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Designingarealisticvirtualbumblebee

TimMarsden

WorcesterPolytechnicInstitute

Advisors:

Dr.RobertJGegear

Dr.ElizabethRyder

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TableofContentsAbstract...................….......................................................................................................3Introduction......................................................................................................................4Methods.............................................................................................................................6 ODD.........................................................................................................................6 TheOptimalDietModel...................................................................................9 SimulationParameters...................................................................................10Results...............................................................................................................................12 TheSimBeeModel.............................................................................................12 SimBeeProcedureOverview..........................................................................13 DeterminingEnvironments............................................................................14 PartialPreferenceinODM..............................................................................15 LimitedMemoryImpact..................................................................................16 HandlingTime....................................................................................................17 ValidatingtheModel........................................................................................19Discussion........................................................................................................................22References.......................................................................................................................24Appendix1:CodeStructure.......................................................................................28Appendix2:FullCode..................................................................................................30

FiguresFigure1:ODMEquations.............................................................................................10Figure2:SimBeeuserinterface.................................................................................12Figure3:Beedetectionradius.....................................................................................13Figure4:SimBeeProcedureOverview.....................................................................14Figure5:DeterminationofEnvironments..............................................................15Figure6:Percentageyellowflowersaccepted.......................................................16Figure7:Schematicofenvironmentvariability....................................................17Figure8:HandlingTimeinSimBee...........................................................................18Figure9:Environmentsbyhandlingtimemode...................................................19Figure10:ValidatingSimBeeinlabsetting...........................................................20

TablesTable1:StatevariablesforSimBeeAgents...........................................................6

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Abstract

OptimalForagingTheoryisasetofmathematicalmodelsusedinthefieldofbehavioralecologytopredicthowanimalsshouldweighforagingcostsandbenefitsinordertomaximizetheirfoodintake.Onepopularmodel,referredtoastheOptimalDietModel(ODM),focusesonhowindividualsshouldrespondtovariationinfoodqualityinordertooptimizefoodselection.ThemainpredictionoftheODMisthatlowqualityfooditemsshouldonlybeacceptedwhenhigherqualityitemsareencounteredbelowapredictedthreshold.Yet,manyempiricalstudieshavefoundthatanimalsstillincludelowqualityitemsintheirdietabovesuchthresholds,indicatingasub-optimalforagingstrategy.Here,wetestthehypothesisthatsuch‘partialpreferences’areproducedasaconsequenceofincompleteinformationonpreydistributionsresultingfrommemorylimitations.Totestthishypothesis,weusedagent-basedmodelinginNetLogotocreateamodelofflowerchoicebehaviorinavirtualbumblebeeforager(SimBee).Weprogramvirtualbeeforagerswithanadaptivedecision-makingalgorithmbasedontheclassicODM,whichwehavemodifiedtoincludememory.Ourresultsshowthattheprobabilityofcorrectlyrejectingalowqualityfooditemincreaseswithmemorysize,suggestingthatmemorylimitationsplayasignificantroleindrivingpartialpreferences.WediscusstheimplicationsofthisfindingandfurtherapplicationsofourSimBeemodelinresearchandeducationalcontexts.

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IntroductionAnimals routinely face the problem of deciding how and what to eat in complex

foraging environments. To gain a better understanding of how animals adaptively address these foraging-related problems, behavioral researchers have developed numerous optimization models derived from the field of economics, collectively referred to as Optimal Foraging Theory (OFT). The central assumption of OFT is that natural selection has shaped the behavioral system of animals to weigh foraging costs and benefits and adopt foraging strategies that maximize their net rate of energy gain and therefore their probability of survival (Darwinian fitness) [Charnov, 1976]. Thus, each model predicts how animals should respond in a particular foraging environment within a given specific set of constraints. Such predictions are then tested empirically to determine whether foraging decisions in a particular floral environment are optimal [Zhang, 2014; Pyke, 1984].

One of the most widely used models within the OFT framework deals with the problem of diet selection. In this ‘prey choice’ model, foragers randomly encounter prey items that vary in quality and must decide whether to consume the item or reject it and continue searching for an alternative item [Sih, 2001]. This scenario assumes that animals are ‘all-knowing’ and therefore have all of the prey information needed to make the optimal decision. Given this assumption, the diet model predicts that animals will develop a foraging strategy that always rejects a lower quality prey item if the abundance of a higher quality item is above a particular threshold [Holt, 2013; Gonzales-Varo, 2013; Sih, 2013; Beecher, 2014]. Yet, most empirical tests of the prey choice model have found that animals still accept low quality items to some extent even when high quality items are abundant, a phenomenon known as partial preference. Although there have been several explanations for partial preferences proposed over the years, its cause remains unknown [Arundel, 2013; Couvillon, 2015]. Here, we describe a series of virtual experiments designed to investigate the role of memory limitations in driving partial preferences in bumblebee foragers.

Bumblebees are an ideal behavioral system to study mechanisms of adaptive prey choice. As social insects, they form colonies comprised of a single queen and up to several hundred workers. A small subset of workers called ‘foragers’ have the sole task of finding and collecting food for the colony in the form of floral nectar and pollen rewards [Dyer, 2004; Goulson, 2009]. Each forager faces the daunting task of maximizing nectar delivery to the colony in habitats containing multiple flower types that vary in their reward quality [Dyer, 2004; Das, 2013; Lourenco, 2015]. Foragers are not pre-programmed with information on floral reward quality; rather, they must learn and remember the reward level and sensory cues (color, odor, shape) associated with each type of flower that they visit [Muth, 2015; Faruq, 2013]. Memory therefore plays a fundamental role in bumblebee survival and reproductive success [Muth, 2015; Zhang, 2014].

To investigate the relationship between memory capacity, floral choice behavior, and reward intake, we used the agent-based modelling (ABM) software NetLogo to develop a virtual bumblebee-plant system called ‘SimBee’. Many computational simulations rely largely on equation-based or analytical modeling, which does not allow for model flexibility at the individual level [Castello, 2013; Liu, 2015]. In contrast,

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agent-based modelling allows variability by defining the behaviors of individuals with their own set of decision rules, allowing the user to study interconnections between the agents themselves, as well as modelling collective behaviors [Helbing, 2012; Janssen, 2014; Mills, 2015]. Additional characteristics of ABM that are important with respect to biological applications: the modular structure is useful by allowing the modification of existing agent rules or the addition of new agents into pre-existing model structure, emergent properties of higher level relationships are the result of individual agents’ local interactions, and abstraction of new behavior information can occur when there is incomplete knowledge about the target biological process based on known information [Politopoulos, 2007].

