ASIAN TOAD ERADICATION FEASIBILITY REPORT FOR

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AsianToadEradicationFeasibilityReport McClellandetal.2015

ASIANTOADERADICATIONFEASIBILITY

REPORTFORMADAGASCAR

Fig.1a.Duttaphrynusmelanostictus,Asiantoad.Female,TamataveMada-gascar.PhotoJ.Reardon.

PeteMcClelland,JamesT.Reardon,FredKraus,ChristopherJ.RaxworthyandChristianRandrianantoandro

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Fundedby:

Supportedby:

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Reviewedby: KeithBroomeandAndyCox(IslandEradicationAdvisoryGroup,NewZealandDepartmentofConservation).

Citation: McClellandP.,J.T.Reardon,F.Kraus,C.J.RaxworthyandC.Randrianan-toandro.AsianToadEradicationFeasibilityReportforMadagascar.2015.TeAnau,NewZealand.75p.

Correspondingauthor:[email protected]

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FOREWORD

ItisimportanttorecallthatMadagascarisacountryofexceptionalbiodiversityworldwide.Forex-ample,among the300speciesofamphibians reported, the rateofendemism isnearly100%.TherecentincursionoftheinvasiveAsiantoadconstitutesadirectthreattothisuniquebiodiversitybutalsotohumanhealthandthecountry’seconomy.WesuspectthetoadsimpactmaybecomparabletotheCanetoadinAustralia;wemustactswiftlytopreventasimilardisasterunfoldinginMadagas-car.

Thepublicationofthisreportisbeingenthusiasticallyawaitedbythescientificcommunityandcon-servation, organizations aswell as government authorities inMadagascar. In order to ensure thesuccessofthiseradicationfeasibilityreport,recommendationsrequirethesupportandcommitmentofallstakeholders;anydelayindecisionmightlessenourcapacitytoresolvethisurgentissue.

Thepresentreportareresultsofworkcarriedoutbyeradication,invasivespeciesandherpetologyexperts:PeteMcClelland,JamesT.Reardon,FredKrausandChristopherJ.Raxworthy.Nationalandlocal authorities, Malagasy scientists and non-governmental organizations have contributed im-measurablytotheeradicationplan.

TheplanincludescurrentknowledgeoftheAsiantoadsituationinMadagascar,nextstepsanddis-cussion of available options. Critically, the eradication feasibility criterion of possible correctivemeasures is given careful consideration against the facts. It is important to emphasize capacity-buildingactivitiesandtestingoferadicationmethods(whichhasneverbeforebeenattempted)be-forealargeprogrammeofthissortcaneffectivelycommenceandbesuccessful.

Dissemination of this report is essential for all stakeholdersworking in the fields of conservation,resourcemanagement,humanhealth,importandexporttradeandeconomicpolicy.TheMalagasygovernmentauthoritiesandvariousentitiesshouldbewellrecognizedforhelpingmakepossibleitscompletion.

CHRISTIANRANDRIANANTOANDRONATIONALCOORDINATOR

EMERGENCYCELLAGAINSTTHEASIANTOADINVASIONMADAGASCAR

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TABLEOFCONTENTSEXECUTIVESUMMARY 61INTRODUCTION 102GOALS,OBJECTIVES&OUTCOMES 18 2.1Goals 18 2.2Objectives&outcomes 193THESITE 22 3.2Targetspecies 29 3.3Impacts 34 3.4Benefitoferadication 374REQUIREMENTSFORSUCCESSFULERADICATION 38 4.1Technicalapproach 38 4.2Sustainability 38 4.3Socialacceptability 40 4.4Political&legalacceptability 41 4.5Environmentalacceptability 42 4.6Capacity 42 4.7Affordability 445CONCLUSIONS 456ACKNOWLEDGEMENTS 467REFERENCES 46APPENDIXI:SiteVisit 49APPENDIXII:TermsofReference 51APPENDIXIII:PreliminaryTechnicalStrategy 531URGENTISSUES 53 1.1Governing/leadershipbody 53 1.2Management&administration 53 1.3Financing 54 1.4Biosecurity&education 54 1.5Mapping/GIS 54 1.6Delimitation 552METHODTESTING&EVALUATION 55 2.1Baselinedata,importantissuesandmonitoringmethods 55 2.1.1Densityestimation 56 2.1.2Humaneeuthanasia 57 2.1.3Trackingtunnels 58 2.1.4Acousticmonitoring 60 2.1.5EnvironmentalDNA 61 2.2Detection&eliminationmethods 62 2.2.1Detectionandremovalthroughdelimitedhandsurveys 62 2.2.2Driftfencing&pitfalltrapping 64 2.2.3Citricacid/sucrosespray 65 2.2.4Acousticlocationandphysicalcapture. 66 2.2.5Tadpoletraps 67 2.2.6Herbicides 67 2.2.7Eggcollection 68 2.2.8Refusemanagement 68 2.2.9Toaddogs 69 2.2.10Cappingwaterbodies 70 2.2.11Chemicaltreatmentofwaterbodies 70 2.2.12Toadtraps 70 2.3.Prioritisationofmethods&proposedtestingschedule 723BUDGETPLANNING 73

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EXECUTIVESUMMARYAneradicationofanamphibianspecieshasneverbeenachievedonthescalebeingconsideredhereandtheAsiantoadincursioninMadagascarpresentsaplethoraoflogisticalchallenges.

However,therehasbeennosystematictestingordevelopmentoferadicationtoolsforthisspeciesinthisenvironmentandsotechnicalfeasibilitycannotbeproperlyjudgeduntilmethodsaretested.Humanhealth,ecologicalandeconomicimpactsofdisregardingeradicationasanoptionaresimplytoo great for the authors to recommend abandoning eradication under our current state ofknowledge.Wethereforerecommenddevelopmentoferadicationmethodsproceedinatwo-stageprocessthusevaluatingtheviabilityofmethodologiesbeforeadvancingtoemployingthosepractic-esatthelandscapescale.

Shouldtheevaluationoferadicationmethodsdemonstrateseriousfailureofmultiplemethods,seri-ously threatening the likelihoodof success of an eradication attempt,we recommenderadicationefforts be abandoned to avoid wasting resources that could be better used toward mitigationmeasures, species and habitat focused conservation efforts and public health education pro-grammes to ameliorate thedamage and impacts ofAsian toads inMadagascar. It is important tonotethatmitigationinthelong-termislikelytocarryafarhighertotalcostthaneradicationintheshortterm.

Fig.1b.AsiantoademergingafterraininKandy,SriLanka.Photo:J.Reardon.

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This reportconsiders the logisticsand feasibilityoferadicatingapopulationofAsiantoads,Dutta-phrynusmelanostictus (Fig. 1.), a non-native invasive species recently established inMadagascar.Theseconsiderationsareforgovernance/leadershipbodiesthatmustmakerapidanddecisivedeci-sionswhicharepracticalandappropriategiventhecurrentstateandsituation.

Eradicationfeasibilityreportsusuallystateclearlywhetheraneradicationoperationshouldproceedornot.Unfortunatelyinthiscase,theissuesarecomplexandsofollowstherecommendations.

TheCurrentsituationasweunderstandit

Basedonthecurrentsizeoftheincursionandobservationsbylocals,AsiantoadsarrivedinMadagascarbyat least2010andhavenowspreadoveranareaofapproximately98km2.Givenanaverageapproximateddensityof400toadsperhectare(basedonreplicatedsam-pling across stratified habitat types in areas where no previous disturbance of toads isknown)itisestimatedthecurrentpopulationisestimatedataroundfourmilliontoads.Theinvasionfrontoftoadsappearstobeexpandingapproximatelytwokmperyear.Toadscur-rentlyoccupylowlandhabitats(bothruralandurban)andtherearenolikelyknownbarrierstotheirpopulationexpansioninMadagascar.Thesetoadsarerapidbreedersproducingupto40,000eggsperyear,longlived,poisonoustootheranimalsandopportunisticpredatorsdevouringanythingtheycanswallow.

WhatwepredictwillhappenifnothingisdoneIftheseinvasivetoadsarenoteradicated,oratleastcontrolledandcontained,theywillcon-tinue to spread over themajority ofMadagascar. Thepresence of these invasive toads islikely to causemajor ecological andeconomic negative impactswith thepotential for themajorreductionoreventotal lossof toadpreyspecies,bothendemicandunique inverte-brateandvertebratespeciesinMadagascarandthusexacerbatingspeciesextinctions.Pred-atoryspeciesthatfeedontoadswillalsobeimpactedandthreatenedthroughtoadpoison-ingupon ingestion.Economic impacts includean increase inBlackrat (Rattusrattus)num-bersoncepredatorpopulationsarereducedbytoadpoisoning,leadingtoincreasedlossofstored food supplies anddamage to commercial goodsandequipment.An increase in ratnumberswillhavehumanhealthramificationsthroughratbornediseaseselevatingtheinci-dence of plague already present in the incursion area. Economic costs will be incurredthroughimpactstotheexportindustrywherebiosecurityconcernsincreasefreighthandlingtimesandcostsorbecomingbarrierstoexport.

ThetoadsundermineMadagascar’senvironmentaltourismsector—anindustrywhichhashugeval-uetothenation,nowandinthefuture.CriticallytheAsiantoadisarisktohumanhealthofMala-gasycitizenswherefrogsareacommonpartofthediet.AsiantoadshaveprovedtobelethallytoxictohumaninSouthEastAsia(Chietal.1998).

Therearefourbasicstrategicoptionsfordealingwiththeissue:

1. DonothingandacceptthesetoadswillbecomeapermanentpartofMadagascar’sbio-diversitywiththeconsequentialenvironmental,economicandhumanhealthimpacts.

2. Undertakesustainedcontroloftoadpopulationsinprioritysiteswhichmayprotecthigh

priorityspecies,orsites,but(thiswillhaveanongoingfinancialcostinperpetuity)and

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accept any environmental, economic and human health impacts across most of thecountry.

3. Contain the spread of toads to their current distribution, if this is possible given the

rangeofhabitatstheypresentlyinhabitandtheuncertaintyofdetectingandremovingtoadsatlownumbers.

4. Completely eradicate these toads fromMadagascar. This would eliminate all possible

ecological, economic and social impacts the toadsmay have onMadagascar; with nolong-termcost implicationsotherthanon-goingbiodiversity improvements—whicharepresumedaprerequisiteforalloptions.

Prosandconsofoptions

While eradication is the most financially expensive option in the short term, benefits ofpermanentlyremovingalltoadsandthustheir impactandassociatedriskfaroutweighthebenefitsofsustainedcontrol.Controlprogrammesrequirecommitmentinperpetuitysinceany benefit(s) would be lost shortly after the programmewas discontinued. Control pro-grammesquicklybecomemoreexpensivethaneradication,thuscompleteeliminationout-ranksopposingcontrolmethods.Eradication, along with high intensity control, requires the development/confirmation oftechniquestodetecttoadsatlowdensityandefficientlyremovetoadsatalldensities.

Recommendedstrategicoption(eradication)

WerecommendanattemptbemadetocompletelyeradicatetoadsfromMadagascar.Thisstrategicoptionoffersthebestsolution inthe long-termbutwillhavethedisadvantageofhighshort-termcost.Aneradicationplanshouldbeimplementedunderconsistentreviewasnewmethodologiesaretestedandlogisticalmethodsofeliminationarefurtherestablished.

Whatisrequiredtoachieveeradication?

ToeradicatethesetoadsfromMadagascarwillrequiredetectionmethodswhichwillbesen-sitive to every individual animal, across the entire incursion area. Toad capture/removalmethodsmustremovetoadsfromthepopulationfasterthantheybreedandrecruit.Finally,acriticalfactorforsuccessistoensurenofurtherAsiantoadsarebroughtintothecountry.Thereareanumberofpotentialremovalmethodswhichwillrequirefurthertestingandtri-alstodeterminewhatcombinationoferadicationtechniquesworkbestunderMadagascanconditions.Trialswillberequiredtodeterminewhatlevelofeffortwillbeprescribedtode-ploythedeterminedmethodsacrossthelandscapepredictedtobeinfestedbythetimetheprojectbecomesoperational.Withsomanyunknownsatthisstage,particularlythechoiceofdetectionandremovaltech-niquestobesuccessfullyusedineradication,itisdifficulttoestimatethefinalcostandthateradicationispossible.OurbestcostestimateproducesacostofbetweenUS$2millionandUS$10million,butthisfigurecanbefurtherrefinedthroughtheprocessrecommendedbe-low.

Toundertakeeradicationrequires:

• Establishmentofagovernanceandleadershipbody.

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• Installationofasuitablemanagementandadministrationstructure.• Confirmationoffinances—initiallyfortrialsfollowedbydevelopederadicationoper-

ationsshouldtrialsofferfeasibleeradicationoptions.• Establishmentofadequatebiosecuritymeasurestopreventhumanassistedspread

of toads into, out of andwithinMadagascar; to prevent the introduction of addi-tional invasive species, and if the eradication is successful, to prevent the reintro-ductionoftoadsbackintoMadagascar.

• Educational programmes established to inform residents of the impacts and risksposedby toads, the techniques tobeused for eradication, how to assistwith theeradicationandhelpingidentifythescaleoftheincursionanddetermininganypos-siblesatellitepopulationswhichcouldexistoutsidetheincursionarea.

• Maphabitats,theextentoftheincursion,andanypotentialbarrierstotoadmove-ment.

• Developadensityestimationfortoadsacrossvarioushabitatstoinformthestrate-gicdeploymentoftoadeliminationmethods.

• Develop/confirmhumaneeuthanasiatechniques.• Develop/confirm sensitivity of detection techniques including acoustic detection,

trackingtunnelsandenvironmentalDNA.• Confirmationofdetectionandremoval techniques includinghandremoval;barrier

fencingandpitfall traps; citric acid/sucrose spray; acoustic location; tadpole traps;herbicide; egg collection; refuse management; toad detector dogs; capping ortreatmentofwaterbodiesandtoadtraps.ThesepotentialmethodsofdetectionanderadicationwillrequireinitialtrialstoconfirmtheirefficacyforuseinanAsiantoaderadicationprogramme.

Regardless ofwhether the eradication proceeds or not, it is recommended that biosecuritymeasuresareput inplace toprevent further incursionsandapublicawarenessprogrammeestablishedtoeducateMadagascanresidentsaboutthetoads, theirnegativeenvironmentalinfluenceandassociatedhealthriskstohumans(toadpoisoningisknowntobefatalbutnev-erthelessassociatedsicknessesareextremelyunpleasantandcostlyifhospitalized).

Howtoproceed:Decideonstrategicoption(s)–iferadicationisdecided:

1. Identifyparticipatingagenciesandinstituteproject.2. Securephaseonefunding:testeradicationmethodsandevaluateoperation.3. Initiaterequiredbiosecurityandeducationprograms.4. Carryouttheprescribedexperimentaltrialsforevaluationoferadicationmethods.5. Reassessfeasibilityandcosts.6. Securephasetwofundingtoexecuteapprovederadicationprogramme.7. Createacomprehensiveplancoveringallaspectsofproposalandapprovedworkingplan:pro-

jectgovernanceanddecisionmaking;methodsandprioritiesforremoval;publicengagement;research and adaptive management; procurement and recruitment; training and develop-ment.

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1 INTRODUCTION

ThisdocumentconsidersthefeasibilityoferadicatingarecentlyestablishedpopulationofAsiantoads(Duttophrynusmelanostictus)fromMadagascar.

Tobesuccessfulaneradicationprogrammustmeetsevenessentialcriteria:

• Technical feasibility: Technique(s) tobeusedat theproject siteareable to removeallindividualsofthetargetpopulation(s).

• Sustainability:Preventingre-invasionbytargetspeciescanbeachieved.• Sociallyacceptable:Theprojecthas full support fromthecommunityandotherkey

stakeholders.• Politicallyandlegallyacceptable:Allrequiredpermitsandconsentssecured.• Environmentallyacceptable:Environmentalimpactsoftheeradicationaremanagea-

bleandacceptable.• Capacity:Alldeterminedskills,resourcesandequipmentcanbeacquired.• Affordability:Therequiredfundingisavailableandsecured.

Toachieveeradicationyouneedtobeablekillthetargetspeciesfasterthanitcanbreedatalldensities.Tobeabletoachievethisrequirestheabilitytodetectthematlowdensitiesinallhabitats.

ThisreportconsidersthecurrentinvasiveAsiantoadsituationinMadagascar,asofJune2015,againstthesestatedcriterialisted.Itsaimistostatewhatisneededinordertoachieveeradication,whatlimitationsstandinthewayofthatobjective,andwhatneedstobedonetosur-mountthoselimitations.

Theconceptsandpracticeofspecieseradicationcanbecomplex. It iscriticalthatreadersof this report are familiar with the basic conceptual differences between “pest control”and“pesteradication,”asthesetwoobjectiveshaveverydifferentgoalsrequiringequallydifferent strategic approaches (Table 1.). There is growing data supporting the presentthinkinginthisreportbutmanyofthefundamentalsoferadicationhavebeenwellunder-stoodformorethantwodecades(BomfordandO’Brian1995).

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Table1.Comparisonoferadicationversusongoingcontrol.

CONTROL ERADICATIONProjecttarget Tomaintaintargetspeciespopula-

tiontoanagreedlevelwhereim-pactsaretolerable.

Toeliminatethetargetspeciesentirely,thereforerequiringnoongoingmanagementexceptforexternalbiosecurityattheborder.

Strategy&tactics Focusonsitesofhighestvalueorwherebenefitsofcontrolexceedcostsofcontrol.Focusonsustainabilityofaction–socially,financiallyandtechnically.Monitorbenefits,costsandimpacts.

Preventspread,targeteveryindi-vidual,andpreventreinvasion.Focusonmeetingeradicationcri-teriathroughskilleddeploymentandadaptationofmethodsandappropriatescaleofeffort.

Ongoingimpacts Impactsonnon-targetspeciesandhumanswillbeongoingrelativetotheagreedlevelofcontrol.Averyhighlevelofcontrolisrequiredtogainameaningfullevelofbenefit.

Nonexistent–oncetoadsarere-movedtherearenoongoingim-pacts.

Biosecurity Internalbiosecuritystillrequiredtopreventtheexpansionoftheincur-sionarea.

Externalbiosecurityrequired;(whichwouldcovermanyspecies)topreventreinvasion.

Risks ControlfortheAsiantoadisunlikelytobepossibleonalargescalemean-inglimitedhighvaluesiteorspeciesleadprotectionislikely.Ifforanyreasonfundingorsupportceasescontrolwillstopandbenefitsrapidlylost.Ongoingriskofexpansionofincur-sionareaincreasingthecostsofacontrolprogrammeormakingitun-feasible.

Thereisaninherentriskoffailureinanyeradication.Henceitisim-portanttoadequatelytesttheproposedtechniquesbeforecom-mittingtoanyeradicationpro-gramme.Inadequatefundingmeansthattheprojectcouldnotbefullyimplementedandthere-foreisverylikelytofail.Failuretoadequatelyimproveborderbiosecuritymightmeanriskofreinvasion.

FinancialCostNote:actualcostsforbothcontrolanderadicationcanonlybecalculatedoncetechniquesandscaleofcontrolareagreedupon.

Initiallylowerthaneradicationbutongoinginperpetuitysototalcostlikelytosoonexceederadicationcosts.Thisstrategymakeson-going,albeitreducedeconomicandsocialimpactsinevitable.

Initially,largeone-timecostbutiferadicationsuccessful,nocontin-uedlargecostsexceptbiosecurity;long-termeconomicandsocialcostsofpestspeciesareamelio-rated.

Benefits Reducedinitialcosts(butvarygreat-erovertime).

Targetspeciesremoved,noongo-ingcostsexceptbiosecurity;noongoingimpacts.

Further,differencesbetweenpestcontrolandpesteradication it is important toacknowledgethedifferentcostmodels.Pestcontrolfocusesonidentifyingcosteffectivecontrolmethodscapableof

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targetingthelargestproportionofthepestpopulation(s).Incontrast,eradicationbeginswithtoolsthattargetthemajorityofthepopulationinthemostcosteffectivemannernotcompromisingtheefficacyofsubsequentmethodsandusuallyreservesthemostsensitivetools fortargetinghardtocapture individuals that remain.As such, the cost profile of multi-method eradications are onewherethecostof removingthe initialmajority isequal toor less thanthecostof removingthefinalfewindividuals.

The Asian toad,Duttaphrynusmelanostictus (also known as the Asiancommontoad,Black-spectacledtoad,Asianblack-spottedtoad,Commonsundatoad,andJavanesetoad,Fig.1a,1band1c) is widespread throughout Asia, occurring from Pakistan through central Asia andacross southernChina, including Taiwan, extending across SouthAsia, covering Sri Lanka,the Malay Archipelago and Indonesia incorporating the island of Borneo and associatedisland groups. Across this range the species is known to occur from sea level to 1,800mand isgenerallyassociatedwithdisturbedandagriculturalhabitats (vanDijiketal.2004).Asian toads do occur in undisturbed habitats, including rainforest (southern Sri Lanka,easterncentralThailand,Sabah,NorthernBorneo,Reardon,pers.obs.),butapparentlyatlowdensities. The species is listed as “LeastConcern”under the IUCNRed List of Threat-ened Species. TheQueensland StateGovernment (Australia) lists the Asian toad as a sig-nificantpestintheirpestriskassessment(Pestanimalriskassessment2010).

