Wherearewenow?

Anupdatedassessmentofthenationalefforttowardsferalcatcontrol

AreportfortheAustralianGovernmentDepartmentoftheEnvironmentandEnergy

October2018

Authors:

DrAlexanderM.Kusmanoff,ProfSarahA.Bekessy,DrYanWang,DrAliceJohnstone,ChathuriSamarasekara,DrGeorgiaE.Garrard

ICONScienceareateamofacademicresearchersbasedwithinRMITUniversity’sSchoolofGlobal,UrbanandSocialStudies.Ourresearchfocusesonunderstandingtheinteractionbetweensocietyandourenvironment.

Werecognisethatmanagingbiodiversitydemandsamultidisciplinaryapproachthatreconcilesecological,socialandeconomicconcerns.

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ExecutiveSummary

Australiahasoneofthehighestmammalextinctionratesintheworld.ThirtyAustralianmammalspecieshavebeenlostsinceEuropeansettlementandmanymoreremainthreatenedwithextinction.OneofthemostsignificantthreatstoendangeredAustralianmammalsandreptilesispredationbyferalcats.Inrecognitionofthis,theAustralianThreatenedSpeciesCommissionerhascommittedtoreducingferalcatnumbersacrossthecontinent,asakeyactionintheAustralianGovernment'sThreatenedSpeciesStrategy.Amongstotherimportantobjectivesforthreatenedspeciesmanagement,theStrategymakesacommitmenttocull2millionferalcatsacrossAustraliaby2020,andtodeliverbestpracticeferalcatcontrolacross10millionhaofopenlandscapesand2millionhaofCommonwealthland.Thisresearchprojectassessesprogresstowardsthesetargets.

Wehavedrawnonnumerousdatasources,includingknowndatarepositories,reportsfromAustralianGovernmentprograms,andstrategicsurveysofindividualsandorganisations,toproduceaplausibleestimateofthenumberofferalcatsremovedfromtheenvironmentin2017-18and2016-17,aswellasaconservativeestimateoftheuniqueareamanagedforferalcatcontrolin2017-18.Weestimatethatinthe2017-18financialyear,316,859feralcatswereremovedfromtheAustralianenvironment,withplausibleboundsbetween298,571and335,147.In2016-17,weestimatethisfiguretobe316,188feralcats,withplausibleboundsof297,891to334,485.Whencombinedwiththepreviouslyreportedestimatefor2015-16(211,560feralcats,withplausibleboundsbetween135,522and287,598),wearriveatathree-yearcumulativeestimateofthenumberofferalcatsremovedfromtheenvironmentof844,607feralcats,withplausibleboundsbetween764,289and924,925.

Informationontheareamanagedforferalcatcontrolislessstraightforward,owingtothecurrentinabilitytocollectspatially-explicitinformationaboutwhereferalcatcontrolisoccurring.Informationreportedbyorganisationsandindividualsrevealsthatthetotal,non-uniqueareamanagedis41,602,727hectares.Whenweconsideronlythoseorganisationsandindividualsforwhichwearereasonablyconfidentthatthereportedareasareindependent(conservationorganisations,IndigenousProtectedAreasandfarmers),weestimatetheuniqueareamanagedforferalcatcontrolin2017-18tobe18,934,994hectares,withplausibleboundsbetween16,437553and21,948,005hectares.

Inaddition,wecollectedinformationusingatargetedsurveythathelpsbetterunderstandwhoisparticipatinginferalcatcontrolandtheirmotivationsfordoingso.

Theboundedestimatespresentedinthisreportarebasedonanumberofassumptions,andrelyonprojectionstopopulationsbeyondtherangeofoursampleddata.Bybeingconservativeinourassumptions,weareconfidentthattheestimatesreportedhererepresentaplausibleminimum.However,giventheaforementionedlimitations,theyshouldbeinterpretedwithcare.

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Contents

ExecutiveSummary......................................................................................................................2

Introduction..................................................................................................................................5

Methodology................................................................................................................................6

Datasources..............................................................................................................................6

Datareportedtocentralrepositories...................................................................................6

Unreporteddatafromorganisations–capturedviaastrategiconlinesurvey...................6

Unreporteddatafromindividuals–capturedviaastrategiconlinesurvey.......................7

Estimatingferalcatcontrolnumbersandareamanaged.........................................................11

Datareportedtocentralrepositories....................................................................................12

Catsremoved......................................................................................................................12

Areamanaged.....................................................................................................................13

Unreporteddatafromorganisations,capturedviaastrategiconlinesurvey......................13

Catsremoved......................................................................................................................13

Areamanaged.....................................................................................................................13

Unreporteddatafromindividuals,capturedviaastrategiconlinesurvey...........................14

Catsremoved......................................................................................................................14

Areamanaged.....................................................................................................................14

Reliableminimumestimatesofferalcatremovalandareamanagedforyear3(2017-18)14

Projecting2017-18feralcatcontroldatatothenationalscale............................................16

Projectingthenumberofferalcatsremoved....................................................................16

Three-yearcumulativeestimateofthenumberofferalcatsremovedfromtheenvironment(2015-18)..........................................................................................................21

Whensummingprojectedestimateswith95%credibleintervals,weassumedtheestimateswereindependentandnormally-distributedinordertocalculatethe95%credibleintervalforthefinalestimate...............................................................................21

TotalUniqueAreaManaged2017-18....................................................................................22

Overviewofqualitativeresultsforthestrategicsurvey............................................................26

Whoparticipated?..................................................................................................................27

Individualsaremakingun-recordedcontributionstothenationaleffort............................27

Methodsforremovingferalcatsfromtheenvironment......................................................27

Changeovertime....................................................................................................................28

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Respondents’observedchangesresultingfromremovingferalcats...................................28

Whydoindividualsremoveferalcats?..................................................................................28

Attitudestowardsferalcatmanagement..............................................................................29

Keythemesinoppositiontoferalcatmanagement..............................................................30

Beliefsaboutferalcats...........................................................................................................30

Encouraginggreaterparticipationinferalcatmanagement.................................................31

AwarenessoftheThreatenedSpeciesCommissioner...........................................................32

Responsibilityforferalcatmanagement,willingnesstocontributeandmessagingeffects33

NodisadvantageinusinganAustralianGovernmentemphasisframe.................................35

Concludingremarks....................................................................................................................36

Howreliablearetheseresults?..............................................................................................36

Howcouldweimprovereliability?.........................................................................................37

ProgresstowardsThreatenedSpeciesStrategytargets........................................................37

Acknowledgements....................................................................................................................37

References..................................................................................................................................38

AppendixA–Outlineof2018strategiconlinesurveyfororganisations..................................40

AppendixB–Listoforganisations.............................................................................................48

AppendixC–Outlineof2018strategiconlinesurveyforindividuals.......................................55

AppendixD–Estimatednumberofferalcatsremovedbyorganisationsin2016-17.............69

AppendixE–Graphicaldemonstrationofthefitofnegativebinomialandlognormalmodelstoferalcatremovalandareamanageddata.............................................................................70

AppendixF-Strategiconlinesurveyresults..............................................................................72

AppendixG–Analysisofquestion28withrespondentsopposedtoremovalofferalcatsexcluded......................................................................................................................................93

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Introduction

Australiahasoneofthehighestmammalextinctionratesintheworld.ThirtyAustralianmammalspecieshavebeenlostsinceEuropeansettlementandmanymoreremainthreatenedwithextinction(Woinarskietal.2011).OneofthemostsignificantthreatstoendangeredAustralianmammalsandreptilesispredationbyferalcats(Woinarksietal.2011).Inrecognitionofthis,theAustralianThreatenedSpeciesCommissionerhascommittedtoreducingferalcatnumbersacrossthecontinent,asakeyactionintheAustraliaGovernment'sThreatenedSpeciesStrategy(AustraliaGovernment2015).GainingabetterunderstandingofthescaleofferalcatcontroleffortsacrossAustraliaiskeytodeterminingappropriatemanagementstrategiesforthefuture.

Thisprojectwillprovideanupdateofourpreviousresearchonthedegreetowhichindividualsareactingtocontrolferalcats,includingtheapproximatenumberofferalcatsbeingremovedacrossAustralia(Garrardetal.2017).

The2017assessmentofthenationalefforttowardsferalcatcontrolcollectedinformationfromavarietyofsources,including:

• existingrepositoriesofdatafromorganisationssuchastheRSPCA,localcouncils,conservationagenciesandstategovernmentdepartments;

• datareportedbyindividualswhoengageinferalcatcontrolderivedfromastrategiconlinesurvey;and

• estimatesandextrapolationstoindividualsandorganisationswhoarelikelytoengageinferalcatcontrol,butforwhichnodatawasavailable.

Thisallowedanapproximateannualferalcatcullratefor2015-2016of211,560cats,withplausibleboundsofbetween135,522and287,598cats.Thecurrentprojectaimstoprovideanupdatedestimateoftheferalcatcullrateandtoreducetheuncertaintyinherentinthisestimate.

Specifically,thegoalsofthecurrentprojectaretoprovide:

1. AnestimateofthenumberofferalcatsremovedacrossAustraliain2017-18;2. Anestimateofthetotalnumberofferalcatsremovedsince2015;3. Totheextentpossible,anestimateoftheareathattheyarebeingcontrolledacross

Australia;4. Animprovedunderstandingofthemotivationsofindividualstoparticipatein,ortobe

opposedto,feralcatmanagement;and5. Someunderstandingofhowferalcatcontroleffortsandactivitiesmayhavechanged

overthelastthreeyears.

Toachievethesegoals,thecurrentprojecthasemployedasimilarapproachtothatusedinthepreviousassessment,includingastrategicsnowballsurveyofthoseindividualslikelytobe

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involvedinferalcatcontrol,aswellascollectingadditionalinformationviacomplementarysurveystargetedatkeyorganisations.

Methodology

Havingpreviouslydeterminedaboundedestimateofthenumberofferalcatsremovedfromtheenvironmentinyear1(2015-2016),thegoaloftheupdatedassessmentwastoestimatea3yeartotalfortheperiod2015-2018.Thismeantcollectingsimilarinformationasusedinthefirstassessment,butforsubsequentyears.Ourmethodologicalapproachwasagaintoproduceaboundedestimateofthenumberofferalcatskilledinthelastyearbyaddingtogethermultiplesourcesofdatawithvaryingdegreesofuncertainty.

Somedata,suchasthatcontainedincentralrepositories(e.g.FeralCatScan),haslittleassociateduncertainty.Otherdatasourcesareassociatedwithlargeuncertainty,drivenbyvariationinthedataitselfaswellasuncertaintyintheassumptionsthatweremadetoarriveatanestimate.Ourapproachwastobeginwiththedataweweremostcertainabout,andthensystematicallyaddnewdatasources,eachofwhichwasunderpinnedbyanexplicitlystatedsetofassumptions.Uncertaintyinindividualdatasetswaspropagatedthroughtheanalysisandincorporatedintothefinal,boundedestimate.Below,wedescribethekeysourcesofdatawecompiledtoinformourestimateofthenationalferalcatcontroleffort,followedbythestatisticalmethodologyusedtoarriveatindividualestimatesaswellasafinal,boundedestimate.

Datasources

DatareportedtocentralrepositoriesThestartingpointforcollectingdataonthenumbersofferalcatsremovedwastoobtainthedatarecordedbycentralizeddatabasesthatwereavailable.

Theseincluded:

• 237conservationprogramsfundedbytheAustralianGovernment;• TheFeralCatScandatabase;and• TheRSPCA.

Unreporteddatafromorganisations–capturedviaastrategiconlinesurveyTofacilitatedatacollectionfromorganisationsthatarelikelytohavesomeinvolvementinferalcatmanagement,particularlylocalandregionalcouncils,wecreatedashort5-10minuteonlinesurvey.TheThreatenedSpeciesCommissioner,DrSallyBox,wrotetoallcouncilsinAustraliatorequesttheirparticipation.ThesurveywasalsopromotedmorewidelybytheOfficeoftheThreatenedspeciesCommissioner,particularlyviasocialmedia.

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Organisationsalsohadtheoptionofsendingtheirdatadirectlytotheresearchers.Thesurveywasundertakenoverafive-weekperiodfrom23July2018to24August2018.

