A National Assessment of the Conservation Status of the Platypus Assessors: Tahneal Hawke, Gilad Bino, Richard T
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A national assessment of the conservation status of the platypus Assessors: Tahneal Hawke, Gilad Bino, Richard T. Kingsford. Contributors: Tom Grant, Josh Griffiths, Andrew Weeks, Reid Tingley, Emily McColl-Gausden, Melody Serena, Geoff Williams, Tamielle Brunt, Luis Mijangos, William Sherwin, Jessica Noonan. Acknowledgements: This report was funded through a research grant from the Australian Conservation Foundation (ACF) in collaboration with WWF-Australia and Humane Society International (HIS). Date: 17/11/2020 We acknowledge the Traditional Owners of this country and their continuing connection to land, waters and community. We pay respect to elders both past and present. Table of Contents Table of Contents ....................................................................................................................... 2 Table of Figures ......................................................................................................................... 5 Table of Tables .......................................................................................................................... 8 Executive summary ................................................................................................................... 9 Taxonomy ................................................................................................................................ 11 IUCN threated species assessment status ................................................................................ 11 EPBC threatened species assessment status ............................................................................ 11 Species description .................................................................................................................. 11 The platypus in indigenous culture .......................................................................................... 12 Utilization of taxon .................................................................................................................. 12 Geographic Range ................................................................................................................... 13 Countries of occurrence ....................................................................................................... 13 Distribution .......................................................................................................................... 13 Change in distribution ......................................................................................................... 15 Extent of Occurrence/Sub-catchments ............................................................................ 16 Area of occupancy ........................................................................................................... 24 Habitat and ecology (see Appendix for additional information) ............................................. 27 Systems ................................................................................................................................ 27 Generation length ................................................................................................................ 27 Ecology ................................................................................................................................ 27 Habitat ................................................................................................................................. 28 Population ................................................................................................................................ 29 Historical numbers ............................................................................................................... 29 Contemporary numbers ....................................................................................................... 31 Population trends ................................................................................................................. 38 Case study: Greater Melbourne region ............................................................................ 41 2 Estimated current population size ........................................................................................ 45 Extinction probability and viability models ........................................................................ 48 Life history ...................................................................................................................... 50 Incorporating threats to metapopulation models ............................................................. 51 Models ............................................................................................................................. 53 Threats (See Appendix for additional information) ................................................................ 61 Vegetation clearing .............................................................................................................. 61 Urbanisation ......................................................................................................................... 63 River regulation ................................................................................................................... 64 Fishing by-catch, predation & pollution .............................................................................. 67 Disease ................................................................................................................................. 67 Climate change .................................................................................................................... 67 Cease to flow and drought ................................................................................................... 72 Bushfires .............................................................................................................................. 73 Conservation ............................................................................................................................ 76 Current knowledge gaps ...................................................................................................... 76 Conservation actions in place (See Appendix for additional information) ......................... 77 Monitoring actions in place ................................................................................................. 77 Conservation actions needed (See Appendix for additional information) .......................... 78 Future surveys .................................................................................................................. 78 Mitigating threats ............................................................................................................. 79 Research ........................................................................................................................... 79 Legislation ....................................................................................................................... 80 Summary of declines ............................................................................................................... 81 A. Population size reduction ............................................................................................. 82 B. Geographic range .......................................................................................................... 82 C. Small population size and decline ............................................................................... 82 3 D. Very small population size and decline ....................................................................... 83 E. Quantitative analysis .................................................................................................... 83 Potential listing category ................................................................................................... 83 References ............................................................................................................................... 84 AppendiX ................................................................................................................................. 95 Appendix 1 .......................................................................................................................... 95 Appendix 2 .......................................................................................................................... 99 Appendix 3 ........................................................................................................................ 101 4 Table of Figures Figure 1. All reported sightings of platypuses (Atlas data bases, iNaturalist, museum records, Trove, platypusSPOT; 1885-2020; green since 2000, red prior to 2000), the current IUCN platypus distribution (blue shading) and sub-catchments (HydroBASIN Level 6 sub- catchment; Lehner et al. (2008)) which intersect the IUCN distribution or contain a platypus record. ...................................................................................................................................... 14 Figure 3. Last year of platypus record in each sub-catchment (HydroBASIN Level 7) across the distribution of platypus. ..................................................................................................... 19 Figure 4. Last year of platypus record in each of the sub-catchments (HydroBASIN Level 8). ................................................................................................................................................