Asiantoadsarean introducedspecies inanumberofcountries, includingwesternregionsofNewGuineaand theIndonesianislandsofBali,Sulawesi,TimorandAmbonbutnoinvestmenthasbeenmadetomeasuretheirimpacts.Across its rangethespeciesappears toberegardedasbenign,although ithasbeennotedasanuisance inSriLankabecauseof itsabundanceinwatertanksusedforlaundryandcookingwaterinvillages.

The Asian toad females can reach 200mm in snout-to-vent lengthwith typical drywartyskinand isacrepuscularpredatorof invertebratesandsmallvertebratescaptured largelybyambushpredation.

Asiantoadreproductionbeginbymalescallingtoattractfemalesfrominoraroundbreed-ing poolswhere toads later engage in amplexus and end in production of strings of eggslayed by the female. Females are able to produce many thousands of eggs per season,whichhatchintotadpolesmetamorphosingintotoadletsthesameseason.

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TheAsianToadinMadagascarTheAsian toadwasanecdotallynoted inMadagascarasearlyas2010 (Mooreetal.2015)butnotreporteduntil2014(Arnaud2014).HowtheoriginalfounderanimalsgottoMada-gascarhasnotyetbeenconfirmed,howevertheirpathwaywasalmostcertainlyviafreightand/or containers brought to the site of the incursion from South East Asia. TheMalagasypopulationofD.melanostictuswasstudiedfromafragmentofmitochondrialND3gene,basedon11specimensprovidedbyR.D.Randrianiaina,twospecimensprovidedbyR.DolchandF.GlawandonespecimenprovidedbyA.P.Raselimanana.Allspecimenshadanidenticalhaplotype,suggestinganoriginfromthesamesourcepopulation(M.Vences,unpub.data).Phylogenetically,comparedtoarange-widedataset,thishaplotypebelongstoalineageoccurringinChina,Vietnam,ThailandandCambodia, and thehaplotype is identical toone found inCambodia likely tobe representativeofAsian toad populations from Thailand, Cambodia and Vietnam (G. Wogan and B. Stuart, pers.comm.)—thisstronglysuggestsanintroductionoriginatingfromthisgeographicalregion.Researchison-goingintotheflowofmaterialsviafreightfromSouthEastAsiaintotheareaoftheMadagascanincursionofAsian toads.Multiply companies import shipping containers into the regionmaking itdifficulttopinpointtheexactoriginofintroduction.ItisnoteworthythattheincursiondoesnotappeartoextendtotheTamataveportthoughnothavingdirectaccesstothisporthasnotallowedustoverifythisinformation.

From our visit it appears there are negligible biosecuritymeasures in place at either theport of Tamatave or at the Ambatovy mine. While we did not inspect any other majorbusinesses in the region it is likely lack of biosecuritymeasures iswidespread among thebusinesscommunity.Futureinvasionsarepossiblewithoutimprovedbiosecuritymeasuresinplace.

Wehavebeenabletoidentifyanumberofimporterfacilitieswithintheincursionarea,allof which have, in theory, the potential to have brought the toads to Madagascar fromSouthEastAsia.Towardsthecoreoftheincursionareaare:

1. Malgapro– Importerof products suchas rice, sugar andoil fromChina,Dubai, In-diaandPakistan.

2. Ambatovy–TheAmbatovyplantsitewasconstructedwithconsiderableassistancefromtheSrirachaConstructionPublicCompany,basedinThailandandworkingwiththeAmba-tovyprojectsince2008.Itislikelythatduringplantconstruction,considerablequantitiesofmaterials,suppliesandequipmentwereshippedfromThailandbySrirachaConstruction(http://www.sricha.com/eng/current_projects.html).

3. COLAS–Construction,involvedinImportationofunspecifiedgoods/materials.

Towardstheperipheryoftheincursionislocated:

4. SolCimentCallidu–Importersofunspecifiedgoods/materials.

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Further research is necessary to investigate the timingandquantitiesof freight importedby these companies and the geographic origins of freight shipments.With these data, itmaybepossibletoidentifythemostlikelypathwayofinvasion.Identifyingthispathwayisavitalelementof learningandensuringbiosecuritymeasuresareappropriately improvedtopreventreinvasion.

There is little informationavailableonthespecific likely impactsofthetoadsontheecol-ogyofMadagascar.However, there is a significant literaturedescribing theeffectsof theCane toad,Rhinellamarina,(Fig.2.)as it has spreadacrossAustralia (Burnett1997).Due tothe general ecological similarity between the two toads, both having cosmopolitan dietsandhabitatrequirements,itisreasonabletoanticipatesimilarecologicalimpactsfromtheAsian toad invasion inMadagascar. Like the Cane toad, the Asian toad is potentially poi-sonous to naive predators and is likely to negatively impact many native and endemicpredators, includingsnakesandmammals.Madagascarhasnonative toadsbutdoeshavea globally significant, rich and vulnerable endemic herpetofauna. Research and climatemodellinghas investigatedthepotentialecological reachof theAsiantoad inMadagascarand a recent publication illustrates that the Asian toad has the potential to establishacrossthemajorityofthecountry(Pearson2015).

A high profile concern for the Asian toad incursion inMadagascar is the potential for le-thalpoisoning fromtheconsumptionof toadsandtoadtissuebyhumans.Thisalongwithother details of the toads potential impacts are given amore detailed description in sec-tion3.3butitshouldbeclearlynotedthatmultiplecasesofpoisoning,includingdeathsinchildrenarereportedfromLaos,which iswithintheAsiantoadsnaturalrange,andwithincommunitieswithahigh levelofawarenessof the toxicityofAsian toads (Keomanyetal.2007).

ItistooearlytopredictwhatformtheeconomicconsequencesoftheAsiantoadinMada-gascar will take but they may include negative impacts on agriculture, tourism (throughloss of biodiversity) andWorld TradeOrganisation restrictions on exports fromMadagas-cardueto theriskof transportingtoadstonew locations. SuchsanctionsareapossibilityiftheAsiantoadisdeemedtobeanecologicalandeconomicthreattotradepartnersasaresultofitsimpactsinMadagascar.

Soon after the identification of the toads in Tamatave their potential ecological impactwas recognised by scientists and the desirability of eradicating them promoted by theMalagasy government, non governmental agencies (NGO) and individuals. InternationalexpertsworkedwithNGO’s,includingtheMadagascarFaunaandFloraGroupandAssocia-tionMitsinjoand theMadagascanGovernment togather support foranAsian toaderadi-cationprogrammeandseekfundingforaformalstudyofitsfeasibility.

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TheAsian toad incursionhas raisedseriousconcernsamong theconservationcommunity.Not only are direct impacts on native biodiversity feared but there is concern the toadmight vector amphibian diseases such asRanavirus. However, the science community ac-tively engaged with amphibian issues in Madagascar lack experience and skills in pesteradication. As such, three of the authors, who have research and applied experience inpest-animal eradication were contacted and requested to lead the study. Mr. PeterMcClellandhasextensiveexpertiseandexperience ineradicationsglobally, includingNewZealand,Australia, theUSAandthePacific.Althoughprimarilyhavingworkedonrodents,the operational parameters and processes for eradication programs apply across taxa.Doctor James Reardon is a herpetologist with operational experience in eradication pro-grammes targeting reptiles and amphibians. He is currentlyworking on two invasive her-petofaunal eradication programmes in New Zealand. It was decided that in combinationtheyprovidedtherequiredexpertiseonamphibianspecificapproachestoeradicationandits requirements.The feasibilitystudy isalsosupportedbyDr.FredKraus,who isaglobalauthority on invasive herpetofauna, and was the instigator of the eradication feasibilitystudy. Our team includes Dr. Christopher Raxworthy, who first identified this species ofinvasive toad inMadagascar, andwho has 30 years of herpetological experienceworkinginMadagascar, andChristianRandrianantoandro,whoisanexperiencedherpetologistinMada-gascar,andhasbeendesignatedtheinterimnationalcoordinatorfortoaderadicationefforts.

LocalpopulationperspectivesDuring the feasibility report field visit the authorsmade an effort to gather opinions andinformation on the Asian toad from members of local communities within the incursionarea. Littleadditional knowledgewasgatheredbeyond thatofMooreetal. (2015). Therewas a common opinion in Tamatave/Toamasina among local communities surveyed thatthe toadsarrivedwith theestablishmentofnickel-miningandprocessing facilities. In thisarea the toads were referred to as the 'Dynatec' toad, Ambatovy's predecessor. No evi-dence was presented for this belief other than apparent timing of the toads first detec-tion,whichoccurredatthesametimetheplantsitewasbeingconstructed.

Theauthorsareawareofrecentreportsofa“spinytoad”likenedtotheAsiantoadknowninToamasina,beingreportedfromMahanoro,lessthan200kmtothesouthofthecurrentincursion. The report byMichella Raharisoa is difficult to verify without local inspectionand includes implausibleclaimsofcowdeathcausedby the toads.However,giventhedi-rect road connection to this sitewith theAsian toad incursion a satellite incursion is en-tirely plausible and verifying this report is now among the priorities of the programme(http://www.lexpressmada.com/blog/information-live/biodiversite-le-crapaud-epineux-debarque-a-mahanoro-12315/).

Eradicationperspectives

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Therehasbeenlimitedinvestmentinamphibianeradicationsglobally,withonlythreesuc-cessful toad eradications recorded: 1) a small-scale operation in Europe which utilisedtechniques thatarenotsuitable for theAsian toad incursion inMadagascar (shooting);2)the removal of a small incursion on an Americanmilitary base inOkinawa, Japan; and 3)theeradicationofCanetoadsfromaverysmall(6.5ha)islandinBermuda(Wingate2011).The difficulties with even controlling the spread of Cane toads in Australia and reducingtheir rateof spreadhighlight the likelyproblems tobe faced inundertakinga toaderadi-cationinMadagascar.

OptionsforthemanagementoftoadsonMadagascarare:

1. Donothing.ThiswouldhaveimplicationsforMadagascar’sbiodiversityandeconomyaswellasthehealthandwell-beingofMalagasycitizens.

2. Developandputinplaceacontrolprogrammetopreventorlimitthespreadofthespecieseitherindefinitelyoruntileradicationtechniquescanbedeveloped.Thisisahigh-riskstrat-egy due to thedifficulty inmaintaining a non-physical boundary i.e., not fenced. Contain-mentcostswillquicklygrowtosurpasseradicationcosts.Identifyspeciesathighriskofex-tinctionfromtoadimpactsandundertakeprotectioneitherinsituorincaptivity(species-ledprogram).Theresources toachievethisare largeandthemanagementoutcomes likely tobefinanciallyandlogisticallyunsustainable.Further,notallimpactedspeciesarelikelytobeidentifiedapriori,meaningthatsomewillbeleftunprotecteduntiltoolate.

3. Identify high-value sites containing a range of species of concern, and undertakework toprotectthosesites(site-ledprogram).Again,itisquestionablesuchlong-termprogrammes,evenifpracticable,couldbefinanciallysustainedinthelong-term.

4. Undertakeaneradicationandputinplaceanassociatedbiosecurityprogramtopreventre-invasion.Althoughthiswouldbeexpensiveintheshort-term,itwouldbefarcheaperinthemedium to long-term than any seriousongoing control programme,whichwouldneed toexistinperpetuity.

Unlessphysical barriers arepossible2, 3 and4all require thedevelopmentof techniques for thedetectionandremovaloftoadsatlowdensity,whicharealsocrucialfortheeradicationoption.

Eradication is the preferred solution to any invasive organism incursion, but not alwaysfeasible.Assuch,eradicatingtheAsiantoadfromtheTamataveregionhasbeenadefaultpositionoflocalauthorities,environmentalNGOsandtheAmbatovyMiningCompany,alt-hough the author’s encountered serious confusion over the technical difference between“eradication”and“control.”Unfortunately, itseemsthatwhiletoadswereapparentlyob-servedby locals at least as early as 2011andpossibly earlier, the issueonlybecame rec-ognisedbyboththemineandNGOsandreportedtogovernment in2014—bywhichpointpreliminarysearcheshaveshowntheextentofthetoadincursiontobeatleast98km2.

Given the technicaland logistical challenges involved inundertakinga toaderadication inMadagascar, itwasagreedthefirststepwastoundertakeaneradicationfeasibilitystudy.This is internationally recognisedasabestpractice foreradicationsallowingadecisiontobe made with confidence and with good knowledge of the costs, benefits and risks in-volved.

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It is important to note that this feasibility study is designed to consider all the require-ments for undertaking an eradication and then advise on the overall feasibility of Asiantoad species eradication fromMadagascar. It covers the known constraints and require-ments of undertaking an eradication programme and highlights where additional infor-mation needs to be compiled. It is NOT an eradication plan, whichwould require signifi-cant additionalworkon confirmingeradication techniques, application strategies, projectgovernanceandmanagementstructures,costsandatimeline.

This report is designed to beused todecidewhether eradication is feasible andpracticaltopursuebytherelevantMalagasygovernmentagenciesandNGOsholdingresponsibility.If itisdeemedworthwhiletoproceedwitheradication,thisdocumentcanbeusedtohelpdevelopanappropriatestrategy,raisesupportandfundingthroughadiscussionofpoten-tialtoolsasbrieflydescribedinAppendixIII.

Itisimportanttorecognisethedifferencebetween“control,”wheretheaimissimplytoreducethepopulationtoadesiredlevel,and“eradication,”whereeveryindividualofthetargetspecieshastoberemoved.Itisalsorecognisedreducingthepopulationbyeven99%istheeasypartofanyeradi-cationproject.Thedifficultpartistoeradicatetheremaining1%andthenconfirmnoneareleft.In-deed,itshouldbeexpectedthecostmodeloferadicationsusuallydemonstrateafargreaterpropor-tionofaneradicationbudgetisspentdetectingandremovingthefinal1%thanspentremovingtheinitial99%—thiscannotbestressedenough,especiallyforthosewithoutexperienceinpesteradica-tions.

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1. GOAL,OBJECTIVESandOUTCOMES

2.1 GoalToexaminethefeasibilityofcompleteeradicationofAsiantoadsfromMadagascar—includingiden-tifyingtechniquessuitableforlocatingandremovingtoadsandwhatisrequiredtodeterminetheirefficacy.Ifitisdecidedtoattempttheeradication,theproject(AsianToadEradicationfromMada-gascar)willaimtoeradicatethetargetspeciesD.melanostictusfromtheislandcountryofMadagas-car,thuseliminatingexistingandfutureimpactofthisspeciesontheislandsecologyandeconomy.

Successfuleradicationwillrequireseveralseparatebutinterlinkedtasks:

• Confirm and maintain required political and public support for the project for thedurationoftheoperation.

• Setupappropriateoperationalandfinancialmanagementsystemsandgovernance.• Delineate current extent of invasion, including identifying the location and sizeof any

possible satellite populations; this will need to be continually confirmed and updatedduringtheproject.

• Prevent establishment of satellite populations through transport of goods from thecurrentincursionarea.

• Establishsuitablebiosecuritysystemsatlikelyportsofentryandhighlighttheneedforsuchmechanisms tobe future industrial investments inMadagascar; toprevent toads(andotherbiosecuritythreats)reinvading—thiswillhaveadditionalbenefitsinkeepingoutotherpotentialinvasives.

• Confirm methods to be used for the eradication. As there is no current “one hit”techniquecomparable toa singleaerialbaitdrop for rodents,eradicationwould likelyrequireuseofmultipletechniques.It iscrucialthatnotonlythetechniquestobeusedbutalsotheorderinwhichtheyareusedbeconsidered.

• Confirm suitability and accuracy of detectionmethods to both establish the extent oftheincursionandtogivetherequiredlevelofconfidenceinknowingtherearenotoadsleftinthetreatedarea.

• Confirm funding for the project. The two stage approach involving a testing ofmethodologies,aheadoffull-scaleeradication,enablessomefundingflexibility.

• Begineradicationasearlyaspossiblesoastominimisetheareatobetreatedandthecostsinvolved.

A secondary issue not dealt with in this report, but will need consideration, is what responsecould/shouldbeundertakeniferadicationisdeemedinfeasible.

Eradicationistheonlyobjectivethathasadefinitiveendpoint.Allotherresponseswouldneedtobecarriedoutinperpetuity.

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Theauthors’believe/meaningfulcontroltocontainthetoadtoitscurrentrangecannotbeachievedconsideringtradeandinfrastructurewithinMadagascar.Itwouldbeeasytokillthousandsoftoads,but at best this will only slow the rate of spread, asmost killed animalswould come from high-densityareasduetothedifficultyinlocatingtoadsatlowdensities.

2.2 ObjectivesandOutcomesThisdocumentrepresentsapreliminaryfeasibilitystudyfortoaderadication.Theobjectivesofaneradicationprojectandtheoutcomesthatwouldresultare:

Objectives OutcomesObjective1.Primeobjective• RemovalofallinvasivetoadsfromMad-

agascar–PHASE2.

Outcome 1.1. Toads removed from Mada-gascar.Outcome1.2.Nativespeciesprotected.Outcome1.3.Associatedso-cial/human/economicimpactsremoved,andbenefitsachieved.

Objective2.• Developandtestmethodologies

requiredtoeradicatetoads.–PHASE1.

Outcome 2.1. Options for methodologiesinvestigated.Outcome2.2.Methodstested.

Objective3.• Feasibility study updated as new

informationbecomesavailable.

Outcome3.1.Fieldtrials(large-scale)under-takentoconfirmefficacyofselectedtech-niques.Outcome 3.2. Feasibility agreed upon ordiscounted.

Objective4.•Biosecurity implemented to prevent rein-vasion.

Outcome 4.1. Biosecurity plan developedandimplemented.Outcome4.2.Reinvasionoftoadsprevented(iferadicationissuccessful).Outcome4.3.Preventionofestablishmentofadditionalinvasivespecies.

As there are no confirmed techniques for eradicating toads on the scale required inMadagascar, it will be important to consider the feasibility of all possible techniques andthen test the efficacy of the most promising methods; costs would then need to bedetermined.It isprobablethatnoonetechniquewillbesuitableandmultipletoolswillberequired,e.g.,manual captures, chemical control andability to targetdifferent lifehistorystages.

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Itiseasytoremovelargenumbersoftoads,butthosenumbersmustexceedreplacementratesforeradicationtobesuccessful.Giventhehighfecundityoftoads,thiswillbedifficulttoachieve.Fur-ther,itisthelastfewindividualtoadsthemostdifficulttodetectandremove,butwithouttheircap-tureallpreviouseffortwouldbewastediftheysurviveandreproduce.Thelastremainingindividualsineradicationprogrammesoftenexhibitaberrantbehaviours,sometimestheresultofconditioningby previous eradication methods. While toads are less likely to exhibit learned behaviours thanmammals (rodents and ungulates have been known to adopt very unusual behaviours followingeradicationefforts) those last toadsmaysurvivebecauseofunusualbehaviourssuchasextremelyconservativemovement patterns, or use of novel refugia or choices of breeding sites, non-callingbreedingmales.Hence,techniquesadoptedforatoaderadicationonthescalerequiredwillneedtobeappliedstrategically.

Acrucialcomponentofanyeradicationisbeingabletoensuretheriskofreinvasionismanageable.Todothiswillrequirethedevelopmentandimplementationofsuitableborderbiosecuritysystems.Appropriatebiosecuritywould ideallybe inplacepriortocommencingtheeradication inorderfortestingbutduetotheurgencytocommencetheeradicationquicklytheywouldneedtobeimple-mented in conjunction with the eradication. Because of the multi-agency nature of biosecurity,working throughmultiple government agencies, national and regional governments, port compa-nies, transport companies andmajor industries, thismaybeunrealistic. Implementing suitablebi-osecuritymeasureswillnotonlyminimisechancesofreinvasionbytoadsbutalsobyotherunwant-edspecies.Eveniftoadsarenoteradicated,therearemajorbenefitstoimplementingbiosecuritytopreventotherinvasiveshavingmajorecological,economicand/orhumanhealthimpacts.Thisobjec-tivecanbecompletedregardlessofwhethertoaderadicationproceedsornotandislikelytohavesignificantenvironmentalandeconomicbenefitstothecountry.

Aseparatebutrelatedissueisoutgoingbiosecurity.Whilethecurrentincursionpersists,thereisarisktotradepartnersoftoadsbeingtransportedingoodsandmaterials(mechanicalmachineryandmaterials).Thetoadshaveshownhowtheycanbesuccessfullytransportedlongdistances(this in-cursion),andthereisarealriskoftransferringtoadstoanyportthatisservicedfromMadagascar,andespeciallyfromTamatave.ThisincludesReunionandMauritius,butalsomostotherportsregu-larlyreceivingcargofromorviaMadagascar.