Becausecouncils(andotherorganisations)oftenrecordtheiractivities,weusedthesurveytocollectinformationaboutthenumberofcatsremovedforboththecurrentyear,andyeartwo.Organisationswereabletoreportexactlyhowmanyferalcatstheyhadremovedineachofthelasttwofinancialyears,oralternatively,toselectanapproximatecategory(e.g.1to5,5to10,10to20,etc.).Thisfacilitatedcollectionofthisinformationfrommoreorganisationsthanifwehadrequiredexactnumbers,butalsointroducessomeuncertaintyintothereportednumbersofferalcatsremoved.

AnoutlineofthestrategiconlinesurveyfororganisationsisprovidedatAppendixA.

Responseswerereceivedfrom316organisations,althoughnotalloftheseorganisationswereengagedinferalcatmanagement,notallresponseswerecompleteandsomeorganisationschosetoremainanonymous.Theseincluded:

• 201Localorregionalcouncils;• 25Conservationorganisations;• 14communitygroups;• 8Farmersassociations;• 8IndigenousProtectedAreaorindigenousrangergroupadministrationorganisations;• 2sportingshootersassociations;and• 57otherorganisationsofvariedkinds.

Alistoforganisationswhichparticipated,includingthosenotinvolvedinferalcatmanagementisprovidedatAppendixB.

Unreporteddatafromindividuals–capturedviaastrategiconlinesurveyThepreviousassessmentconfirmedthatasignificantproportionoftheferalcatcontroleffortinAustraliagoesunreportedandistypicallyundertakenonprivatelandbyindividuals.Tocapturethisdata,wedesignedanonlinesurveytostrategicallycaptureunreportedinformationonferalcatcontrolacrossAustralia.Thiswasbasedonthesurveydevelopedforthepreviousassessmentandaimedatthosewhoarelikelytoengageinferalcatcontrolactivitiesbutmaynotrecordtheireffortsinaformalrepositoryordatabase.Inparticular,wetargetedthoselikelytoengageinferalcatcontrolasapartoftheirlivelihood(i.e.land-managers,farmers)orrecreationally(huntersandsportingshooters).

Itwasimportanttoensureanonymityofsurveyrespondents(toimprovethechancesofgettingwide-scalesurveyparticipation,andtoadheretotherequirementsofRMIT’sHumanResearchEthicsCommittee).Assuch,wedidnotcollectanyinformationthatwouldenableparticipantstobeidentified.Respondentswerealsoundernoobligationtoanswerany

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questiontheydidn’twantto;however,wedidasksurveyrespondentstoprovidetheirpostcodeanddescribethemselvesbyselectingoneormoreoccupationtype(includingFarmer,SportingShooter,Hunter,LandManageretc.).Thisenabledustomonitorthespatialextentofthesurvey’sreach,andtoconfirmthatwewerecapturingthetargetaudience.

Thestrategicsurveywasdesignedtocapturethefollowinginformationfromeachparticipant:

• Whethertheyengagedinferalcatcontrolandifso,howmanyferalcatstheyhadkilledinthelast12months.Participantswereinvitedtoprovideanexactnumberiftheyknewit.Otherwise,participantsreportedarange(e.g.1to5,5to10,10to20,etc.);

• Theferalcatcontrolmethodstheyused;• Howlongtheyhadbeenengaginginferalcatcontrol,andwhethertheyhadchanged

theireffortsoverthistime;• Howmuchefforttheyinvestedinferalcatcontrol,includingtheareacoveredand

timespent;and• Whethertheyreportedtheirferalcatcontroleffortselsewhere.Thisenabledusto

negatedouble-countinginourestimateofthenumberofferalcatsremoved.

Althoughweareinterestedingainingestimatesforferalcatsremovedforovertheprevious24months,weonlysoughttocollectthisinformationfortheprevious12months.Thiswasdoneinordertokeepthesurveyasshortandaseasytocompleteaspossible,aswellasowingtothegreateruncertaintyassociatedwiththereportingofunrecordedfiguresthatrelyuponaccuraterecallofeventsfrom2yearsago.Instead,anapproximationofyear2feralcatremovaldataforindividualswasestimatedbasedontheyear1andyear3data,includingonthebasisofwhetherindividualsreportedchangesintheirmanagementeffortandinthevariabilityofthenumberofferalcatstheyremovefromyeartoyear.

WedevelopedthestrategicsurveyandadistributionstrategyincollaborationwiththeOfficeoftheThreatenedSpeciesCommissioner.Thedistributionstrategywasdesignedtoguidethedistributionandpromotionofthesurveythroughrepresentativeorganisationsforfarmers,recreationalshootersandhunters,conservationistsandlandmanagersoverafive-weekperiod(23July2018to24August2018).

Thesurveyalsoincludedanumberofquestionsdesignedtoimproveourunderstandingoftheperceivedimpactsofferalcatsinthecommunity,andpotentialoptionsforreducingthoseimpacts,includingoptionsthatarealternativestoculling.Insodoing,wenotedthatthesurveywastargetedtoparticularcommunitygroupsandtheresultsmaynotberepresentativeofthebroadercommunity.EthicsapprovalforthesurveywasgrantedbyRMITUniversity’sHumanResearchEthicsCommittee(ProjectNumberCHEANA21547-05/18).

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Weknowfromthestrategicsurveyundertakenasapartofthepreviousassessmentthatmuchoftheunreportedferalcatmanagementisundertakenbyfarmersandshooters/hunters.Shooterswerewellrepresentedinthestrategicsurvey,butfarmerswerelesswellrepresented.Thisislikelyaresultofthesurveyonlybeingavailableonline.Inordertoensureagoodrepresentationoffarmers,particularlyolderfarmers,weadditionallyundertookamail-outsurveyof3000farmersacrossAustralia(addressesweresuppliedbyAxiomAgrimarketing),fromwhichwereceived326completeresponses.

TherepresentativenessandreachofsurveyparticipantsareindicatedbyFigures1&2.Farmers,sportingshootersandhunters,ecologistsandconservationistsandvolunteersarewellrepresentedinthesurvey.Landmanagers,consultantsandTraditionalOwnersarelesswellrepresented(Fig1).

Figure1.Numbersofrespondentsthatself-identifiedwitheachoffereddescriptionfor:thoseinvolvedinferalcatmanagement(red);andthosenotinvolvedinferalcatmanagement(green)(n=4781).

0

200

400

600

800

1000

1200

Involvedinferalcatmanagement Notinvolvedinferalcatmanagement

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Figure2.Numberofsurveyrespondentswhoengageinferalcatcontrol,by2-digitpostcode.

Toaidcontinuityandcomparability,thesurveyismostlyconsistentwiththatusedforthepreviousassessment.However,inordertogainabetterunderstandingofhowindividualsrespondtodifferentferalcatcontrolprogramsandactivities,andhoweffortshavechangedinresponsetodifferentcampaignsandinterventions,weincludedsomeadditionalquestions.

Additionaltothepreviousassessment,thesurveywillalsocollectinformationabout:

• attitudestowardsferalcatcontrolofrespondentswhomaybeopposedtothepractice;

• awarenessoftheThreatenedSpeciesCommissionerandherroleinferalcatmanagement;and

• willingnesstocontributetoferalcatmanagementandperceptionsofresponsibilityforferalcatmanagement.

Thefinalpointabovewasinvestigatedusingabetween-subjectsdesign,inwhichrespondentswererandomlyassignedoneofthreeslightlydifferentversionsofthesurvey.Theseversionsdifferonlyinrelationtooneparagraphtowardstheendofthesurvey:oneversionincludesastatementfromtheThreatenedSpeciesCommissioneraboutferalcatmanagementthatemphasisesactionsundertakenbytheAustralianGovernment;anotherversionincludesanalternativestatementfromtheThreatenedSpeciesCommissioneraboutferalcatmanagementthatemphasisessharedactions;andacontrolversionthatdoesnotincludeeitherstatement.

AnoutlineofthestrategiconlinesurveyforindividualsisprovidedatAppendixC.

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Estimatingferalcatcontrolnumbersandareamanaged

Thissectiondescribestheprocessofestimatingferalcatcontrolnumbersandareasfromdatasetswithvaryinglevelsofuncertainty.Theareathatismanagedforferalcatsisnotavailableforsomesources,suchasFeralCatScanortheRSPCA.Webeginwiththedataforwhichthereisleastuncertainty:reliableestimatesofferalcatdeathsfromexistingrepositoriesandotherharddata.

Next,wecompilethedatafromthestrategiconlinesurveysforboththeorganisationsandindividuals.Becausethisdataincludesrangesofcatsremoved(e.g.1to5,5to10,etc.)andalsoareasmanaged(lessthan10hectares,10to50hectares,etc.),thereissomeinherentuncertaintyassociatedwiththisdata.

Wethendescribetheprocessofprojectingknowninformationaboutthenumberofferalcatskilledbysurveyrespondentsandlocalandregionalcouncilstothenationalscale.Thisprojecteddataistheleastreliable,asitrequiresextrapolationtounknownpopulationsthatarepotentiallybeyondtheboundsofthedata.However,wehavedrawnonreliableinformationwherepossibleandotherwisehavebeenconsistentlyconservativeinourassumptions.Wethereforefeelconfidentthatthisprocesshasproducedaplausible,yetconservativeestimateofthenumberofferalcatskilledacrossAustraliainthelastyear.

Wealsouseasimilarapproachtoprojectuniqueareadatatothebroaderpopulation.Inthiscaseweareinterestedinascertaininganestimateoftheuniqueareamanagedeachyear.Forthisreason,theareadataisonlyprojectedtofarmerswhodidnotrespondtooursurvey–apopulationforwhichwehavereasonableknowledge,andwhowemayassumemanageuniqueareas.Thisprocessisdescribedingreaterdetailbelow.

Finally,wecombinethecurrentassessment(year3)andthepreviousassessment(year1)withanestimateforyear2toreportaboundedthree-yearcumulativetotalofferalcatsremovedfromtheenvironmentfor2015-18.Inthisassessment,organisationsandcentraldatarepositoriesprovidedinformationonthenumberofferalcatsremovedfromtheenvironmentforyears2and3,sowecanprovideauniqueestimateofthenumberofferalcatsremovedineachyear.Individualswhorespondedtooursurveyprovidedonlyanestimateforyear3;whencalculatingthe3-yeartotal,weusedthisestimateforbothyears2and3.

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Datareportedtocentralrepositories

CatsremovedAustralianGovernmentfundedconservationprograms

Informationabout237conservationprogramsfundedbytheAustralianGovernmentwasprovidedbytheOfficeoftheThreatenedSpeciesCommissioner.Manyofthesearemulti-yearprogramsthatoperatedacrossvariousperiodsofthethreeyearsfrom2015-18,withthosereportingferalcatremovalnotspecifyingwhichyearthesewereundertaken.Inordertoallocatethereportednumberstothespecificyearsofinterestinthisassessment,werelieduponanassumptionthattherateofcatremovalwasconstantacrosstheperiodforwhichtheprogramoperated.

Onthisbasis,thenumberofcatremovedbytheseprogramswereasfollows:

• 296feralcatsremovedin2017-18;and• 612feralcatsremovedin2016-17.

FeralCatScandatabase

DatafromtheonlineferalcatreportingtoolFeralCatScanwassuppliedbyDrPeterWest.Thisincludedthefollowing:

• 64feralcatsremovedin2017-18;and• 106feralcatsremovedin2016-17.

Itislikelythatthesereportsaresomewhatconservative,asthereportingincludedanumberofinstancesof‘morethan2’;thesewerecountedonlyas2.

RSPCA

TheRSPCAhavetheunfortunatetaskofeuthanisingmanycatseachyearforavarietyofreasons.In2016-17,theRSPCeuthanised3,863feralcats,althoughatthetimeofwriting,thenumbersofferalcatseuthanisedin2017-18isnotavailable.However,weknowthat4,484feralcatswereeuthanisedin2015-16andwehavecalculatedalikely2017-18estimateof4,174basedontheaverageoftheprevioustwoyears.WehavealsoassumedthatcouncilshavenotalsoreportedferalcatsremovedfromtheirmunicipalitiesthathavebeeneuthanisedbytheRSPCA.

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AreamanagedAustralianGovernmentfundedconservationprograms

Asimilarapportioningapproachwasusedtodeterminetheareasmanagedbyeachprogramin2017-18aswasusedtoallocatecatsremovedacrosstheyearsduringwhichtheprogramoperatedasoutlinedabove.

