Resource Use by the Eastern Grey Kangaroo and the Black Wallaby in a Managed Remnant Woodland Community Ferdinand (Fred). G. de Munk BSc. (Hons). MSc. Dip.Ed (Melb) G.Dip.Ed.Admin. (Deakin) A Thesis Presented for the Degree of Doctor of Philosophy School of Ecology and Environment Deakin University June 1999 CANDIDATES CERTIFICATION The work in this thesis is solely the work of the candidate except for the following: The histological preparation of plant specimens for the reference herbarium was done by Ms. Carole Hair of RMIT. Honours and third year students from RMIT Environmental Science assisted in the collection of faecal pellets and biomass material from the Coranderrk Reserve. Assistance with the identification of vascular plants was provided by the horticulture department staff of the Healesville Sanctuary. No material in this thesis has been accepted for a degree or a diploma by any other institution. This thesis may be made available for consultation, loan and limited copying in accordance with the Copyright Act 1968. The author verifies that the thesis does not contain more than 100,000 words. PLAIN LANGUAGE SUMMARY This work studies the interactions and relationships that exist between Eastern Grey Kangaroos and Black Wallabies in their utilisation of spatial and trophic resources in a managed remnant woodland community. The thesis provides a closer understanding of the way in which these species impact upon their habitats. The Coranderrk Reserve, near Healesville in eastern Victoria, Australia was the study site. A floristic analysis of the communities of the study site was conducted. This consisted of plant biomass measurements, estimates of plant abundance and cover determinations. Faecal pellets from Eastern Grey Kangaroos and Black Wallabies were collected from ten vegetation communities during three different plant productivity periods. The spatial and temporal distribution of the animals was identified by analysing the frequency of occurrence of faecal pellets in the various communities. The use of faecal pellet density as a measure of habitat utilisation was examined. Eastern Grey Kangaroos utilised communities which were characterised by the presence of a dense grassy stratum. Black Wallabies were able to utilise all of the communities of the study site regardless of their floristic composition. A reference herbarium of the leaf epidermis of 233 possible forage plant species was accumulated. These epidermal specimens were prepared for Confocal Scanning Laser Microscopy. The information gained was enhanced and stored digitally. Diagnostic information critical for the identification of plant epidermal fragments was assembled into a computer database. This was used to assist in the recognition of unknown epidermal fragments in macropodid faeces. These epidermal plant recognition techniques enabled a list of the contents of Eastern Grey Kangaroo and Black Wallaby faeces during the sampling periods in the individual communities, to be accumulated. Eastern Grey Kangaroos utilised forage which consisted largely of grass and their diets were similar regardless of their feeding sites or the time of the year. Black Wallaby diets were heterogenous with wide variations over space and time observed. The implications of these findings for current wildlife management practices were considered. Black Wallaby and Eastern Grey Kangaroo herbivory have significant impacts on ecosystem integrity. Management strategies should seek to establish ecologically sustainable populations of both species in remnant woodlands where conservation values are important. ACKNOWLEDGMENTS The author is very grateful to Dr. David Middleton, Mr. Geoff Underwood, Mr Paul Slinger and Dr. David Ramsay who provided invaluable advice and guidance. Professor Peter Temple-Smith from the Conservation Department of the Zoological Board of Victoria is thanked for allowing free access to the Coranderrk Reserve. Professor Robert Wallis and Dr. Graeme Coulson have been outstanding supervisors of the work in this thesis and of the candidate. Professor Robert Wallis has provided inspiration and encouragement as well as expert assistance in the preparation of this thesis and in the field work upon which it is based. His leadership and genuine desire for scholarship has been invaluable. Dr. Graeme Coulson from the University of Melbourne, Department of Zoology, has examined every aspect of this work with meticulous care and attention to detail. His advice, suggestions and sense of humour have been seminal in the supervision and completion of this project and have contributed significantly to its final state. I am very grateful to Graeme without whose assistance and encouragement the work would not have been completed. Dr. Robyn Adams provided expert assistance with the botanical