GWF Turtle Report 2008
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Gnaraloo Turtle Conservation Program Gnaraloo Bay Rookery Gnaraloo Cape Farquhar Rookery Report 2008 - 2018 www.gnaraloo.org Gnaraloo Wilderness Foundation & Gnaraloo Turtle Conservation Program File name: 180626_ReportGTCP0818_1.docx 28 June 2018, Page 1 of 177 www.gnaraloo.org Gnaraloo Turtle Conservation Program - Gnaraloo Wilderness Foundation This report may be cited as: Hattingh, K., Bosshard, S., Concannon T., DeSerisy T., Shipp, H., and Soulsby, M. (2018). Gnaraloo Turtle Conservation Program. Gnaraloo Bay Rookery and Gnaraloo Cape Farquhar Rookery, Report 2008 - 2018. Gnaraloo Wilderness Foundation, Western Australia, www.gnaraloo.org Dates in the report concern the Australian fiscal calendar which is annually from 1 July – 30 June. The Gnaraloo Wilderness Foundation acknowledges and thanks: The Gnaraloo Station Trust. Paul Richardson and the Richardson family in Northern Ireland and the United Kingdom. The Australian Government’s National Landcare Program and Caring for our Country grants. GTCP scientific teams 2008/09 – 2016/17 (onsite and offsite). Alan Gillen, Colleen Mason and Barbara Gadomski. Alistair Green. Brendan Slade and Andrew Greenley. Aubrey Strydom. The Baiyungu People of Cardabia Station for use of the name ’Baiyungu’ for one of our two satellite tagged turtles. Mike Butcher and the team of Animal Pest Management Services. Dof Dickinson, Rachel Courtright, Kishore Kumar and the other teams of Brains. Mark Scholmann, Linda Brnjich and Leonie Jones of Chilli Finance. Soundwave Nomad Production. esri Australia. Ricoh. Microsoft. Department of Biodiversity, Conservation and Attractions, Western Australia. Cover photo by Heather Shipp. Design by Claire Guillaume. Copyright © 2018 Gnaraloo Wilderness Foundation. All rights reserved. The report may be duplicated, copied and reproduced provided that the Gnaraloo Wilderness Foundation and the authors are acknowledged in writing in such materials and dealings. Contact Karen Hattingh, [email protected] File name: 180626_ReportGTCP0818_1.docx 28 June 2018, Page 2 of 177 www.gnaraloo.org CONTENTS 1 EXECUTIVE SUMMARY............................................................................................. 11 2 BACKGROUND .......................................................................................................... 23 2.1 Program overview ............................................................................................. 23 2.2 Sea turtle conservation: global to regional perspectives ............................... 24 2.3 GTCP and GFACP in context ............................................................................ 26 2.4 Focal species: loggerhead turtle ...................................................................... 27 Distribution and population ....................................................................... 27 Nesting in WA .......................................................................................... 28 Conservation status ................................................................................. 29 2.5 Recruitment and team composition ................................................................. 30 2.6 Training .............................................................................................................. 31 2.7 Funding and resourcing .................................................................................... 31 2.8 Approvals ........................................................................................................... 32 3 GNARALOO WEATHER ............................................................................................ 36 3.1 Introduction ....................................................................................................... 36 3.2 GBR Survey Area ............................................................................................... 36 3.3 GCFR Survey Area............................................................................................. 40 4 FERAL ANIMAL MERI MONITORING ........................................................................ 44 4.1 Introduction ....................................................................................................... 44 4.2 Objectives .......................................................................................................... 45 4.3 Material and methods ........................................................................................ 45 Data analysis ........................................................................................... 46 4.4 Results ............................................................................................................... 46 Feral animal activity in GBR Survey Area ................................................. 46 10-year trends of feral animal activity in GBR Survey Area ...................... 47 Feral animal activity in GCFR Survey Area .............................................. 50 7-year trends of feral animal activity in GCFR Survey Area ...................... 51 Comparison of GBR and GCFR Survey Areas ......................................... 53 4.5 Discussion ......................................................................................................... 55 GBR Survey Area .................................................................................... 56 GCFR Survey Area .................................................................................. 57 4.6 Conclusion ......................................................................................................... 58 5 GBR DAY SURVEYS .................................................................................................. 59 5.1 Introduction ....................................................................................................... 59 5.2 Objectives .......................................................................................................... 59 5.3 Material and methods ........................................................................................ 60 Study area ............................................................................................... 60 GBR Day Survey protocol ........................................................................ 60 Estimating the number of nesting female loggerhead turtles .................... 61 Correlating Nesting Activities with spring and neap tides ......................... 61 File name: 180626_ReportGTCP0818_1.docx 28 June 2018, Page 3 of 177 www.gnaraloo.org Wind effects on track interpretation .......................................................... 62 Data analysis ........................................................................................... 62 GBR Maps ............................................................................................... 62 5.4 Results ............................................................................................................... 63 Nesting Activities ...................................................................................... 63 Spatial distribution of Nesting Activities .................................................... 64 Temporal distribution of Nesting Activities ................................................ 65 Multi-year trends in GBR .......................................................................... 67 Number of nesting female loggerhead turtles ........................................... 73 Nesting Activities correlation with lunar and tidal cycles ........................... 73 Wind effects on track interpretation .......................................................... 74 Mortalities and strandings ........................................................................ 76 5.5 Discussion ......................................................................................................... 77 Seasonal and long-term Nesting Activities and Nests .............................. 77 Nesting Activities correlated with lunar and tidal cycles ............................ 79 Wind effects on track interpretation .......................................................... 80 5.6 Conclusion ......................................................................................................... 80 6 GBR NIGHT SURVEYS .............................................................................................. 81 6.1 Introduction ....................................................................................................... 81 6.2 Objectives .......................................................................................................... 81 6.3 Material and methods ........................................................................................ 82 Night Survey protocol ............................................................................... 82 Target sample sizes ................................................................................. 83 Nest detection bias................................................................................... 83 6.4 Results ............................................................................................................... 83 Summary of Night Surveys ....................................................................... 83 Clutch sizes.............................................................................................. 84 SI accuracy .............................................................................................. 84 NAD accuracy