Other investigators have developed agent-based models simulating pollinator behavior. In particular, the ‘A-bees-see’ model simulates the differences in the scanning approaches of honeybees and bumblebees to targeting flowers, to develop a better understanding of the evolution of these behaviors [Bukovac, 2013]. The BEEHAVE model simulates multiple environmental stressors on honeybee colonies [Becher, 2014], while the EcoSimInGrid model explores the effects of multiple pollinators on plant communities [Qu, 2014]. Our SimBee model focuses on the behavior of an individual virtual bumblebee, which is programmed with the ability to learn the properties of a simulated floral environment and then use information stored in memory to make foraging decisions based on mathematical components contained in the classic prey selection model. Our long-term goal is to observe the collective impact of individual decisions using this foraging model on population dynamics over time.

In the work presented here, we describe the SimBee model, and use it to study the effects of limited memory capacity on behavioral choices of an individual bee interacting with varied floral environments. We show that partial preferences emerge from the optimal diet model as a natural consequence of bees with limited knowledge interacting with a random floral environment. We further show that how the virtual bee calculates the search time for a rewarding floral type has a large impact on its behavioral choices. Finally, we describe the ability of SimBee to generate environments that can be used to verify model predictions experimentally.

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MethodsSimBeeModelOverview,Designconcepts,andDetails(ODD)TheODDisastandardmethodofdescribingABMmodels[Grimm,2010]. AcompletedescriptionforeachsubroutineprocessandislocatedintheCodeStructuresection(Appendix1),adetailedflowchartofthedecision-makingprocessislocatedintheresultssection(Figure4),andtheactualNetlogoprogramwithcommentdescriptionscanbefoundinAppendix2.PurposeThismodelisdesignedtoserveasanaccuraterepresentationofthebasicforagingbehaviorofbees.Itincludesthebehaviorsthatareinvolvedinthebeescollectingnectar,andbringingitbacktothehive.Thebee‘decides’whichflowerstovisitbasedontheoptimaldietmodel(ODM)thatwehavemodifiedtoincludealearningandmemorycomponent.Thereasonforcreatingthismodelistoprovideamorerealisticandconsistentbaseuponwhichmoreinvolvedmodelscanbebuilt,andtesthowindividualbeebehaviorhasbeenshapedbynaturaladaptivelyrespondinheterogeneousfloralenvironments.Entities,StateVariables,andScalesThemodelhasthreedifferentindividuals:bees,flowers,andhives.ThestatevariablesfortheagenttypesaresummarizedinTable1.Therearenospecialunitsorenvironmentinthissimulation.

Table1:StateVariablesforSimBeeAgents(ML=memorylist)Hive Flower BeeNectarAccumulated NectarContent Location HandlingTime Heading DetectedFlowers OnFlower? LastFlowerVisited NectarHeld NextFlower TimeofLastBlueflowervisited TimeofLastYellowflowervisited SampleMode? MLyellowhandlingtime MLbluehandlingtime MLyellowsearchtime MLbluesearchtime MLyellowenergycontent MLblueenergycontent

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ProcessoverviewandSchedulingEachtick,thebeemovesforwardonepatchinarandomdirection(seestochasticitybelow)onwherethebeeis,itcallsdifferentfunctions.Eachtick,eachofthethreebreedsupdatestheirvariablevaluestoaccountfornectartransferifitoccurs.Eachtick,beesstoreandadjustinformationinmemorylistsifapplicable.Inthissimulation,10ticksareequivalentto1second.Abeeisexpectedtoremainonaflowerfortheflower’shandlingtime,defaultis2seconds(20ticks).Abeecanholdupto800unitsofnectarbydefault,andsincethedefaultnectaramountforblueflowersis40ulandyellowflowersis10ul,thebeeisexpectedtovisitbetween60and120flowersbeforereturningtohive.(20ifallbluevisits,80ifallyellowvisits)DesignConceptsBasicprinciples:SimBeemodelscontinuousforaging;thereisnoday/nightcycle.Whenahiveispresentandthebeehasthemaximumamountofnectarthattheycanhold,theybringitbacktothehive.Ifnohiveispresent,thebeewillcollectnectarindefinitelyuntilsimulationend.Objectives:Inthismodel,thebees’objectiveistocollectnectar,andifahiveispresent,tobringitbacktoitshive.Learning:Thebeesrememberthehandlingtimes,energycontent,andsearchtimesofthepastflowersencountered.Thenumberofpastflowersremembered(memorylength)isuser-defined,rangingfrom1to1000.Prediction:Thebeeschangewhethertheirnextflowerencounterwillbeacceptedornotbasedontheinformationfrompastflowervisitsstoredinmemorylists,usingtheODMequation:S1>((E1*h2)/E2)-h1.Therightsideofthisequationisreferredtoasthethreshold.S1=averagesearchtimeforpastblueflowersE1=averageenergycontentforpastblueflowersE2=averageenergycontentforpastyellowflowersh1=averagehandlingtimeforpastblueflowersh2=averagehandlingtimeforpastyellowflowersIfS1>threshold,thebeewillacceptbothflowertypesifencountered.IfS1<threshold,thebeewillacceptonlyblueflowersifencountered.Sensing:Thebeeshaveaconeofsight,whichtheyusetoseenearbyflowersinthedirectioninwhichtheyareheading.Theyareabletoselectarandomflowerwithinthiscone