aspects of this work and her advice was greatly appreciated. The work was financially supported by a staff development award from the State Government of Victoria, by a Royal Melbourne Institute of Technology Faculty of Science Research Grant and by a small grant from the Australian Research Council. I am very grateful to the obliging staff from the off-campus section of the Deakin University library. Their service is amazing. Mr Colin Findlay and Associate Professor Reg Poole are owed a debt of gratitude for their encouragement in a substantial fashion along the way. Without their prompting, support and friendship this would never have been possible. Honours and third year environmental science students from RMIT were willing assistants in the collection of field material. Their assistance is recognised and gratefully acknowledged. Excellent laboratory assistance was provided by Ms. Carole Hair from the Department of Medical Laboratory Technology at RMIT in the preparation of specimens for histological examination. To Dianne, Dean, Lisa, Ryan, Joel and Casey de Munk I wish to express my sincere thanks for the support and morale boosting encouragement which was always there at the right time. This thesis is dedicated to them. CONTENTS PAGE Abstract 1 Chapter 1: Introduction 4 1.1. The Background for the Work 4 1.2. The Problem 5 1.3. The Objectives of this Study 5 1.4. The Structure of the Thesis 7 Chapter 2: Resource Use And Management Of Eastern Grey Kangaroo And 9 Black Wallaby Populations 2.1. Introduction 9 2.2.1. Resource Use 10 2.2.2. Competition Between Eastern Grey Kangaroos and Black Wallabies 12 2.3. Utilisation of Habitat by Macropodid Populations 13 2.3.1. Hierarchy of Resource Utilisation 13 2.3.1.1. First Order Distribution of Eastern Grey Kangaroos and Black Wallabies 13 2.3.1.2. Second Order Distribution of Eastern Grey Kangaroos and Black 14 Wallabies 2.3.1.3. Third Order Distribution of Eastern Grey Kangaroos and Black Wallabies 19 2.3.2. Indirect Indicators of Habitat Utilisation 22 2.3.2.1. Faecal Pellet Density Measurements 22 2.3.2.2. Faecal Pellets as Indicators of Habitat Use 22 2.3.2.3. Assumptions, Uncertainties and Weaknesses of Faecal Pellet Density 23 Estimations 2.3.2.4. Improvements to the Methodology 24 2.4. Diet Selection by Eastern Grey Kangaroos and Black Wallabies 24 2.4.1. The Role of Diet 24 2.4.2. Direct Methods of Determining Diet 25 2.4.3. Ingesta Examinations 27 2.4.3.1. Mouth or Stomach Contents 27 2.4.3.2. Fistula Derived Diet Sampling 28 2.4.3.3. Faecal Pellet Analysis 28 2.4.3.4. A Comparison of Indirect Methods 29 2.4.4. The Limitations of Faecal Examinations 30 2.4.4.1. Identification 30 2.4.4.2. Differential Digestibility 31 2.4.5. Sample Preparation. 33 2.4.6. Sample Examination 34 2.4.7. The Problem of Diet Selection 36 2.5. Conclusions 39 Chapter 3: The Study Site: The Coranderrk Reserve 40 Abstract 40 3.1. Introduction 40 3.2. The Coranderrk Reserve 41 3.2.1. Location 41 3.2.2. History 43 3.2.3. Physiography 45 3.2.4. The Climate 47 3.2.5. The Soils 49 3.3. The Biota of the Coranderrk Reserve 49 3.3.1. The Flora of the Coranderrk Reserve 49 3.3.2. The Fauna of the Coranderrk Reserve 57 3.3.3. Macropodids in the Coranderrk Reserve 58 3.4. Ecology and Management 62 3.5. Conclusion 65 Chapter 4: The Vegetation Structure Of The Coranderrk Reserve 66 Abstract 66 4.1. Introduction 66 4.2. Methods 68 4.2.1. Sampling Strategy 68 4.2.2. Cover and Abundance 71 4.2.3. Biomass 72 4.3. Results and Discussion 76 4.3.1. Cover and Abundance 76 4.3.2. Biomass 91 4.3.2.1. July Biomass 91 4.3.2.2. December Biomass 94 4.3.2.3. February Biomass 99 4.4. Discussion 102 4.5. Conclusion 103 Chapter 5: Community Selection And Habitat Use By Macropodids In The 104 Coranderrk Reserve Abstract 104 5.1. Introduction 105 5.2. Methods 106 5.2.1. Pilot Studies 106 5.2.2. Sampling Strategy and Faecal Pellet Collection Techniques. 109 5.3. Results 111 5.3.1. Faecal Pellet Collections 111 5.3.2. Estimates of Community Selection 115 5.3.3. Macropodid Habitat Use 117 5.4. The Interaction Between Community, Macropodid Species and Season and 120 its Effect on Habitat Use 5.4.1. The Interaction Between Community and the Two Macropodid Species 120 (AB Interaction) 5.4.2. The Interaction Between Community and Season (BC Interaction) 122 5.4.3. The Interaction Between Species, Community and Season (ABC 124 Interaction) 5.5. Spatial Resource Use by Macropodids 127 5.5.1. The Selection of Space 127 5.5.2. The Location of Macropodids in the Coranderrk Reserve 130 5.6. Selected Community Characteristics Summary 133 5.7. Conclusions 134 Chapter 6: The Development Of A Confocal Scanning Laser Microscope 136 Herbarium Of Coranderrk Reserve Plant Epidermis Abstract 136 6.1. Introduction 136 6.1.1. Confocal Scanning Laser Microscopy 136 6.1.2.