FEASIBILITY OF RAT ERADICATION FROM AHND ATOLL, FEDERATED STATES OF MICRONESIA (PROJECT DESIGN DOCUMENT) Prepared by: Gregg Howald1 Alex Wegmann2 and Holly Jones3 Prepared for: CONSERVATION SOCIETY OF POHNPEI Kolonia Pohnpei, Federated States of Micronesia 1. Island Conservation Canada, 680 — 220 Cambie St. Vancouver, BC V6B 2M9 [email protected] 2. Island Conservation, 100 Shaffer Rd., Santa Cruz, California, 95060 3. Yale University, New Haven, Connecticut 1 Table of Contents TABLE OF CONTENTS ............................................................................................................................. 2 EXECUTIVE SUMMARY .......................................................................................................................... 4 THE FOLLOWING TABLE SUMMARIZES THE PROPOSED ERADICATION OF RATS FROM SEVERAL SMALL ISLANDS ADJACENT TO POHNPEI, AND ULTIMATELY FROM AHND ATOLL. ......................................................................................................................................................... 5 Table 1: Ahnd Atoll Rat Eradication Project Summary .............................................................................. 5 JUSTIFICATION ......................................................................................................................................... 6 CONTEXT .................................................................................................................................................... 6 IMPORTANCE OF ISLAND ECOSYSTEMS ....................................................................................................... 7 Figure 1: Causes of seabird extinctions and endangerment ........................................................................ 7 INTRODUCED RATS ON ISLANDS ................................................................................................................. 7 OVERVIEW OF GLOBAL RAT ERADICATIONS .............................................................................................. 8 Rodenticide ........................................................................................................................................... 9 Acute Rodenticides ......................................................................................................................................... 10 Zinc Phosphide, Bromethalin .......................................................................................................................... 10 Subacute Rodenticides .........................................................................................................................10 Cholecalciferol ................................................................................................................................................ 10 Anticoagulants ................................................................................................................................................ 11 First Generation Anticoagulants ................................................................................................................ 11 Second Generation Anticoagulants ............................................................................................................ 11 Absorption & Degradation in Soil: ....................................................................................................... 12 Half Life in Living Organisms: ............................................................................................................ 12 Soil Mobility of Brodifacoum: ............................................................................................................. 12 Effects on Humans: .............................................................................................................................. 12 Effects on Marine and Terrestrial Invertebrates: .................................................................................. 12 Effects on Reptiles: ............................................................................................................................... 13 Effects on Native Birds: ....................................................................................................................... 13 BAIT DELIVERY TECHNIQUES ....................................................................................................................13 Bait Application ...................................................................................................................................14 Table 2: Comparison of Aerial Broadcast, Hand Broadcast, and Bait station bait delivery methodologies for the Ahnd Atoll rat eradication ...................................................................................... 15 Bait Competition with Land crabs .......................................................................................................16 Bait Selection .......................................................................................................................................16 TIMING THE ERADICATION ........................................................................................................................17 PROJECT STAKEHOLDERS ..................................................................................................................18 FEASIBILITY .............................................................................................................................................18 LOCATION .................................................................................................................................................18 Figure 2: Map of Ahnd Atoll ........................................................................................................................ 19 WEATHER ..................................................................................................................................................19 ISLAND SIZE AND TOPOGRAPHY ................................................................................................................19 FLORA AND FAUNA ...................................................................................................................................20 Fauna ...................................................................................................................................................20 Flora ....................................................................................................................................................20 Introduced Mammals on Ahnd Atoll ....................................................................................................20 IMPACTS OF INVASIVE MAMMALS ON AHND ATOLL .................................................................................21 Plants ...................................................................................................................................................22 Avifauna ...............................................................................................................................................22 Land Crabs ..........................................................................................................................................23 Figure 3: Ahnd Atoll Land Crab Population Index: May 2006. Population Index from Palmyra Atoll, Line Islands, included for comparison ........................................................................................................ 23 Terrestrial Invertebrates ......................................................................................................................24 2 PROJECT DESIGN ....................................................................................................................................24 GOAL .........................................................................................................................................................24 OBJECTIVE.................................................................................................................................................25 OUTPUTS ...................................................................................................................................................25 Output 1: Trial phase and planning for Ahnd Atoll eradication .......................................................25 Output 2: Ahnd Atoll Eradication ......................................................................................................26 ACTIVITIES ................................................................................................................................................27 Trial Eradication .................................................................................................................................27 Demonstration Eradication / Skills Building .....................................................................................27 Conservation Symposium in Pohnpei on Invasive Animal Eradications on Islands........................27 Ahnd Atoll Rat Eradication – Planning ...............................................................................................27 Ahnd Atoll Rat Eradication – Public Education Campaign ..............................................................27 Ahnd Atoll Rat eradication – Implementation......................................................................................27 Post bait delivery