FeralCatScandatabase

Noareadataisrecordedbythisdatabase.

RSPCA

TheRSPCAdonotmanageanyareasforferalcats.

Unreporteddatafromorganisations,capturedviaastrategiconlinesurvey

CatsremovedOrganisationsengagedinferalcatmanagementwereaskedtoreportanestimateofthenumberofferalcatstheyhadremovedintheprevioustwofinancialyears.Someorganisationsprovidedarange(i.e.1-5cats),andothersreportedanexactnumber.Weextractedthisinformationforthe134organisationsthatreportedengaginginferalcatcontrol.Whentallied,thisinformationproduced3estimatesofthenumberofcatsremoved:theconservativeestimateassumedthelowervalueofthereportedrange;themostlikelyestimateassumedthemedianvalueofthereportedrange;andthegenerousestimateassumedtheuppervalueofthereportedrange.Whereanexactnumberwasprovided,thisnumberwasusedwhencalculatingtheconservative,mostlikelyandgenerousestimates.

Basedontheseassumptions,wearriveatthefollowing:

• Thenumberofferalcatsremovedbyorganisationsinthe2017-18financialyear,asreportedbyorganisations,rangedfrom10,697to13,420,withamostlikelyestimateof11,984.

• Thenumberofferalcatsremovedbyorganisationsinthe2016-17financialyear,asreportedbyorganisations,rangedfrom11,492to14,187,withamostlikelyestimateof12,783.

AreamanagedOrganisationsengagedinferalcatmanagementwerealsoaskedtoreportanestimateoftheareaforwhichtheyremoveferalcats.Someorganisationsprovidedarange(i.e.10to50hectares,etc.),andothersreportedanexactnumber.Weextractedthisinformationforthe134organisationsthatreportedengaginginferalcatcontrol.Becausethesecategoriesareverywide(e.g.100to1000hectares),wehavetakenaconservativeapproachandreportedonlytheminimumareas.

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Basedonthis,theminimumareamanagedforferalcatsin2017-18,asreportedbyrespondentstoourstrategiconlinesurvey,is22,687,157hectares.However,owingtothelackofspatialinformationabouttheareadata,itisimpossibletodeterminehowmuchofthisisuniquelymanaged.

Unreporteddatafromindividuals,capturedviaastrategiconlinesurvey

CatsremovedSurveyrespondentswereaskedtoreportanestimateofthenumberofferalcatstheyhadremovedinthelastyear.Somerespondentsprovidedarange(i.e.1-5cats),andothersreportedanexactnumber.Weextractedthisinformationforthe2,618respondentswhoreportedengaginginferalcatcontrol(thisincludesthemailoutsurveydirectedtowardsfarmers).Whentallied,thisinformationproduced3estimatesofthenumberofcatsremoved:theconservativeestimateassumedthelowervalueofthereportedrange;themostlikelyestimateassumedthemedianvalueofthereportedrange;andthegenerousestimateassumedtheuppervalueofthereportedrange.Wherearespondentprovidedanexactnumber,thisnumberwasusedtocalculatetheconservative,mostlikelyandgenerousestimates.Whentallyingtheseresults,weremovedobservationsthathadbeenreportedthroughotherchannelsthatwerealreadyaccountedforindataalreadycounted(e.g.FeralCatScan,councildata,etc.).

Basedontheseassumptions,thenumberofferalcatsremovedinthelastyear,asreportedbyrespondentstoourstrategiconlinesurvey,rangedfrom13,946to25,942,withamostlikelyestimateof19,658.

AreamanagedIndividualsengagedinferalcatmanagementwerealsoaskedtoreportanestimateoftheareaoverwhichtheyremoveferalcats.Someprovidedarange(i.e.10to50hectares,etc.),andothersreportedanexactnumber.Weextractedthisinformationforthe2,618respondentsthatreportedengaginginferalcatcontrol.Becausethesecategoriesareverywide(e.g.100to1000hectares),wehavetakenaconservativeapproachandreportedonlytheminimumareas.

Basedonthis,theminimumareamanagedforferalcatsin2017-18,asreportedbyindividualrespondentstoourstrategiconlinesurvey,is19,120,497hectares.However,owingtothelackofspatialinformationabouttheareadata,itisimpossibletodeterminehowmuchofthisisuniquelymanaged.

Reliableminimumestimatesofferalcatremovalandareamanagedforyear3(2017-18)

Summingtheabovedata,weprovideareliableminimumestimateofthenumberofferalcatsremovedin2017-18thatrangesfrom29,177catsto43,896cats,withamostlikelyestimateof36,175cats(Table1).Likewise,thereliableminimumestimatefor2016-17

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rangesfrom28,247to43,118cats,withamostlikelyestimateof35,430feralcats(AppendixD).

Wealsoprovideaminimumestimateoftheareaoverwhichferalcatmanagementisbeingundertakenas41,602,727hectares(Table1).Ifweassumethatconservationorganisations,IndigenousProtectedAreaorganisationsandfarmersareallmanaginguniqueareas(ie.areasthatarenotcoveredbyanyoneelse),areliableminimumestimateoftheuniqueareamanagedforferalcatsin2017-18is11,359,172ha.

Table1.Estimatednumberofferalcatsremoved,asprovidedbyreporteddata.‘Conservative’,‘MostLikely’and‘Generous’estimatescorrespondtolower,mediananduppervaluesofthenumberofcatsremoved,asreportedintheonlinesurvey.

Areamanaged

(Ha)

FeralcatsremovedConservative Mostlikely Generous

Repositories

AustralianGovernmentprograms

1,053,373 296 296 296

FeralCatScan N/A 64 64 64RSPCA N/A 4,174 4,174 4,174

Subtotal 1,053,373 4,534 4,534 4,534Organisations

Localorregionalcouncil

11,774,346 7,960 8,996 10,156

Sportingshootersassociation

110,000 240 245 250

Farmersassociation 13,260 173 244 315Conservationorganisation

9,535,024 656 681 708

IndigenousProtectedAreaorrangergroup

administration

553,100 64 68 74

Communitygroup 1,350 123 132 142Other 700,077 1,481 1,618 1,775

Subtotal 22,687,157 10,697 11,984 13,420Individuals

Farmer 1,271,048 3,181 4,416 5,770Sportingshooters

andhunters8,886,466 6,406 8,927 11,734

Landmanager 1,262,099 535 838 1,158Consultant/Contractor

857,189 593 790 1,017

Ecologist/Conservationist

2,131,651 890 1341 1,817

Volunteerwithaconservationgroup

1,005,177 371 594 825

Traditionalowner 304,451 371 492 640Other 3,402,417 1,599 2261 2,981

Subtotal 17,862,197 13,946 19,658 25,942TOTAL 41,602,727 29,177 36,175 43,896

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Projecting2017-18feralcatcontroldatatothenationalscale

WhilewecanproduceareliableminimumestimateofthenumberofferalcatsremovedfromtheenvironmentfromtheharddatareportedinTable1,weknowthatthedatareportedbyorganisationsandrespondentstoourstrategicsurveyrepresentonlyaproportionofthetotalnumberofferalcatsremovedin2017-18bylocalcouncils,otherorganisationsandindividualsinvolvedinunreportedferalcatcontrol.

Weusedadvancedstatisticalmodellingmethodstodescribethevariationintheferalcatcontroldatareportedinthesurveyandprojectthistoanationalscale.Thisprocesswasapplicableonlytopopulationsforwhichwehadsomereliableinformationaboutbroaderpopulations,namelycouncils,farmers,andshooters/hunters.Thesewerealsothemostsignificantcontributorsofferalcatremoval,representing65%ofallrespondentstothesurveyand60%ofreportedferalcatremoval.

ProjectingthenumberofferalcatsremovedProjectionsofthenumberofferalcatsculledbycouncils,farmersandshooters/huntersweremadebasedonthelowerboundofthereportednumberofferalcatskilledor,whereitwasprovided,theexactnumberofferalcatskilled.Foreachgroup,dataweremodelledusinganegativebinomialdistribution.Thenegativebinomialdistributionisadiscreteprobabilitydistributionthatisusefulformodellingcountdatathatareclumped(McCarthy2007).Forexample,asisthecasewithourdata,theremaybeahighproportionofcountsinthelowervaluesnearzero.Undertheseconditions,thevarianceamongcountsisgreaterthanassumedbythePoissondistribution,anotherdiscreteprobabilitydistributioncommonlyusedtomodelcounts(McCarthy2007).Thisdistributionwasassessedtobeagoodfittothenumberofferalcatsculleddata(AppendixE)andoutperformedthePoissondistributionwhencomparedusingthedevianceinformationcriterion(DIC:Speigelhalteretal.2002),aparsimoniousmetricthatbalancesthegoodnessoffitofamodelwithitssimplicity.

Ineachcase,modelswerefittedtotheavailabledatainJAGS,anopensourceprogramforBayesianstatisticalmodellingusingMarkovChainMonteCarlosimulation(Plummer2003)viatherjagspackage(Plummer2016)inR(RCoreTeam2018).Intheabsenceofreliablevariablesforthetargetpopulations,modelswerefittedwithoutcovariates.Theprojectedestimatesandunderlyingassumptionsforeachprojectionaredetailedbelow.

CouncilsThisprojectionisbasedonthelowerboundofthereportednumberofferalcatsculledby140localorregionalcouncilswhorespondedtooursurveyandindicatedthattheyengagedinferalcatcontrol.Estimatesfromthismodelindicatethatthemeannumberofferalcatsculledbytheseengagedcouncilsisaround57cats/year(Figure3a).Thisestimatevariedlittlebetweentothetwoyearsforwhichwehaddata.ProjectingthisfiguretotheestimatednumberofAustraliacouncilswhoengageinferalcatcontrolbutdidnotrespondtooursurvey(n=262,seeassumption2,below)givesanestimateofthenumberofferalcats

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culledof15,894(95%CI:11,872;20,106)in2016-17,and15,819(11,721;19,873)in2017-18(Table2;Figure3b).

Table2.Projectednumberofferalcatsculledbylocalcouncilswhoengageinferalcatcontrolbutdidnotrespondtooursurvey

Year Lower95%CI Mean Upper95%CI2016-17 11,872 15,894 20,1062017-18 11,721 15,819 19,873

Thefollowingassumptionsweremadeingeneratingtheseestimates:

1. ThatthedatareportedbylocalcouncilswhorespondedtoouronlinesurveyfororganisationsisrepresentativeoflocalcouncilsaroundAustralia.Australianlocalgovernmentareasarehugelyvariableinarea,environment,populationandferalcatdensity,noneofwhichwerecontrolledforinourmodelling.Unmodelledvariationinthenumberofferalcatskilledacrosslocalcouncilscouldleadtoerrorsinthefinalestimate.

2. Theestimatednumberoflocalcouncilsengaginginferalcatcontrolassumesthat68%ofAustralianlocalcouncilsaredoingso.Weextractedthisproportionfromouronlinesurvey,whichalsoincludedresponsesfromcouncilswhoindicatedthattheydidnotengageinferalcatcontrol.Therearecurrently563LocalGovernmentAreasinAustralia(ABS,2016).Ourmodelestimateswereprojectedtothosecouncilswhoengageinferalcatcontrolbutdidnotcompleteoursurvey,assumedtobeequalto563x0.68–140,where140isthenumberofcouncilswhoengageinferalcatcontrolthatcompletedtheonlinesurvey.

a

b

Figure3.Posteriordistributionsand95%credibleintervalsofa)themeannumberofferalcatsculledbyactivelocalcouncils,andb)theprojectedtotalnumberofferalcatsculledbylocalcouncilswhoengageinferalcatcontrolbutdidnotrespondtooursurvey.

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FarmersThisprojectionisbasedonthelowerboundofthereportednumberofferalcatsculledbyfarmerswhorespondedtoouronlineormailsurveyandindicatedthattheyengagedinferalcatcontrol.Estimatesfromthismodelsuggestthatthemeannumberofferalcatsculledbyengagedfarmersis6catsperyear(95%CI:5;7)(Figure4a).ProjectingthisfiguretotheestimatednumberoffarmersengaginginferalcatcontrolinAustralia(n=5602),givesaconservativeestimateofthetotalnumberofferalcatsculledbyAustralianfarmerswhodidnotrespondtooursurveyof34,051catsperyear(30,245;38,040)(Table3;Figure4b).