Inadditiontotestingeradicationtechniques,itwillbeimportanttoconfirmasuitabletechniquefordetectingtoadsatlowdensitieswithaveryhighlevelofconfidence.Thisisforbothdelineatingtheareatobetreatedandtoconfirmthesuccessoferadication.Asignificantportionofthecostoftheprojectislikelytogointothelatter,asifeventwotoadsarelefttogether,thepopulationislikelytoreturntopreviousdensitieswithinafewyears.

Suitabletechniqueswillneedtobetestedatascalethattrulyreflectsthefieldsituationi.e.,cover-ingthediverserangeofhabitats,landownership,etc.foundintheincursionarea.

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Fig.1c.Asiantoadfemale,Sabah,MalaysianBorneo.Photo:J.Reardon.

NFig.2.Canetoad,Rhinellamarina,PapuaNewGuinea.Photo:J.Reardon.

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3 THESITEThetreatmentsiteforanyeradicationeffortcanbeconsideredinthreeways:

- The confirmed incursion site. This includes the port city of Toamasian/Tamatave and theadjacentAmbatovynickelprocessingoperationsandextensiveurbanandagriculturalareasincludinganumberofwaterways,andisatleast98km2.

- The probable incursion area. This is almost certain to be significantly larger than theconfirmed 98 km2 site. Toad populations will constantly increase while an eradication isbeingconsideredandplanned. Itwill require furthersurveyeffort todelimit theextentofpopulation(s),includingsearchforadditionalsatellitepopulations.

- Thepotential incursionarea.ThiscoversmostofMadagascar (587,041km2),basedonthetransport of goods from Tamatave around the country with no biosecurity in place andminimalecologicalbarrierstospread.

Theconfirmedsiteof theAsian toad incursioncoversabroadrangeofhabitats foundthroughouttheprobableandpossibleincursionsitesincluding:

1. Urbanareas, includinglowersocio-economicurbanandruralcommunities, i.e.,closelivingandlimitedfacilities.Includedareareasofhighersocio-economiccommunitieshavinglargeenclosedhouses.

Fig.3.DrainagechannelincentralTamatave.Photo:J.Reardon.

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Fig.4.DrainagesumpfilledwithrefuseandoccupiedbyAsiantoadsincentralTamatave.Photo:J.Reardon.

Fig.5.PotentialtoadrefugiainwellmaintainedurbancentralTamatave.Photo:J.Reardon.

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Fig.6.Evenwellmaintainedpropertiessuchasthishavemanypossiblerefugia,suchasun-derhouses(CentralTamatave).Photo:J.Reardon.

2. Industrialareas,includingtheextensiveheavyindustrialcompoundsoftheAmbatovymine.

Fig.7.AmbatovyMinenickelrefineryisthelargestindustrialareawithinthecurrentdistri-butionrangeoftheAsiantoadincursion.Photo:Ambatovy.com.

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3. Agriculturalareas.ThecityofTamataveissurroundedbyextensiveagriculturalareasinclud-ingricepaddiesandmarketgardens.

Fig.8.Adrainage“sump”inanareaofextensivericepaddy.Photo:J.Reardon.

Fig.9.Floodedricepaddiesadjoiningvillage.Photo:J.Reardon.

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Fig.10.Extensivericepaddiesadjoiningregeneratingexoticforest.Photo:J.Reardon.

Fig.11.AsiantoadmaleinhumanrefuseatruralfringesofTamatave.PhotoJ.Reardon.

4. Secondaryandregeneratingvegetation.AreasoutofurbanandagriculturaldevelopmentintheincursionareaappeartobedominatedbyseralwoodycommunitiespredominatewithexoticspeciessuchasEucalyptus,MimosaandTamarix.Nosignificantnaturalhabitatareasappeartoexistwithintheincursionarea.

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Fig.12.Mixedlargelyexoticregeneratingforestwithinincursionarea.Photo:JReardon.

AllofthesehabitattypesappeartocontainAsiantoads.Nationally,itisdifficulttoidentifyecologicalbarrierstodispersalandcolonisation.ThedryareasofthewestandsouthmaybelesssuitedtotheAsiantoads,butthepresenceofAsiantoadsinthedrycentralnorthernregionsofSriLankacertainlyhighlights the fact that these toads are highly adaptable. The potential role of altitude in limitingtoadsurvivalisalsounclearastoadsareknowntooccurupto1,800mabovesealevel(vanDijketal.2004).Speciesdistributionmodellingresults,basedonthenativedistribution,indicatethatAsiantoadswilloccupyalmostallofMadagascar(Pearson,2014).

Theproportionalrepresentationofthesehabitatshasnotbeenaccuratelycharacterisedforthein-cursionareabeyondrecognisingallarewellrepresented.Amongthetasksforadvancingthisprojectis theneedforGISskills tobeappliedtoaccuratelydescribehabitatand land-usemosaics.Surveyefforthastodatefocusedondelimitingtheincursionarearatherthancloselyexaminingoccupancyordensityacrossthatarea(Fig.13.)

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Fig.13.AmapoftheknownincursionareaasofFebruary2015withgreenmarkersindicatingsitessurveyedwheretoadswerenotdetectedandredmarkersindicatingtoadsdetected;redpolygon—theminimumpresumedincursionarea(98km2).Note,anadditional12negativesurveylocationssitoutsideofmap(adaptedfromMooreetal.2015).

N

Port

Ambatovyprocessingplant

Asiantoadincursionarea

IvondroRiver

Scale

2km

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Civilsocietyintheincursionarea

Madagascarhascentralisedgovernmentbased in thecapitalofAnatanarivo (Tana),approximately320kmfromtheconfirmedincursionarea.AtsinanaRegionalgovernmentisbasedinTamatave,andvillagesareoverseenbyanelectedVillagePresident.

Thecurrent incursionarea includesa largeportionofTamatavecityand is likely to incorporate inexcess of half amillionpeople in urban and rural areas. Landownership covers the full spectrumfromprivateresidential,corporateandgovernment-ownedlands.

Mostlandisutilisedforagricultureandfoodgathering.Thereislittleforestremainingintheincur-sionarea,althoughmanyofthehillareasareinearlystagesofregeneratingforest,oftenwithintro-duced species (e.g.,Eucalyptus) dominating but appear to be heavily disturbed by fire (Fig. 11)—these are often used for charcoal production. Flat lowland areas are predominately used for riceproduction.Mostwaterwaysarecommerciallyharvestedforfish.

AccesstoTamataveisgood,withamajorport,airportandahigh-qualityroadslinkingittothecapi-tal and the rest of the country. Accesswithin the incursion site is highly variable, ranging from acomprehensiveroadandalleynetwork intheurbanareasto limitedroadaccess inruralzones.Asthe toadshavemoved southandcrossed the IvondroRiver theyhaveenteredanareawhere theprimaryhumanaccessisalongarailwaylinehavingnoadjacentroadsorvillages.

Physicalaccessforanintensiveeradicationproject,orevenforthedelineationsurvey,islikelytobedifficultbecauseofthelackofroadaccesstosomeareas.

There isadefinedwetseason,November toApril,which is likely tobe thepredominantbreedingperiodfortoads,buttherearesuitablewaterbodiespresentthroughoutthe incursionareawhichcouldpermitbreedingallyearlong.TheAsiantoad’sreproductivepatternsareyettobedescribedinMadagascarbutbasedonobservationstodate,andstudieselsewhere,malescongregatearoundwatersourcesandcalltoattractfemaleswhothenlayeggsinthewater.Mostwatersourcescanbeutilisedincludingbrackishwaterandephemeralpoolsprovidedtheylastlongenoughfortheeggstohatchandtadpolestometamorphoseintotoadlets.

3.2 TargetSpecies3.2.1GENERALDESCRIPTION

TheAsiantoadisalargeandrobustmemberoftheBufonidaereportedlyreaching200mmsnouttoventlengthinfemaleswithanaveragesizeof85mmreportedbyMercy(1999);malesareusuallysmaller(vanDijketal.2004;Mercy1999).Adultcolourationisvariable(seeFigs.1a,bandc)andcanrangefromplainbrickred,creamtoalmostblack.Themostcommoncolourpatternispaleyellow-brownmarkedboldlywithdarkorreddishbrownstreaksandspots.Theirdorsalsurfaceandlimbsarecoveredwithwartsvaryinginsize,usuallywithaspinousprotrusionandoftenpigmentedblack.Males have a subgular vocal sac coloured yellow-orange in breedingmaleswhich also exhibit theinner side of the first and second fingers and having nuptial pads. Juveniles apparently possess ablackbandaroundthethroatrunningbetweenthechinandbreastandhavenowarts,havingaverysmallTympanumaccordingtoMercy(1999).Thetoadshavemanyattributesmakingthemanideal

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invasivespecies–theyarephysicallyrobust,canliveinawiderangeofhabitatsandecotypes,highlyfecund(maylayupto40,000eggsperseason)andhavecosmopolitanbreedingtolerance.Theydorequirewaterforbreeding,butitcanbestandingorslowflowing,ofwhichthereisnoshortageintheincursionarea.

3.2.2REPRODUCTIONANDDEVELOPMENTALBIOLOGY

Breedingdependsonaccesstowater.Wherewaterisavailablebreedingwillpersistyearroundbutinmoreseasonallydryhabitatsadistinctbreedingseasonisobservedwithmaximumreproductiveeffortatthebeginningofthewetseason(Mercy1999).Thelunarcycleinfluencesovulation,whichoccursinassociationwithafullmoon.Theovariescanmakeup30%ofthetotalbodyweightofthetoadatthistime.Femaleslayalongstringofblackeggs,externallyfertilizedbythemale.Eggsareenclosed ina thickmucusmembraneanddepositedusuallyonsubmergedvegetation.Breeding ismostcommonlynotedinephemeralorvernalpool(s).MaleAsiancommontoadshaveacontinuousspermatogeniccyclehowevera study inTaiwanshowedtherewasa largerconcentrationof sper-matophoresinthemaletoadduringaspecifictimeoftheyear(Huangetal.1997;Kahn2000;Mercy1999;SaidapurandGirish2001).Malescongregateatbreedingsitesandcallfemales.Theircallcanbenotedassoundinglike“creo-o,o;cro-ro-ro-ro-ro-ro-ro”andintensecompetitionamongmalesforfemalesmeansmanymales areoften found clinging to a single female (Kahn2000;Mercy1999).Thisbehaviourclearlyoffersanexcellentopportunitytotargettoadswhentheyarehighlydetecta-ble,aggregatedandbreeding—anobviousadvantagetoaneradicationeffort.

FemaleAsiantoadscanproduceupto40,000eggsperseasonandthispotentialhasbeenconfirmedinMadagascar(R.Danielle,pers.comm.)andeggshatchwithin24to28hours.Tadpolesaresmallandblackusuallyaround15mminlengthandassociateingroups(Khan2000).ResearchhasshownthatAsiancommontoadtadpolesrearedwithsiblinggroupsgrowatahigherrateanddevelopfast-ercomparedtolarvaerearedinmixedgroups(SaidapurandGirish2001).AstudydonebyMogalietal(2011)illustratesthattadpolesofAsiantoadsemergeatdifferenttimesandsizesinthepresenceofpredatorsandundersuchcircumstancestadpoleswilldecreaseinbodymassupto46%andmet-amorphosiswillalsooccurearlier.

ThesedataarelargelydrawnfromworkwiththeAsiantoadinitsnativerangeandthereiscurrentlyverylimitedinformationavailableonthebiologyandecologyoftheAsiantoadinMadagascar.

Thecurrentareaof incursion inMadagascarsuggeststheyareveryabledispersers,at least indis-turbedandurbanhabitats. Likeall toads, theAsian toadhasparotoidglandsbehind theeyesandabovethetympanumoneithersideoftheneck.Theseglandsproducebufotoxins,whicharesteroidlactonealkaloids,synthesisedtoactasarepellenttopredators.Itisthesetoxinsthatleadtomuchoftheconcernthat invasivetoadswill impactnativepredatorspeciesevolutionarilynaivetotoadsaspreyitems.

LongevityhasbeenestimatedasanaverageoffouryearsinthewildandrecordsexistofAsiantoadsreaching10yearsofageincaptivity(Mercy1999;Khan2000).

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Fig.14.Duttaphrynusmelanostictus,Asian toad female in suburbandrainage,Tamatave.Note themelanic canthal, pre-orbital, supra-orbital, post-orbital, mandibular, maxilla and orbito-tympanicridgesthatthespecificnamemelanostictus,describes.Photo:J.Reardon.

Fig.15.ResearchstudentwithmaleandfemaleAsiantoadcapturedduringdayinthedry,openvegetationpicturedinbackground.Photo:J.Reardon.

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3.2.3INCURSIONORIGINS,RANGE,DENSITYANDABUNDANCE

The presence/absence surveys carried out to date give aminimum incursion area of 98 km2 (Fig.13.).However this is verymuch aminimumestimate as the survey techniqueswere conservative(visualobservationof toadsalongtransects),and itwouldbeeasytooverlooktoads ifnot inhighdensity.Duringtheinitialsurveysonlyonesurveywasundertakenateachsite;itwasnotpossibletocheckforsatellitepopulationseitheralongwaterwaysortransportedbyhumansinrubbishorpro-duce.

Geneticworktoconfirmtheoriginalsourcelocationfortheinvasioniscurrentlybeingundertaken.Thesesamplescouldbeusedasvoucherspecimensforanyfutureincursions.Iftoadsaredetectedafter an eradicationwas deemed successful, genetics can determine if it was a new incursion orwhethertheeradicationattempthadfailed.

Preliminarysurveyshaveattemptedtomeasuretoaddensityinthreedifferentecotypes:urban,ru-ral/agricultural and non-production forest habitat, which largely consists of regenerating exoticwoodyspeciesappearingtobedominatedbyEucalyptus.Ateachecotypethreesiteswereselected(non-randomly) so nine siteswere searched in total.On average, across these sites there are 5.8toadsper100m2or580perhectarewithamaximumdensityof18toadsper100m2or1,800toadsperhectare.Thisestimatecontrastswithaquotedfigureof65toadsperhectarequotedbyAmba-tovy (Mark Sitter, pers. comm. to IUCNASG) for theareaunder theirmanagement.However it isunclearifthisdensityestimatewasgeneratedpreorpostoftheon-goingeffortstoremovetoads,assuchactionswillhavedensitydependenteffectsinfluencinganyestimateofdensity.

Athirdofthesites(3of9),didnotappeartohavetoadspresentandthesesiteswereallrural,non-productionhabitat.Itisveryencouragingtoknowtoadabundanceissuperficiallylowerinthiseco-typealthoughwemustremaincautiousastheincreasedstructuralcomplexitywillreducetoadde-tection probabilities. Equally, the ecotypewith the greatest apparent density of toadswas urbanwithanaverageof51toadper100m2.Thisfiguremaybeinfluencedbythemoresearchablenatureofurbanhabitatandweshouldbemindfuloftheheterogeneityofhabitatsuitabilityinallecotypes.Thesefiguresareofcourseonlylooselyindicativebeingderivedfromasmall,non-randomsamplingeffortbutdidnotallowustounderstandthenumericalmagnitudeof this incursion.Thesefiguresallowustoextrapolateanestimateoftoadnumberswithintheknownincursionarea.Ifweassumethatonly2/3ofthe98km2areaisoccupiedbytoadsthenthereis65km2or6,500haofoccupiedhabitat.Atanaverageof580toadsperhathatisapopulationof3.77milliontoads,notconsideringtadpoles.

Theusefulnessofthisextrapolationistoemphasisethateveniferadicationmethodsmissonly0.01of thetoadpopulation,weare leftwith37,700toadsremaining.Suchanumberwouldbreedandrecruitataratethatwouldneutraliseanyeradicationeffortwithintwoorthreeseasons.

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Fig.16.TheAsiantoadteamdevelopingtechniquestoconductabriefevaluationoftoaddensitiesacrossallpossibleecotypesranges.Photo:J.Reardon.

Fig.17.Leioheterodonmadagascariensis,theMadagascangianthognosesnake,potentiallypoisonedbyAsiantoads.Photo:AndrewRouth.

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3.3 Impacts3.3.1THREATSTOHUMANHEALTHANDWELLBEING

TheAsiantoadposesarealandlethalrisktohumanhealthinMadagascar.Itiswithsomesurprisetheauthorsdiscoveredthisspecies,ubiquitouswithinitsnativerangeis implicatedasthecauseofpoisoningmultiplehumansandhasbeendocumentedas thecauseofdeathandcardiacarrest inchildrenwhohaveconsumedtoadtissue(Keomanyetal.2007).Itisalsosuprisinginthesestudiesisthe common knowledge among those communities suffering these cases of poisoning, that thetoadsarepoisonous.Wefeelthatthishealthriskiselevatedwhenconsideringthetoad’sestablish-mentinanenvironmentsuchasMadagascarwherethereisanextensiveruralpopulationthatpartlyrelyonhuntingandgatheringfortheirsourcesofproteinandwhoareentirelynaïvetothepoison-ousnatureoftheAsiantoad.Further,astudy(Keomany2007)pointsthatanumberofotherrecordsintheliteratureconsidercasesofpoisoningafterconsumingtoadsortheireggs(Chernetal.1991;Kuoetal.2007;Chietal.1998;YeiandDeng1993;Chengetal.2006;Janetal.1997).Together,thisbodyofliteraturesuggeststhehealthimpactsofAsiantoadsinMadagascarmaybesignificantandlethaltohumansespeciallyincommunitiesfamiliarwiththeconsumptionoffrogsasaregularpartofthediet.

Anyreductioninthenumberoflargersnakes,refer3.3.2couldalsoleadtoasurgeinBlackrat(Rat-tus rattus) populations, leading to seriouseconomic consequences suchas lossof stored rice andother food supplies, and damage to commercial goods and equipment as electricalwiring. In the1990’s,theover-collectingofAcrantophissnakesfortheboaskintradeintheAmbato-BoenyregionofMadagascarreportedlyledtoadramaticincreaseinblackratpopulations,withseriouseconomicconsequences.ThiswasthesubjectofastudyfundedbyGTZ(C.J.Raxworthy,pers.comm.).

3.3.2THREATSTOMADAGASCARSFAUNAANDFLORA

The impactsthatAsiantoadswillhaveontheMadagascar faunaandfloraarecurrentlyunknown.Fullimpactsfromthetoadscannotbeknownwithoutdetailedstudieswhichwilltakeyearstocom-plete.Althoughthisworkshouldbedone,thetimetakentoobtainthedatawouldallowtheinva-siontoexpandbeyondanyhopeoferadication.Consequently,managementdecisionsforthetoadsmustnecessarilybebasedonimpactsseenfromwhatisknownaboutecologicallysimilarspecies.Inthis instance,wecanderive reasonableestimatesof likely impacts fromwhat is knownabout im-pactsderived fromtheecologically similarCanetoad,Rhinellamarina, inAustralia. InbothMada-gascarandAustralia,largegeneralisttoadsadaptabletohuman-degradedenvironmentswereintro-ducedto isolatedlandscapeswhosenativefaunawerehistoricallyunexposedtotoadsand,hence,highlysusceptibletotheirnoveltoxins.BasedonimpactsseeninAustralia,thehightoaddensitiesalreadyreportedinMadagascar,andthepredictedmassivespreadoftoadsintomostregionsoftheisland(seePearson2015),wecanexpectthatnegativeimpactswillbesubstantialandoccurinmanyhabitatsandcommunities.

Themostobviousdirectthreatconcernspoisoningofnaïvepredators.Thistoohasbeenthegreat-estimpactfromCanetoadsinAustralia.Largefrog-eatingendemicsnakesarelikelytobeespeciallyvulnerable (e.g., Leioheterodon, Ithycyphus andDromicodryas spp.). There have already been re-ported observations of snakes dying after eating toads in the Tamatave area (M. Moore, pers.

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comm.)nowconfirmedasLeioheterodonmadagascariensis (Fig.17). In the remainingnativehabi-tats,manyother locally endemic smaller species of snakeswill also be vulnerable if they feedontoadlets or tadpoles—the reduction of snake populationswould disrupt the food supply to otherpredators(suchashawks).

Otherendemicgroupsthatfeedonfrogsarelikelytobevulnerable,includingTenrecs(Tenrec,Mi-crogale spp.), carnivorousmammals suchas theFosa (Cryptoprocta ferox), and theendemicmon-gooses (Mungotictis spp.),Mouse lemurs (Microcebus spp.) and birds such as the spectacular en-demicradiationsofMadagascargroundrollers(Brachypteraciassp.,Geobiastessp.,Uratelornissp.and Atelornis spp.) andVangas (Family:Vangidae).Manyof these species represent an importantpart ofMadagascar’s charismatic biodiversity, helping drive the ecotourism industry. In addition,toads are voracious feeders. Their high density is likely to reduce populations of ground-dwellinginvertebrates and small vertebrates, such as endemic frogs (Stumpffia spp. Gephyromantis spp.,Mantidactylusspp.), skinks (Amphiglossusspp.)andchameleons (Brookesia spp.)due topredation(Figs.18,19,20).Directcompetitionforfoodmayalsoaffectother largegrounddwellingendemicamphibians such asDyscophus, Scaphiophryne and Plethodontohyla genera, although this of lesscertain.Alloftheseimpactsareexpectedtobegreatestinthemostdiverseandsensitivecommuni-ties,whichare located in the10%areaofsurvivingnaturalhabitat inMadagascar.Thesenegativeimpactsare thus likely toaffectmostof theprotected reservesandnationalparks inMadagascarbelow1,800melevation.