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ofdetection.Beesalsoknowthelocationofthelastflowervisitedsotheydon’timmediatelyreturntoit.Interaction:Whenthebeeisonthesamepatchastheflowerithaschosentoencounternext(fromthementionedabovedetectedflowers)thebee“lands”onthatflowerandgathersallofitsnectar,askingtheflowertochangeitsenergyvalueto0,andsetitsoccupied?variabletotrue.Thebeestaysonthatpatchforthehandlingtimecorrespondingtotheselectedflower,andthenectarquantitytransferringfromflowertobee.Oncethebeeleavesthislocation,theflowerdetectsnobeesarepresentandchangesitsoccupied?Booleanbacktofalse.Stochasticity:Thedirectioninwhichthebeetravelsisbasedonpseudorandomnumbers,thepseudorandomnumbergeneratorusedbyNetlogoalwaysusesJava’s“strictmath”libraryanddetailscanbefoundintheNetlogoUserManual[Wilensky,1999].Ifithasnotdetectedaflowertoencounter,thebee’sheadingisadjustedrandomlybetween30degreesrightto30degreesleft.Thisistoemulatethenatural‘drifting’flightpatternsbeesexhibitinreallife.TheflowerchosenbybeestobenextencounteredisalsoastochasticprocessbecauseaccordingtoODM,preyisrandomlyencounteredbeforetheacceptancedecisionoccurs. This means that if the bee has more than one flower in the detected range, the selection is based on pseudorandom numbers. Collectives:Thebeesareallpartofacolonyandallcoloniesarepartofthepopulation.Theactivityoftheindividualcontributestohowthewholepopulationisdoing.Inthismodeleachtrialonlyhasonebeeactiveatatime.Observation:Thedataoutputsneededtoobserveinternaldynamics,solvetheproblemthemodelwasdesignedfor,aswellassystem-levelbehaviorinclude:totalnectargathered,thetotalnumberofflowersencountered,thenumberoftimesthebee’saveragebluesearchtimefluctuatedrelativetothethreshold,Thenumberofyellowflowersencountered,thenumberofyellowflowersaccepted,thenumberofblueflowersencountered,thenumberofblueflowersaccepted,andthetimestampofwhensamplingphaseended.Outputofthebee’sinformationstoredinmemorylistsisalsorequiredtoconfirmcertainaspectsofbeebehaviorarecorrect,suchaskeepingsearchtimeandhandlingtimemutuallyexclusive.ThetoolsneededtoobtaintheseoutputsincludeExcelandBehaviorSpace.InitializationUponclickingthesetupbutton,anumberofblueflowersdeterminedbytheblue-flower-countslideraregeneratedinrandomlocations,andanumberofyellowflowersdeterminedbytheyellow-flower-countslideraregeneratedinrandomlocations.Theseflowershavevariablesdefinedbythefollowingsliders:blue-

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handling-time,yellow-handling-time,blue-energy,yellow-energy.Abeeisalsogenerated,withmemorylengthdefinedbythebee-memory-lengthslider.Iftestingidenticalenvironmentswithvaryingbeememorylengths,the‘generate-worlds’buttonshouldfirstbeused.Thiswilloutputworldfileswiththesameuser-definedflowervariables,eachwithadifferingbeememorylength:1000,10,5,3,2,1.Theseworldscanbemanuallyimportedafterwardusingthe‘setup-imported’button,orautomaticallyusingBehaviorSpace.InputDataIftestingaspecificenvironment,orasetofidenticalenvironmentswithvaryingbeememorylengths,worldinputfilesareneeded(fromthe‘generate-worlds’buttondescribedabove).Thesefilesarenamedg(number).csv,rangingfromg0.csvtowhateverthenumberofworldsgeneratedendsat.TheOptimalDietModel(CharnovandOrians,1973) Theoptimaldietmodelassumesthatthepredatorencounterspreyitemsofdifferenttypessequentiallyandrandomly,andmustdecidewhethertoacceptorrejectthepreyitemonceencounteredinordertomaximizerateofenergeticgain.Theprofitability(P)ofeachpreyitemequalstheenergycontentofthepreyitemdividedbythehandlingtimeofthepreyitem(P=E/h).Forourmodel,thehandlingtimeistheamountoftimeittakesthebeetoconsumealltheavailablenectarfromaflower.SearchtimeandhandlingtimesareconsideredmutuallyexclusiveeventsintheODM,meaningthepredatorisalwayseithersearchingorconsumingprey,butneverboth.IntheSimBeemodel,onlytwopreytypesareconsidered.Fortheexperimentsconductedhere,themoreprofitablepreytypeisblueflowers,whichhaveanenergycontentof40Jandhandlingtimeof2s,whichequalsaprofitabilityof20J/s.Thelessprofitablepreytypeisyellowflowers,whichhaveanenergycontentof10Jandhandlingtimeof2s,whichequalsaprofitabilityof5J/s. Thebeemustdeterminewhetherspecialization(acceptingthemoreprofitablepreytype)orgeneralization(acceptingbothpreytypes)willoptimizetherateofenergygain,whichisthetotalenergygainedoverthetotaltimespentforaging,asshowninFigure1.Withbothspecialist(R1)andgeneralist(R1,2)ratescalculated,thebeewillspecializeifR1>R1,2,andgeneralizeifR1<=R1,2.Sincetheencounterrateistheinverseofthesearchtime,thisinequalityreducestoEqn3(Figure1).Thus,thedecisiontospecializeonlydependsonthesearchtimeforthemoreprofitablepreytype.Iftheblueflowersareplentiful(shortsearchtimes),thebeeshouldn’tspendtimeacceptinglessprofitableflowers;however,ifblueflowersarescarce,thebeeshouldacceptbothflowertypes.IfthepredatorhascompleteknowledgeoftheparametersgiveninFigure1,itshouldalwayschooseeithertospecializeorgeneralizeatalltime(referredtoasthe‘all-or-none’ruleforselectingthelessprofitabletype);thus,theODMpredictsthatanimalsshouldnevershowapartialpreference.