Table3.Projectednumberofferalcatsculledbyfarmerswhoengageinferalcatcontrolbutdidnotrespondtooursurvey

Projectedpopulationsize Lower95%CI Mean Upper95%CIn=5602 30,245 34,051 38,040n=8053(Forcomparisonwith2016report)

43,208 48,919 54,451

Thefollowingassumptionsweremadeingeneratingtheseestimates:

1. ThattheferalcatcontroldatareportedinoursurveybyfarmerswhoengageinferalcatcontrolisrepresentativeoftheAustralianfarmingpopulation.ThereissignificantvariationinfarmingpropertiesacrossAustralia,includinginsizeandproduction,bothofwhichcouldaffectfarmerengagementinferalcatcontrol.Wedonothavesufficientdatatocontrolforthisvariationinourmodels,andestimatesoftheprojectednumberofferalcatsculledmaybeerroneousasaresult.Nonetheless,wehaveprovidedwhatwebelievetobeaplausibleestimatebasedonconservativeassumptions.

2. That7%ofAustralianfarmersengageinferalcatcontrol(whichwedrewfromtheABARESPestandWeedManagementSurvey:Stenekesetal(2017)),andthatthisfiguredoesnotvaryacrossstates.

3. ThatthenumberoffarmsinAustralia,asregisteredbytheABS,isagoodapproximationofthenumberoffarmersinAustralia.

4. OurestimatesassumethetotalnumberoffarmsinAustraliais88,073(ABS2018).ThisclassificationdefinesfarmsasthosewhoseEstimatedValueofAgriculturalOperationsis³$40,000,andsoexcludessmallerfarmsandhobbyfarms.Webelievethisisareasonableassumptionforourpurposes,butisakeydifferencetothenumberoffarmsassumedinthe2016feralcatcontroleffortsurvey,whentheABSclassifiedanyfarmwithEVAO³$5,000asaregisteredfarm.Usingthisnewclassificationwillensurethatfutureestimatesarebasedonconsistentinformation.Forcomparison,anequivalentestimate,producedusingthepreviousclassificationoffarms,isprovidedinTable3.

5. Basedonthisdata,thetotalnumberoffarmsengaginginferalcatcontrolinAustraliain2016-17and2017-18is6,165(88,073x0.07).Togetthefinalnumberforprojections(n=5,602),wedeductthenumberoffarmersengaginginferalcatcontrolwhorespondedtooursurveys(563).

6. Toarriveatourfinal3-yearestimateofthenumberofferalcatskilledacrossAustralia,weassumethatthenumberofferalcatskilledbyfarmersin2016-17isthesameasthatin2017-18.Webelievethisisareasonableassumption,as76%offarmerswhorespondedtooursurveyandengageinferalcatcontrolreportedthatthenumberofferalcatstheykillfromyeartoiseither‘Aboutthesame’or‘Variesalittle’.

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a

b

Figure4.Posteriordistributionsand95%credibleintervalsofa)themeannumberofferalcatsculledbyactivefarmerswhorespondedtooursurveys,andb)theprojectedtotalnumberofferalcatsculledbyfarmerswhoengagedinferalcatcontrolbutdidnotrespondtooursurvey.

Shooters/HuntersThisprojectionisbasedonthelowerboundofthereportednumberofferalcatsculledbyshootersandhunterswhorespondedtotheonlinesurveyandindicatedthattheyengagedinferalcatcontrol.Estimatesfromthismodelsuggestthatthemeannumberofferalcatsculledbyactiveshooters/huntersis6catsperyear(95%CI:5.8;6.7)(Figure5a).Projectingthisfiguretotheestimatednumberofshooters/huntersengaginginferalcatcontrolinAustralianotcapturedbyoursurvey(n=36,930),givesawhatwebelievetobeaconservativeestimateofthetotalnumberofferalcatsculledbyshooters/hunters(butnotcapturedbythesurvey)acrossAustraliaof230,812catsperyear(213,857;248,651)(Table4;Figure5b).

Table4.Projectednumberofferalcatsculledbyshooters/hunterswhoengageinferalcatcontrolbutdidnotrespondtooursurvey

Projectedpopulationsize Lower95%CI Mean Upper95%CIn=36,930 213,857 230,812 248,651n=17,223(Forcomparisonwith2016report)

99,740 107,584 115,845

Thefollowingassumptionsweremadeingeneratingtheseestimates:

1. Thattheferalcatcontroldatareportedbyshootersandhunterswhorespondedtooursurveyisrepresentativeofshooters/hunterswhoengageinferalcatcontrolmorebroadlyinAustralia.

2. Thatthemembership(n=190,500)oftheSportingShootersAssociationofAustralia(SSAA)isareasonableapproximationofthenumberofshootersandhuntersinAustralia.

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3. ThereportedestimateassumesthattheproportionoftheSSAAmembershipwhoactivelyengageinferalcatcontrolis20%,andthatthisdoesnotvaryacrossstates.ThisfigurewasobtainedfromtheSSAA(MGodson,perscomm),whoregularlysurveytheirmembership,butissignificantlyhigherthanreportedinthe2016FeralCatSurvey(9.6%).Forcomparison,anequivalentestimate,producedusingtheproportionpreviouslyreportedinthe2016report(9,6%),isprovidedinTable4.

4. Basedonthisdata,weassumedthatthetotalnumberofshooters/hunterstargetingferalcatsinAustraliain2016-17and2017-18is38,100(190,050x0.20).Togetthefinalnumberforprojections(n=36,930),wedeductedthenumberofactiveshooters/hunterswhorespondedtooursurveys(1170).

5. Toarriveatourfinal3-yearestimateofthenumberofferalcatskilledacrossAustralia,weassumethatthenumberofferalcatskilledbyshooters/huntersin2016-17isthesameasthatin2017-18.Thisembodiestwoseparateassumptions;thattheaveragenumberofferalcatsremovedfromtheenvironmentbyindividualshooters/huntersisconstantacrossyears,andthattheproportionofshooters/huntersengaginginferalcatcontrolisconstantacrossyears.Webelievethefirstisareasonableassumption;74%ofshootersandhunterswhorespondedtooursurveyandengageinferalcatcontrolreportedthatthenumberofferalcatstheykillfromyeartoiseither‘Aboutthesame’or‘Variesalittle’.Thesecondislessreliable;estimatesoftheproportionofsportingshootersengaginginferalcatcontrolhaveincreasedsincethefirstassessmentofthenationalefforttowardsferalcatcontrol.Inourassessment,webelievewehavebeenconservative,assumingthat20%oftheSSAA’smembershipareengagedinferalcatcontrol–thisfigureistakenfromarecentSSAAsurveyandcorrespondstotheproportionofrespondentswhoindicatethattheyactivelytargetferalcats(MGodson,perscomm).However,thisfigureishigherthanthatusedinthepreviousassessmentandlowerthanthatreportedbytheSSAAmembershipina2016survey.Furtherinvestigationofthemotivationsforandscaleofengagementofsportingshootersinferalcatcontrolmayhelptoresolvesomeofthisuncertainty.

a

b

Figure5.Posteriordistributionsand95%credibleintervalsofa)themeannumberofferalcatsculledbyactiveshooters/hunterswhorespondedtooursurvey,andb)theprojectedtotalnumberofferalcatsculledbyshooters/hunterswhoengageinferalcatcontrolbutdidnotrespondtooursurvey.

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Three-yearcumulativeestimateofthenumberofferalcatsremovedfromtheenvironment(2015-18)

Inordertoarriveata3-yearcumulativeestimateofthenumberofferalcatsremovedfromtheenvironmentfrom2015to2018,weproceededintwosteps.First,foreachofthelasttwofinancialyears(2017-18and2016-17),wesummedtheminimumreliableestimatescollectedfrommanageddatarepositoriesandreportedinoursurveys,andtheprojectedestimatesforlocalcouncils,farmersandshooters/huntersoutlinedintheprevioussections.Fororganisations,wehadseparateestimatesforthetwoyears,andforindividuals,weusedthesameestimateforbothyears.ThenationalestimatesofthenumberofcatsremovedfromtheenvironmentaredetailedinTable5(2017-18)andTable6(2016-17).Therewaslittledifferencebetweenyears.

Inthesecondstep,wesummedthetwoestimatesfor2017-18and2016-17withthe2015-16estimateproducedinthefirstassessmentofthenationalefforttowardsferalcatcontroltoarriveatafinal3-yrcumulativeestimatethatrangesbetween764,289and924,925cats,withamostlikelyestimateof844,607cats.

Whensummingprojectedestimateswith95%credibleintervals,weassumedtheestimateswereindependentandnormally-distributedinordertocalculatethe95%credibleintervalforthefinalestimate.

Table5.Nationalestimateand95%credibleintervalsofthenumberofferalcatsremovedfromtheenvironmentin2017-2018.

DataSource Lower95%CI Estimate Upper95%CIOrganisations

RepositoriesReportedinsurveyProjectionstocouncils

--

11,872

4,53411,98415,894

--

20,106Organisationsubtotal 28,239 32,337 36,391

IndividualsReportedinsurveyProjectionstofarmersProjectionstoshooters/hunters

-

30,245213,857

19,65934,051230,812

-

38,040248,651

Individualssubtotal 266,694 284,522 302,350TOTAL2017-18* 298,571 316,859 335,147

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Table6.Nationalestimateand95%credibleintervalsofthenumberofferalcatsremovedfromtheenvironmentin2016-2017.

DataSource Lower95%CI Estimate Upper95%CIOrganisations

RepositoriesReportedinsurveyProjectionstocouncils

--

11,721

2,98912,78315,819

--

19,873Organisationsubtotal 27,644 31,666 35,878

IndividualsReportedinsurveyProjectionstofarmersProjectionstoshooters/hunters

-

30,245213,857

19,65934,051230,812

-

38,040248,651

Individualssubtotal 266,694 284,522 302,350TOTAL2016-17* 297,891 316,188 334,485

Table7.Cumulativenationalestimateofthenumberofferalcatsremovedfromtheenvironmentfrom2015-2018.

Year Lower95%CI Estimate Upper95%CI2015-16^ 135,522 211,560 287,5982016-17 297,891 316,188 334,4852017-18 298,571 316,859 335,147TOTAL* 764,289 844,607 924,925

^Fromfirstassessmentofthenationalefforttowardsferalcatcontrol(RMIT2016).

*Assumingthepredictednumberofcatsineachdatasetareindependentandnormally-distributed,theoverallmeanisequaltothesumoftheindividualmeans,andtheoverallvarianceisequaltothesumoftheindividualvariances.

TotalUniqueAreaManaged2017-18

Thereliableminimumestimateoftheuniqueareamanagedforferalcatcontrolinyear3(2017-18)includestheareasmanagedbyorganisationsandindividualsthatcanreasonablybeassumedtobeindependentofallotherferalcatmanagementefforts;namely,thoseareasmanagedbyconservationorganisations,IndigenousProtectedAreasorareasmanagedbyIndigenousRangerprograms,andfarmers.Wedonotbelieveitisreasonabletoassumeindependenceinanyoftheotherareasreported.Forexample,feralcatmanagementsupportedthroughAustralianGovernmentProgramsmayhappenonprivatelandoronlandmanagedbyconservationorganisationsorTraditionalOwners.Similarly,areasmanagedbylocalcouncilsmayincludefarmsorlandmanagedbyconservationorganisations,andsocannotbeassumedtobeindependentoftheareareportedbythesegroups.Amoreaccurateestimateoftheuniqueareamanagedforferalcatcontrolwouldrequirethe

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collectionofspatially-explicitinformationfromindividualsandgroupscontributingtothenationalferalcatcontroleffort.ThiswasimpossibletocollectinthisassessmentbecauseofsensitivitiesassociatedwiththelegalstatusofcatcontrolinVictoria;however,thisinformationmaybeeasiertocollectinthefuturefollowingrecentchangestoVictorianregulations.

