Wherearewenow?
Anupdatedassessmentofthenationalefforttowardsferalcatcontrol
AreportfortheAustralianGovernmentDepartmentoftheEnvironmentandEnergy
October2018
Authors:
DrAlexanderM.Kusmanoff,ProfSarahA.Bekessy,DrYanWang,DrAliceJohnstone,ChathuriSamarasekara,DrGeorgiaE.Garrard
ICONScienceareateamofacademicresearchersbasedwithinRMITUniversity’sSchoolofGlobal,UrbanandSocialStudies.Ourresearchfocusesonunderstandingtheinteractionbetweensocietyandourenvironment.
Werecognisethatmanagingbiodiversitydemandsamultidisciplinaryapproachthatreconcilesecological,socialandeconomicconcerns.
2
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.
3
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
4
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
5
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
6
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.
7
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
8
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).
9
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
10
Figure2.Numberofsurveyrespondentswhoengageinferalcatcontrol,by2-digitpostcode.
Toaidcontinuityandcomparability,thesurveyismostlyconsistentwiththatusedforthepreviousassessment.However,inordertogainabetterunderstandingofhowindividualsrespondtodifferentferalcatcontrolprogramsandactivities,andhoweffortshavechangedinresponsetodifferentcampaignsandinterventions,weincludedsomeadditionalquestions.
Additionaltothepreviousassessment,thesurveywillalsocollectinformationabout:
• attitudestowardsferalcatcontrolofrespondentswhomaybeopposedtothepractice;
• awarenessoftheThreatenedSpeciesCommissionerandherroleinferalcatmanagement;and
• willingnesstocontributetoferalcatmanagementandperceptionsofresponsibilityforferalcatmanagement.
Thefinalpointabovewasinvestigatedusingabetween-subjectsdesign,inwhichrespondentswererandomlyassignedoneofthreeslightlydifferentversionsofthesurvey.Theseversionsdifferonlyinrelationtooneparagraphtowardstheendofthesurvey:oneversionincludesastatementfromtheThreatenedSpeciesCommissioneraboutferalcatmanagementthatemphasisesactionsundertakenbytheAustralianGovernment;anotherversionincludesanalternativestatementfromtheThreatenedSpeciesCommissioneraboutferalcatmanagementthatemphasisessharedactions;andacontrolversionthatdoesnotincludeeitherstatement.
AnoutlineofthestrategiconlinesurveyforindividualsisprovidedatAppendixC.
11
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.
12
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.
13
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.
14
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
15
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
16
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
17
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.
18
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’.
19
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.
20
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.
21
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
22
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
23
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).
24
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).
25
a
b
Figure6.Posteriordistributionsand95%credibleintervalsofa)themeanareamanagedforferalcatcontrolbyfarmerswhoengageinferalcatcontrolandrespondedtooursurvey,andb)theprojectedtotalareamanagedforferalcontrolbyfarmerswhoengageinferalcatcontrolbutdidnotrespondtooursurvey.
26
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.
27
• 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.
28
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).
29
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
30
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%).
31
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.
32
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
33
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.
34
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.
37
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.
38
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.
39
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.
40
AppendixA–Outlineof2018strategiconlinesurveyfororganisations
NATIONALFERALCATCONTROLSURVEY
YourorganisationisinvitedtoparticipateinasurveyaboutferalcatcontrolinAustralia.TheinformationprovidedinthissurveywillhelpgenerateabetterunderstandingofferalcatmanagementinAustralia,includinghowtomakeimprovements.ThissurveyisbeingconductedbyDrAlexKusmanoff,DrGeorgiaGarrardandProfessorSarahBekessyatRMITUniversity(contactdetailsareprovidedbelow).ThisprojectisfundedbytheAustralianGovernment.Bycompletingthissurvey,youarehelpinguscollectthehighestqualitydatainaconsistentmanner.However,ifyouwouldprefertoprovidedatadirectly,ratherthanthroughthissurvey,[email protected]?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)[email protected]
ThissurveywillbeopenuntilWednesday22August.Whatwillhappentotheinformationtheorganisationprovides?Responsestothesurveyquestionswillbecollatedandstoredinaspreadsheet,beforebeinganalysed.Resultswillbepresentedinaresearchreportandmayalsobepublishedinacademicjournalsandpresentedatacademicconferences.Yourorganisationmayremainanonymousifpreferred.Oncewehavecompletedourdatacollectionandanalysis,datawillbestoredsecurelyontheRMITserverforfive(5)yearsbeforebeingdestroyed.Followingyourparticipation,youmaycontactAlex([email protected])orGeorgia([email protected])toobtainasummaryoftheresults(expectedtobeavailableinlate2018).WhomshouldIcontactifIhaveanyquestions?Ifyouhaveanyquestionsaboutyourparticipation,pleasecontactDrAlexKusmanoffon(03)[email protected].
Investigators:
• ProfessorSarahBekessy,SchoolofGlobal,UrbanandSocialStudiesRMITUniversity(03)[email protected]
• DrGeorgiaGarrard,SchoolofGlobal,UrbanandSocialStudiesRMITUniversity(03)[email protected]
• DrAlexKusmanoff,SchoolofGlobal,UrbanandSocialStudiesRMITUniversity(03)[email protected]
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?
43
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,[email protected]
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
44
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
45
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)_____________________________________________
46
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
47
efforttowardsferalcatcontrol.Ifyouhaveanyquestionsorconcernsregardingthesurvey,ornoticedanyproblems,[email protected]
48
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