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Figure1:ODMEquationsforspecializationandgeneralization.Forspecializing,thetotalenergyequalstheproductoftheencounterrate(#ofblueflowersencountered/time),Energygainedfromeachblueflower,andthetotaltimespentsearching.Thetotaltimespentforagingissearchtimeaddedtothetotaltimespenthandlingblueflowers,whichequalstheproductofencounterrate,handlingtimerequiredforeachblueflower,andtotaltimespentsearching(Eqn1).Forgeneralizing,theideaissimilarexceptnowthetotalenergyisthesumoftotalyellowflowerenergygainedandtotalblueflowerenergygained,andthetotaltimeincludestotaltimespenthandlingyellowflowersandtotaltimespenthandlingblueflowers(Eqn2).IfEqn1>Eqn2,thebeeshouldspecialize;thisinequalityreducestothethresholdequation(Eqn3).IfS1<threshold,thebeeshouldspecialize.Simulationexperimentalparameters Unlessstatedotherwise,simulationexperimentswereperformedinbatchmode(BehaviorSpaceinNetlogo)usingthedefaultsettingsdescribedbelow.Beememorylengthwasoneofthefollowingsettings:1,000,10,5,3,2,or1.Thetimerequiredforeachsamplingperioddependedonthismemorylength.Forexample,ifthememorylengthwas10,thebeewouldsample10blueflowersand10yellowflowersbeforeenteringforagemode.Theforagetimeperiodwasalways300,000ticksaftersamplingended,whichisapproximately8hoursinrealtime(1second=10ticks).

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Themoreprofitableflowers(prey1)werealwaysblue,contained40ulofnectar,andrequired2secondsofhandlingtime.Thelessprofitableflowers(prey2)werealwaysyellow,contained10ulofnectar,andrequired2secondsofhandlingtime.Eachflowerinstantlyregeneratesthestorednectaramountonceabeehasharvestedtheflowerandlefttheparticularlocation.Forgeneralizedforagingenvironments,wherebothpreytypesarealwaysacceptedduringforaging,theenvironmentcontained10blueand50yellowflowers,randomlyplacedwithinthelandscape.Forspecializedforagingenvironments,whenonlythemostprofitablepreytypeisacceptedduringforaging,theenvironmentcontained20blueand50yellowflowers,randomlyplacedwithinthelandscape.

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ResultsTheSimBeemodel TheSimBeeuserinterfaceisillustratedinFigure2.Uponsetup,thevirtualenvironment,termeda‘world’,isgenerated.Auser-definednumberofflowersisrandomlydistributedintheworldforeachflowertype.Currentlytwotypesofflowersareallowed,depictedbyblueandyellowflowericons.Theuserdeterminestheenergycontentandhandlingtimesforeachflowertype.Forexperimentsreportedhere,theblueflowersarealwaysmostprofitable(energycontentof40J,handlingtime2seconds),andtheyellowflowersarealwaysleastprofitable(energycontentof10J,handlingtime2seconds).Flowersrefillinstantaneouslyafterbeingacceptedaspreybyabee. Thebeeisplacedatarandomlocationintheenvironment.Thebeemovesaroundthesimulationuntilitdetectsaflower.Thebeedetectsadjacentflowerswithinitslineofsight,usingauser-definedviewradiusandarc.Forexperimentsreportedhere,aviewradiusof9patchesandanarcof140°wereused.(Figure3).Iftherearemultipleflowerswithindetectionrange,thebeewillchoosearandomflowerandtraveltothislocation;thisactionistermedanencounterwiththeflower.Thebeewillaccepttheflower(takenectarfromit)basedontheoptimaldietmodelstrategydescribedbelow.Ifthebeeacceptstheflower,itwillremainattheflowerlocationforthehandlingtimeassociatedwiththatflower.Thebeestoresthesearchtimeandprofitabilityfromitsmostrecentacceptancesofeachflowertype,uptoitsmemorycapacity,whichcanrangefrom1to1000.Theusercanchoosewhetherornottoincludehandlingtimeinthesearchtimesforeachflowertype.

Figure2:SimBeeuserinterface:Theusercansetmodelparametersusingtheslidersandinputsontheleft,whileobservingthesimulationinrealtimeontheright.

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Figure3:Beedetectsflowerswithinauser-definedradiusandangle.Thegreencirclesurroundingthebeedemonstratesthedistancethebeecandetectfrominrelationtoitself,whilethewhiteareavisualizestheradiusandanglethebeeconsiderswithinitsdetectionarea.Here,oneyellowandtwoblueflowersaredetectedbythebee.SimBeeProcedureOverview TheSimBeemodelprocedureoverviewisshowninFigure4.Aftertheinterfaceissetup,aninitialsamplingmodeisutilizedbythebeeinordertodetermineprofitabilityoftheavailableflowertypes.Insamplingmode,thebeewillalwaysacceptbothpreytypesuponencounteringthem.Oncethebeememorycapacityisreachedforbothflowertypes,thebeeswitchestoforagingmode.Inourexperiments,foragingmodeisrunfor300,000steps(simulatingapproximately8hours,whereeachmodelstepcorrespondsto0.1seconds).Duringthistime,eachencounterdecisiontoacceptorrejectaflowertypedependsonthethresholdinequalityderivedfromtheOptimalDietModel(SeeMethods,Fig.1,Eqn3).Iftheencounteriswithablueflower(mostprofitable),itisalwaysacceptedbythebee,andtheflower’sprofitabilityandsearchtimevaluesareaddedtothebeememory.Iftheencounteriswithayellowflower(lessprofitable),thebeewillacceptthefloweriftheaverageblueflowersearchtimeiscurrentlygreaterthanthethresholdcalculation.Otherwise,thebeewillrejectthisyellowflowerandcontinueforaging.

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Figure4:SimBeeProcedureOverview.Uponsetup,thebeeenterssamplingmode,whereeveryflowerencounteredisacceptedtodetermineprofitabilityofflowertypes.Onceasetnumberofflowersareacceptedforeachflowertype,thebeewillswitchtoforagemode,andusetheinformationgatheredduringsamplingmodetodeterminewhetheroneofbothflowertypesshouldbeaccepted.Uponflowerencounter,iftheflowertypeisblue(mostprofitable),itisautomaticallyaccepted,addstheinformationintoitsmemory,andreturnstosearchingforflowers.Iftheflowertypeisyellow(lessprofitable),itdeterminesiftheaveragesearchtimeforblueflowersisaboveorbelowthethreshold.Ifbelow,itrejectstheyellowflowerandcontinuessearching.Ifabove,itacceptstheyellowflower,addstheinformationtoitsmemory,andreturnstosearchingforflowers.Thiscontinuesforasetintervaloftime(300kticks,whichisroughly8hoursoronedayofforaging).DeterminingSpecialized(S)andGeneralized(G)environments Inordertotestthebehavioraleffectsofchangesinmemory,wefirstwantedtocreateenvironmentsinwhichabeewithcompleteknowledgeoftheenvironment(an‘all-knowing’bee)willeitheralwaysspecialize(Senvironment)oralwaysgeneralize(Genvironment).Foroursimulatedenvironments,wedeterminedthatabeewithmemorylengthof1000was‘all-knowing’,withessentiallycompleteknowledgeoftheenvironment.Weranmultipletrialsofwithbeememorylength1000forarangeofblueflowercounts,anddeterminedtheenvironmentsinwhichbeesalwaysspecializedoralwaysgeneralizedforeverytrial.Byrunning10trialsforenvironmentswith50yellowflowersandvariablenumbersofblueflowers,itwasdeterminedthat10blueflowersand50yellowflowersalwaysresultedingeneralizationwhile20blueflowersand50yellowflowersalwaysresultedinspecialization(Figure5).Forenvironmentswithintermediatenumbersofblueflowers,thesimulationsometimesgeneratedGandsometimesSenvironments,duetotherandomplacementofflowerswithintheenvironment.Thuswechose10and20blueflowerstodefineourGandSenvironments,respectively.