Inadditiontotheminimumreliableestimateobtainedfromdatarepositoriesandrespondentstotheonlinesurveys,wehavemadeaprojectionoftheareamanagedforferalcatcontrolbyfarmers,usingsimilarstatisticalmethodstothosedescribedforthenumberofferalcatsremoved.Thisprojectionisbasedonthelowerboundoftheareareportedby563farmerswhorespondedtotheonlineandmailoutsurvey.Thisdatawasmodelledusingalognormaldistribution.Thelognormaldistributionisacontinuousprobabilitydistributionthatisusefulfordescribingarandomvariablewhoselogarithmisnormally-distributed(Bolker2008).Inotherwords,itisusefulformodellingdatawhichhaslongright-tails(ie.manysmallvaluesandfewverylargevalues).Usingthelognormaldistributionforsuchdataisconsideredpreferabletoalternativemethodsinwhichthenaturaldataistransformedtoreduceskewnessbecauseitavoidserrorsthatcanoccurintheprocessofback-transformingparameterestimates(Limpertetal2001).Thisdistributionisshowntobeagoodfittotheareamanagedforferalcatcontrolbyfarmersdata(AppendixE).

Asabove,wefitthelognormalmodeltotheavailabledatainJAGS,anopensourceprogramforBayesianstatisticalmodellingusingMarkovChainMonteCarlosimulation(Plummer2003)viatherjagspackage(Plummer2016)inR(RCoreTeam2018).Estimatesfromthismodelsuggestthatthemeanareamanagedforferalcatcontrolbyindividualengagedfarmersis1352ha(95%CI:907,1890)(Figure6a).Projectingthisfiguretotheestimatednumberoffarmerswhoengageinferalcatcontrolbutdidnotrespondtooursurvey(n=5602),givesaconservativeestimateoftheadditionaltotalareamanagedforferalcatcontrolacrossAustraliaof7,575,822ha(95%CI:5078381,10588833)(Table8;Figure6b).

Table8.Projectedarea(ha)managedforferalcatcontrolbyfarmerswhoengageinferalcatcontrolbutdidnotrespondtooursurvey,including95%credibleintervals.

Projectedpopulationsize* Lower95%CI Mean Upper95%CIn=5602 5,078,381 7,575,822 10,588,833n=8053(Forcomparisonwith2016report)

7,244,404 10,942,238 15,209,303

Addingtheseprojectionstotheminimumreliableestimategivesafinalestimateofthetotaluniqueareamanagedforferalcatcontrolin2017-18of18,934,994ha,witha95%credibleintervalrangingbetween16,437,553and21,948,005ha(Table9).

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Table9.Estimateoftheuniquearea(ha)managedforferalcatcontrolinAustraliain2017-18,including95%credibleintervals.

DataSource Lower95%CI Estimate Upper95%CIOrganisations

ConservationorganisationsIndigenousProtectedAreas/rangers

--

9,535,024553,100

--

IndividualsFarmersProjectionstofarmers

-

5,078,381

1,271,0487,575,822

-

10,588,833 16,437,553 18,934,994 21,948,005

Thefollowingassumptionsweremadeingeneratingtheseestimates:

1. Thisestimateissubjecttomanyoftheassumptionsunderpinningthenumberofferalcatculledprojectionsforfarmers.TheareamanageddatareportedbyfarmerswhoengageinferalcatcontrolinouronlineandmailoutsurveysisrepresentativeofAustralianfarmerswhoengageinferalcatcontrolmorebroadly.ThereissignificantvariationinfarmingpropertiesacrossAustralia,includinginsizeandproduction,bothofwhichcouldaffectfarmerattitudestowardsferalcatcontrol.Wedonothavesufficientdatatocontrolforthisvariationinourmodels,andestimatesofareamanagedmaybeerroneousasaresult.Nonetheless,wehaveprovidedwhatwebelievetobeaplausibleestimatebasedonconservativeassumptions.

2. That7%ofAustralianfarmersengageinferalcatcontrol(whichwedrewfromtheABARESPestandWeedManagementSurvey:Stenekesetal(2017)),andthatthisfigureisequalacrossstates.

3. ThatthenumberoffarmsinAustralia,asregisteredbytheABS,isagoodrepresentationofthenumberoffarmersinAustralia.

4. TheconservativeestimateassumesthetotalnumberoffarmsinAustraliais88,073.ThisclassificationdefinesfarmsasthosewhoseEstimatedValueofAgriculturalOperations(EVAO)is³$40,000,andsoexcludessmallerfarmsandhobbyfarms.Webelievethisisareasonableassumptionforourpurposes,butisakeydifferencetothenumberoffarmsassumedinthe2016feralcatcontroleffortsurvey,whentheABSclassifiedanyfarmwithEVAO³$5,000asaregisteredfarm.Usingthisnewclassificationaswehavedoneherewillalsoensurethatfutureestimatesarebasedonconsistentinformation.Forcomparison,anequivalentestimate,producedusingthepreviousclassification,isprovidedasaLiberalestimateinTable8.

5. Basedonthisdata,thetotalnumberoffarmsengaginginferalcatcontrolinAustralia2017-18is6,165(=88,073*0.07).Togetthefinalnumberforprojections(n=5,602),wedeductedthenumberoffarmerswhorespondedtooursurveys(563).

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a

b

Figure6.Posteriordistributionsand95%credibleintervalsofa)themeanareamanagedforferalcatcontrolbyfarmerswhoengageinferalcatcontrolandrespondedtooursurvey,andb)theprojectedtotalareamanagedforferalcontrolbyfarmerswhoengageinferalcatcontrolbutdidnotrespondtooursurvey.

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Overviewofqualitativeresultsforthestrategicsurvey

Thissectionprovidesanevaluationofthequalitativeresultsofthestrategicsurveyforindividuals.Anoutlineofresponsestoeachquestion(excludingtextresponses)withfiguresisprovidedatAppendixF.Respondentswerenotrequiredtoanswereachquestion,whichresultsinsomemissingdata.

Outlinedmorefullybelow,thefollowingkeypointsarisefromthisdata.

• Thecontributionsthatindividualsmaketothenationalferalcatmanagementeffortaremostlyunrecorded.

• Themostcommonmethodofremovingferalcatswasshooting.• Mostrespondentswhoremovecatsfromtheenvironment:

o havebeendoingsoformorethan10years;o havenotchangedtheireffortsovertime;o experiencelittlevariabilityinthenumberofcatstheyremoveeachyear;ando removeferalcatsbecausetheyareconcernedforwildlife;

• Amongstrespondentsnotinvolvedinremovingferalcats,themajorityarenotopposedtoremovingferalcatsfromtheenvironment.

• AmajorityofrespondentswhoidentifiedasTraditionalOwnersandwhowerenotinvolvedinferalcatmanagementwereopposedtoremovingferalcatsfromtheenvironment.

• Respondents:o agreedthatferalcatsarebadforwildlifeandcauseadeclineinnativespecies;o disagreedthatasapredator,feralcatsplayanimportantroleinfoodchains;

ando disagreedthatferalcatshavearighttoexistwherevertheyareandwhatever

impacttheyhave.• Thereislimitedawarenessofthethreatsthatferalcatspose:

o tolivestock;o inspreadingdiseasetohumans;ando forharassingandinjuringdomesticcats.

• Veryfewrespondentsindicatedthattheywerenotatallwillingtocontributetoferalcatmanagement.

• However,amongstrespondentscurrentlyinvolvedinferalcatmanagementornotinvolvedandnotopposed,mostindicatedanunwillingnesstoincreasetheircurrentefforts,despitetheirsupportforarangeofmeasurestoencouragethiseffort,anddespitetheirindicatedcapacitytoincreaseefforts.

• AlittlemorethanhalfofrespondentswereawarethatAustraliahasaThreatenedSpeciesCommissioner,butmostdonotfollowheronsocialmedia.

• Therewasabroadagreementfromrespondentsthatarangeoflistedstakeholderssharedsomeresponsibilityforferalcatmanagement.

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• Thejointresponsibilityframewasmoreeffectiveatpromotingferalcatmanagementasasharedresponsibility,butthiseffectissmall.

• Keythemesofthoserespondentsopposedtoremovingferalcatsfromtheenvironmentincluded:

o ethicalreasons,avoidingcrueltyandotherharm;o scepticismthatcatswereasdamagingtotheenvironmentandtonative

speciesashasbeenreported;o scepticismaboutthebenefitstotheenvironmentandnativespeciesof

removingcats;o preferencefornon-lethalmethodsofcontrol;ando thepotentialforincreasedabundanceofmice,rabbitsandotherpestsifcats

areremoved.

Whoparticipated?

Thestrategicsurveywascompletedby4812uniquerespondentswhoseageswerewellspreadacrossallagecategories,with‘55+’beingthelargestsinglecategory.Interestingly,thevastmajorityofrespondentsdidnotparticipateinthepreviousstrategicsurveyin2016(86%).

Respondentsself-identifiedintoanumberofcategories.Excluding‘others’(26%),huntersandsportingshooters(25%),ecologists/conservationists(15%)andfarmers(14%)weremostwellrepresentedandTraditionalOwnersweretheleastrepresented(3%).Sportingshooters/hunters(41%)andfarmers(22%)werethegroupswithmostrespondentsinvolvedinferalcatmanagement(Figure1,above).Althoughthe‘other’categoryappearsratherlarge,themajorityofthesewererespondentswhowerenotinvolvedinferalcatcontrol(72%).

Individualsaremakingun-recordedcontributionstothenationaleffort

Ofthoserespondentswhoareinvolvedinferalcatcontrol(i.e.thosewhoindicatedthattheyeitheractivelyremoveferalcats,sometimesremoveferalcatsorsometimesremoveferalcatsasaby-productofotheractivities),thevastmajority(92%)donotrecordtheiractivitieswithanyotherbody.Thisconfirmsthatmanyindividuals,particularlysportingshooters,huntersandfarmersaremakingun-recordedcontributionstothenationalferalcatcontroleffort.

Methodsforremovingferalcatsfromtheenvironment

Themostcommonmethodforremovingferalcatswasshooting(72%)withtrappingandshootingnextmostcommon(31%)followedbytrappingandtakingtoafacilityforeuthanasia(15%)andbaitingleastcommon(6%).Sixpercentofrespondentsindicatedthattheyusedotherhumanemethods.

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Changeovertime

Themajorityofrespondentswhoareinvolvedinferalcatmanagementindicatedthattheyhavebeenremovingferalcatsformorethanfiveyears(69%)andmorethanhalfforlongerthan10years(52%).Most(76%)indicatedthattheireffortshavenotchangedsincetheybeganremovingferalcats.Givenalsothatonly16%indicatedthattheyhavebegunremovingcatsinthelast2years,thisindicatesthatthemajorityofthisefforthasbeenundertakenformanyyearsandhasnotcomeaboutspecificallyinresponsetothecurrentfocusoncontrolofferalcatsbytheAustralianGovernment.

Overall,respondentsindicatedthatthevariabilityinthenumberofcatsremovedfromyeartoyearissmall.Although26%indicatedthatforthemthisdoesvaryagreatdeal,74%indicatedthatitisaboutthesameorwithonlyalittlevariabilityfromyeartoyear.

Respondents’observedchangesresultingfromremovingferalcats

Respondentsreportedarangeofchanges,themostcommonbeing:

• Lessferalcats(28%);• Nochanges(27%);• Anincreaseinnativewildlife(27%);• Lessdeadwildlife(25%);and• Feralcatnumbersremainedthesame(24%).

Itisdifficultfromthistodeterminehoweffectiveindividualsperceivetheirferalcatmanagementeffortstobe.However,onlyveryfewrespondentsindicatedthattheyhadobservedtheadverseeffectsofincreasedfoxnumbers(7%)orgreaterabundanceofmiceand/orrabbits(6%).

Whydoindividualsremoveferalcats?

Byfarthemostcommonreasonsforremovingferalcatsreportedbyrespondentswasthattheywereconcernedforwildlife(87%)andbecauseferalcatsarepests(67%).Onlyaveryfewrespondentsindicatedthattheremovedferalcatsbecausetheyadverselyaffectedtheirlivelihood(5%).

Thissuggeststhatmostpeoplewhoareinvolvedinferalcatmanagementareinvolvedbecausetheyhaveanintrinsiccarefornature,andnotbecausetheydirectlybenefitfromtheirinvolvement.Thisintrinsiccarecouldbefurtherfosteredthroughinformationcampaignsdesignedtopromoteferalcatmanagement.Onacautionarynote,crowding-outtheseintrinsicmotivationsispossiblethroughthepromotionofextrinsicmotivations,forexamplebypromotingtheeconomicbenefitsofferalcatcontrolorthroughpoliciesthatwouldprovidefinancialincentives(seeforexampleFreyandJegen2001andKusmanoff2017).