Toads could also havemore indirect, but potentially serious, impacts on invaded communities. Inparticular,theymayalteranimalcommunitiesthroughservingasnutrientsinks,storingnutrientsintheir bodies thatwouldnormallybepassedup the food chainbypredator consumption.Becausenativepredatorswilleitherquicklydiefromtoadconsumptionorlearntoavoideatingthem,toadswillquicklybeavoidedasafoodsourceandendupasadead-endstoreofnutrientsinlocalcommu-nities.Thiswillshort-circuitnativefoodchains,therebydeprivinghighertrophiclevelsofnecessarynutrients.InAustralia,theinvasiveCanetoadhasbeendocumentedtohavethiseffect,formingfourtimes themassof thepre-invasionnative frogcommunities,nutrientsnowunavailable tosupportnativepredatorcommunities.

Lastly, toadsmay serve to introduceor spread foreigndiseases tonativeamphibiancommunities.ThegreatestconcerninthisrespectisthedualthreatfromRanavirusandchytrid,Batrachochytriumdendrobatides,whichhasbeenspreadgloballybytradeinalienfrogspeciesandhascausedmassivedeclinesandextinctionsinamphibianfaunasworldwide.Todate,chytridhasnotaffectedMadagas-car’s largeanduniquefrogfaunabutconcernsareelevateddueto itsrecentdiscoveryamongnu-merousAnuran taxa (Bletz et al. 2015).However, should toads carry this disease, itwouldbeex-pectedtoproducewidespreadextinctionsinMadagascar,asithaselsewhere.

Insummary,despiteitsheavilydegradedstateMadagascarstillhasalargenumberofendemicspe-cieslikelytobeimpactedbythetoad.Toadswillimpactfoodchainsfromboththetop(consumingprey and serving as an energy sink) and the bottom (poisoning predators), either ofwhich couldeventuallyaffecttheecologyacrossmuchofthecountry.

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Fig.18.Dyscophusantongilii(Tomatofrog),apotentiallyvulnerablespeciestotheadvanceofAsiantoadsintoremnantnativeecosystems.Photo:C.J.Raxworthy.

Fig.19.Mantidactylusmelanoplura,apotentiallyvulnerablespeciestotheadvanceofAsiantoadsintoremnantnativeecosystems(MantadiaN.P.Madagascar).Photo:J.Reardon.

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Fig.20.Brookesiasupraciliaris(Leafchameleon)apotentiallyvulnerablespeciestotheadvanceofAsiantoadsintoremnantnativeecosystems(Andasibe,Madagascar).Photo:J.Reardon.

3.4 BenefitsofEradicationThebenefitsoferadicationwilllargelybeecologicalthroughremovingtheriskofpoisoningofnaivepredatorsnaivetotheAsiantoad.Toaderadicationwouldalsoeliminateanyimpactsoftoadpreda-tiononmany smaller specieswhich in turn reducesanunnatural levelof competitionwithnativespecies.Many species inMadagascar are already under significant human-induced stress throughhabitat destruction, hunting and collecting and the impactsof other introduced species. The toadwillincreasethatpressureandmaydrivesomespeciestoextinctionoratleastreducethemtothepointwherespecificsite-ledorspecies-ledmanagementisrequiredtosavethem.

Economicimpacts,suchasmajorchangestotheislandsecologyoragricultureareunknownbutmayinclude an increase in rat numbers affected by reduction of larger snakes—most likely to be poi-sonedbythetoads.Thisisaconcernasrats(Rattusrattus)arealreadyamajoreconomicprobleminMadagascar.

ThebenefitstohumanhealthofaneradicationoftheAsiantoadisclear—removingtheriskoflethalpoisoningtohumansandanimalspecies.Attheveryleast,failuretoeradicatetheAsiantoadneces-sitates theMadagascangovernmentengage inaneffectiveeducationprogramme topromote themessagethatthesetoadsarepoisonoustopeopleandsomelivestock.Thereisalsoariskthatthe

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toads,by reducingpredators likesnakes throughpoisoning,will increase theprevalenceofplagueinfectionswhicharealreadypresentwithinthetoadincursionarea.

Puttinginplacecomprehensivebiosecuritysystemswillhavebenefitsfarwiderthanjustthereduc-ing toad populations and/or expansions. Incoming biosecurity, if put in place,will significantly re-ducethechanceoftoads,aswellasotherfutureinvasivespecies,establishingthuspreventinganynegativeimpactstheymayhave.

Outgoingbiosecurityalso requiresattention,especially if the toadsarenoteradicated.Considera-tionwillneedtobegiven topossibleactionswhichmaystop themestablishingatother locationswhichreceivegoodsfromorareservicedbyshipswhichhadvisitedMadagascar.FailuretodothiscouldleadtoWorldTradeOrganisationsanctionsbeingputinplaceongoodsoriginatingfromMad-agascaraccordingtothelegislationsupportingtheWTOsTradeLiberalisationagenda.

4 RequirementsforSuccessfulEradication

4.1Technicalapproach

As there are no examples of amphibian eradications over such a large area, it is important thatmethodologies are testedandevaluated for their efficacy for eradicating toads fromMadagascar.ThereisarangeoftechniquesavailablethattargetvariouslifestagesasdetailedinAppendixIIIandsummarisedhere:

• Tadpolesviaremovalwithtadpoletrapsorchemicaltreatmentofwaterbodies.• Breedingadultsviaphysical removal, includingusingaudiostimuli toelicit calling fromhidden

males. • Juvenilesviaspot-sprayingwithcitricacidorsugarsolutions,physicalremoval. • Eggsviaremovalofstringsfromponds. • Breedingadultsthroughfencingordrainingsomewaterbodies.• Non-breedingterrestrialadultsandjuvenilesthroughphysicalcapture.

It is therefore crucial to develop by trial an array of options tomeasure their efficacy. The infor-mationfromthetrialswillthenbeusedtodeterminethetechnicalapproachtobeconsidered,alongwiththescaleofthetreatmentsitetoseeiferadicationcanbetechnicallyfeasibleacrosstheentireincursionlandscape.Ifsuitabletechniquesareidentifiedtheywouldbeimplementedusinganadap-tive-managementprocess,constantlyreviewingtheirefficacyandadaptingthemasrequired. If in-sufficientsuitablemethodsarevalidatedduringtrials—eradicationwillnotbefeasible.

ItmaybehelpfultonoteherethatrecentworkonthecontrolofCanetoadsinAustraliahasprovid-edsomehope for thecontainmentof toadswhereeradication isdeemed impossible (Letnicetal.2015).InthiscaseitneedstobestressedthattheAsiantoadincursionareainMadagascarissignifi-

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cantlymorehumidwithfargreateraccesstowatersourcesthanthearidareaofAustraliaconsid-eredintheLetnicetal.(2015)study.

It isestimatedtherearecurrentlyapproximatelyfourmilliontoadsinMadagascarbasedonanex-trapolatedcalculation.Thisiscertainlynotexactlyaccuratebutanessentialpreliminarycalculationtoprovidesomenumericalperspectivefortheissue.Inthecalculationweexpecta1:1sexratioandthat75%ofthepopulationareofbreedingage.Whileeachfemalecanlayupto40,000eggsthereisonlyanaverageof20,000laidperfemaleperyear,andonly1%ofeggssurvivefromhatchingtojointhebreedingpopulation.Undertheseplausibleassumptionsacontrolprogrammerequiresustokill1,500,000toadsperyearjusttomaintainnumbersattheircurrentlevel.Inordertoeradicatethemwithin fouryears itwillbenecessary tokillover2,500,000peryear. Failure to remove toadsatagreaterratethanthiswillresultinthefailureofaneradicationeffort.

4.2 Sustainability

Foraneradicationtobesuccessfulitiscrucialthatoncetoadsareremoved,theyarenotallowedtore-establishbyrenewedimportation.Thecurrentincursionshowsthatunlesschangesinbiosecurityaremade,thereisaclearpathwayfortoadstobetransportedagaintoMadagascarfromSoutheastAsia.

Althoughundertakingacomprehensivebiosecurityprogrammecanbecomplicatedandexpensive,therearebasicactionsthatcanbeimplementedcheaplyandquickly,whichcansignificantlyreducetheriskofnewpopulationsestablishing.Thiscanincludeeducatingstaffespeciallyattheportandatbusinessesorfacilitiesengagedinimport/exportactivities;tonoteandreportanynewspeciestheyobserve; inspectinghigh-riskgoods;andhavingarapid-responseplaninplacetofacilitateimmedi-ateremovalactionifandwhenanewincursionoccurs.Enforcingstandardsofcleanlinessandordercanalsoincreasetheabilitytodetectinvasiveorganismswhilealsoraisingthegeneralstandardsofoperation.Expertassistanceshouldbesoughttodevelopabiosecurityplanthat isappropriateforthelocalconditions.

ParticularthoughtwillneedtobegiventobiosecurityinandaroundTamatavewhetheraneradica-tionproceedsornot.Ifaneradicationproceedsitwillbeimportanttominimisetheriskoftoadsbe-ingmovedoutside the infestedareawhere theycouldestablish satellitepopulationselsewhere inthe country, potentiallyputting thewholeeradicationproject at riskof failure, or at least, signifi-cantlyincreasingtheoperationalriskandcostoftheproject.

Ifaneradicationprojectisnottoproceed,thoughtwillneedtobegiventowhetheritisfeasibletotrytoreducetherateofexpansionofthetoads.Itispossiblethatsomeofthetechniquesthatareputforwardforconsiderationforaneradicationareeffectiveatsignificantlyreducingtoadnumbersbutwon’treachthelevelrequiredforeradication;thesecouldbeusedforanongoingcontrolpro-grammeiftherequiredongoingresourceswereavailable.Thiswouldpotentiallybuytimewhilead-ditionalworkontoadcontrol,anderadicationoptionsareinvested.Thatis,itispossiblethatgivenadequate resources, a methodology could be developed which is not currently available, and it

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shouldbenotedthegreatertheareathetoadsinhabittheharderandmoreexpensiveitwillbetoimplementsuchamethod.Itisnotconsideredlikelythatacontrolprogrammewilldoanythingoth-erthanreducetoadnumbersandpossiblydecreasetheirrateofexpansion.

Althoughallevidencecurrently indicatesthatAsiantoadshavenotyetreachedtheport facilityofTamatave,giventhecurrentrateofspreadestimatedtocurrentlybeapproximatelytwokmperyear(seeFig.13andconsideranincursiontimeframeof4–7years),itwillnotbelongbeforetheydo.ThiswillposeagreatriskofintroducingtoadstonewsitesacrossMadagascarandinternationally.

4.3 SocialacceptabilityWhilefurtherworkwillberequiredtoconfirmthelevelofsupportwithinthecommunity,fromoursitevisitthereappearstobeaveryhighlevelofsupportwithinthecommunitytoremovethetoads.Thereisakeendesireforeradicationand,insomequarters,anexpectation;althoughthereisnotagoodunderstandingofwhatisrequiredtodothis(asopposedtocontrol).Somelocalisedcontrolisalreadybeingundertaken,andmanypeoplebelievethateradicationissimplyintensivecontrol,i.e.,thatitissimplyanumbersgameandthelasttoadwillbeaseasytoremoveasthefirstifyousimplykeepatit—hisisnottrue!

Concernsoverhumanhealthrisksarelikelytobeamajorreasonforthecommunitysupportshownfortheeradicationtodate,andtheconcern is likelytoremain.Similarlythereareconcernsaboutthe impactof toadson chickens,whichare common through the inhabitedareaandofeconomicimportance,especiallytolowereconomicgroups.Therearestoriesofchickensbeingkilledbytoadsreported to Reardon andMcClelland during the site visit but no carcasses were observed. Onceagainthisconcernhasledtosignificantsupportforeradication.

Communitysupportmaydependoncontroltechniquestobeused;hence,itwillnotbeabletocon-firmfinalcommunitysupportuntilthepreferredtechniquesareidentified.Forexample,peoplemaybeveryhappywithphysical removalbutnothappywith theuseof chemicals,even thoughsomelevelofremovalviasafechemicalssuchascitricacidandsugarsolutionmaybefeasible.Requiredaspectsofpublicsupportneededforsuccessfuleradication:

• Access to all properties in the possible incursion area both for removal and monitoringacrossmultiplevisits.

• Acceptanceofthetechniquestobeused.• Avoiding the use by the public of any techniques that may be required for follow up

monitoringsoastoavoideducatingindividualtoads(behaviouralmodification).• Animpressionthatabountysystemwillnotbeanelementofaneradicationplantoprevent

thestock-pilingandmanipulationof toadpopulations.Theeradicationeffortwill stillyieldextensiveemploymentopportunities.

• Ongoing support for biosecurity, initially to prevent the establishment of satellitepopulationsandtodetectanythatmayalreadybepresentandthentodetectanyfurtherincursions.

Therewillinevitablybesignificantpressuretointroduceabountysystemasaquick,easyandsocial-lydesirable(itputsmoneyintothecommunity)wayofreducingtoadnumbersthatwillbeseenas

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doingsomething.Bountieshavebeenusedforanimal-controlprojectsgloballyforcenturiesandalt-houghtheydoreduceanimalnumbers,veryfewhavesucceededineradicatinginvasiveanimals.Itismorecommonfor themto leadto“farming”of theanimals toprovideasustainable income.Oneadditionalproblemwithbountiesistheyplacethesamevalueonallindividuals,whereasremovinganimalsattheperipheryofanincursionismorevaluablethanremovingthosetowardsthecoreofthe range, as doing so reduces the rate of spread,whereas those towards the core are generallymucheasiertocatch.Also,animalssurvivingtowardstheconclusionoftheproject,whenthereareveryfewandhardtocatch,aremoreimportantthaneliminatingthoseatthestart,whentheyareplentiful.Inshort,thenegativeaspectsofattemptingabountyoutweighanypossiblebenefits,andtheideashouldbeclearlyavoidedpublicly.

TableofKeyContributors

Keystakeholdersidentifiedsofar:*

Name Organization/function ContactdetailsMadameSahondraRabesihanaka

Malagasy Government – MEEMF: Head of Service,BiodiversityConservation

[email protected]

Mr.EricRobsomanitrandrasana

Malagasy Government – MEEMF: Responsible fornativefauna.

[email protected]

Ms.MayaMoore MadagascarFaunaandFloraGroup [email protected] MitsinjoAssociation [email protected] NewZealandDepartmentofConservation [email protected] Invasivereptileandamphibianexpert [email protected] AmericanMuseumofNaturalHistory [email protected] Independenteradicationconsultant [email protected] AmphibianSurvivalAlliance [email protected]

*WeacknowledgethattherewillbenumerousincountrystakeholdersplayingacriticalroleinanyprogrammeofworktoaddresstheAsiantoadincursionbutthefeasibilitystudydidnotenableustodiscussthesituationwithsufficientpotentialstakeholderstomakelistingthemhereappropriate.

4.4 Political&legalacceptabilityFrom the limited discussions had withMEEF Represented byMadame Sahondra, it appears thatthere isahigh levelofgovernmental support for theeradicationof the toads. Itneeds tobecon-firmedthatthisisreflectedatapoliticallevelandwillresultinongoingsupport.ThefuturepoliticalsituationinMadagascarisunknown,butifthereisstrongsupportinitially,theprimaryriskwouldbewithdrawalofsupportbytheGovernment.

NGOs,National,RegionalandLocalgovernmentwouldneedtoworkcloselytogetherwithclearlinesofcommandandcontrolsothatoncetheoperationstartedtherearenounexpecteddelays.

Whether eradication is legally acceptable will depend to a large part on the techniques used, assomeof thesemay require governmentalpermitsor consents, althoughenvironmental legislationseemsminimal inMadagascar.Anexample couldbe registrationof apossible ranicide,whichwillnotbeabletobeconfirmeduntil therequiredtrialsarecompleted.Alternatively, ifatechnique isnotabletobelegallyimplementedthereisnouseincarryingoutthetrials.Issuesmayincludeani-malwelfareandhumanhealthconcerns.

AmajorconcernisobtainingaccesstoALLpropertieswithintheknownincursionareaaswellasanypotentialoutliers,bothcurrentandfuture.Thereviewteamwere informedthataccesswouldnot

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beaproblem,butwhendealingwiththousandsof landowners,aswouldbethecaseforthispro-ject, not having access to evenoneproperty could lead to failure if it harboured toads. Althoughthereislittledoubtthatmostlandownersaresupportive,thereareconcernsaboutsomeindustri-al/businesssitesthathaveahighlevelofsecurityandalsosomeofthegatedhousesinthecity. Itwouldbe important tohavea legalmechanism toallowaccess to suchareas if required. It isnotknownifthiscurrentlyexists.Ifnot,itneedstobeprovidedbyeitherlocalornationalgovernment.

Thebiosecurityrequiredfortheeradicationwillalsoneedpoliticalandlegalsupporttoenforcethestandards required toprevent reinvasion—there aremanyexamplesof islandbiosecurity systemsavailableworldwidetobasethison.

4.5 EnvironmentalacceptabilityThe environmental impact of the eradication on non-target species or habitatswill largely be de-pendentuponthetechniquesused.Forexample,theimpactsofastand-alonephysicalremovalpro-grammecouldbequitedifferenttoaprogrammewhichinvolvestheuseofchemicals.

Aphysicalremovalprogrammewouldhaveahighlevelofdisturbance,i.e.,anintensivegridsearch,butprobablyonlyshort-termimpact.Thiscomparestotheuseofsomechemicals,whichmayeitherdestroyvegetationorharmotherwildlifee.g.,anychemicalwhichkillstoadsor inanywayaffectstheirbiologymayhaveanequalorgreatereffectonnativeamphibiansdependinguponhowtheyareapplied.Itisbelievedthattheareasofarinhabitedbythetoadshasonlyafew,common,widelydistributednatives.Theircollaterallossisunlikelytobesignificant.Anyimpacthastobeconsideredagainstthelikelylong-termimpactacrossthewholecountryofnoteradicatingtoads.

Oncetrialshavebeenundertakentoconfirmpreferredcontroltechniques,theacceptabilityoflikelyorpotentialimpactsofthosemethodswouldneedtobeconsidered.

4.6 CapacityThis relates to thesystemsthatwouldneedtobeput inplace togive therequiredadministrativesupportfortheprojectandthecapacityoftherelevantorganisationstoprovidethatsupport.

ProjectAdministration

EradicationoftoadsfromMadagascarwouldbeamultiyear (estimatedtobeat leastsevenyears,includingplanningandresultmonitoring),logisticallychallengingandveryexpensive(millionsofdol-lars)project.Thescaleoftheprojectwouldrequireextensivegovernanceandfinancial-managementsystemstobeinplace.

ProjectGovernance

Anyeradicationattemptwould require cleargovernanceandmanagement structureswithagreedroles,responsibilitiesandaccountabilities.Thisnotonlyreducestheriskofpotentialdisagreementamonginvolvedparties,whichcanbehighlydisruptivetoaneradicationprogramme,butallowsforfastdecisionstobemadeonoperationalandfundingactivities.

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Fortunately theMadagascar Fauna and FloraGroup (MFG) under the local direction ofMs.MayaMoorehaveagreedtofunctionastheleadorganisation.CriticalskillsprovidedbyMFGincludethatitisalreadyworkingontheisland,intheareaoftheincursionandwithastaffandcontactnetworkat the local and national level and excellent links to the international conservation community. Itwouldbe infeasible foraneworganisation tobeestablishedsolely to run theproject,as itwouldneedtosetupalltherequiredinfrastructureaswellasprocesses,e.g.,labormanagementwithoutanyexistinglocalknowledge,takingtoolongconsideringthetoad’srangewouldhaveincreasedintheinterim,increasingcostanddurationoftheproject.Aswithmanysuchdevelopingnations,themost important skill agoverningorganizationwillneed tohave tobesuccessful is familiaritywiththe localsociety,governmentandabilitytofacilitateskills transferto locallysourced labour,whilebeingskilledinnavigatingpoliticalandprocessweaknesses.