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Figure5:DeterminationofSpecializedandGeneralizedEnvironments.‘All-knowing’beesweresubjectedtodifferentworldscontainingaspecificnumberofblueflowers(8,10,12,etc.)and50yellowflowers.Weran10trialspernumberofblueflowers,witheachtrialcontainingadifferentdistributionofeachflowertype.Inthesetrials,searchtimesforpreydidnotincludehandlingtimes.Atrialwasconsideredtobe‘generalized’ifbothpreyitemswereselectedoverthesimulationperiod.Changingmemorysizeaffectsbeebehavior:PartialpreferenceinODM

Inordertotestwhethermemorystrengthaffectsbehavioralchoices,weranthesimulationwithvirtualbeesofvariousmemorylengthsinthespecializedandgeneralizedenvironmentsdefinedabove.Wegenerated10randomSenvironmentsand10randomGenvironments.Withineachenvironment,wetestedabeeforeachmemorylength(1000,10,5,3,2,1).Wemeasuredthepercentyellowflowersaccepted;0%acceptanceindicatesthebeehadcompletelyspecializedonblueflowers,while100%acceptanceshowsthebeehadcompletelygeneralizedandacceptedbothflowertypes.Anypercentagebetweenindicatesthatthebeefluctuatedbetweenspecializationandgeneralizationatcertainpointsinthesimulation.Averagesforageneralizedenvironmentandspecializedenvironmentweregraphedwith95%CI(Figure6).Thesefindingsshowthatreducedmemorycanresultintheappearanceofpartialpreferenceswhenthesamebeewith‘all-knowing’memorywouldalwayseitherspecializeorgeneralizeforeachtrial.Notethatasmemorysizedecreases,thevirtualbeeshowsgreaterpartialpreferences;thatis,itacceptsyellowflowersmorefrequentlyinaspecializedenvironment,orlessfrequentlyinageneralizedenvironment.

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Figure6:Percentageyellowflowersacceptedoverencounteredbybeeswithvaryingmemorylengthsingeneralized(a)andspecialized(b)environments.‘Mx’denotesthenumberofblue-bluetransitions(bluesearchtimes)thatcanbestoredinmemory.Partialpreferencesareobservedwhenvaluesarebetween0and1.N=10foreachmemorylength.Theimpactoflimitedmemoryandenvironmentalvariabilityonbeedecisionmaking

Byexaminingpaths,abeemighttakeduringasimulationtrial,wecanunderstandwhypartialpreferencesareobserved.Environmentalvariability’seffectondecisionmakingisillustratedinfigure7withbeememorylength3.Here,thebeeisinageneralizingenvironment,whereabeewithamemorylengthof1000wouldalwaysacceptyellowflowers.Forthebeetakingthevioletpath,theaverageofthepastthreebluesearchtimesisgreaterthanthethresholdof60,sothebeewillacceptthenextyellowflowerencountered(Figure7).Forthebeetakingtheredpath,theaverageofthepastthreebluesearchtimesislessthanthethresholdof60,sothebeewillrejectthenextyellowflowerencountered(Figure7).

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Figure7:Schematicofhowenvironmentalvariabilitycaneffectoptimaldecisionmakingprocesses.Forthebeefollowingtheredpath,thepast3blueflowerencountershaveanaveragesearchtimeof23ticks,whichisbelowthethresholdof60.Thisindicatesthatthemoreprofitablepreytypeisfrequentenoughthatlessprofitablepreytypesshouldberejected,sotheincomingyellowflowerencounterwillberejected.Forthebeefollowingthevioletpath,however,theaveragesearchtimeforthepast3blueencountersis64.Thisisabovethethresholdof60,whichindicatesthatthemoreprofitablepreytypeisuncommonenoughthatacceptingallpreytypesisoptimal,andtheincomingyellowflowerencounterwillbeaccepted.Inclusionofhandlingtimewithinsearchtimes

TheODMdefinessearchtimeandhandlingtimesasmutuallyexclusive.Inactuality,it’sunclearwhetherbeesarecapableofcalculatingpreyhandlingtimesseparatelyfromsearchtimes,especiallywhenconsideringhundredsofpastencounters.Bydefault,SimBeeremoveshandlingtimesofyellowflowerencountersthatoccurredbetweenblueflowerencounters,sothattheaveragesearchtimeofblueflowers(S1)followstheODMdefinition(HandlingTimeExcludedmode,Figure8).Wealsoincorporatedtheabilitytoincludehandlingtimesinthecalculationofsearchtimes,possiblymorecloselyfollowinganactualbee’sperceptionofsearchtimes(HandlingTimeIncludedmode,Figure8).