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Attitudestowardsferalcatmanagement

Thequestion“Whatisyourviewaboutremovingferalcatsfromtheenvironment?”wasansweredby2073peoplewhowerenotinvolvedinremovingferalcats.Aclearmajorityof75%oftheserespondentsindicatedthattheywere‘notopposed’and21%wereopposed(thisquestionwasframedinthiswayinanefforttoidentifythosewhowereclearlyopposedandnotsimplywaveringin‘support’forremovingferalcatsfromtheenvironment).Itshouldbenotedofcoursethatthissurveywasintendedprimarilytocapturedatafromthosepeoplemostlikelytobeinvolvedinferalcatmanagement,andassuchthisshouldnotbetakenasindicativeoftheattitudesofthebroaderpopulation.

Ifweexaminetheresponsestothisquestionbyself-allocatedidentity,itisinterestingthatTraditionalOwnersaremuchmoreevenlysplit,andwithamajorityof51%whoareopposedand41%notopposed(Figure7).GiventherolethatTraditionalOwnersandIndigenouscommunitiesplay(orhavethepotentialtoplay)inferalcatmanagement,itwouldbeinterestingtofurtherunderstandthisresult.

Figure7.Percentageofrespondents(inself-allocateddescriptions)notinvolvedinferalcatmanagementwhoareopposed,notopposed,orhavenostrongopinionabouttheremovalofferalcatsfromtheenvironment(n=2073).

0

10

20

30

40

50

60

70

80

90

100

Iamnotopposedtotheremovalofferalcatsfromtheenvironment

Iamopposedtotheremovalofferalcatsfromtheenvironment

Ihavenostrongopinionabouttheremovalofferalcatsfromtheenvironment

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Keythemesinoppositiontoferalcatmanagement

Thoserespondentswhoindicatedthattheywereopposedtoremovingferalcatsfromtheenvironmentwerethenaskedtolistthemostimportantreasonswhytheydidnotsupportremovalofferalcatsfromtheenvironment;405respondentsprovidedreasons.Asummaryexaminationofthesesuggeststhatthekeyreasonstendtorelatetothefollowingkeythemes:

• Forethicalreasons,includingtoavoidinflictingcrueltyandotherharms;• Beingdoubtfulthatcatsaretheenvironmentalproblemthattheyarerepresentedto

be;• Becauseremovingferalcatswillnotbeeffectiveinachievingconservationoutcomes,

includingthatthereareotherfactorsthatshouldbeahigherpriority;• Thatnon-lethalmechanisms(e.g.trap-neuter-release)shouldbepreferredon

groundsofethicsandefficacy;and• Thepotentialofincreasedabundanceofmice,rabbitsandotherpestsifcatsare

removed.

Beliefsaboutferalcats

Allparticipantswereaskedthedegreetowhichtheyagreedwithanumberofstatementsaboutferalcats.Someofthesestatementseschewedabroadagreementordisagreementfromrespondents,whilstotherselicitednoclearview.Understandingthedegreetowhichthesebeliefsareheldmaybehelpfulindesigningfutureinformationcampaignsaboutferalcatmanagement.

Astrongmajorityofrespondents:

• agreedwiththestatementFeralcatsarebadforwildlifeandcauseadeclineinnativespecies(88%),and

• disagreedwiththestatementso Feralcatshavearighttoexistwherevertheyareandwhateverimpactthey

have(87%),ando Asapredator,feralcatsplayanimportantroleinfoodchains(70%).

Thisindicatesthatamongstthoseatwhomthesurveywastargeted,itiswellacceptedthatferalcatsareaproblemforwildlife,andthatinlightofthistheyshouldnotenjoyanintrinsicrighttoexistinthewild.

Abouthalfofrespondentsagreedwiththestatements:

• Feralcatsareathreattolivestock(47%);• Feralcatscanbedangerousandspreaddiseasetohumans(54%);and• Feralcatsharassandinjuredomesticcats(54%).

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Thissuggeststhatalthoughthereissomeawarenessofthesemattersamongstthetargetedaudience,theremaybevalueforfuturecampaignstoemphasisethesepoints.

Respondentsgavemixedresponsestothestatement:

• Feralcatskeepnumbersofmiceandrabbitsdown(35%disagreed,26%neitheragreednordisagreedand39%agreed).

Encouraginggreaterparticipationinferalcatmanagement

Allparticipantswereasked,inresponsetoanumberofstatements,thedegreetowhichtheyagreedthatthesewouldmakethemmorelikelytobeginorincreasetheireffortstoremoveferalcats.Althoughthisquestionwaspresentedtoallrespondents,itmakessensetoexaminetheseresultsforthoserespondentswhoindicatedthattheyarenotopposedtoferalcatmanagement(i.e.byexcludingtheresponsesofthosewhoindicatedtheyareopposedtotheremovalofferalcatsfromtheenvironment).AsummaryoftheseresultsareprovidedinAppendixGandaresummarisedbelow.

Respondentsindicatedmoretotalagreement(i.e.‘stronglyagree’plus‘somewhatagree’)thantotaldisagreementforallofthesuggestedmeasurestoencourageorfacilitateparticipationinferalcatmanagement;inthefollowingorderofgreatestagreement:

• Iflawstoenforceferalcatcontrolwereintroduced(75%totalagreement);• Iftherewasmoreinformationavailableonthevariousmethodstocontrolferalcats

(69%);• Iftherewasmoreinformationabouthowferalcatcontroleffortshelpprotectwildlife

(69%)• Iftherewasanincreaseinthepublicacceptanceofferalcatremoval(69%);• Iftherewasmoreinformationonthepositivesofcatcontrol(66%);• Ifitwereeasiertorentorborrowtraps(65%);• Ifareimbursementfeewasavailable(58%);• Ifitwereeasiertogetapermit(55%);• Trainingonhowtodoitinahumaneway(54%);and• Ifitwereeasiertoaccessbaits(46%,comparedto23%totaldisagreement).

Despiterespondents’agreementthatmanyofthesemeasureswouldencouragetheirincreasedparticipationinferalcatmanagement,75%agreedthat“nothingwouldencouragemetobeginorincreaseeffortstocontrolferalcats”,despiteonly34%agreeingthatthey‘currentlyhavenocapacitytoincreasetheireffortstocontrolferalcats’.Thissuggeststhatwhilesomeofthesemeasuresmayprovidesomebenefittofacilitatingparticipationinferalcatmanagement,thereislikelysomeotherbarriertoparticipationthathasnotbeenidentifiedhere.

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AwarenessoftheThreatenedSpeciesCommissioner

AlittlemorethanhalfofrespondentswereawarethatAustraliahasaThreatenedSpeciesCommissioner(58%),althoughmostdonotfollowheronsocialmedia(73%).Figure8showsawarenessoftheCommissionerbyself-assignedidentity.Notsurprisingly,awarenessoftheCommissionerisgreatestamongstecologistsandconservationists(83%).However,awarenessislowestamongstthosegroupswhoseindividualeffortscollectivelymakeupmuchoftheunreportednationalferalcatmanagementefforts,hunters(44%),shooters(41%)andfarmers(37%).Giventhatmostrespondentswhoareinvolvedinferalcatmanagementindicatethattheydosoforconservationreasons,informationcampaignsaboutferalcatmanagementmayprovideanopportunitytoincreaseawarenessoftheroleoftheThreatenedSpeciesCommissioneramongstthesegroups.

Figure8.Percentageofrespondents(inself-allocateddescriptions)whoareawarethatAustraliahasaThreatenedSpeciesCommissioner(n=4767).

0

10

20

30

40

50

60

70

80

90

100

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Responsibilityforferalcatmanagement,willingnesstocontributeandmessagingeffects

Inexaminingparticipants’perceptionsofwhohasresponsibilityforferalcatmanagementandtheirwillingnesstocontributetoferalcatmanagement,wesoughtalsototesthowdifferentlyframedmessagesmightaffectthis.Thisinvolvedparticipantsbeingrandomlyassignedoneofthreeslightlydifferentversionsofthesurvey.Immediatelybeforequestion34,participantsreceivedeither:

• astatementfromtheThreatenedSpeciesCommissioneraboutferalcatmanagementthatemphasisedactionsundertakenbytheAustralianGovernment(n=1512);or

• astatementfromtheThreatenedSpeciesCommissioneraboutferalcatmanagementthatthatemphasisedsharedactionsandjointresponsibility(n=1557);or

• nostatementatall(i.e.acontrolcondition)(n=1743).

Itiswellestablishedthathowinformationisframedcaninfluencehowpeopleinterpretandrespondtothatinformation(e.g.Entman1993),andwewerecurioustounderstandwhetheranemphasisonactionsundertakenbyoneofthekeystakeholdersinferalcatmanagement(theAustralianGovernment)mightinfluencewiderperceptionsofwhereresponsibilityoughttolay,ortoinfluencethewillingnessofindividualstocontributetoferalcatmanagement.

Respondents’opinionsofwhoisresponsibleforferalcatmanagementisshowninFigure9.Onthewhole,thereisbroadagreementthatallofthelistedstakeholderswereresponsible,although,interestingly,conservationorganisationswerethestakeholdergroupthatfewestrespondentsthoughthadsomeresponsibility.

Bycalculating95%confidenceintervals,wecanunderstandthedegreetowhichthedifferencesbetweeneachframearemeaningful.Wherethereisalargeoverlap,thedifferencesarelikelytobenoiseinthedata,andwherethereislittleornooverlap,thesedifferencesarelikelytorepresent‘real’differences.Itisclearthatanyeffectsduetotheframestestedaresmall.However,wecanseethatthejointresponsibilityframe,tovaryingdegrees,ismoreeffectiveatpromotingtheresponsibilityofallstakeholders(Figure9).Inparticular,thisframeisbetterthanboththeAustralianGovernmentemphasisframeandthecontrolframeatpromotingtheopinionthatresponsibilitylieswithcatownersandmembersofthepublic.TheAustralianGovernmentemphasisframeisslightlymoreeffectiveinmostcasesthanthecontrolandisthemosteffectiveframeatpromotingtheopinionthatferalcatcontrolistheresponsibilityoftheAustralianGovernment.

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Inyouropinion,whoisresponsibleforferalcatmanagement(selectallthatapply)

Figure9.Percentageofrespondentsoftheviewthateachstakeholderisresponsibleforferalactmanagement,forthejointresponsibilityframe(blue;n=1557),theAustralianGovernmentframe(red;n=1512)andthecontrol(green;n=1743).Errorbarsare95%confidenceintervals.

Wecanalsoobservesmallframingeffectsonrespondents’willingnesstocontributetoferalcatmanagement(Figure10).Onlyaveryfewrespondentsineachframewereunwillingtoparticipateinferalcatmanagement,withnodifferencebetweentheframes.However,bothnon-controlframesweremoreeffectiveatgeneratingresponsesof‘I’mveryinterestedincontributingtoferalcatcontrol’thanwasprovidingnostatement(i.e.thecontrol),withthejointresponsibilityframeslightlymoreeffectivethantheAustralianGovernmentEmphasisframe.Thereisalsoacuriousresultdemonstratedinresponsesof‘yesI’dbewillingifitwasrelevantandconvenienttome’;sayingnothingatallismoreeffectiveatelicitingthisresponsethaneitherofthetworesponsibility-framedstatements(Figure10).Furtherinvestigationofthiseffectmaybenefitfutureengagementcampaigns.

0

10

20

30

40

50

60

70

80

90

100 Jointresponsibility AusGovfocus Control

35

Howwillingareyoutocontributetoferalcatmanagement?

Figure10.Percentageofrespondentswillingnesstocontributetoferalcatmanagement,forthejointresponsibilityframe(blue;n=1548),theAustralianGovernmentframe(red;n=1509)andthecontrol(green;n=1724).Errorbarsare95%confidenceintervals.

