Strategic Management of Artificial Watering Points for Biodiversity Conservation Rebecca Montague-Drake Bachelor of Science (Resource and Environmental Management) Hons A Thesis submitted for the Degree of Doctor of Philosophy School of Biological, Earth and Environmental Sciences The University of New South Wales, Australia 2004 Certificate of Originality I hereby declare that this submission is my own work and to the best of my knowledge it contains no material previously published or written by another person, nor material which to a substantial extent has been accepted for the award of any other degree or diploma at The University of New South Wales or any other educational institution, except where due acknowledgement is made in the thesis. Any contribution made to the research by others, with whom I have worked at The University of New South Wales or elsewhere, is explicitly acknowledged in the thesis. I also declare that the intellectual content of this thesis is the product of my own work, except to the extent that assistance from others in the project’s design and conception or in style, presentation and linguistic expression is acknowledged. Rebecca Montague-Drake July 2004 Abstract Since pastoralism began in Australia’s rangelands, the number of artificial watering points (AWPs) has increased dramatically, such that today, few areas of rangeland are further than 10 km from water. This increased availability of water has caused many ecological impacts. Unfortunately, such impacts are poorly understood in the context of an Australian conservation reserve, thus hindering strategic management. This study examined the spatial distribution of vertebrate (kangaroos, small mammals, lizards and avifauna) and vegetative variables around open AWPs as well as AWPs that have been closed since pastoralism (sheep-grazing) ceased nearly thirty years ago in Sturt National Park, arid New South Wales. The study also examined vertebrate use of AWPs, with a particular emphasis on kangaroos and avifauna. The study revealed that most variables showed few differences in spatial distribution with distance from open and closed AWPs, thus suggesting that the observed piospheric impacts were primarily attributable to historical sheep-grazing. Indeed, piospheric patterns were weak suggesting some recovery over the last thirty years. That kangaroos did not exhibit water-focused grazing is no surprise, since despite their regular use of AWPs, particularly during hot, dry times, the current spatial arrangement of AWPs facilitates regular travel to, and from, such resources allowing kangaroos, like much other fauna, to distribute themselves in relation to food and shelter preferences rather than in relation to water supply. In contrast, the majority of avifaunal groups (excluding ground-dwelling species) were clustered around open AWPs, often irrespective of season, because of food and water requirements. Such spatial concentrations of avifauna are thought to cause a range of interspecific effects. Experimental AWP closure and GIS modelling showed that whilst closure of AWPs will increase the average distance to water, which will have key benefits, the majority of areas in Sturt National Park would still be accessible to most water- dependent species even if all unused AWPs were closed. Strategic retention of AWPs to replace water sources lost since European settlement, aid threatened and migratory species’ conservation and enhance nature-based tourism opportunities is thus recommended and an example of a strategic management and monitoring plan outlined. i Acknowledgements I would firstly like to greatly thank my supervisor, Dr David Croft, for all of his varied assistance. I would especially like to thank him for his constructive feedback, statistical advice, sourcing of funding and equipment, design of specialised computer programs and his field assistance, particularly his time spent collaring kangaroos and installing the remote data units. I would also especially like to thank him for entrusting this project to me. The experience has not only greatly increased my understanding of ecology, but has left me with wonderful memories of my time in Sturt National Park. I would also very much like to thank the NSW National Parks and Wildlife Service, Tibooburra Area, for their generous in-kind support and especially for allowing me to work in Sturt National Park and stay at Olive Downs Homestead. I would particularly like to thank Lars Kogge, John Jackson, Ingrid Witte, Dan Hough and Anne-Maree Smith for their varied assistance over the study and great friendship. In particular, I would like to thank the Tibooburra Area for diesel, use of the tractor for pitfall digging, mechanical assistance, personnel hours and use of office facilities. I would sincerely like to thank the many volunteers (a.k.a. the “Germans”), for their assistance, friendship and laughs in the field and Dr Udo Ganslosser for organising volunteers. Without such assistants, the project would not have been as comprehensive. I would also like to thank staff at the University of NSW, in particular Paul Adams (Fowlers Gap Research Station) for assistance with, and use of, the good ol’ Navara, Jan de Naardi and Frank Hemmings (John T. Waterhouse Herbarium) for helping to identify plant specimens and Assoc. Prof. Paul Adam for his varied support. I also would like to thank the NSW National Parks and Wildlife Service Kangaroo Management Program for financial and other support and the NSW National Parks and Wildlife Service, Threatened Species Unit, Dubbo for pitfall funding. I would also like to thank the people of Tibooburra for their many kindnesses over the study, particularly John and Mavis Jackson and Caroline and Wayne Betts. I wish to heartily thank Anke Frank and Amanda Bilton for their friendship, without which, my experiences in far western NSW would not have been the same. I would especially like to thank Anke for her untiring field assistance and enthusiasm. I would also like to thank my parents for their interest, love and understanding and for kindling my passion for nature. Finally, but especially, I would like to lovingly thank my partner, Josh Bean, who has been an unfailing source of support in every aspect of my project, and to whom words can not express my immense gratitude. This project was funded by a federal government ‘Strategic Partnerships in Research and Training’ (SPIRT) grant with the Western Directorate of the NSW National Parks and Wildlife Service and an Australian Postgraduate Award scholarship. ii Table of Contents Abstract .......................................................................................................................... i Acknowledgments......................................................................................................... ii Table of Contents .........................................................................................................iii List of Tables .............................................................................................................viii List of Figures ............................................................................................................... x List of Plates................................................................................................................ xii List of Commonly Used Abbreviations .....................................................................xiii Chapter 1 Introduction............................................................................................... 1 1.1 Study Rationale ....................................................................................................... 1 1.2 A Brief History of Pastoralism in the Rangelands.................................................. 3 1.3 Changes in the Rangelands since European Settlement.......................................... 4 1.4 Twentieth Century Management of the Rangelands............................................... 9 1.5 Impacts of Artificial Watering Points ................................................................... 10 1.5.1 Background.................................................................................................. 10 1.5.2 Temporal Distribution around AWPs.......................................................... 10 1.5.3 Spatial Distribution around Open AWPs .................................................... 13 1.5.4 Spatial Distribution around Closed AWPs.................................................. 24 1.6 Faunal Use of AWPs............................................................................................. 26 1.6.1 Introduction ................................................................................................. 26 1.6.2 Kangaroo Use of AWPs .............................................................................. 26 1.6.3 Small Mammal Use of AWPs .................................................................... 29 1.6.4 Herpetofaunal Use of AWPs ....................................................................... 29 1.6.5 Avifaunal Use of AWPs .............................................................................. 30 1.7 Strategic Management of AWPs........................................................................... 32 1.8 Scope of the Thesis .............................................................................................. 33 1.9 Structure of the Thesis .......................................................................................... 34