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Figure8:SearchtimeandHandlingtimerelationshipintheSimBeemodel.Whenhandlingtimeisexcludedfromsearchtime,thebluesearchtimeequalsthesumof5searchtimes(purplearrows)for93ticks.Whenhandlingtimeisincludedinsearchtime,thebluesearchtimeincludesthehandlingtimesforthe4yellowflowersencountered;thetotalsearchtimeis173ticks.Specialized(S)andGeneralized(G)environmentsbyHandlingTimemode Whenhandlingtimeisincludedinsearchtime,thesearchtimeismuchlonger,andthenumbersofflowersrequiredtogenerateSpecializedandGeneralizedenvironmentschange.Byrunning10trialswitharangeofblueflowercountsandplottingthepercentageofgeneralizedtrials,wedemonstratedthatthenumberofblueflowersrequiredtogenerateSpecializedenvironmentsshiftsfrom10blueflowersforhandlingtimeexcluded,to20blueflowersforhandlingtimeincluded(Figure9).ForGeneralizedenvironments,thenumberofblueflowersshiftsfrom20blueflowersforhandlingtimeexcluded,to40blueflowersforhandlingtimeincluded(Figure9).Thisshiftwasconsideredsignificantforthepurposeofdemonstratinghowtherelationshipbetweenhandlingandsearchtimecanalterhowbeesperceivegeneralizedorspecializedenvironments,whilefurthertrialsareneededinordertoconsiderthisshifttrulystatisticallysignificant.

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Figure9:Specialized(S)andGeneralized(G)environmentsbyhandlingtimemode.Withhandlingtimeexcluded,Genvironmentisachievedwith10blueflowers,andSenvironmentisachievedwith20blueflowers.Whenhandlingtimeisincludedinsearchtimes,however,Genvironmentisshiftedto20blueflowers,andSenvironmentisshiftedto40blueflowers.ValidatingtheSimBeeModelinalabsetting Inordertotestwhetherthemodelcorrespondstorealbeebehavior,wewantedtogeneratesimulationworldsthatcouldbereplicatedandusedinalaboratoryenvironment.Comparisonofrealandsimulatedbeebehaviorwouldthenenableustovalidateandrefinethesimulation,aswellasprovidingawayofestimatingactualbeememorylengthandbehavioralstrategies.Toaccomplishthis,wedevelopedaswitchtofacilitatelaboratoryparametersfortheSimBeemodel.Forthefloralenvironmentlayout,possibleflowerlocationswereconstrictedtoagrid:15rowsby22columnstotaling330possibleflowerpositions.Eachrowandcolumnwere6.5cmapart,andknowingbeesflightspeedapproximated15cm/sbetweenencounters,thesimulationparameterswerestructuredtoemulatethisbehavior(Figure10).Blueflowerswereadjustedtocontain13ulofnectarandhavea4.5secondhandlingtime.Yellowflowerswereadjustedtocontain6.5ulofnectarandhavea4.5secondhandlingtime. UsingtheSimBeeinLaboratorymode,wegeneratedalaboratoryenvironmentcorrespondingwithasimulationworld(Figure10).Thelaboratoryreplicareplacescolordiscriminationwithodordiscrimination,becausethisforcesbeestoapproachflowersverycloselyinordertodiscriminaterewardingandnon-rewardingodors,similartotheprogrammedbeebehaviorinthemodel.Laboratorytestswillallowustodeterminewhetherweobservespecializedand

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PercentageofGeneralizedTrialsbySamplingend(BothHandlingTimemodes)(10trials,always50yellow)

HandlingTimeIncluded

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generalizedenvironments,aswellaspartialpreferences,similartothoseobservedinoursimulations.Theaccuracyofthismethodofdesigningmodelparameterstoemulateknownlabspecificationswillremainunclearuntilassessmentmetricsareincorporatedforcomparisonagainstactualbeebehaviordata.

Figure10:Testingsimulationpredictionswithlaboratorydata.InLaboratorymode,thesimulationgeneratesfloralenvironmentsonagrid(toppanel)thatiseasilytranslatedtoafoamboardwithslotsforpositioningartificialflowers–microfugetubesfilledwithsugarwater‘nectar’surroundedbyfoam‘petals’(bottompanel).Odorantsonthesurfaceofflowersenablesbeestodifferentiatelowandhighqualityflowers.Theboardfitsintoabeecage;beescanbereleasedintothecageandtheirbehaviortrackedbyvideomonitoring.

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Discussion:

Byprogrammingvirtualbeeforagerswithanadaptivedecision-makingalgorithmbasedonOptimalDietModeldevelopedbyCharnov(1976),modifiedtoincludememory,arealisticvirtualbumblebeewasdevelopedthatcanbeusedtoemulateactualbeebehaviorandbetterassistfuturestudiesinvolvingforagingbehavioronthepopulationlevel.Bycomparingpercentageofpreyacceptanceoverencounterofvaryingmemorysizesinthesameenvironments,theresultsshowthatreductionsinmemorycausebeestomakenon-optimalchoiceswhenfloralresourcesarerandomlydistributedintheenvironment.Previousdietmodeldesignscannotexplainpartialpreferencesduetomodelconstraints,howeverbyincorporatingmemoryabilityintothemodel,partialpreferencesareanaturaloutcomefromenvironmentalvariability.Byinvestigatinghowhandlingtimesareincorporatedintosearchtimes,themodelallowscomparisontoactualbeebehaviortodeterminehowbeesactuallyperceivesearchtimesduringforaging,andalsotoestimateactualbee’smemorycapacity.Theseresultssuggestthatenvironmentalstressorsaffectingmemorymaycontributetopopulationdeclinebyincreasingnon-optimalforagingchoices,whichcouldultimatelyreducethereproductivepotentialofbumblebeecolonies.

TheBeeSimmodelisnovelbecauseitisamemory-basedextensionoftheoptimaldietmodelrulesintheforagingmodel.InBecheretal’sBEEHAVEmodel,anagent-basedforagingmodelisderivedforhoneybeecoloniesthatincorporatescolonydynamicsandanagent-basedforagingmodel,howeveritdoesnotincorporatetheoptimaldietmodelforagentdecisionmaking.Dyeretal’s,Beereverse-learningbehaviorsimulationsincorporateagent-basedcomputersimulationsthatinvolveparametersofflowerhandlingtimesandrewardsinordertohelppredictefficiencyinbeebehaviorwhenadjustingtorewardingflowerschangingtounrewardingflowers,butdoesnotaddressthedietmodelintheirmodeldesigns.Quetal’sEcoSimInGridmodelisaspatiallyexplicitagent-basedsimulatorforcomplexanalysesofpollinatorsonplantpopulations,howevertheirdesigndoesnotincorporatebehavioralchoicesbasedontheoptimaldietmodel.

