work would not have made it to the people who can actually use it. I especially thank Rachele Bernasconi, Casper Avenant, Melissa Karlinski, Emily Lette, Rosh McCallum, and Charlie Phelps for their moral support and for tolerating my eccentricity, frightening desktop, and questionable musical taste through the writing process. Your contributions to my sanity were critical to getting this dissertation finished. vii Statement of contribution of others Research Funding The Holsworth Wildlife Research Endowment via The Ecological Society of Australia BirdLife Australia Stuart Leslie Bird Research Award Edith Cowan University School of Science Postgraduate Student Support Award Eastern Metropolitan Regional Council’s Healthy Wildlife Healthy Lives program The Society for the Preservation of Raptors Sian Mawson Stipend Edith Cowan University Postgraduate Research Scholarship Edith Cowan University Merit Award Supervision Dr. Robert A. Davis Dr. Allan H. Burbidge Field Assistance Casper Avenant, Rachele Bernasconi, Simon Cherriman, Jakeb Cumming, Angela Febey, Sian Glazier, Melissa Hetherington, Tyson Isles, Michael Just, Candice Le Roux, Gabe Mach, Paul Radley, Calan Rance, Geoffrey Schoonakker, Nakisa Shahrestani, Lia Smith, Steven Spragg, Paula Strickland, Mitch Wright Laboratory Technical Assistance and Advice A/Prof. Annette Koenders, Louise Pallant, Dr. Jamie Tedeschi, Co-Authors Dr. Janet Anthony, Dr. Allan H. Burbidge, Simon Cherriman, Dr. Robert A. Davis, Dr. Siegfried Krauss, Dr. Cheryl A. Lohr, A/Prof. Peter B. S. Spencer The research included in this dissertation is my original work. I conceived and developed all hypotheses, led all field work, designed or conducted the majority of analysis,wrote all first drafts, and made the majority of edits to