AlthoughitmaybetheoreticallypossibletoruntheadministrationfromalocationremotefromTa-matave,it isconsideredimportanttohavethemajorbaseinTamatavesothatthereisacloselinkwiththefieldprogramme.This,combinedwiththerequirementforlocalknowledgefortheopera-tionitself,meansthattheNGOwouldneedtobebasedinorclosetoTamatave.Theonlyorganiza-tionwhichappearssuitableforthisistheMadagascarFaunaandFloraGroup(MFG),basedinTama-tave. Although it has a staff of approximately 30, they are already fully committed to their otherwork,andtakingtheroleonwouldmeansignificantlyexpandingtheirstaffandsystems.Thiswouldobviouslyneedtobecostdeterminedintoanyeradicationbudget.

Therewouldbearangeoforganisationsandindividualsthateitherhavetobeorareinterestedinbeinginvolvedinaprojectsuchasthis.Manyofthesewouldhaveminimalunderstandingofwhatisrequired for undertaking a successful eradication, as opposed to control i.e., they are focused onkillinglargenumbersoftoadsandnotonkillingthelasttoad.Howthesegroupsinteractwillneedtobecarefullymanagedtoavoidconflictordiversionofresourcesfromtheeradicationitself.

Astructurewhichhasbeenshowntoworkwellforengagingkeyplayersthroughtheplanningandimplementationof amajoreradication is themodelused inAustralia for theMacquarie and LordHoweIslanderadicationswhereasteeringcommitteewasestablished.Thisincludedrepresentationfromthegovernment,whohaveoverall responsibility fortheenvironment,major fundersandtheimplementationorganisation(s),aswellaseradicationexpertise. It is important that thisgroupbekeptsmall(nomorethansixpeople)tofacilitatefunctionalitybecauselargegroupsinvariablyspendalotoftimediscussingtangentialissuesandare,consequently,inefficientatreachingdecisions.Thisgroupcanthenactastheconduitforinformationbothintoandoutofthesteeringgrouptotherela-tiveagenciesandindividuals.

Therolesandresponsibilitiesofthesteeringgroupneedtobelaidoutclearlyina“TermsofRefer-ence”forthegroup.Thiswillincludewhichgroupsordepartmentseachgroupmemberisresponsi-ble for keeping informed.A crucial component of a successfulworking group is that allmembershaveas theirgoalasuccessfuleradicationsothedebate isoveronwhatcanbedoneto facilitatethatgoalratherthanrepresentingtheinterestsoftheirparentorganizations.Whileultimatelyapo-liticaldecisiononwhethertheprojectshouldcontinue,needstobeinformedbyeradicationexperts.

Itisfurtherrecommendedthatascientificandtechnicaladvisorygroup(TAG)beestablishedassoonaspossible,bothtooverseethetrialsandanyeradicationitself.Thisgroupcanprovideadvicetothe

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projectmanagerandthesteeringcommitteeontechnicalissuesrelatingtoeradication.Thisislikelyto include eradication expertise, non-target expertise and social/local expertise. Once again, thisgroupshouldbekepttoamanageablesize(nomorethaneightpeople),withadditionalpersonnelwith specific skills andexpertiseable tohelpon specific issuesas required. It is recognized thatalargenumberofindividualsandgroupsmaywanttobeinvolvedwiththisgroup(e.g.,peoplework-ingonpotentiallyaffectednon-targetspecies),somanagingthesocialdynamicofthisgroupwillbeimportant,asisrecognizingthegroupisadvisoryonly,andthesteeringcommitteeandoperationalteamwillmakedecisionsbasedonallinformationavailable.

Aswith any eradication, the quality of thework and hence the skills andmotivation of theworkforce,isparamount.Althoughthereisaplentifulandrelativelycheaplabourforceavailable,carefulconsiderationwouldneedtobegiventoensurethatallfieldstaffarefocusedondoingtheworktotherequiredstandardsothatonceanareahasbeenclearedtheteamcanmoveontonewareaswithahighlevelofconfidence—fieldleadershipskillswillbeimportant.

Whether partner organisations or businesses become a functioning part of an eradicationprogrammeitiscriticalthattheyworkcollegiallywiththecoordinatorsoftheeradicationeffortandshowcommitmenttoapplyagreedoperationalstandardsandprofessionalism.

Table1.Keyskillsneededtocompletetheproject.Note:thisonlyrelatestoStageOneEradicationanddetectiontechniquedevelopmentandanincursiondelineationsurvey.

KEYSKILL PURPOSE METHODTOOBTAINSKILLSPROJECTMANAGEMENT Oversightandadministration:

eradicationexperience.Targetpersonnelwiththerequiredskillsandexperience.

FIELDOVERSIGHT Oversightofthefieldtrialsanddistributionsurvey.

Sourcelocallabour.

FIELDWORKERS Undertakethetrialsandsurvey.

Uselocallabour,tobeselectedusinglocalcontract,ideallyskilledpersonnel.

APPLIEDSCIENCE Designandcoordinatetherequiredtrialsandproducerelevantreports.

Jointroleforinternalandexternalpersonnel,probablyprovidedbytheTAG.

ADMINISTRATION Coordinatebudgetandprojectreporting.

LocalNGO.

4.7 AffordabilityItisnotpossibletodevelopadetailedbudgetforaneradicationitselfuntil:• Techniques for both the eradication and surveying for toads at low density have been

developed.• Sizeoftheincursionisconfirmed,includinganysatellitepopulations.• Administrationoftheprojectisestablished.

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ItisapparentthatanyeradicationwillcostprobablybetweenUS$2millionandUS$10millionandasinsufficientfundingwill inevitablyleadtofailure.Itisimportantthatadequatefundingisidentifiedbefore theproject is startedasotherwise, it isawasteof time,moneyandgoodwill.Theneed toconfirm the fundingmust be balanced against the need to commence the eradication as soon aspossibleastheincursionareaandhence,costsarelikelytoincreaseexponentiallywithtime.

CostsforPhase1—selectionofdetectionanderadicationtechniquesandconfirmationoftheextentoftheincursionneedtobeundertakenbypersonnelwhoknowthecostofoperatinginMadagascar.Weestimatethecostsforyearonetobeapproximately$US385,000(seeAppendixIII).Delays in implementing theeradicationwill increase the cost as the incursionwill continue toex-pand,includinganincreasedriskofsatellitepopulationestablishingthroughhumanassistedmove-ment.

6CONCLUSIONWebelievethattheeradicationofAsiantoadsfromMadagascarisnotcurrentlyfeasiblebecause:

1. No proven methods of removal are known which will eliminate toads faster than theyreproduceandrecruit.

2. No tested detectionmethods are sufficiently sensitive to ensure all animals are detectedwithaprobabilityenablingremovalgreaterthanreproductionandrecruitment.

3. No sufficient confidence of the current toad distribution and how rapidly the incursion isexpanding,includinghumanassistedmovements.

Howeveriftheseissuescanallbeanswered,andthereissufficientfundingavailable,itispossiblethateradicationispossible.

AppendixIIIofthisreportbrieflydetailsthetechnicalinvestigationsneededtoundertakeinordertoconfirmwhethertoadscanbeeradicated.Iftechniquesaresuitable,anoperationalplancanbede-velopedandcostdeterminedtoconfirmthefinancialfeasibilityoftheproject.

KEYISSUES.Requiredtoenableeradicationprogramme:

Issue Action

Detectiontechniques. Refinepossibleoptionsandundertaketrials.Eradicationtechniques. Refinepossibleoptionsandundertaketrials.Delineatingtheextentincursion. Useselectedtechniquetoundertakesurvey.Develop a complete operationalplan.

Basedonatechnique(s)beingavailable.

Costoferadication. To be cost determined once the operational plan isdeveloped.

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6Acknowledgements:The authors thank theAmphibian Survival Alliance andParis Zoo for funding this feasiblystudy;MadagascarFaunaandFloraGroup(MFG)forprovidinglogisticsandadministrationsupportforsiteinspections;MayaMoore(MFG)andDevinEdmonds(AssociationMitsinjo)for supporting a site visit, aswell as coordinating thedistribution surveys (a crucial com-ponentofthisstudy)andforlastlyundertakingatranslationrole.Itisrecognisedthatthistook these individuals away from their existing commitments and added significantly totheirwork load—for thisweareappreciativeof theireffortsandcontributions to this re-port.

Weespecially thankJeanFrançois (Parc Ivoloina/MFG) forundertakingmanyof thedistri-butionsurveysandforcoordinatingthesitevisitsincludingliaisonwithlocalresidents.Weare very grateful toMFG and AssociationMitsinjo for providing staff for the distributionsurveys.

We greatly appreciate the contributions of Dr.RogerDanielRandrianiaina of the UniversityD’Antananarivo forvaluable input to thediscussionsand translationassistance.WethankLydia Randrianasolo for coordinating the site visit to the Ambatovy processing plant andwaste site. The authors acknowledgeMadagasikara Voakajy for their kind provision of ChristianRandrianantoandro’stimetotheproject.

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Cheng,C.J.,C.S.Lin,L.W.Chang,andS.H.Lin2006.Perplexinghyperkalaemia.Nephrol.Dial.Trans-plant21:3,320–3,323.

Chi,H-T.M.,D-Z.Hung,W-HHu,D-Y. Yang. 1998. Prognostic implicationsof hyperkalemia intoadtoxinintoxication.HumanExperimentalToxicology17:343–346.

CrosslandM.R.,M.N.Hearnden,L.Pizzatto,R.A.Alford,R.Shine.2011Whybeacannibal?Thebene-fits to cane toad (Rhinellamarina) tadpoles of consuming conspecific eggs.Animial Behaviour82:775–782.

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Huang,W-S,J-Y.Lin,J.Y-L.Yu1997.MaleReproductiveCycleoftheToadBufomelanostictusinTai-wan.ZoologicalScience14(3):497–503.

Jan,S-L.,F-L.Chen,D-ZHung,C-S.Chi1997.Intoxicationafteringestionoftoadsoup:reportoftwocases.ActaPaediat.Sin.38(6):477–480.

Khan,M.2000."Duttaphrynusmelanostictus.AmphibiaWeb.Available:http://amphibiaweb.org/cgi-bin/[Accessed:17February2012].

Keomany,S.,M.Mayxay,P.Souvannasing,C.Vilayhong,B.L.Stuart,L.SrourandP.N.Newton2007.ToadpoisoninginLaos.AmericanJournalofTropicalMedicineandHygene77(5):850–853.

Kuo,H.Y.,C.W.Hsu, J.H.Chen,Y.L.Wu,Y.S.Shen2007.Life-threateningepisodeafter ingestionoftoadeggs:acasereportwithliteraturereview.Emerg.Med.J.24:215–216.

Kraus,F.2009.AlienReptilesandAmphibians:Ascientificcompendiumandanalysis.SpringerSci-enceandBusinessMediaB.V.,Dordrecht,Netherlands.563p.[ISBN:978-1-4020-8945-9].

Letnic.M.,J.K.Webb,T.S.Jessop,andT.Dempster.2015.Restrictedaccesstoinvasionhubsenablessustainedcontrolofaninvasivevertebrate.JournalofAppliedEcology52(2):341–347.

Mercy,M.1999.StudiesonsomeaspectsoftheBiologyandEcologyoftheCommonIndianToadBufomelanostictusSchneider(ClassAmphibia;OrderAnura).MahatmaGandhiUniversityThesesLibrary.Moore,M.,J.Francois,andD.Edmonds.2015.Thenewtoadintown:DistributionofDuttaphrynusmelanostictusintheToamasinaareaofeasternMadagascar.TropicalConservationScience8(2):440–455.

Mogali,S.,S.Saidapur,andB.Shanbhag.2011.LevelsofPredationModulateAntipredatorDefenseBehaviorandMetamorphicTraitsintheToadBufomelanostictus.JournalofHerpetology,45(4):428–431.O’Shea,M.,A.Kathriner,S.Mecke,C.Sanchez,andH.Kaiser2013.‘FantasticVoyage’:aliveblindsnake(Ramphotyphlopsbraminus)journeysthroughthegastrointestinalsystemofatoad(Duttaphrynusmelanostictus).HerpetologyNotes6:467–470.Available:http://www.herpetologynotes.seh-herpetology.org/Volume6_PDFs/Shea_HerpetologyNotes_volume6_pages467-470.pdf[Accessed:08October2015].Pearson, R.G. 2015. Asian common toads inMadagascar: an urgent effort to inform surveys anderadicationefforts.GlobalChangeBiology21:9.Pestanimalriskassessment:Asianspinedtoad(Duttaphrynusmelanostictus)TheStateofQueens-land,DepartmentofEmployment,EconomicDevelopmentandInnovation,2010.Available:https://www.daf.qld.gov.au/__data/assets/pdf_file/0003/56658/IPA-Asian-Toad-Risk-Assessment.pdf[Accessed:16October2015].Saidapur,S.,S.Girish.2001.GrowthandMetamorphosisofBufomelanostictusTadpoles:EffectsofKinshipandDensity.JournalofHerpetology35(2):249–254.

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vanDijk,P.P.etal.2004."Duttaphrynusmelanostictus". IUCNRedListofThreatenedSpecies,Ver-sion2012.2.IUCN.Wingate,D.B.2011.ThesuccessfuleliminationofCanetoads,Bufomarinus,fromanislandwithbreedinghabitatoffBermuda.BiologicalInvasions13(7):1,487–1,492.

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APPENDICES

AppendixI:SiteVisitsTwo of the authors (McClelland and Reardon) visited the incursion site from 23–29th November2014.Thefirsttaskwastodevelopa“termsofreference”forthevisitandsubsequentreport.Thiswaspromotedbytheapparentmisconceptionbysomepeopletheoutputfromthetripwastobetheprovisionofaneradicationplantellingthemhowtoeradicatethetoadsandhowmuchitwouldcost.Thetermsofreferenceweresignedoffbytherelevantpartiesanddisseminatedtoeveryonecurrentlyinvolvedintheproject.

Duringthestaytheyvisitedarangeofdistributionsurveysitesaswellaslookedatthefullrangeofurbanandruralhabitats,includingmajorwaterways,potentialbreedingareas,bothinthecityandinruralareas,andarangeofterrestrialhabitats.VisitedweresiteswithintheAmbatovynickelpro-cessing plant and associated staff accommodation, including ameetingwith Samuel, the environ-mentalmanagerforthecompany.Guidedby:JeanFrancois,secondinchargeattheMFG,whohadundertakenmostofthedistributionsurveys;accompaniedbyDevinEdmondsoftheMitsinjoAssoci-ation,whohadbeeninvolvedinmanyofthesurveysalongwithMayaMooreofMFG;andDr.RogetDanielleoftheUniversityofAnatanarivo,whohasbeenundertakingsomepreliminaryresearchonthepossibleimpactsofthetoad.

ThroughJeanFrançois’ localknowledgeandconnectionsthegrouptalkedtoseveralof theVillagePresidents(theelectedvillageleader)tofindoutthelocalviewonthetoadsandtrytoidentifyanypotentialissueswithundertakinganeradicationoftheirarea.

Onthe24ththegroupmetwithAroRatovomonehjaryandLydiaRandrianasolooftheAmbatovymin-ingcompanytodiscussthesituationandAmbatovy’sroleinanyeradication.TheystatedthatAmba-tovywere currently undertaking surveyworkwithin their site and theywould follow the require-mentsofanyeradicationplan, i.e., theywouldundertaketheworkonAmbatovy landrather thanhaveanyexternalpersonnelworkingontheirproperty.Thisapproachwasconfirmedduringalldis-cussionswithAmbatovypersonnel.

Onthe27ththegroupwasjoinedbyChristianRandrianantoandro,nationalcoordinatorfortheAsiantoadprojectandEricRobsomanitrandrasanaofMEEF(MinistryofEnvironment,EcologyandForests)todiscuss the issuesand thoughts to thatpoint.The followingday,McClelland,Reardon,DanielleandRandrianantoandrometwiththeRegionalOfficeofEnvironment,EcologyandForeststoupdatethemontheproject’sprogress.

McClellandandReardon,alongwithDanielleandRandrianantoandro,mettheSecretaryforMEEF,aswell andothergovernmentofficialsandNGOrepresentatives inAnatanarivo.On the5thofDe-cember.McClellandandReardonupdatedthegroupontheirthoughtstodateandstressedthedif-ferencebetweenacontroloperationandaneradication,inwhicheverylastindividualhadtobere-moved,asitappearedtherewassomeconfusionbetweenthetwomethods.Theyalsostressedtheyweretheretolookatthe“feasibilityofundertakinganeradication”andthereportwouldcoverfea-sibilityonly,andnotbeaneradicationoperationalplan.Therewasarealdesiretostartaresponse

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straightawaysoitwasnecessarytostatethataneradicationrequiresplanningandcoordinationandwhileitwouldbeeasytogooutandkillthousandsoftoadsimmediatelythesewouldbeinthehighdensityareasand,giventheanimal’srapidbreedingrateandotherfactors,wouldmakevery littledifferencetotheoverallexterminationofthespecies.Therewasdiscussiononputtingabountyontoadsbut itwasagreedthat thiswouldhavethesameeffectas justkilling toads—killing theeasyones,withtheaddedriskoffarmingtoads.

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AppendixII:TermsofReferenceThis report has been requested by the Amphibian Survival Alliance and the IUCN SSC AmphibianSpecialistGroupMadagascar onbehalf of theGovernmentofMadagascar. The feasibility study isbeingdevelopedbyMr.PeterMcClelland,anexpertineradicationofpestanimals,Dr.JamesRear-don, a scientist for theNew ZealandGovernmentDepartment of Conservationwho specializes ineradicationofinvasivereptilesandamphibians,Dr.FredKraus,theheadoftheeradicationfeasibil-ity study group and expert in global invasive reptile and amphibian issues and RandrianatoandroChristian,nationalcoordinatorfortheeradicationproject.OurcontributionofexpertopiniontothegovernmentofMadagascarandotherstakeholdersisintendedfortheinclusivebenefitofsecuringsecurityforMalagasysocial,economicandbiodiversityvalues.

1. Thedocumentisnotaneradicationoperationalplanbuta“feasibilitystudy.”2. Thisdocumentisdesignedtoexploreanddiscussfeasibilityofaneradicationprojectbased

oncurrentincursionstatusincludingenvironmental,socialandtechnicalparameterstomin-imizeriskoffailureandwasteresources.

3. Controlanderadicationareverydifferentconcepts:thecontrolofapestanimalaimstodi-minishtheirabundancetoaprescribedlevel.Eradicationisthetotalremovalofallindividu-alsinanincursion,andassuchspecificoperationalparametersmustbemet.Theseare:

a. Technical feasibility: Technique(s) be used at the project sitemust be capable ofremovingallindividualsofthetargetpopulation.

b. Sustainable:Re-invasionofthetargetspeciescanbeprevented.c. Sociallyacceptable:Theprojecthasfullsupportfromthecommunityandotherkey

stakeholders.d. Politically and legally acceptable: It is possible to secure all required permits and

consentstoconductaneradicationproject.e. Environmentallyacceptable:Anynegativeimpactoftheeradicationareacceptable

fortheenvironmentduetothebenefitsoferadication.f. Capacity: It ispossibletoassembleordevelopthenecessaryskilled individuals,re-

sourcesandequipmentfortheeradicationproject.g. Affordability:Theeradicationprojectmustbeachievablewiththeresourcesavaila-

ble(beingconsciousoftheoveralllong-termcostsofcontrol).h. Detectionandinterception:Itmustbepossibletodetectallindividualsintheincur-

sionareaandplacethemallatriskofcapture.Thisislikelytorequiretheuseofmul-tiple techniques in carefully prescribed order to reserve the most sensitive tech-niquesforthelastremainingandthereforemostdifficulttotargetindividuals(Thisiswhywemustbecautiousaboutrushingintoemployingtoadremovaltechniques).

4. AnyplanninganddevelopmentofaneradicationplanmustbeconsiderateofMalagasyso-

cialandpoliticalconditions.5. Anydevelopmentofaneradicationprojectfollowingthisfeasibilitystudymustbeacknowl-

edgedasan“eradication-by-research”projectasnotoolsorprocessesarecurrentlyprovenfortheeradicationoftoadsfromlargeareas.

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6. It is critical that prior to the receipt of the feasibility study report that accountability andleadershipstructuresbeacceptedbyasuitableorganizationorpartnershipoforganizationsleadbyaMalagasyorganisation.

7. ThisfeasibilitystudyreportwasintendedfordeliveredtoMalagasypartnersbyJanuary30th2015.Duringthewritingofthefeasibilityreportitbecameclearthatthedocumentneededto function as much more than the traditional feasibility report for a broader audienceincludingNGOs,Governmentandstakeholders.Becauseofthisthereporthadbeendelayedin it’s release until November 2015 to allow for further research and discussion withpartnersonitscontent.Followingthesubmissionofthisreportanditsrecommendationsitisimportantthatpartnersunderstandthetime-boundednatureofprogressinganyeradicationplanning.Testingandevaluationoftoolsandtechniquesfordetectingandremovingtoadsmustprecedetheirwide-scaleemployment.

8. Giventherisksofextendingthedelaytooperationalizingeradicationduetofundraisingde-lays, it is important to immediatelybegin canvassing for financial supporton theprovisonthatiftheeradicationdoesnotproceedthenfundswillbereturned.