Zhangetal’srecentexperience-driven(RED)decision-makingforagingmodelexplainspartialpreferencesbyusingaprobability-basedmodelthatdeterminespreyacceptancebycomparingtheprofitabilityofthecurrentencountertotheaverageofthemostrecentflowerencounters.Insteadofincorporatingsearchtimesforvarioustypesintodecision-makingasintheoptimaldietmodel,Zhangetal.includeanaversionfactorrelatedtothehungeroftheforagerovertime:foragersthathaven’teatenrecentlyaremorelikelytoacceptencounteredprey.Whileaninterestingmodel,thissimulationislesslikelytoberelevanttobumblebeeforagers,sincetheirbehaviorisnotdrivenbyindividualhunger[Goulson,2009].

FutureworkusingtheSimBeemodelwillinvolvemorerealisticaspectsofthesimulation,includingchangingfloralenvironments,alternatememoryweights,andadditionalpreytypesthatofferarangeofavailablerewardsinsteadofastaticvalue.Adjustingthedecision-makingalgorithmtoincludemultiplepreytypesthatplacemoreweightonthemostrecentdatagatheredwillcreateamorerealisticsystem,allowingbeestoadapttoconstantlychangingresourcesavailable.

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PredictingtheeffectofmemoryimpairmentontheoverallbeepopulationisthefinalgoaloftheSimBeemodel.Themodelwillcomplementandenhanceinformationgainedfromlaboratoryandfieldstudies.

TheSimBeemodelcanalsobeusedinaneducationaltoolthatallowsstudentstolearnaboutbiologicalconceptsthroughagent-basedmodelling.Thesimulationseparatesaspectsofforagingintosinglevariables,whichgivesstudentstheabilitytohypothesistestbyadjustingsingleparametersofthemodelwithseparateslidersforeachapplicablemodelaspect.Themodelbydesignisuserfriendlyandinteractivewiththereal-timeabilitytoadjustenvironmentalvalues,whichcanfacilitatepubliceducationandagreaterunderstandingoftheimportanceofbumblebeedecline.

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Becher,M.A.,Grimm,V.,Thorbek,P.,Horn,J.,Kennedy,P.J.,Osborne,J.L.(2014)BEEHAVE:asystemsmodelofhoneybeecolonydynamicsandforagingtoexploremultifactorialcausesofcolonyfailure.JournalofAppliedEcology51:470–482.

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Charnov,E.(1976).OptimalForaging:AttackStrategyofaMantid.TheAmericanNaturalist110:141-151.

Couvillon,M.J.,Toufailia,H.A.,Butterfield,T.M.,Shrell,F.,Ratnieks,F.L.W.,Shurch,R.(2015)CaffeinatedForageTricksHoneybeesintoIncreasingForagingandRecruitmentBehaviors.CurrentBiology25:2815-2818

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Dyer,A.G.,Dorin,A.,Reinhardt,V.,Garcia,J.E.,Rosa,M.G.P.(2014)Beereverse-learningbehaviorandintra-colonydifferences:Simulationsbasedonbehavioralexperimentsrevealbenefitsofdiversity.EcologicalModelling277:119-131.

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Goulson,D.Bumblebees:Behaviour,Ecology,andConservation(2ndEdition).2009.OxfordUniversityPress.

Grimm,V.,Berger,U.,DeAngelis,D.L.,Polhill,J.G.,Giske,J.,Railsback,S.F.(2010)TheODDprotocol:Areviewandfirstupdate.EcologicalModelling221:2760–2768

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Lourenco,R.,Delgado,M.,Korpimaki,E.,Penteriani,V.(2015)Evaluatingtheinfluenceofdiet-relatedvariablesonbreedingperformanceandhomerangebehaviorofatoppredator.PopulationEcology57:625-636

Mills,R.,Correia,L.(2015)TheInfluenceofTopologyinCoordinatingCollectiveDecision-MakinginBio-hybridSocieties.ProgressinArtificialIntelligence9273:250-261

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Appendix1:CodeStructure:Bees

• Move-bees:o Ifnoton-flower?[bees-search-for-flower]o Ifon-flower?[bees-collect-nectar]

• Bees-search-for-flowero ifchosen-flower=NOBODY[bees-decide-next-flower]o Ifnoflowers-in-view[moverandomly]o Ifchosen-flower!=NOBODY[facechosen-flower,movetowards]

• Bees-decide-next-flowero IFanyflowers-in-view[chooserandomflower]o Determinewhichpreytypeshouldbeacceptedo Ifcolorofchosen-flower=next-color[acceptencounter]

• Bees-collect-nectaro Bees-determine-memory-valueso Update-memoryo bee-decide-preyo Iftimespentonflowerreached,forageandleave

• Bees-determine-memory-valueso Ifmutually-exclusivehandlingtime:

§ Subtracthandling-timeofbetweenencountersrecordedo Storesearch-timeinsearchmemoryo Ifaccepting-encounter?true

§ Storeenergyandhandlingtimesinmemory• Update-memory

o Ifmemorylistlength>bee-memory-length§ removeoldestmemoryvalue

o Ifsamplingandallmemorylistsfilled§ Setsamplingfalse§ Resetnectarheld,encountertrackingvariables

• Bee-decide-preyo Calculateaveragesformemorylists

§ Searchtimes§ Handlingtimes§ Energycontents

o Determineprey1=greatestenergy/handling-timeo Determinethreshold

§ ((p1energy*p2handling)/p2energy)–p1handlingo Ifaveragep1search-time>threshold,generalize

§ Acceptanypreytypeencounterednexto Ifaveragep1search-time<threshold,specialize

§ Acceptonlyprey1fornextencounterFlowers

• Regenerate-flower-nectar

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o Ifnectarcontent<flower-max-nectar[refillnectar]• Flowers-track-occupation

o Ifanybees-here[setoccupied?true]o Else[setoccupied?false]

