(2013) Floreana Island Ecological Restoration: Rodent and Cat Eradication Feasibility Analysis Version 6.0
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Floreana Island Ecological Restoration: Rodent and Cat Eradication Feasibility Analysis Author: Chad Hanson, Karl Campbell Reviewers: Richard Griffiths, Erin Hagen, Victor Carrion, Alex Wegmann Version History: VERSION DATE AUTHOR REASON FOR CHANGE v1 7.16.2012 Hanson Initial Draft v2 1.2.2013 Hanson Incorporated comments from K. Campbell review v3 1.25.2013 Hanson Incorporated comments from R. Griffiths, V. Carrion, E. Hagen v4 5.29.2013 Hanson Incorporated final comments from K. Campbell v5 7.23.2013 Hanson Incorporated comments from R. Griffiths and A. Wegmann v6 10.19.2013 Hanson Formatted for Spanish translation v6.1 11.16.2013 Hanson Final Citation: This report should be cited as: Island Conservation (2013) Floreana Island Ecological Restoration: Rodent and Cat Eradication Feasibility Analysis version 6.0. Island Conservation, Santa Cruz, California. 85 pp. Floreana Feasibility Study Report Page 2 TABLE OF CONTENTS TABLE OF CONTENTS ............................................................................................................................... 3 EXECUTIVE SUMMARY ............................................................................................................................ 6 PROJECT AND CLIENT .............................................................................................................................. 7 INTRODUCTION ....................................................................................................................................... 7 Preceding Eradications ........................................................................................................................ 7 GOAL, OBJECTIVES and OUTCOMES ....................................................................................................... 9 Goal ..................................................................................................................................................... 9 Objectives and Outcomes ................................................................................................................... 9 Background ........................................................................................................................................... 12 Biodiversity Value of Islands.............................................................................................................. 12 Floreana Island .................................................................................................................................. 12 Floreana Island Fauna and Flora ....................................................................................................... 14 THE TARGET SPECIES, IMPACTS AND BENEFITS OF ERADICATION ....................................................... 19 Target Species ................................................................................................................................... 19 Rodents ........................................................................................................................................... 19 Rodents on Floreana Island ............................................................................................................ 20 Benefits of rodent eradication ........................................................................................................ 22 Feral Cats ........................................................................................................................................ 23 Feral Cats on Floreana Island .......................................................................................................... 23 Benefits of cat eradication .............................................................................................................. 24 Benefits of rodent and cat eradication ........................................................................................... 25 Technical Feasibility .............................................................................................................................. 26 Technical Principles of Eradication .................................................................................................... 26 Proposed Methods ............................................................................................................................ 26 Recommended Techniques for Rodent Eradication ............................................................................. 27 Strategy Overview for Rodents ......................................................................................................... 27 Background on Recommended Methodology .................................................................................. 27 Rodenticides and bait products......................................................................................................... 28 Preferred rodenticide ..................................................................................................................... 28 Bait formulation .............................................................................................................................. 29 Bait Broadcast ................................................................................................................................. 29 Bait application in commensal areas .............................................................................................. 30 Bait application in agricultural/farmland area ............................................................................... 30 Early detection of survivors and response ..................................................................................... 30 Suggested Research to inform Rodent Operational Planning ........................................................... 31 Pre-eradication monitoring ............................................................................................................ 31 Monitoring to Confirm Rodent Eradication ...................................................................................... 31 Recommended Techniques for Cat Eradication ................................................................................... 32 Strategy overview for Cats ................................................................................................................ 32 Population reduction during rat eradication .................................................................................... 32 Broadcast baiting ............................................................................................................................... 33 Trapping............................................................................................................................................. 34 Hunting with dogs ............................................................................................................................. 35 Fumigants .......................................................................................................................................... 35 Spotlight Hunting............................................................................................................................... 35 Floreana Feasibility Study Report Page 3 Monitoring techniques and tools to confirm eradication ................................................................. 35 Combined Techniques .......................................................................................................................... 36 Environmental and Social Principals of Eradication .............................................................................. 36 Impacts to Island Residents and Visitors Pertaining to Eradication Efforts .......................................... 36 Human Habitation ............................................................................................................................. 37 Commensal Environment .................................................................................................................. 38 Pets and Livestock ............................................................................................................................. 38 Project Approach in Regards to Risk ..................................................................................................... 39 Sustainability ......................................................................................................................................... 39 Biosecurity to, and within the Galápagos ......................................................................................... 39 Socially acceptable ................................................................................................................................ 41 Politically & legally acceptable .............................................................................................................. 43 Environmentally acceptable ................................................................................................................. 43 Capacity ................................................................................................................................................. 45 PROJECT CONTINGENCIES ..................................................................................................................... 46 FUNDING ..............................................................................................................................................