Anumberofassumptionswillneedtobemadeinthedevelopmentofthefeasibilityreportandthe-sewillbestatedinthereport.

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AppendixIII:PreliminaryTechnicalStrategy

Thisdocument is not aneradicationoperationalplan,however it is acknowledged there is urgentneed to consider the potential operational methodologies and parameters to be able tomake aquantitativelyinformeddecisiononwhethertoprogresstheprogrammeofwork.Thisrequiresustoconsidercostand,insomecases,testprospectivemethodologiestoinformthatdecision.Also,someurgentissuesneedtoberapidlyaddressedtomaintainoptionsforadvancinganeradicationopera-tionandprovidingaframeworkandaccountabilitiesforthedecisionsthatneedtobemade.

Wemustacknowledgethataneradicationofanamphibianhasneverbeenachievedonthescaleweareconsideringhere,orinsuchacomplexenvironment.Thus,wecannotconfirmwhethereradica-tionisfeasibleuntilwehaveevaluatedpotentialeradicationtools.Eachpotentialtoolmustbetest-edpromptlytoevaluateitsrelativeefficacy,bearinginmindfactorssuchaslife-historystage(eggs,tadpoles,metamorphs, juveniles,adults,breedingadults),seasonandecotype,whenrelevant. It isprobablethatanyonemethodwillbeinadequatetoachieveeradicationwithinagivenarea.There-fore,wehavetoconsiderastrategythatusesmultipletools(Methodswillneedtobeusedconcur-rentlytoo.),basedonefficacyataparticularpopulationdensity.Thisorderofapplicationofthosetools isalsoastrategicallycriticalelementofsuccessfuleradicationtoavoidcreatingadifficult-to-targetresidualpopulation.

1URGENTISSUES

1.1Governing/leadershipbody–It isextremelyimportantasmallbodybeidentifiedtoleadallef-fortsrelatedtothetoadincursionissue.Noeradicationprogrammeispossibleuntilaccountabilityisclearlyidentifiedandtheremittoleadtheprogrammeofworkisdefined.

Recommendation: Discusswith current lead organisations and key in-country partners todate(Malagasygovernment,MFG,AssociationMitsinjo,ASA)howthisbodyshouldbemadeupandhowtheywillbesupported.Itisvitallyimportantthatagovernance/leadershipbodybedesignatedassoonaspossibleasitisnecessaryforevaluatingandactingontherecom-mendationsofthisreport.Thisbodyneedstoberesponsibleforimmediatelyraisingfundstoachievethegoalsdiscussedbelow.Oncefundingisavailableandadministrativestructurein place (see next item), secondary administrative structure canbe responsible for raisingsubsequentfunding,asneeded.

1.2Managementandadministrationstructure–Beyondtheleadershipandaccountabilitynecessaryto steer suchaprogrammeofwork it is essential there is accountability for administering the re-sources and infrastructure required. This ideallywould be undertaken by a single organisation sothatthereareclearlinesofaccountabilityandresponsibilityandpreferably,byanorganisationthathas an existing structure in place inMadagascar—facilitating faster implementation of any work.Considering the limitationsoncapacity inMadagascar, this functionmayneedtobesourcedelse-where.

Recommendation:DuringdiscussionsinMadagascar,itwassuggestedadequateresourcingwereavailabletosupportthefullcosts;MFGmaybeabletoconsidersucharole.Thispossi-

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bleoptionshouldbeurgentlyexploredfurther.Theauthorsarenotawareofalternativeop-tions.

1.3Financing–Costsofdevelopmentoferadicationmethodsortheunderpinningresearchtosup-port suchmethodswill require funding. It is extremely difficult to secure fundingwithout a veryclear,prescribedproposal,yetdelaysinsecuringfundswillseriouslyundermineeradicationpoten-tial.

Recommendation:Leadorganisationshouldcommunicatewithmajorpossibledonors,fun-ders and partners (e.g., IUCN, UNEP, UNDP, ADB) to highlight the issue and potential re-quirement for rapid funding.Ourproposalhere is to seekUS$385,000 for the first twelvemonthsofresearch,developmentandtesting.ShoulderadicationproceedbeyondthispointtheprojectislikelytocostbetweenUS$2m–US$10mandtakeatleastafurther5–6yearstocomplete.

1.4Biosecurity&education–Itisanimmediateconcernthatthetoadmaybeinadvertentlyspreadbeyonditscurrentincursionareabyaccidentaltransportationingoodsandequipmentbeingmovedoutofthe incursionarea. It isclearlyextremelychallengingtoachieveadequatebiosecurityforallinternal trademoving through the incursion area. However,minimummeasures should include anation-wideawarenesscampaignidentifyingthetoadsandrecommendingactions,includingreport-ingany interceptionswith theaccountablegoverningbodyofanyeradicationeffortaswell as re-portinganynewincursionsites.

ThesecondmajorconcernregardingbiosecurityistheseaportofToamasina/Tamatave.Duringourevaluationwewerenotabletogainaccesstotheinnerportarea,butexaminationoftheareaanditsperimeterhighlightsthefactthatthereisnoeffectivebarriertothespreadofthetoadintotheportarea.Thepresenceoftoadsintheportfacilitywouldsignificantlyincreasetheriskoftoadsbe-ingtransportedtootherlocations,especiallythosewithsignificanttradefromTamatave.

Recommendation: Leadorganisation shoulddevelopa communicationandeducationpro-grammetoraiseawarenessoftheinvasivetoadandprovidechannelsforreportingnewlo-cation sightings. Although international standards in biosecurity vary greatly, and weacknowledge the limited infrastructure inMadagascar, suggestingactionsas simpleasen-forcing cleanliness and tidiness in port storage and handling areas, together with well-displayed and easily understood instructions to collect and report any organisms to staffmaderesponsiblefortheirremoval,couldsignificantlyreduceriskoftoadsandotherorgan-ismsbeingtransportedtoandfromtheport.

1.5Mapping/GIS–Thereisaneedtoaccuratelymapanddelimithabitattypesandidentifytheex-tentof the incursionareaaswell aspotentialbarriers to toadmovementswithinandaround theincursionareatoassistinstrategicplanningofanyeradicationeffort.

Recommendation:LookforGISmappingexpertswithingovernmentandtheprivatesectorwhocanbecontractedtoworkontheproject.Itisimportanttheyhaveaclearunderstand-ingofworkingwithenvironmentaldata.

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1.6Delimitation–Althougheffortshavebeenmadetodescribethefullextentofthetoadincursion,themethodsusedarelikelytobeinsensitivetotoadsinlow-densitypopulations.Aswedonotun-derstandthepopulationdynamicsoftheexpandingincursionwemustassumetoadsmayoccuroverawiderareaindensitieslowenoughtoavoidcasualobservation.

Recommendation: Specificefforts shouldbemade throughacommunicationplan to raiseawarenessofthetoads intownsanddestinations likelytohavereceivedsignificantfreightfromtheincursionarea.Surveyteamsabletoefficientlyquestionlocalcommunitiesabouttoad presence and conduct their own searches should be dispatched to the highest-risksites.Toachievethis,thecommunicationplanwillneedtohaveanationalreachandbeap-propriatelydesignedtoensurethekeymessagesreachrural,aswellasurbancommunities.

2METHODTESTINGANDEVALUATION

Although this report isnotaneradicationoperationalplan, it isessentialanyeradicationplanwillconsistoftheapplicationofasuiteofdetectionanderadicationtoolstogivetheprogrammehopeofmeetingtheminimumcriteriaoferadication.

Alleradicationmethodswillrequiretestingtoevaluatetheirefficacytoremovethetargetanimal.Aseradication against this species has never been attempted before, nor any eradication conductedaround Tamatave, nor any amphibian eradication conducted at such a large spatial scale,we areconsidering the use ofmethodologies untested against such a large incursion. Hence, it is criticalthatweevaluateefficacyofpotentialtoolsacrosstherangeofecotypesoverwhichweneedtoop-erate.Theapplicationofmethodswill relyonunderstandingthenumbersof individualsbeingtar-geted, their life-historystagesandtheproportionof those individuals thatcanbe interceptedandremovedwitheachtechnique.

Due to the time constraints of this project the methodologies proposed are not exhaustive, buthopefully cover themajority of tools andmethods likely to be relevant for an eradication effort.Shouldresearchanderadicationbeoperationalised,thenfurtherinvestmentshouldbemadeincon-sultingthoseinthefieldofvertebrateeradication.

2.1BASELINEDATA,IMPORTANTISSUESANDMONITORINGMETHODS

The followingmethodologicalproposals focusonbaselinedatagatheringanddetection tools. It isnecessary for us to evaluate variables such as average density to assist in the evaluation of tech-niquesasacomponentofaneradicationplan.Estimatesareacknowledgedasindicativeonlybutarenecessarytoprovidethebestinformationtoinformresponsedecisionsneededtobemadeswiftlyandpragmatically.

Itmay seem inefficient to considermethodologiesonly able todetect toads rather thanmethodsthatbothdetectanddestroytoads. Inaneradicationscenario it is importanttoconsidermethodsthathavethegreatestprobabilityofdetectingthetargetanimalaswellasmethodsthatdetectandkill.Iftherearemonitoringmethodssignificantlymoresensitivetotoaddetectionthanthoseableto

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alsoresultintoadcapture,thentheywillbeimportantcomponentsofaccuratelydelimitingthein-cursionarea,aswellasconfirmingsuccessfuleradication.

2.1.1Densityestimation

Purpose:Fromthedatagatheredtoestimateaveragetoaddensitywithintheincursionareaitwillbepossibleforustoevaluatetheapparentdemographics(ageandsex)ofthetoadpopulationandanyanomaliesthatmayprovideopportunitiestostrategizeeradication.Mostimportantlywillbetheabilitytoextrapolatethedatatothefullknownextentofthecurrentincursionandmakemoreap-propriateestimationsoftheeffortrequiredforeradicationplanning,andtherelativeriskofmeth-odologiesbeinginadequatetoachieveeradication.

Method:Aninitialandmoderatelylow-costactionshouldbetoevaluatetheapparentdensityinarangeofecotypesknowntocontainmoderatetohightoaddensities:urban(suburbansettlement),intensiveagricultural,andunmanagedvegetatedhabitat.Werecommendthattoaddensitiesbees-timatedatseveralsites,preferably,2–3sitesinallmajorecotypes.Thiscanbedonequicklyandcosteffectivelybysmall-scaledestructivehabitatclearance.Thescaleonwhichsuchmethodsshouldbeemployedshouldbelimitedtoonly2–3sitespermajorecotypeastheinformationgatheredisindic-ativeonlyforthescalingofsubsequentmethodstesting,forextrapolatingapproximatetoadpopula-tionsize,andthereforeforenablinganimprovedevaluationofriskofproposederadicationstrate-gies.Theproposedmethodologyistodemarkanareabeingnolessthan10x10mandnogreaterthan20x20m.Ifpossible,constructa“toad-proof”temporaryfenceusingstandarddrift-fencede-signsor,ifthismethodisnotpossible,employadditionallabourtocleartheperipheryoftheareatobesearchedandensurethearearemainsunderobservationsotoadsdonotmoveinoroutofthearea.Ateamofsearchersthenworkthroughtheareafromonesideoftheareatotheotherwithin2–3mofeachotherclearingvegetationandanymaterialsinorunderwhichtoadsmaybehiding.Itwillbenecessarytohavemacheteandspadesavailablefortheclearanceofvegetationthatcannotbeeffectivelysearchedwithoutremoval.Assuchitisimportanttheareasselectedforthesearchesmeetcertaincriteria:

1. Landownerconsentisachievedamicably.

2. Theareatobesearcheddoesnotcontaincropsoranythingtheownerisnotcomforta-bletobemovedordamagedduringasearch.

Alltoadsobservedmustbecollectedandplacedinanescape-proofbucketprotectedfromexcessivedirectsunlight.Oncetheteamhavemadeonethoroughsweepoftheareatheyshouldrepeattheprocessensuringthatnoopportunityremainsfortoadstooccupytheareabeingsearched.

Once the search is completed the collected toads shouldbe swiftly examinedandeach individualmeasured(SVL),sexedandhumanelyeuthanisedbypithing,orbyothermeansdeemedhumanebyveterinaryexperts.Ifskeletalchronology(furtherdiscussionofthismethodbelow)istobepursued,thenlimbsamplesshouldbecollectedandstoredinlabelledappropriatemedia.

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Logisticsandcosts:Thisproposedworkwillrequireateamofatleastsixindividualsledbysomeonewithcompleteoversightandunderstandingof thetechniquebeingpursuedandtheskills toaccu-rately record the data gathered. Transport will be necessary, involving vehicle and driver. Teamsshouldbeabletoexaminethreesitesperday,andifweaimfor3xsitesinurban/suburban,3xsitesinruralagriculturaland3xsitesinunmanagedhabitatwewillneed21mandaysforthesurvey,anadditional sevenmandays to reconnoitre sites, and fourmandays to recorddata and synthesiseintoabriefreport.WorkingonabudgetofUS$20/person/dayplusUS$120forvehiclecosts (bothcostsapproximatedfromobservedcostsduringfeasibilitystudyvisit)thenthisworkwillcostamin-imumof:

• Surveylabour:US$3,080.

• Vehiclecosts:US$600.

• Analysisandbriefwriteup:US$80.

Total:$3,760

The logisticsof suchaneffortwill require local knowledgeandcommunity-relations skills thatap-peartobeexclusivelyofferedbyMFG intheregionof the incursion.Staffwouldthenbeamixofthosewith skills (as previously provided by the AssociationMitsinjo), local knowledge (MFG) andprobablysometechnicaloversightfromsomeonewithecologicalskills(e.g.,DevinEdmonds,RogerDanielRandrianiana).Itisourunderstandingthatthisworkisinpartalreadyunderway.

2.1.2Humaneeuthanasia

Purpose:Methods of humane euthanasia are essential to the testing or employment of any toaderadication tools.Methodsneed tobe approvedby an appropriate animal ethics body. This is animportant issueas theuseofhumanemethodswillbeaprerequisite foranydonorsupportinganeradication or research programme. Failure to develop and adhere to ethical practices risk bothfundingandthereputationoftheprogramme.Thismayseemlikeanunnecessarycomplicationbutitisanessentialcomponentofconsideringtheeradicationofanyinvasivevertebrateorganism.

Method:Theleadbodyaccountablefortheeradicationshouldconsultwithveterinaryexpertsandanappropriateanimalethicscommitteetoidentifyappropriatemethodscurrentlyacceptedforthehumaneeuthanasiaoftoads.Thiswillneedtobedoneinaninformedmannerwithconsiderationoftheneedtohavemethodsappropriateforusebyunskilledworkerswithinthecontextoftheincur-sionenvironment inMadagascar. It isnecessarydifferentmethodswillbedeveloped fordifferentlife-historystages.Eggsmayhavetobeeuthanizedusingdesiccationmethodsensuringalleggsarequicklyrenderedincapableoffurtherdevelopment.Thereareestablishedchemicalmethodsfortheeuthanasiaoftadpolesprobablynotsuitableforthewidespreadusebyunskilledlabourers.There-fore,amethodof traumaor rapidexposure toextremeheatmaybeappropriate, suchas thede-cantingoftadpolesandtoadlets intomeshbasketscanberapidlyexposedtofire.Similarly,newlymetamorphed toadletsandsmall juvenile toadsmay require similarmethodsofeuthanasia.Adulttoadsarelikelytobequiterobustanimalsandwillrequiremethodsensuringswiftdeath,probablythroughtrauma.Pithingand/ordecapitationusingspecifiedtoolsarelikelytobethesolution.Dueto the large numbers of toads thatwill need to be killed in this operation, the development of a

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spring-loadeddevisethancanreleaseaboltunderpressuretocauselethaltraumatothebrainmaybeaworthwhileinvestment.Obviouslydecapitationwithamacheteisamethodwellworthconsid-eration,asunskilledworkersareabletohandlesuchtools,andthestrategyavoidsdevelopmentandmanufacturing costsof alternativedevices.Personnel trainingwill ensureproperexecutionofanychosenmethod(s)andensureunnecessarysufferingtoanimalseuthanizedasquickandpainlessaspossible.

Costsandlogistics:Verydifficulttoestimatewithoutfurtherinvestigationbutweimaginethetimecostofanimalethicsgroups,togetherwiththedevelopmentoftoolsislikelytocostintheregionofUS$10,000. Theproductionof any tools to support eradicationwould require themanufactureofhundredsofdevices.Theuseofavailabletechnologysuchasmachetedecapitationandtheuseoffire for tadpoles/toadletswould significantly reduce this cost butmust be approvedby an animalethicsauthorities.

2.1.3Trackingtunnels

Purpose: Tracking tunnels are a low-techmethod of passively detecting the presence of animalsthroughtherecordingoftheirtracks.Althoughvisualsearchesandlocalreportsmaybeveryeffec-tiveasmethodsofdeterminingpresenceorabsenceatmoderatetohighdensitiesoftoads,weneedtofocusonmethodsabletodetecttoadsatmuchlowerdensitiesavoidingfalsenegativeswhenas-sessingdistribution.Suchmethodshavebeenincreasinglyusedforthepassivemonitoringofherpe-tofaunainNewZealand(NZ).

Method:Trackingtunnelsaremass-producedcardswithacentralportioncoveredinpersistentink.Theywork either passively, recording the tracks of whatever animal passes through them duringtheirdeployment,orcanalsoincludealuretoincreasethelikelihoodofthetargetanimalenteringthe tunnel. They are used extensively in New Zealand tomonitor abundance of invasive rodentsbaitedwithpeanutbutteranddeployedinlinesoftenatspecificspacingsforasinglenight(Fig.1).Thetrackingcardsareplacedwithinplasticorcorflutetunnelsthatcaneitherbepurchasedorcon-structed.

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Fig.1.AtrackingtunnelshowingrattracksinNewZealand.

Thesedevicescouldbetestedtoevaluatetheirusefulnessbydeployinglinesoftentunnelsatpre-scribedspacings (e.g.,no less than20m) focusingon likely locations,suchasagainstwalls,withinvegetation,andadjacenttowaterbodies.Ideallythetoolwouldbetestedinareasofknowndensi-tiesoratleasthigh-densityandlow-densitysitesandwithinexperimentalenclosedareaswhereverylowtoaddensitiescanbecontrolled,todeterminetheirusefulness.Asnotestedanuranlureiscur-rentlyavailable,itisrecommendedtunnelsbetestedunbaited.Againthisavoidsattractingrodents,whosetrackswouldpotentiallyobscuretoadtracks.Theinkdoesdryoutslowlyanddependingonweather,tunnelsshouldberetrievedwithin3–5daysandtheirabilitytodetecttoadsassessed(e.g.,how dry the ink has become, the level of print coverage from non-target animals). The tracks oftoadsshouldalsobecollectedbyencouragingcaptivetoadstotravelthroughtunnelssoobservershavegoodreferenceprintsofdifferent-sizedtoadsaswellaslikelylocalnon-targetspecies(rodentprint patterns are readily available digitally, but other non-target native species, especially frogs,wouldneedtobeobserved).Ifprovenuseful,thistoolcanbedeployedrelativelycheaplyatmultiplelocationsandislikelytoprovidegreatersensitivitytoatleastmoderatetoaddensities,comparedtovisualsearches.Itdoesnotseemthismethodhasbeenusedtomonitorthepresenceofamphibianselsewhere;hence, theneedtotest thismethod isofutmost importance indetermining itsuseful-nessfortoadmonitoringpurposes.

Logisticsandcost:Theprimarylogisticalconcernisinterferencewiththedevices.Inurbanareas,thepublicmayremoveordisturbtunnelsoutofcuriosityandiftheconstructionmaterialsaredeemeduseful,theymaybecollectedforalternativeuses.However, iftheyaredeemedeffective,staffareabletoidentifytoadprints,theinkremainseffectiveforasufficientperiodandtracksarenotregu-larly obscured by non-target animals, then theymay be an appropriate detection tool. Their de-

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ploymentcostswilldependonthenumberofsitesdeployedandthenumbersusedateachsite.Thecostsofexperimentallyevaluatingthesetoolsarehardtoestimate,butUS$5,000isprobablysuffi-cient.Ifprovenusefulasamonitoringtool,asingleworkershouldbeabletodeploylinesoftentun-nelspersiteatfour locations/day,allowingtimeforcarefulplacement.Thiswould involvethefol-lowingcosts:

• 50 tracking cards and 40 tunnels: US$470 (example costs: http://www.gotchatraps.co.nz/theremaybemorecost-effectivelocalalternatives).

• Vehiclecosts:US$240.

• 4xfulldaylabour(driverandworker,deploymentandcollection):US$80.

• Totalperfoursites:US$790

Allfieldworkwillneedtoincludeacommunity-relationscomponentseekingpermissionfromlocallandownersandcommunityleaders.Thismayaddadditionalcostspriortotunneldeployment.