NodisadvantageinusinganAustralianGovernmentemphasisframe

AlthoughtherearedetectableframingeffectsarisingbetweenthesharedresponsibilityframeandtheAustralianGovernmentemphasisframe,thesearesmallandthereappearstobenoparticulardisadvantageinuseanAustralianGovernmentemphasisframetopromoteferalcatmanagement.

0

10

20

30

40

50

60

notatall willing,ifrelevantandconvenient

veryinterested alreadyinvolved

Jointresponsibility AusGovfocus Control

36

Concludingremarks

ThisresearchprojectassessesprogresstowardsachievingthetargetarticulatedintheThreatenedSpeciesStrategyof2millionferalcatsculledby2020(AustralianGovernment2015).WehaveprovidedplausibleestimatesofthenumbersofferalcatsbeingremovedacrossAustraliabyusingacombinationofdatasourcesincludingknowndatarepositories,reportsfromAustralianGovernmentprograms,andstrategicsurveysofbothindividualsandorganisationslikelytohaveinvolvementinferalcatmanagement.

• Weestimatethatinthe2017-18financialyear,theapproximatenumberofferalcatsremovedfromtheenvironmentacrossAustraliawas316,859,withplausibleboundsbetween298,571and335,147.

• Thesurveyalsoindicatedthattheeffortofprivateindividualsdidnotchangesubstantiallybetween2016-17and2017-18.Combinedwithdatafromrepositoriesandorganisations,thisallowsustoestimatethenumberofferalcatsremovedin2016-17at316,188withplausibleboundsof297,891to334,485.

• Ourpreviousassessmentfor2015-16estimatedtheremovalof211,560feralcats,withplausibleboundsbetween135,522and287,598.

Together,thisgivesacumulativeestimatefortheperiod2015-18of844,607feralcats,withplausibleboundsbetween764,289and924,925.

Wehavealsosoughttoprovideanestimateofthetotaluniqueareamanagedforferalcatcontrolin2017-18.Weestimatethat18,934,994hectaresofuniqueareaweremanagedforferalcatcontrolinAustraliain2017-18,withplausibleboundsbetween16,437553and21,948,005ha.

Howreliablearetheseresults?

Giventhediverseandfragmentednatureofthedatathatthisreportrelieson,manyassumptionswererequiredtoarriveattheestimateofnationalferalcatcontroleffort,andthereweremanysourcesofuncertainty.Importantly,wewereconservativeinourextrapolationsfromharddatatomitigatethepotentialforover-estimation.Forexample,wereliedonthelowerboundofestimatedrangesprovidedinthestrategicsurvey.Byconsistentlymakingconservativeassumptions,weareconfidentthattheestimatesreportedhererepresentareliableminimumestimate.

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Howcouldweimprovereliability?

Keyuncertaintiesinthisstudystemfromthelackofsystematicdatacollectionandreporting,andthedifficultyinidentifying,samplingandprojectingtothekeypopulationscontributingtoferalcatcontrol.Thisthereforenecessitatesthemakingofassumptions.

Ourprojectionsfromsurveydatareliedonaseriesofassumptionsaboutthenumberofshooters,huntersandfarmersengaginginferalcatcontrolandtheproportionwhoarecurrentlyreportingtheireffortsthroughofficialchannels.Becauseshootersandhuntersmakethelargestcontributionofanysinglegroup,updatedinformationabouttheiractivitieswerethechiefcomponentintheincreasedestimatein2017-18from2015-16;wereliedoninformationprovidedbytheSportingShootersAssociationofAustralia,informedbysurveysofitsownmembership.Thisinformationhasbeeninvaluable;however,itisstillassociatedwithvariousformsofuncertainty.Anincreasedunderstandingofhowshootersandhuntersengageinferalcatcontrolwillallowfutureestimatestobemadewithgreatercertainty.

Withrespecttoestimatingtheuniqueareamanagedforferalcatcontrol,asnoted,thisisinherentlydifficultwithoutspatiallyexplicitdatafromindividualsandgroupscontributingtothenationalferalcatcontroleffort.Thisinformationcouldnotbecollectedinthissurvey,owingtosensitivitiesregardingthelegalstatusofcatcontrolinVictoria.However,recentlegislativechangesmaymakethisinformationeasiertocollectinfutureyears.

ProgresstowardsThreatenedSpeciesStrategytargets

TheplausibleestimatesuggeststhatgoodprogresshasbeenmadetowardstheferalcatcontroltargetarticulatedintheThreatenedSpeciesStrategy.AstheoverallgoaloftheStrategyistoprotectthreatenedspecies,continuousimprovementsinunderstandinghowferalcatremovalimpactsferalcatpopulationsandhowthisultimatelyeffectsthreatenedspeciespopulationsarenecessarytoinformeffectivepolicyinthisspace.Currently,wedon’thaveadequateinformationregardingthespecificlocationofferalcatcontroleffort.Thiscouldhavemajorimplicationsfortheeffectivetargetingofresourcestowardscatcontrolthatdirectlybenefitsthreatenedspecies.

Acknowledgements

Wewouldliketoacknowledgeandthankthecooperationofnumerousorgansiationswhohaveprovideddataandpromotedoursurveys.Theseparticularlyincludeallindividualsandorganisationswhorespondedtothesurvey,staffwithintheOfficeoftheThreatenedSpeciesCommissioner,membersoftheFeralCatTaskforce,DrFreyaThomasofICONScience,MatthewGodsonandtheSportingShooters’AssociationofAustralia,DrNyreeStenekesandABARES,DrBiddaJonesandtheRSPCA,PeterWest,NSWDepartmentofPrimaryIndustries,RichardFaulknerandStuartMurphyfromPhillipIslandNatureParks,andAssociateProfessorSarahLegge,NationalEnvironmentalScienceProgramThreatenedSpeciesRecoveryHub.

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References

AustralianBureauofStatistics(ABS)2016.1270.0.55.003–AustralianStatisticalGeographyStandard(AGSG):Volume3–NonABSStructures.AustralianBureauofStatistics.

AustralianBureauofStatistics(ABS)2018.71210DO005_201617AgriculturalCommodities,Australia–2016-17.AustralianBureauofStatistics.

AustralianGovernment2015,ThreatenedSpeciesStrategy.AustralianGovernmentDepartmentoftheEnvironment,Canberra.

AustralianGovernment2018,FrequentlyAskedQuestionsTacklingFeralCatsandTheirImpacts.AustralianGovernmentDepartmentofEnvironmentandEnergyathttps://www.environment.gov.au/system/files/resources/bb591b82-1699-4660-8e75-6f5612b21d5f/files/factsheet-tackling-feral-cats-and-their-impacts-faqs.pdf(May2018).

BolkerBM(2008)EcologicalModelsandDatainR.PrincetonUniversityPress,Princeton,NJ,USA.

EntmanR(1993),Framing:towardsaclarificationofafracturedparadigm.JournalofCommunication,43:51-58.

FreyBSandJege,R(2001),Motivationcrowdingtheory.JournalofEconomicSurveys,15:589-611.

GarrardGE,FaulknerR,MataL,TorabiN,PetersonI,GordonAandBekessySA(2017),Anassessmentofthenationalefforttowardsferalcatcontrol,RMITUniversity,Melbourne,Australia

GarrardGE,BekessySA,McCarthyMAandWintleBA(2008),Whenhavewelookedhardenough?Anovelmethodforsettingminimumsurveyeffortprotocolsforflorasurveys.AustralEcology,33:986-998.

KusmanoffAM(2017),FramingtheConservationConversation:Aninvestigationintoframingtechniquesforcommunicatingbiodiversityconservation.PhDthesis,RMITUniversitypp.45-60.https://researchbank.rmit.edu.au/view/rmit:162021

LimpertE,StahelWA,AbbtM(2001)Log-normaldistributionsacrossthesciences:keysandclues.Bioscience,51:341-352.

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McCarthyMA(2007)BayesianMethodsforEcology.CambridgeUniversityPress,Cambridge,UK.

MacKenzie,DI(2006).Occupancyestimationandmodeling:inferringpatternsanddynamicsofspeciesoccurrence.AcademicPress.

PlummerM(2003)JAGS:AprogramforanalysisofBayesiangraphicalmodelsusingGibbssampling.http://mcmc-jags.sourceforge.net/.

PlummerM(2016).rjags:BayesianGraphicalModelsusingMCMC.Rpackageversion4-6.https://CRAN.R-project.org/package=rjags.

RCoreTeam(2018).R:Alanguageandenvironmentforstatisticalcomputing.RFoundationforStatisticalComputing,Vienna,Austria.https://www.R-project.org/.

SpiegelhalterDJ,BestNG,CarlinBP&VanDerLindeA(2002),Bayesianmeasuresofmodelcomplexityandfit.JournaloftheRoyalStatisticalSociety:SeriesB(StatisticalMethodology),64:583-639.doi:10.1111/1467-9868.00353

StenekesN,KancansR&BinksB(2017)PestanimalandWeedManagementSurvey:Nationallandholdersurveyresults,ABARESresearchreport17.5,May.CCBY4.0.

WoinarskiJC,LeggeS,FitzsimonsJA,TraillBJ,BurbidgeAA,FisherA,FirthRS,GordonIJ,GriffithsAD,JohnsonCNandMcKenzieNL(2011)ThedisappearingmammalfaunaofnorthernAustralia:context,cause,andresponse.ConservationLetters,4:192-201.

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AppendixA–Outlineof2018strategiconlinesurveyfororganisations

NATIONALFERALCATCONTROLSURVEY

YourorganisationisinvitedtoparticipateinasurveyaboutferalcatcontrolinAustralia.TheinformationprovidedinthissurveywillhelpgenerateabetterunderstandingofferalcatmanagementinAustralia,includinghowtomakeimprovements.ThissurveyisbeingconductedbyDrAlexKusmanoff,DrGeorgiaGarrardandProfessorSarahBekessyatRMITUniversity(contactdetailsareprovidedbelow).ThisprojectisfundedbytheAustralianGovernment.Bycompletingthissurvey,youarehelpinguscollectthehighestqualitydatainaconsistentmanner.However,ifyouwouldprefertoprovidedatadirectly,ratherthanthroughthissurvey,youcansendittoalex.kusmanoff@rmit.edu.auWhatistheprojectabout?TheaimofthisprojectistodeterminetheextenttowhichferalcatcontrolisoccurringacrossAustralia,andtoestimatethenumberofferalcatsthatareremovedfromtheenvironmenteachyear.Thisprojectalsoseekstounderstandhoweffortstocontrolferalcatsarechangingovertime.PreviousresearchhashighlightedthesignificantcontributionthatorganisationsmaketoferalcatcontrolandthreatenedspeciesconservationinAustralia.Weareinterestedtoknowaboutyourorganisation'sactivitiesrelatedtoferalcatcontrol.Wewouldlikeyourorganisationtocompletethissurveyevenifitdoesnotactivelyparticipateinferalcatcontrol.Wewouldalsolikeyourorganisationtocompletethissurveyevenifitreportedthisinformationinthesamesurveyconductedin2016.Tounderstandthenationaleffortsaroundferalcatcontrol,itiscriticalthatwereceiveupdatedinformationfromorganisationsabouttheirferalcatcontrolactivities,includingwheretheyarenotinvolved.Tocompletethesurvey,pleaseensurethatyouhavethepermissionofyourorganisationtoprovidetheinformation,andthatonlyonepersonfromyourorganisationcompletesthesurvey.Beforestartingthesurvey,youshouldmakesurethatyouhaveavailabletoyousummaryinformationabouttheferalcatcontroleffortsofyourorganisation,including,ifpossible,estimatesofthenumberofferalcatskilledinthe2016-17and2017-18financialyears.Approximations,includingranges,areacceptable.

41

Pleasetryandanswerallthequestions.Ifyouareunabletoansweraquestion,pleaseleaveitblankandmovetothenextquestion.Itisimportantthatyougototheendofthesurveytoensurethatyouranswersarerecorded,evenifyouleavesomequestionsunanswered.Ifyou'dratherdiscussthisonthephoneorsendanemail,youmaycontactDrAlexKusmanoffon(03)99259944alex.kusmanoff@rmit.edu.au

ThissurveywillbeopenuntilWednesday22August.Whatwillhappentotheinformationtheorganisationprovides?Responsestothesurveyquestionswillbecollatedandstoredinaspreadsheet,beforebeinganalysed.Resultswillbepresentedinaresearchreportandmayalsobepublishedinacademicjournalsandpresentedatacademicconferences.Yourorganisationmayremainanonymousifpreferred.Oncewehavecompletedourdatacollectionandanalysis,datawillbestoredsecurelyontheRMITserverforfive(5)yearsbeforebeingdestroyed.Followingyourparticipation,youmaycontactAlex(alex.kusmanoff@rmit.edu.au)orGeorgia(georgia.garrard@rmit.edu.au)toobtainasummaryoftheresults(expectedtobeavailableinlate2018).WhomshouldIcontactifIhaveanyquestions?Ifyouhaveanyquestionsaboutyourparticipation,pleasecontactDrAlexKusmanoffon(03)99259944oralex.kusmanoff@rmit.edu.au.

