Edith Cowan University Research Online Theses : Honours Theses 2000 A diet study of Australia's most critically endangered mammal, Gilbert's Potoroo, Potorous Gilbertii (Marsupialia : Potoroidae) Vinh Nguyen Edith Cowan University Follow this and additional works at: https://ro.ecu.edu.au/theses_hons Part of the Zoology Commons Recommended Citation Nguyen, V. (2000). A diet study of Australia's most critically endangered mammal, Gilbert's Potoroo, Potorous Gilbertii (Marsupialia : Potoroidae). https://ro.ecu.edu.au/theses_hons/534 This Thesis is posted at Research Online. https://ro.ecu.edu.au/theses_hons/534 Edith Cowan University Copyright Warning You may print or download ONE copy of this document for the purpose of your own research or study. The University does not authorize you to copy, communicate or otherwise make available electronically to any other person any copyright material contained on this site. 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EDITH COWAN UNIVERSITY LIBRARY Department of Conservation and Land Management A Diet Study of Australia's Most Critically Endangered Mammal, Gilbert's Potoroo, Potorous gilbertii (Marsupialia : Potoroidae) Vinh Nguyen THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE AWARD OF B. SC. (BIOLOGICAL SCIENCE) HONOURS FACULTY OF HEALTH, COMMUNICATION AND SCIENCE SCHOOL OF NATURAL SCIENCES EDITH COWAN UNIVERSITY NOVEMBER 2000 USE OF THESIS The Use of Thesis statement is not included in this version of the thesis. 1. ABSTRACT After 125 years of presumed extinction, Gilbert's Potoroo (Potorous gilbertii) was rediscovered in 1994 in Two Peoples Bay Nature Reserve, Albany. As only one population is known to exist, conservation is of prime importance. Faecal analysis was used to examine the diet of P. gilbertii. The species was found to be predominantly mycophagous (fungus-feeding) with invertebrate and plant matter fanning only a small part of its diet. Fungal material made up more than 90% of faecal matter throughout the year. A total of 44 fungal spore types were discerned. Of these, five were tentatively identified to species level with the remaining spores identified to genus, or assigned a representative name. The fungal genera Mesophellia and Hysterangium were the most frequently found and occurred in all faecal samples. Other fungal types in the faeces were found to change seasonally. Invertebrate and plant material comprise the minor dietary items with proportions of 2.4% and !.6% respectively. The large amount of fungus in the diet of P. gi/bertii closely resembles that of another endangered Potoroid, the Long-footed Potoroo (P. longipes). Diet studies of P. longipes indicate that it too is a specialised mycophagist. Consequently, conservation and diet issues of P. longipes could be incorporated into existing conservation strategies of P. gilbertii. ii Declaration· I certify that this thesis does not, to the best of my knowledge and belief: (i) incorporate without acknowledgement any material previously submitted for a degree or diploma in any institution or 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. Signed: . 'I Date: .........; ,/: .................... zj··ry . iii Acknowledgements I would like to thank first and foremost my two supervisors Dr A. Needham (Edith Cowan University) and Dr. J.A. Friend (Department of Conservation and Land Management). Dr Needham made everything possible and I owe him so much for his guidance, time, patience and most of all, confidence in me. Many thanks also to Dr Friend for his guidance, time and for sharing his wealth of knowledge and years of experience with me. Although there was a distance gap, he was still influential and it was a privilege to have worked with him. I would also like to thank my many work colleagues and friends, notably Bryan Duff, Julia Wilson, Derek Swarts, Ben Bradshaw, Cathy Arrese, Dana Hince and Dr. J. Courtenay for collectively providing constructive criticism and statistical assistance on this paper. They were always there when I cried help. These people will probably be better remembered for keeping me on track and making sure I knew how much time I had left. I will never forget their help. I'm sure they will not only be scientists, but great scientists. Thank you to the many other people who contributed their time for consultations. Special mention goes to Dr. A. Cochrane (Perth Herbarium) for identifying those mysterious seeds, Dr. Sivasitharnpararn and Dr. Park (University of Western Australia) for their time and David Mcdougall for statistical advice. Thanks to my many friends who have made me smile and kept me sane throughout this year. Finally, my loving parents who have always supported me in all situations. iv Table of Contents Abstract ......................................................................... .ii . .. Dec Iaratton ..................................................................... 111 Acknowledgements ........................................................... .iv Table of Contents ...............................................................v List of Tables ................................................................. viii List of Figures ................................................................... x List of Plates ...................................................................xii 2.0 INTRODUCTION ...................... oo o o o o 0 0 o0 o0 0 o.. o.. oo o o o o ....... 1 2.1 Taxonomy and Description of Potorous sp ............................. 2. 2.2 Early Discovery of Gilbert's Potoroo .................................... 3. 2.3 Past and Present Distribution .............................................5. 2.4 History of Two Peoples Bay ............................................. 6. 2.5 Current Status ...............................................................7. 3.0 LITERATURE REVIEW o.o.ooooo ....... ooooooooo.oo ........... ooooo,9. 3.1 Plant, Fungi and Mammals: A Tripartite Relationship ............... 9. 3.2 The Gastrointestinal Tract of a Potoroid and Macropod o•••oo••o•········ .............. o................... 13. v 3.3 Nutritional Quality and Spore Viability after Digestion ............. 17. 3.4 Effect of Fire on Fungal Abundance ................................... 20. 3.5 Mycophagy in North America ........................................... 22. 3.5.1 Chipmunks and Squirrels ....................................... 22. 3.5.2 Fungus Consumption by Voles (Clethrionomys sp.) ....... 24. 3.6 Mycophagous Mammals in Australia ..................................26. 3.6.1 Family Muridae .................................................. 26. 3.6.2 Mycophagy in Bush Rats ....................................... 28. 3.6.3 Family Peramelidae ..............................................29. 3.6.4 Sub-Family Hypsiprymnodontinae and Potoroinae .......... 30. 3.6.4.1 Bettongia sp ......................................... 31. 3.6.4.2 Potorous sp .......................................... 33. 4.0 MATERIALS AND METHODS .................................. 37. 4.1 Study Site .................................................................. 37. 4.2 Climate Conditions in Albany ...........................................39. 4.3 Trapping Procedure ...................................................... .40. 4.4 Faecal Collection and Sampling Regime ............................. .41. 4.5 Fine Fraction Analysis .................................................. .42. 4.6 Coarse Fraction Analysis ............................................... .43. 4.7 Statistical Analysis ...................................................... .43. 4.8 Experimental Considerations .............................................44. vi 5.0 RESULTS .............................................................46. 5.1 Overall Composition of Faecal Pellets ............................... ..46. 5.2 Comparison of Diet between Seasons ................................. 50. 5.3 Comparison of Faeces from Different Sites ........................... 52. 5.4 Faecal Analysis of Males and Females ................................53. 5.5 Diversity of Fungal Species in the Tbree Main Study Sites ........ 54. 5.6 Comparison of Spore Species Between Seasons ...................... 55. 5.7 Analysis of Fungal Species Between Sites ............................ 56. 5.8 Overall Fungal Species Observed in Faecal Samples ................58. 5.8.1 Seasonal Effect of Fungal Species in Faecal Samples ...... 60. 6.0 DISCUSSION .........................................................65. 6.1 Main Dietary Components ..............................................65. 6.2 Diet Rt'~tionship