2.1.4Acousticmonitoring

Purpose:Listeningfortoadcallsmaybeanextremelyeffectivewayofdetectingthepresenceofapopulation of Asian toads. The development of remote acoustic recorders and analysis softwaremakesthistechniqueevenmoreeffectivebutwithsignificantaddedcost.Thetechniqueisonlysen-sitivetocallsofadultmalesandsowillbebestutilisedduringearlywetweatherperiodswhencall-ing frequenciesarehighestamongmales (advertisement calling). This is apassivemonitoring tooldesignedtobesensitiveto low-densitypopulations inwhichonlyafewindividualsmaybecalling.While accompanying a recorderwith a systembroadcasting toad callsmay illicit call responses inmaleswesuspectthatsomethinglikefivedaysrecordingperiodwouldofferasimilarprobabilityofdetectionwithlesscomplexityandcost.Thetoolisexpensiveandlogisticallycomplex(seebelow)soisonlysuitableforthetargetedanalysisofincursiondelimitationandpotentiallyinthemonitoringoferadicatedareasinthefinalyearsoferadication.Foramajorityofsitesitwouldprobablybemoreappropriatetotrainlocalstafftolistenforandrecordtoadcallsandlocationstodescribetherangeandextentofbreedinghabitat.

Method: For theuseofelectronic recorders, there isanumberofcommerciallyavailableacousticrecordersavailable,andwhichevermodelistobeevaluatedfirstneedstobetestedforitseffectiverangefordetectingthecallof toadsunder“average”conditions (ambientnoiseofwind/rainetc.).We thenneed to consider recordingperiods, as recorders can record continuously or only duringprogrammedtimes.Iftoadsaredemonstratedtoonlybecrepuscular/nocturnalcallersthenthere-corders should be programmed accordingly. At the sites chosen in close proximity to potentialbreedingpools, itwillbenecessary tohave fieldworkersmanually record the frequencyofcalls inconjunctionwiththerecorderstodemonstratetheirsensitivityasadequate.Therecordersareun-likely to be as sensitive as the human ear (similar trials with kiwi call recordings in New Zealanddemonstratedthis)butwealsoneedtoknowtherecordersaresensitiveatleasttoanareaof50mradius tobeausefulmonitoring tool. Thegreater the sensitivity themoreuseful the toolwill be.Some acoustic recorders have bespoke software for analysis,whereas othermethodswill requiretheuseofsonogramanalysissoftwaresuchasRaven.Ifdemonstratedassufficientlysensitivetobe

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usedasamonitoringtool, thedeviceswillneedadeploymentstrategydesigned likelytofocusonproximitytowaterbodies.

For themajority of easily accessed sites it will bemore cost efficient to train and dispatch localworkerstolistenforandrecordthelocationsoftoadbreedingpools.

Logisticsandcost:Acousticrecordingdevicesrange inpriceandsensitivity fromtheUS$849Bioa-coustics recorders (http://www.wildlifeacoustics.com/store?slider2=song-meter-sm3#song-meter-sm3) tomuch less expensive units, such as those developed by the Department of Conservation(NewZealand), thatareavailableforUS$200perunit.Softwarecostsvarywithuse.Aswithotherdevice-reliantmethods,theprimarylogisticalconcernisinterferencewiththedevices.Inurbanare-as,thepublicmayremoveordisturbrecordersoutofcuriosityortosell.Thisriskconsideredwiththepotentialalternativeofusingfieldworkersto listenandrecordtoadcallingmeansacousticre-cordersareprobablyonlyusefulforsitessuspectedtobelowdensitytoadareasandsufficientlyin-accessible that costs of regular visitation and diminished risks of recorder loss or theftmean thismethodispreferable.Amajorcostofthistechniquewouldbetheanalysisofacousticdatagathered.It alsooffers logistical challengesof staff access to computers andnecessary training,making thismethodexpensiveandfortargeteduseonlyatperipherysiteswhereeffortsarebeingmadetode-limitincursionarea.

Asmentioned,itwillbemorecostefficienttodispatchtrainedstafftosurveyforcallingtoadsatpo-tentialbreedingpoolsandthiscouldbeachievedattheusualcostoftransportandtrainstafflabourtogetherwithcostsofdatacollation,analysisandreporting.

• Using a vehicle and driver with a trained field worker (calculated atUS$320) this wouldprobablyallowthesurveyingof3–4sitesperday.

2.1.5ENVIRONMENTALDNA

Purpose:Amajorconcerninthedevelopmentofincursionresponsestoinvasivespeciesistheabilitytoensuretheareaofincursionisfullydelimited.Severalmethodsareavailableforconsiderationasdescribed here, and possibly the most efficient and sensitive is the use of environmental DNA(eDNA)sampling.Animalspermanentlyshedtissueandcellsintotheirenvironment,andthosewithaquaticlifestylesshedtheirtissuecontainingDNAintowaterbodiestheyinhabit.ModernDNAam-plificationtechniquesaresopowerfulandcosteffectiveitispossibletonowidentifythepresenceofa species fromaseriesofwater samples.Thepowerof this technique isobviouslynot toconfirmpresenceof, inourcase,theAsiantoad,inawaterbodyinwhichtheyareabundantandeasilyob-served. Thepowerof the technique comeswhenevaluatingwaterbodies of any size thatmaybebeingusedbyonlyaverysmallnumberoftoadsintermittently.Eveniftoadshavebeenabsentforseveraldaysorevenweeks,theirDNAislikelytopersistinthewatercolumnandisavailableforde-tection.UsingthismethoditispossibletodetectthepresenceofAsiantoadsinareasoflowdensityorattheveryperipheryoftheircurrentrange.Poolsthetoadsareusingforbreedingwilllikelyholdeggsand tadpolesatvaryingdevelopmental stages,whichpromises toprovideastrongmolecularsignal of Asian toad presence. Fortunately,Madagascar does not contain Bufonidae congeners sotheprobabilityoffalsepositivesarealsoreduced.ThelongevityofDNAinsedimentsmeansthatthetechniqueisofreducedvalueforfollowupmonitoringonceanareahasbeenclearedoftoadsalt-

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houghthis issuehasnotbeenexamined in tropicalenvironmentswheredegradationofDNAfrag-mentsmaybeaccelerated.

Methods: Samplingofwaterbodies isaverystraightforwardprocedureofcollectingmultiplesam-plesfromthewatercolumn.ConcernsexistthatDNAmaypersistinsedimentforextendedperiodsandsoinotherinstancescarehasbeentakennottodisturbsediment,asthiscancompromisere-sults. This is less of a concernwhendelimiting species such as in our instance, unlesswe believetheremayhavebeendynamicchangesintheareatoadsareoccupyingovertheperiodoftheincur-sion.Themainrisktothemethodiscontaminationbetweensamples,andthereforeasinglesiteusekitwouldneedtobedevelopedsothatcollectionequipment(dippers,etc.)andcontainersareonlyusedonce.Staffwillneedtobetrainedincollectionprotocolstoensuretheyareawareoftherisks.Sampletransportandstoragerequiressamplesaremaintained inachilledstate(2–4degrees)butnotfrozen.

We are not awareof the existing development of primers to sequenceD.melanostictus samples.Oncelabmethodsareavailable it isafairlysimpleautomatedprocessoftestingsamplestodeter-minepresenceorabsenceoftoads.Laboratoryanalysisofsamplesisusuallybestdonecommercial-ly,butthismaybeasituationwhereitisdesirabletodevelopskillsincountrythroughcollaborationwithMalagasyuniversities.

Logistics and Cost: The major logistical challenge with this method will be ensuring all staff aretrained in appropriate collection protocols and all samples are appropriately stored until analysis.ThedevelopmentoflaboratoryfacilitiesinMadagascar,ifnoneexistcurrently,mayposesomelargechallengesbut none insurmountablewith good collaborationwith an experienced lab. The recentuseofeDNAtechniquestodelimitaninvasivenewtinNewZealandallowedustoaccuratelycostthemethodology:

• Technicaldevelopmentofprotocolstohandlesamples:US$8,000.• Sampleanalysisper100samplesUS$1,000.• Samplingequipmentkitsper1,000sitesUS$5,00023k.• Labourandtransporttocollectsamples(@fivesitesperday)US$320perday.• Samplestorageandtransport(guesstimateforfridges,etc.)US$2,000.• Totalfor1,000sitesUS$89,000

2.2DETECTIONANDELIMINATIONMETHODS

The followingmethodological proposals focus on tools necessary to remove toads from the envi-ronment.Toreiterate,whereasonemethodmayprovetobeextremelyeffective,itishighlyunlikelytobeadequatetoremoveall individualsofatargetanimalsuchastheAsiantoadthathassucharangeoflifehistorystagesrequiringnecessitatingdifferentmethodsofcapture.

2.2.1Detectionandremovalthroughdelimitedhandsurveys

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Purpose:TheAsiantoadispresentinsuchnumberswithinmuchoftheincursionareathesizeofthetoadpopulationandlocaleconomymeanhandcollectionispotentiallyaviablemethodoftargetingtheanimals.While toadsaremostlyactivebynight, it ispotentiallypossible tosearch thehabitatduringthedayandachieveanacceptablerateofcollectiontojustifythismethodinclusionintrials.Thismethodwouldrelyon local labourandprobablyactasanearlystagetoolforanyeradicationeffort.Withlocallyrecruitedteamsoftoadcatchers,therewillbeaneedtoevaluatetheproportionof toads collected in different ecotypes.Before themethodology canbe considered as part of aneradicationplan itwillbenecessary tomeasure itseffectiveness.Thus, thereare twoparts to thediscussionofthismethod:

Method:Testingmethodology-Totestthismethoditwillbenecessarytoidentifyexperimentalar-easthatcanbeenclosedbytoad-prooffencing.Suchfencescanbeofthestandardamphibiandriftfencetypebutmayneedtocoveranareaofatleastseveralhectarestoprovidethedatarequired.Sites should be selected in areas of high toad density and preferably replicated in urban, rural-agriculturalandrural-unmanagedecotypes.Oncefenced,theareaissearchedbyasmallteam,andalltoadslocatedarerecorded,removedandkilled.Followingthisknock-downoftheeasilydetectedindividualstheareaissurveyedbyexperiencedstaffthatcollectasmanytoadsofallagestagesaspossible putting inmaximumeffort to ensure asmany individuals as possible are located. As thetoads are detected, a second team implant PIT (Passive Integrated Transponder) tags into toadslargerthan40mmSVL.FortoadletssmallerthanthissizeweshouldconsiderimplantingVIFETs(Vis-ibleImplantFluorescentElastomerTags)intothetoads.Alltoadsarethenreleasedattheexactsiteofcapture.

Oncecompleted,theareaandtaggedtoadsareleftforaminimumoffivedaystoensuretheyreturntonormalbehaviourandrefugia.Atoad-collectionteamconsistingofatleastfourworkersperhec-tarethensearchtheareausingsomedestructivemeasures(e.g.,vegetationremoval)toremoveasmanytoadsasfound.Thedaysearchshouldberepeatedatdusk/nighttotrytointercepttoadsastheybecomeactive.Thesearcheffortshouldberepeateduntilacompletesweepoftheareayieldsnofurthertoadcaptures.

Analternativeandpossiblypreferredstrategywouldbetofindahabitatcurrentlyunpopulatedbytoads,buildtheexperimentalenclosuresandthenpopulatetheenclosureswithtoads,allofwhicharetaggedandconductcollectionsurveysasdescribedabove.Theriskofthismethodistheneedtopopulate experimental enclosureswith toads but considering the extent of the current incursion,thissmallpotentialexpansionisinconsequentialtotheinvestmentinmethoddevelopment.

Astoadsarecollected,theyarescannedforPITtagsandarecordmadeofeachindividualidentified.Theresultswillbescrutinisedaccordingtotwoissues:first,theproportionofthetaggedtoadsthataredetected,andsecond,thenumberoftoadscollectedthatwerenotpittagged.Thefirstanalyseswillinformusofthesensitivityofmanualsearchingfortoadswiththeeffortinvested.Thenumberofuntaggedtoadswillhelpindicatetheproportionofthepopulationthatshouldbeexpectedtobedifficulttodetectwithnon-intensivemethods.

Shouldtheproportionofthetaggedtoadscapturedprovetobeextremelyhigh,bywhich,consider-ingthe120km2areaoftheincursion,shouldbegreaterthan99%,andnountaggedtoadsarede-tectedthenwewouldproposethatthemethodologyisappropriatelysuccessfultosuggestdeclaring

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eradicationfeasiblewithintheecotype inwhichthetrialshavebeenconducted. Ideally,wewouldrecommendreplicatingthetrialtoatleastthreelocationswithineachecotype.

To operationalise thismethod therewill need to be considerable investment in the strategic de-ploymentofbarrierfencestoenableclearedareastobedelimited.

Logisticsandcost:Costsofatrialarelikelytobe:

Costpersite:Labour(12xdays6xlabourersatUS$20perday,includingoverheadcosts)–US$1,440.

Transport(12days@US$120perdayplusdriverat$20perday)–US$1,680.

Fencingmaterials(@US$20perlinearmeterNZmaterialcostsest.)-US$12,000.

Pittaggingequipment(US$4,000–includingreaderone-offcost)–US$2,500.

Total–US$17,620

One-offcosts

Scientific&fieldmanagement–US$8,000.

PitTagreader–US$1,500.

Soforthreelocationsthetotaltrialcostwouldbe:US$62,360

Theconceptofmanuallysearchingaminimumof120km2usingthistechniqueoverat leastthreeseasons entails the employment of probably hundreds of workers and enormous management,communications, transport and administration structures. If we speculate that the delimitation isachievable,thelabouravailableatUS$5perday,anditwilltakefourworkersanaverageoftwodaystoserviceeachhectare,then,byextrapolation,thecostsofthistechniquewillbeUS$240,000perannumwithoutconsiderationofinfrastructure,transport,communicationsandadministrativecosts.WewouldguessthetotalcostofthismethodandadministrationwouldapproachUS$1mperyear.Therearemanylogisticalriskstothismethod,notleastthecomplexityofcoordinatingsuchahugelabour force, negotiating access to all areas and ensuring a communication programme that pre-ventsmisinformationortheunderminingofefforts.

Forthetrials,atechnicalriskhereisthenaturalejectionofPITtags,whichideallywouldrequirere-searchonsub-cutaneousorintra-coelomicimplantationstodeterminewhichmethodworksbetter.

2.2.2Barrierfencingandpitfalltrapping

Purpose:Itwillbenecessarytodelimitareasthathavebeensearched,fromareasthathavenot,soastopreventreinvasionoftoads.Itwillalsobenecessarytodelimitareasrequiringdifferenteradi-

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cationmethods,suchaswaterways.Delimitationwillneedtobemaintainedatascaleadaptedtothe areas being treated andmaintained for the period of the eradication. The inclusion of pitfalltraps along such fenceswouldenable the captureof any toads attempting todispersewithin thearea.Aspecificfocusofthismethodwouldobviouslybebreedingpoolswhereitmaybepossibletointerceptaveryhighproportionofthelocaladulttoadpopulation,iffencesandpitfalltrapsarewellmaintainedandserviced.

Method:Standarddrift fencedesignswillbeappropriate for thesebarriersbuttheuseofdurablematerialswillbenecessarytoensurelongevity.Thefenceswillneedtobedugintothesubstrateashortdistanceand theirdeployment shouldmakeuseofnaturalbarriers suchaswalls,oraccess-wayssuchasroads/tracks.Pitfalltrapscanbesimplebucketsdugintotheground,buttheirhumaneuserequiresdailychecksandtheremovaloftoadsforhumaneeuthanasiaandthereleaseofnon-targetorganisms.Thereisnoneedtotestbytrialthismethod,asitssuccessesanddesignarewelldocumentedintheliteratureandbyourpersonalexperience.

Logisticsandcost:Theissuehereisfeasibility,scaleandtheissueofinterferencebypeople,vegeta-tionandlivestockifdeployedforlongperiods.Thecostsofdelimitationarelikelytobelarge.Ifweassume that there is a smallpool requiring fencingevery fivehawewould requireapproximatelyUS$660,000inmaterialandconstructioncosts.

Theprimary logistical concern is interferencewith thedevices. Inurbanareas, thepublicmay re-moveordisturbfencesforalternativeuses.

2.2.3Citricacid/Sucrosespray

Purpose:A16%citric-acidsprayisknowntobeeffectiveinkillingfrogswithmoistskinandhasbeenusedtoeliminatepopulationsofCoquifrogs(Eleutherodactyluscoqui)inHawaiiformanyyears.Themethodworksbyinducingrapiddehydrationoffrogsduetoosmoticimbalancebetweenthesprayandtheinternaltissuesofthefrog.Theoretically,thissameosmoticeffectcanbehadwithanycon-centratedsolutesprayedonfrogs;hence,sucrose(sugar)mayalsobeusefulinthisregard,althoughit remains untested for toads. Sucrose could be an attractive alternative, if effective, because itshouldbeeasierandcheapertoobtaininMadagascar.However,neithersolutionhasyetbeentest-edon toads,which,becauseof theirdry skin,maynotbeas susceptible toosmoticwater lossasmostfrogs.Hence,testsneedtobedonetoassesswhethereithersolutioncouldbeeffectiveforthispurposeagainstD.melanostictus.

Ifeffective,thismethodislikelytobeofgreatestuseforrapidlytreatingthehighdensitiesofnewlymetamorphosedtoadletsastheyleaveandaccumulatearoundpondmargins.Treatingtheconspic-uousadultswith thismethod is liable tobenomoreeffective thanhandcapturewouldbe, so itsutilityislikelytobeprimarilyforhigh-densityconcentrationsoftoadlets.

Method:Simplelaboratorytrialssprayingahandfuloftoads(ca.teneach)witha16%citric-acidso-lutionora27%sucrosesolutionneedtobe tried.Toadswouldbehoused in individual smallcon-tainers, removedtosprayenoughtowettheirbacks, returnedtothecontainersandobservedformortality/morbidityin24hrs.Iftoadsdonotdiewithinthattimeperiod,themethodwillbeineffec-tiveforcontrol.Testsofeachcompoundshouldbedonebothonasampleofadultsandasampleof

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newlymetamorphosedtoadlets.Adultswouldbetestedprimarilytoascertainspeciessusceptibilitytothemethod,eventhoughitisanticipatedthatthegreatestneedforthemethodwouldbeagainsttoadlets.Ifeffective,sprayingoftoadletswouldallowforrapidandeffectivekillingoflargenumbersandavoidtheneedtocaptureeachsmallanimalwhenathighdensities.

Logisticsandcost:Bothcompoundsaresafeforhumanuseand, indeed,arepresent innumerousfoods hence, concerns about human poisoning are virtually non-existent. If effective, either com-poundwouldonlybeappliedtoterrestriallifestagesofthetoads.Experimentalcoststotestefficacyareexpectedtobelowasallthatisrequiredarethematerialsandasampleof,forexample20met-amorphsand20adulttoadsandbasiclabequipmentsuchasholdingtanksandspraybottles.Somecostwouldbeincurredensuringscientificoversighttoquantifytheconcentrationsandthelevelofsubjectexposure.Wewillalsohavetotesteffectiveapplicationmethods.Ideallythiswouldbedoneusing helicopter mounted agricultural spray equipment but it is doubtful that such equipment isavailableinMadagascar.Therefore,weneedtoevaluatetheuseofbackpacksprayingandtheuseoflocallabour.CostsareestimatedtobeUS$8,000tocoverlabcostsandadvisorexpertise.

Aneducationprogrammewillberequiredtoensurethatlocalsareawaretheuseofthesprayposesno risk to them or the environment so as to ensure that local support for the eradication is notthreatened.

2.2.4Acousticlocationandphysicalcapture

Purpose:Virtuallyallfrogsreproducebymalesattractingfemalestobreedviaacousticcalling.Call-ingamongmalesiscompetitive;hence,malesthathearanothermalecallarefrequentlyinducedtocallthemselves inordertocompeteforthefemales’attention.Thisattributecanoftenbeusedtosurveyforfrogs:ifarecordingofthespecies’advertisementcallisplayed,nearbymalescanoftenbeinducedtocallinresponse,therebyindicatingtheirpresenceinthearea.Thismethodcanpotential-ly be used to illicit toad calls during the breeding season evenwhen they occur at low densities.Hence,thisprovidesasensitivemeansofsurveyingthelimitsofthetoad’sdistributionaroundTa-mataveandalsoapossiblemethodforinterceptingmaletoadsatextremelylowdensities.

Method:Visitpotentialbreedingsitesatnightduringthewetseason,playthecallofthespeciesfortenminutesorso,and listen for respondingmales. Ifmalesareheard to respond, theyshouldbetrackeddown,capturedandkilled.Withtwosearchersandalittleexperienceitisusuallyquiteeasytotriangulatethelocationofacallingtoadandremoveit.