Investigators:

• ProfessorSarahBekessy,SchoolofGlobal,UrbanandSocialStudiesRMITUniversity(03)99251858sarah.bekessy@rmit.edu.au

• DrGeorgiaGarrard,SchoolofGlobal,UrbanandSocialStudiesRMITUniversity(03)99259986georgia.garrard@rmit.edu.au

• DrAlexKusmanoff,SchoolofGlobal,UrbanandSocialStudiesRMITUniversity(03)99259944alex.kusmanoff@rmit.edu.au

42

Q1Whatisthenameoftheorganisationforwhichyouarecompletingthissurvey?

m Organisationname:________________________________________________

m Prefernottosay

Q2Whatisthenatureofyourorganisation?

m Localorregionalcouncil

m Sportingshootersassociation

m Farmersassociation

m Conservationorganisation

m IndigenousProtectedAreaorindigenousrangergroupadministration

m Communitygroup

m Scientificinstitution

m Other(pleasespecify)________________________________________________

Forthepurposesofthissurvey,feralcatsaredefinedas"catsthatliveinthewildandcansurvivewithouthumanrelianceorcontact".

Q3Doesyourorganisationremoveferalcatsfromtheenvironment?

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By'remove'wemeankillonsite,catchandtaketoanotherlocationforeuthanasiabyyouorsomebodyelse,orreceiveferalcatsfromotherpartiesandeuthanize.

m Yes,weactivelyremoveferalcats(note:thiscanincludecontractingthirdparties)

m Yes,wefacilitateindividualsremovingferalcatsfromtheareaswemanage

m Yes,wesometimesremoveferalcatsasaby-productofotheractivities

m No(pleaseskipstraighttoQ17onpage9)

Q4Doesyourorganisationrecorditseffortsandprovidethemtoanorganisationorregionaldatabase?(e.g.uploadtowww.feralscan.org.au,orwithlocalcouncil,NaturalResourceManagementorganisations,CatchmentManagementAuthorities,etc.)

m No,theorganisation'seffortsarenotrecorded

m Yes,theorganisation'seffortsarerecorded(pleasespecifywherethisisrecorded)________________________________________________

Note:Ifyouareunabletocompletethesurvey,youmaysendyourdatatoalex.kusmanoff@rmit.edu.au

Q5Howdoesyourorganisationremoveferalcatsfromtheenvironment(selectallthatapply)

q Shoot

q Trapandthenshootonsite

q Trapandthentaketoafacilityforeuthanasia

q Bait

q Otherhumanemethod(pleasespecify)_________________________________

Q6Howlonghasyourorganisationbeenremovingferalcats?

m 1yearorless

m Forthelast2years

m Forthelast2-5years

m Forthelast5-10years

m Forthelast10-20years

m Formorethan20years

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Q7Howmanycatsdidyourorganisationremoveinthe2017-18financialyear?

m 1-5

m 5-10

m 10-20

m 20-30

m 30-40

m 40-50

m 50-75

m 75-100

m 100-200

m >200

m Weknowexactlyhowmany(pleaseprovidenumber)_____________________

Q8Howmanycatsdidyourorganisationremoveinthe2016-17financialyear?

m Aboutthesameas2017-18

m 1-5

m 5-10

m 10-20

m 20-30

m 30-40

m 40-50

m 50-75

m 75-100

m 100-200

m >200

m Weknowexactlyhowmany(pleaseprovidenumber)___________________

Q9Howvariablefromyeartoyearisthetotalnumberofferalcatsthatyourorganisationremoves?

m Aboutthesameeachyear

m Itvariesalittle

m Itvariesagreatdeal

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Q10Approximatelywhatareadoesyourorganisationcoverinitsferalcatremoval?

m Lessthan10Ha

m 10-50Ha

m 50-100Ha

m 100-1000Ha

m 1000-10000Ha

m 10000-50000Ha

m 50000-100000Ha

m >100000Ha

m Weknowexactly(pleasespecify)__________________________

m Don'tknow

Q11Howmuchtime(personhourspermonth)doestheorganisationspendremovingferalcats?

m 0-3Hrs

m 3-5Hrs

m 5-10Hrs

m 10-20Hrs

m 20-40Hrs

m 40-60Hrs

m 60-80Hrs

m >80Hrs

m Weknowexactlyhowmanyhours(pleasespecify)_________________Q12Whydoesyourorganisationremoveferalcats?(listallthatapply)

q Theyareapest

q Theyadverselyaffectthelivelihoodoftheorganisationand/oritsmembers

q Weareconcernedaboutwildlifeandthisisonewaywecanhelp

q Itispartoftheorganisation'srole

q Removingferalcatsisacomponentofourconservationmanagementprogram

q It'sjustsomethingthattheorganisationhasalwaysdone

q Other(pleasespecify)_____________________________________________

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Q13Whatchangeshasyourorganisationobservedasaresultofremovingferalcats?(selectallthatapply)

q Therearelessferalcats

q Feralcatnumbershaveincreased

q Feralcatnumbershaveremainedaboutthesame

q Thereisanincreaseinnativewildlife

q Lessdeadwildlife(birds,lizards,etc.)

q Therearemoremiceand/orrabbits

q Foxnumbershaveincreased

q Nochangeshavebeenobserved

q Other(pleasedescribe)________________________________________

Q14Isyourorganisationachievingwhatyouhopedforbyremovingferalcats?

m Yes

m No

Q15Pleasebrieflyexplainyouranswerabove

________________________________________________________________

Q16Overthepastthreeyears(since2015),hasyourorganisation'sferalcatremovaleffortalwaysbeenaboutthesame,orhasitincreasedordecreasedoverthistime?

m Aboutthesame

m Effortshaveincreased

m Effortshavedecreased

m Idon'tknow

Q17Doyouhaveanyothercommentsorsuggestionsthatyoubelievewouldbehelpfulinfurthermanagingferalcats?

________________________________________________________________

Thankyoufortakingthetimetocompletethissurveyonbehalfofyourorganisation.Theinformationprovidedwillbeinvaluableinhelpingusbetterunderstandthenational

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efforttowardsferalcatcontrol.Ifyouhaveanyquestionsorconcernsregardingthesurvey,ornoticedanyproblems,pleaseemailAlexatalex.kusmanoff@rmit.edu.au

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AppendixB–Listoforganisations

Thefollowingisalistoforganisationswhichprovidedtheirnameintheonlinestrategicsurvey.Notallorganisationswereinvolvedinferalcatmanagementandnumerousotherorganisationschosetoremainanonymous.

Organisationname NatureoforganisationNaturalResources,SAAridLands,SADept.Env.&Water

Other

AdelaideHillsCouncil LocalorregionalcouncilAdoptARescue OtherAlexandrinaCouncil LocalorregionalcouncilAlpineShireCouncil LocalorregionalcouncilAnimalManagementinRuralandRemoteIndigenousCommunities

Other

AnimalPestManagementServices OtherAnimalRehomingTablelands OtherAraratRuralCityCouncil LocalorregionalcouncilArkabaConservancy ConservationorganisationAustraliaWideEnvironmentalConsultants OtherAustralianPetWelfareFoundation ScientificinstitutionBananaShireCouncil LocalorregionalcouncilBANJUPANIMALRESCUE OtherBarcooShireCouncil LocalorregionalcouncilBarungaWestCouncil LocalorregionalcouncilBassCoastShireCouncil LocalorregionalcouncilBaysideCouncil LocalorregionalcouncilBegaValleyshireCouncil LocalorregionalcouncilBenallaRuralCityCouncil LocalorregionalcouncilBerriBarmeraCouncil LocalorregionalcouncilBerriganCouncil LocalorregionalcouncilBirdlifeAustralia ConservationorganisationBirdLifeAustraliaGluepotReserve ConservationorganisationBlacktownCityCouncil LocalorregionalcouncilBoroondaraCityCouncil LocalorregionalcouncilBoroughofQueenscliffe LocalorregionalcouncilBouliaShireCouncil LocalorregionalcouncilBrewarrinaShireCouncil LocalorregionalcouncilBrightonCouncil LocalorregionalcouncilBrisbaneCityCouncil LocalorregionalcouncilBullooshire LocalorregionalcouncilBushHeritageAustralia ConservationorganisationBusseltonNaturalistsClub ConservationorganisationCampaspeShireCouncil Localorregionalcouncil

49

CampbelltownCityCouncil LocalorregionalcouncilCampbelltownCouncil(SA) LocalorregionalcouncilCatRescue901Limited OtherCentralCoastCouncil LocalorregionalcouncilCentralCoastCouncil LocalorregionalcouncilCentralHighlandsRegionalCouncil LocalorregionalcouncilChallengerGoldOperations OtherCHARTERSTOWERSREGIONALCOUNCIL LocalorregionalcouncilCircularHeadCouncil LocalorregionalcouncilCityofAlbany LocalorregionalcouncilCityofBayswater LocalorregionalcouncilCityofBelmont LocalorregionalcouncilCityofBoroondara LocalorregionalcouncilCityofCharlesSturt LocalorregionalcouncilCityofGosnells LocalorregionalcouncilCityofGreaterBendigo LocalorregionalcouncilCityofGreaterGeelong LocalorregionalcouncilCityofGreaterGeraldton LocalorregionalcouncilCityofHobart LocalorregionalcouncilCityofJoondalup LocalorregionalcouncilCityOfKalmunda LocalorregionalcouncilCityofKarratha LocalorregionalcouncilCityofMandurah LocalorregionalcouncilCityofMarion LocalorregionalcouncilCityofMelbourne LocalorregionalcouncilCityofNedlands LocalorregionalcouncilCityofPalmerstonCouncil LocalorregionalcouncilCityofPortAdelaideEnfield LocalorregionalcouncilCityofProspect LocalorregionalcouncilCityofRyde LocalorregionalcouncilCityofSalisbury LocalorregionalcouncilCityofStirling LocalorregionalcouncilCityofSubiaco LocalorregionalcouncilCityOfVincent LocalorregionalcouncilCityofYarra LocalorregionalcouncilClarenceCityCouncil LocalorregionalcouncilCoffsHarbourCityCouncil LocalorregionalcouncilColacOtwayShire LocalorregionalcouncilColibanRegionalWaterCorporation OtherConservation&WildlifeManagement(SA)Inc.

Sportingshootersassociation

CookShireCouncil LocalorregionalcouncilCoolamonShireCouncil LocalorregionalcouncilCoorongDistrictCouncil LocalorregionalcouncilCorangamiteShire LocalorregionalcouncilCoreEnviroSolutions Other

50

CradleCoastNRM OtherCroydonShireCouncil LocalorregionalcouncilCumberlandCouncil LocalorregionalcouncilDCElliston LocalorregionalcouncilDeloraineLandcaregroup FarmersassociationDepartmentofBiodiversity,ConservationandAttractions

Conservationorganisation

DepartmentofEnvironmentandScience ConservationorganisationDepartmentofEnvironmentandWaterSouthAustralia

Other

DeptEnvironmentandWaterSA-BimbowrieConservationPark

Conservationorganisation

DistrictCouncilofLowerEyrePeninsula LocalorregionalcouncilDistrictCouncilofPeterborough LocalorregionalcouncilDistrictCouncilofStreakyBaySA LocalorregionalcouncilDorsetCouncil LocalorregionalcouncilDubboRegionalCouncil LocalorregionalcouncilDUNROAMIN Othereastgippslalndshirecouncil LocalorregionalcouncilEdnaMayOperations OtherEurobodallaShireCouncil LocalorregionalcouncilFairfieldCityCouncil LocalorregionalcouncilFoundHearts Oth