Logisticsandcost:Recordingsofthisspeciesarealreadyavailableontheinternet.Theymerelyneedtobedownloadedorobtainedfromtheoriginalposterwithpermissionstouse.Equally,itwouldbeveryeasytorecordcallsfromwithinthecurrentincursionarea.Equipmentneededwouldbeafewdigitalrecordershavingpowerfulenoughaudioplaybacktobroadcastthecallaroundsurveyedwet-lands. Professional equipment is available for this purpose, such as the Foxpro(http://www.gofoxpro.com/site/products/digital-calls/wf2), which is robust to field use and costUS$200each.Costsfortheuseofthistechniquewoulddependonthenumberofteams,amountoftransportrequiredandthenumberofcallplayersrequiringpurchase(one/team,withafewbackupsin case of damage to original equipment). Themethodmight be combinedwith remote acousticmonitoringforthedetectionofextremelylow-densitytoadpopulations.

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2.2.5Tadpoletraps

Purpose:ResearchontherelatedCanetoadinAustraliahasshownthattadpolesofthatspeciesareattractedtothechemicalssecretedbythepoisonglandsoftheadulttoad.Experimentshaveshownifthesepoisonsecretionsarecollectedonmicroscopeslidesandplacedinsideasmallaquatictrap,tadpolesofcanetoadscanbecollectedinlargenumbers,evenremovingmostoralltadpolesfromsmallpondswithinafewdays.WhetherthismethodcanworkforthespeciesoftoadatTamataveneedstobeassessed.

Method:Constructadozenorsotadpoletraps(designgiveninCrosslandetal.2012),collectadulttoadsfromwhichtoobtainpoisonsecretions,collectthesecretionsonmicroscopeslidesandplacetheslidesinthetrapsandthetrapsintestpondsknowntoharbourtadpoles.Checkthetrapseveryday,removeandcounttrappedtadpolesanddeterminehowlongthetrapsremaineffectiveineachpond.Ifsmallisolatedpondsaretestedbytrial,oncethetrapsareremoved,visuallycheckfortad-polesorusefinenetstocheckforefficacy(i.e.,howmanytadpolesremain).

Logisticsandcost:Thismethodshouldbeabletobetestedinfairlycost-effectivemanner in“lab”conditionspotentiallysomewhereliketheParcIvoloinabylocalresearchers.Costswillbethemate-rialstoconstructthetraps,microscopeslides,oneboxoflatexsurgicalgloves,labourandvehicletocollecttadpoles/toadsanddeploythetraps.AnestimatewouldsuggestabudgetofUS$5,000wouldcover fieldand labcosts foramethodstrial thatdeterminedrelativeeffectivenessunderdifferentenvironmentalconditions.

2.2.6Herbicide

Purpose:Itmaybeappropriatetoconsidertheuseofcertainherbicidestoclearriparianvegetationsurroundingwaterbodiesusedbytoadsforbreedingandalsofortheclearanceofdensevegetationthatotherwiserestrictstheabilityofsearcherstoexamineandcapturetoads.

Method: Standard application of glyphosate herbicides such as Roundup can be used. The use ofsuchchemicalsaroundwaterbodiesiscontentiousandsoformulationswithhigherglyphosatecon-centrationsandnosurfactantshavebeendeveloped.

Logisticsandcost:Labourandchemicalcosts,togetherwithsometrainingofoperators,wouldre-sult in a per ha cost thatwill be influenced by the cost of locally acquiring glyphosate herbicide.Planningandtransportwouldbeadditionalcostsand,duetothevisual impactsandpotentialeco-logicalimpacts,bothlocalecologicalassessmentandaconsultationandcommunicationplanwouldneedtobecomponentsofthiswork.Weimaginethetotalcostsofthismethod,ifappliedbroadlywithintheincursionarea,wouldbe intheregionofUS$100,000,consideringtheopportunitiesforitsuse.WearenotawareoftheenvironmentallegislationthatmayexistinMadagascartodescribethelimitsofuseforsuchmethods.

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Fig.2.Asiantoadeggstrings insmallpond,HongKong.Photo:LungFuShanEnvi-ronmentalEducationCentre.

2.2.7Eggcollection

Purpose: Prior to hatching into tadpoles, Asian toad eggsmay be able to be efficiently collected,thus reducing population productivity in areas where the toads breeding pools can be easily ac-cessedandsearched.ThismethodhasbeenusedasacomponentofsuccessfulBullfrogcontrolpro-grammes in North America but we acknowledge that the Asian toad is known to lay eggs at alldepthswithinwaterbodies(Fig.2)andsotheeffectivenessofsuchcollectionmightberestrictedtosmaller,shallowwaterbodies.

Method:Workerswouldvisuallysearchwaterbodieswithbagsorbuckets intowhichtheeggsarecollected.Acost-effectivemethodofdestroyingtheeggswouldbedesiccationinthesun,buryingorincineration.

Logisticsandcost:Labourandtransporttosites.Itmustbenotedthatthismethodwillbequestion-ableifAsiantoadslayeggsatvaryingdepthsinwaterbodies.Also,itwouldrequirethesearchingofallwaterbodiesinanyareadelimitedassuitable.TheproximityofanylargeunsearchedwaterbodiesandevenamodestnumberofsmallerwaterbodieswouldquicklynullifyanyeffortsmadeduetothenumbersofeggsproducedbyAsiantoads.

2.2.8Refusemanagement

Purpose: The incursion area in and around the port city of Tamatave has a serious urban refusemanagementproblem.Althoughthisissueislikelytobeahumanhealthissue,itisalsoapotentialreservoirandvectorfortheAsiantoad.Refuseappearstoaccumulatealongroadwaysintheurban

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areasandiscommunallydumpedatsitesaroundtheperipheryofthecity.Thesepilesofrefusepro-videhabitatfortoadstoseekrefugeandareextremelychallengingtosearchfortoadsbecauseoftheir complexandhazardousnature.The transportationofwaste to thesesites isalsoapotentialvehicleforthespreadoftoads.Therefore,werecommendthatrefuseclearanceanddisposalproto-colsbedevelopedfortheincursionsitethatdonotriskspreadingthetoadsfurtherandusemethodstodestroytoadsconcealedintherefuse.

Method: The details of this proposedmethod require civil engineer input, butwewill tentativelysuggest conventional land-fill type disposal of refuse accompaniedby the rapid coveringwith soilcouldbeasolution.Currentlythereisaprogrammeofworkthatistakingrefusetothetailingsdis-posal siteof theAmbatovynickel processingplant. Thismightbe appropriate, but toprevent thespreadoftoads,thisprogramshouldbeevaluatedintermsofthesecurenatureofthetrucksusedto transport the refuse and also the timeframe from refuse dumping to coverage. This should bedoneswiftlyenoughtopreventtoadsescaping.DataprovidedbytheAmbatovyMinesuggeststhatthetransportofrefusetothesitehasalreadyspreadAsiantoadstothearea.

Logistics and cost: Local civil authorities andmunicipal engineerswould be necessary to properlydesignandcommentonthissuggestion.

2.2.9Toaddogs

Purpose: To thosewith limitedexperience in vertebrateeradications, the suggestionof traininga“toaddog”mayatfirstappearexpensiveand inefficient.However,shouldaneradicationeffortbeundertaken and prove to bemaking positive progress towards success, then the training of toaddogsmayprovetobeextremelyusefulforthelocationofthefinalindividuals.Dogsarewellrecog-nisedfortheirolfactoryskillsandabilitytobetrainedtoaspecifictarget.Althoughthereisnorea-sontobelievetoadsposeaproblemtothistechnique,itmustbestatedthatitwillbeessentialtouseoperatorswithexperiencetooverseeatoad-dogprogramme.

Method:WhiletraineddogscouldbebroughttoMadagascaritisprobablybesttoconsiderengag-ingthetimeofanexperiencedhandler/trainertoworkoveraperiodofmonthswithaprospectivehandlerandcandidatedogsinMadagascar.Wecan’tdeterminewhetherMadagascarhasanexistingdetectordogprogrammeattachedtoeither themilitaryorothergovernmentagencies.AmethodthathasprovidedquickresultsinNZistheretrainingretiredsecuritydogsthathavedemonstratedtheir ability in detecting explosives/narcotics. This has been achieved with retired bomb-locatingdogsinNZforlocatingtheinvasivealpinenewt.Itwilltakeatleastayeartosuccessfullytrainadogtobeareliabletoaddog,andprovisionmustbemadetomaintaintheskillsofanydogtrainedforthedurationof theeradicationprogramme. It iscritical that theeffectivenessofdetectordogsbedeterminedthroughcontrolledtrials.

Logisticsandcost:Internationalexpertisewillbethelargestcostinvolvedinthismethod.Wewouldestimate that trainingwould require at least three extended visits by a trainer,which if obtainedfromacountrysuchasNZ,wouldprobablycostintheregionofUS$90,000forthreevisits,eachofaneightweekduration(includingflights).

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2.2.10Cappingwaterbodies

Purpose:Theincursionareaisunfortunatelyinanareawithagreatdealofstandingnaturalwaterand drainages,which provide obvious obstacles to any amphibian eradication. However, inmanyareas,includingurbanareas,itmaybepossibletodrainandfillsmalltomedium-sizedwaterbodiesthatareofnomunicipalorsignificantecologicalvalue.Thismayhavethedualbenefitofreducingpotentialbreedingsitesfordiseasevectoringmosquitoes.

Method:Civil engineer engagement will be essential for larger projects, but smaller waterbodiesshouldbeeasily drainedusing conventionalwajaxpumpsandearth-movingequipment to fill andcaptheareawithsoil/substrate.

Logisticsandcost:CostswillbeaspercivilengineeringcostsinMadagascar.Nodoubttherewouldbechallengesofobtainingskillsandaccess toaplant ina location likeTamatave.Communicationandconsultationwithlocalcommunitieswillbeessentialforthismethod.

2.2.11Chemicaltreatmentofwaterbodies

Purpose:AstadpoletrapsareasyetuntestedforAsiantoads,itisimportanttoconsideradditionalmeans of targeting tadpoles. One method worth consideration is the use of rotenone or similarcompounds to kill tadpoles. Rotenone is only effective on individualswith gills and sowill not beequallyeffectiveforalldevelopmentalstages.However,theuseofsuchamethodhasgreatapplica-tionforwaterbodiesotherwisedifficulttosearchoraccess. InNewZealand,wearecurrentlycon-ductingtrialsfortheuseofrotenonewithnewtlarvae.Weshouldalsoconsiderwhetherthereareexistinglocalmethodsusingplantbasecompoundsforfishingpurposes.

Method:Thereis literatureavailableto instructontheuseofrotenoneforthecontroloffishthatcouldbeeasilyadaptedforthispurposeintadpoles.ItwouldbeveryusefultosequentiallyexposeAsiantoadtadpolestoknownconcentrationsofrotenoneatdifferentdevelopmentalstagestode-termineefficacy.Wealsorecommendinvestigatinglocalmethodsofchemicalfishcapture.Itmaybethatlocalplantsorplantbasedsubstancesarecurrentlyusedandthereforearesociallyacceptableandappropriateforourpurposes.StandardcontrolledmethodsinvolvingtheengagementofskilledindividualssuchasDevinEdmondsoftheAssociationMitsinjowouldseethiseasilyachieved.

Logisticsandcost:Materialcosts fora lab trial shouldnotbehigh in thatall is requiredaresmallcontainers, basic husbandry skills and rotenone. If rotenone is not available inMadagascar, theremay be some issuewith its importation. The operationalisation of themethod involve transport,planningand chemical costs that aredifficult toestimatebutprobablyare comparable to thede-scribed surveymethods. Amajor risk could be community perceptions and consequences of thismethod,especiallyiflocalcommunitiesrelyonfishfromthesewaterbodies.

2.2.12Toadtraps

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Purpose:Whilesomeofthemethodsproposedfortestingherearedesignedtoreduceorremoveaccess tobreedingpoolswemayuse the toadsnaturalabilityandneedto locatewaterbodies forbreedingasatrappingopportunitythroughtheconstructionoftemporarywaterbodies.Thesemaybe specifically suitable for use in locations where other waterbodies have been capped and thisstrategyiscurrentlybeingusedinNewZealandtointerceptalpinenewtswhosebreedingpoolshavebeendrainedandcappedtosomesuccess.

Method: Itmaybepossibletodesignanddeveloptrapsforbreedingtoads ifwaterbodiessuchasbarrels areusedas an attractive sourceofwater, surroundedbyeasily searched refugia to retaintoadsneartheinaccessiblewatersourceandaccompaniedbytoadcallrecordingstoattractbreed-ing females andmales. The trap siteswould thenbeeither surroundedby ahelical fence tohelpcontaintoads(Fig.3)or,ifhabitatallowsaone-way“drop-wall”thatpreventsthetoadsfromleav-ing.Refugiashouldbecomplexandsolidenoughtoprovidegoodcoverandsuitablemicroclimatefor toadsso theyarenotencouraged to try to leave the traps.The retainingwall structureof thedropwalldesignshouldbeconstructedof firmplasticormetalsheetingtoensureanunclimbablesurfaceismaintained.Thedropwallshouldbeatleast40cmdeepanditwouldbeworthwhiletest-ingthetoadspreparednesstoentertrapswithdifferentheightwallstoensurewehaveanoptimumheightforcaptureandretention.Ifplasticmineralbarrelsareusedasawaterbodybybeingcutver-ticallyinhalfthenthesurfaceareaofwaterwouldapproach2.5m2whichhopefullyissufficientwa-tertoactasanattractant.Suchtrapswillworkbestwhendeployedwithdriftfences.

Fig.3.Twotoadtrapdesigns,adrop-walltrapandadriftfencetrapwitheasilysearchedre-fugia.

Logisticsandcost:Theconstructionoftoadtrapsneednotbeterriblyexpensiveorcomplicated.Theissuesforbothdesignswillbetheregularcheckingoftrapsforcollectionanddestructionoftoads.The“drop-wall”designwillneedsomemaintenancetoensurethat thetrapsremaineffectiveandthedriftfencetrapwillneedbothmaintenanceandregulartoadcheckingastheyaremoreabletoescape from this design. It is estimated that a teamof threeworkers could construct these trapsquickly so that3–4mightbeconstructedperday.Allowing forUS$100materialsper trapand thelabouroftwoworkersplusadriverandvehiclewewouldexpecttheconstructionofthesetrapsto

Drop-walltrapwithmetal/plasticwall

Artificialwaterbodynotaccessibletotoads

Artificialrefugia

Driftfencetohelpcon-tainattractedtoads

Waterbodyaccessibletotoads

SIDEVIEWPLANVIEW

Drift-fencetrap

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costUS$520perdayorUS$130pertrapwithoutservicingcosts.Itmightbepossibletocontractlo-calcommunitiestoservicethesetrapsandkeeprecordsoftoadscapturedanddisposedof.

Foratrialofthemethodswewouldwanttocloselymonitortoadentryandanyescapesfromthetrapspreferablywithinanenclosedareacontainingmarkedtoadssowecanevaluatetheeffective-nessofthetrapsovertimeandparamteriseexposuretimestomaximizecapturesofbothsexesandofthemaximumdemographicrange.WithexpertinvolvementandfieldtimethisworkisexpectedtocostnomorethanUS$10,000.

2.3Prioritisationofmethodsandproposedtestingschedule

Thepurposeofproposingthetestingofmethodsistoreducetheriskofcommittingtoalargeandexpensivebodyofworkwithoutknowingthatwehaveappropriatetools.

1. PHASEONE–TESTINGANDCAPACITYDEVELOPMENT:Raiseinitialfundsandcreatecapaci-ty to test keyeradicationanddetection tools toevaluateoptions toeradicateAsian toad.Thisworkshouldstartimmediatelyandbecompletedwithin12months.

2. PHASETWO–ERADICATION:Iferadicationisviable,fundraisewhiledevelopingastrategicplantodeploydetectionanderadicationtoolsfortheremovalofAsiantoadswithaproba-blefieldcommitmentofthreeyears.Iferadicationisnotfeasible,thenresearchintomitiga-tionandimpactsbecomethepriority.Theeradicationoperationisnecessarilyiterativeinitsprogressinformedbylevelsoftoaddetections.Weguessthatitwilltakeatleastthreeyearsoftheapplicationofmost,ifnotallofthetoolsdescribedheretoprogresstoapointwheretoadsarenolongerdetected.Iftheratesofdetectiondonotdiminishaccordingtoexpecta-tionthentheprojectwillneedre-evaluation.Howevertheprojectshouldbeevaluatedan-nuallyforperformanceagainstgoalsandexpectations.

3. PHASETHREE–POSTERADICATIONMONITORING:Afterhopefullythreeyears (or less)oferadicationoperationsnomoretoadswillbedetectedbytheexistingsurveillancemethods.At thispoint theprogrammeneeds toprioritise toaddetectionacross theentire incursionareaandmaintainastrongcommunicationstrategytoensurethatanyresidualtoadsarelo-catedanddestroyed.Thisphasecouldeasilylastforadecade.

Byadoptingaprocessthatfirsttestsefficacyofpotentialeradicationtoolsandifprovedineffective,wecanabandonthegoaloferadicationwithclearandquantitativereasonsforsuchadecision.

Duetothecostsofemployingthesetechniques,itwillbeimportanttoimplementtheleastexpen-sive and most efficacious (by area) methods as early as possible, delaying use of more costlymeasuresuntil therearefarfewertoadstobe located. It isalso importanttoensurethemethodsusedlaterinaneradicationprogrammeareadequatelysensitivetotoadstobeeffectivefortoadsinextremelylowdensity,aswewouldhopetheywouldbebythefinalstagesofaneradicationeffort.

Wealsohavetoconsidermonitoringandresponseoptionsforevaluatingeradicationresultsacrossthe incursionareaandtriggers fordeclaringsuccessorabandonmentof theproject.Althoughthe

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methodsproposedheremightcompriseaneradicationeffort,weneedclearmeasuresofsuccessorpointsof failure.Weestimate thateven if theproposedmethodsproveextremelysuccessful, it islikelytorequireatleastthreeyearsoferadicationefforttoachieveaneradicationoutcome.Howev-er,withourabilitytodetecttoadsatextremelylowdensitiesuntested,wemustbepreparedforatleastafurtherthreeyearsofmonitoringtoensurethatnosmalltoadpopulationswereabletoes-capetheeffort.Methodsofmonitoring,asdescribedabove,areasyetunprovenforextremelylow-densitytoadpopulations.

Therefore,weproposethefollowingimmediateactions:

1)Designate thegovernancegroupand invest inoperationalcapacitybuildingwith localorganisa-tionbasedwithintheincursionarea.

2)IdentifycollaboratorsandsupporterstobeginPhaseOneofmethodologytestingthatwillexam-ineattheveryleast,thefollowingmethods:

• Handcapturemethods.

• Testofcitricacid/sucrosespray.

• Testoftoadtraps.

• Testoftadpoletraps.

Andequal priority is thedevelopmentof anational communicationand responseplan to identifyanysatellitepopulationsandtopreventfurtherinadvertentspread.

It is also critical thatdrift fencingand toadcaptureprogrammesbedevelopedand installedatallmajorwaterbodiessuitablefortheirbreedingpriortothenextrainyseason.

AttheendofthePhaseOneoperationalperiodsoatminimum,beforeJuly2016,theexpertgroupmustconvenetoevaluateresultsandconsidertheevidenceforproceedingtoafulleradicationplan.Accompanying thismustbea strategicplan for theeradicationoperation that is informedby trialoutcomes.

3Budgetplanning:

Yearonecostestimates.

Infrastructurefororganizationoverseeingoperations.

Inthecostdeterminationdetailedabovelabourhasbeenaccountedfor,forthetrialefforthoweverotherdemandsmustbemetbythehostorganizationandthesemustbecostdetermined:

ProjectmanagerFTE(fulltimeequivalent) US$35,000–75,000

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AssistantmanagerFTE US$8,000

Datamanagementcapacity0.5FTE US$4,000

Humanresources(employmentandpay)FTE US$5,000

Communityliaisonstaff2.0FTE US$6,000

AccountantFTE US$6,000

DriverFTE US$2,400

Additionalofficespace US$12,000

Communicationsmaterials US$1,000

InternaltravelbetweenTanaandTamatave US$3,000

4WDrental/purchaseoneyear US$15,000

Computingcapacity US$3,000

Communicationscosts(postage,internet,phone) US$1,000

GISoperator US$8,000

Consultation(time&traveloferadicationexperts) US$40,000

Evaluationworkshopandsupport(foryearonereview) US$60,000

INFRASTRUCTURE&SUPPORTTOTAL US$243,400

Minimumessentialoperationalcostsyearone

Testhandcapture US$62,360

Densityestimation US$3,760

Testcitric/sucrosespray US$8,000

Testtoadtraps US$10,000

Testtadpoletraps US$5,000

Communicationplanandbiosecuritydevelopment US$6,000

Furtherdelimitationeffort(usingcombinedmethods) US$15,000

OPERATIONALTOTAL US$106,360

Contingency(10%) US$32,000

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YEARONEPROJECTTOTAL US$385,520

Documents

ASIAN TOAD ERADICATION FEASIBILITY REPORT FOR