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Appendix2:FullSimBeeCode;--------------------------------------------------breeds------------------------------------------------------------------------------breed[flowersflower]breed[beesbee]breed[hiveshive];-------------------------------------------------variables----------------------------------------------------------------------------globals[;-ticks-at-sampling-end;-----outputvariable:timewhensamplingendedspecialized-at-sampling-end?;-----outputvariable:ifbeespecializedatsamplingendworld-name;-----outputvariable:whattheworldoutputfileisnamedhive-1;----IDof1sthivehive-2;----IDof2ndhiveswitch-count;-----outputvariable:#timesflowercolor!=lastvisittotal-count;-----outputvariable:#flowervisitstotalerror-visit-count;-----debugvariable:ifbeevisitsunintendedflowertravel-distances;-----outputvariable:distancesbetweenvisitedflowersthreshold-switch-count;-----outputvariable:#timesS1wentabove/belowthresholdNectarGathered;-----outputvariable:totalnectarbeegatheredcurrent-iteration;-----behaviorspacevariable:trackscurrentrunnext-run?;-----behaviorspacevariable:iftrue,behaviorspacedeletescurrentworldfile,startsnextrundone-time?;-----behaviorspacevariable:alsousedtoendstartnextruninsomecasesblue-search-mean;-----OFTvariable:averagebluesearchtimeofbeememoryyellow-search-mean;-----OFTvariable:averageyellowsearchtimeofbeememoryyellow-handling-mean;-----OFTvariable:avgyellowhandlingtimeblue-handling-mean;-----OFTvariable:avgbluehandlingtimeyellow-energy-mean;-----OFTvariable:avgyellowenergycontentblue-energy-mean;-----OFTvariable:avgblueenergycontentprey-1;-----OFTvariable:defineswhichpreytypeismostrewardingnext-prey;-----OFTvariable:definesifnextencounterwillbespecializedorgeneralizedsearch-threshold;-----OFTvariable:calculateswhatthresholdis:(E1*h2)/E2)-h1last-visit-yellow;-----graphvariable:updatessequencegraphwithyellowbarlast-visit-blue;-----graphvariable:updatessequencegraphwithbluebarsame-color-inarow;-----graphvariable:trackssetsofsame-colorvisitpatternsPropNecBlue;-----graphvariable:displaysproportionofnectarhascomefromblueflowersPropNecYellow;-----graphvariable:displaysproportionofnectarhascomefromyellowflowersblue-population;-----graphvariable:tracks#blueflowersinenvironmentyellow-population;-----graphvariable:tracks#yellowflowersinenvironmentlast-flower1;-----debugvariable:displayslastflowervisitedthis-flower1;-----debugvariable:displayscurrentflowervisitingblue-accepted;-----graphvariable:displays#blueflowersacceptedblue-encountered;-----graphvariable:displays#blueflowersencounteredyellow-accepted;-----graphvariable:displays#yellowflowersacceptedyellow-encountered;-----graphvariable:displays#yellowflowersencounteredblue-ratio1;-----graphvariable:displays%blueflowersaccepted/encounteredyellow-ratio1;-----graphvariable:displays%yellowflowersaccepted/encounteredseq-update?;-----graphvariable:iftrue,updatesvisitsequencegraphsampling-file-name;-----outputvariable:nameofseparateexportfileforsamplingdataifneededspecialized?;-----outputvariable:indicatesofbeespecializedornotatsamplingendlandscapeID;-----outputvariable:unique#foreachgeneratedenvironment,formultiplerunswithsamelayout;-]bees-own[on-flower?;-----indicatesifflowerpresenthive-belongs-to;-----whichhiveitbelongstobee-nectar-collected;-----amountofnectarcollectedtime-on-flower;-----howlongbeehasbeensittingonflowerflowers-in-view;-----agentsetofallflowersdetectedinviewlast-flower;-----IDoflastflowervisitedchosen-flower;-----IDofnextflowertovisitnext-color;-----colorofnextfloweryellow-handling-memory;-----listofpastyellowflowerhandlingtimesblue-handling-memory;-----listofpastbluehandlingtimes

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yellow-energy-memory;-----listofyellowenergycontentsblue-energy-memory;-----listofblueenergycontentsyellow-search-memory;-----listofyellowsearchtimesblue-search-memory;-----listofbluesearchtimeslast-blue-time;-----timestampoflastblueencounterlast-yellow-time;-----timestampoflastyellowencounterflower-landing-memory;-----listoftimestampswhenpastflowersvisitedjust-landed?;-----indicatesifbeejustarrivedtoflowerornotsampling?;-----indicatesifbeeisstillsamplingprey1;-----indicatesthemorerewardingpreytypeprey2;-----indicatesthelessrewardingpreytypenextprey;-----equals"both"ifbeeisgeneralized,"blue"ifspecializedlast-color;-----coloroflastflowervisitedaccept-encounter?;-----indicatesifbeewillacceptthecurrentencounter]flowers-own[flower-nectar-content;-----amountofnectarinflowerflower-handling-time;-----amountofhandlingtimeforfloweroccupied?;-----indicatesifabeeisontheflowerflower-type;-----indicatespreytypeblock-number;-----indicateswhichregionflowerislocatedin]hives-own[hive-nectar-content;-----amountofnectarthat'sbeenreturnedtothehive]togenerate-worlds;------------------------------createworldsforbehaviorspaceletoriginal-numbernumber-of-worlds;-----tooffsetworldfilenamesletoriginal-handlingyellow-handling-time;-----savesoriginalyellowhandlingtime,toresetonceworldsgeneratedsetnumber-of-worldsnumber-of-worlds+last-world-offset;-----offsetsworldfilenameswhile[number-of-worlds>last-world-offset=true][setupsetbee-decision-type"prey-model"setbee-memory-length1000;-----exportworldfor'all-knowing'beesetnumber-of-worldsnumber-of-worlds-1setworld-name(word"g"number-of-worlds".csv")export-worldworld-namesetbee-memory-length10;-----adjustworldnameandbeememorylength,exportworldsetnumber-of-worldsnumber-of-worlds-1setworld-name(word"g"number-of-worlds".csv")export-worldworld-namesetbee-memory-length5;-----*setnumber-of-worldsnumber-of-worlds-1setworld-name(word"g"number-of-worlds".csv")export-worldworld-namesetbee-memory-length3;-----*setnumber-of-worldsnumber-of-worlds-1setworld-name(word"g"number-of-worlds".csv")export-worldworld-namesetbee-memory-length2;-----*setnumber-of-worldsnumber-of-worlds-1setworld-name(word"g"number-of-worlds".csv")export-worldworld-namesetbee-memory-length1;-----*setnumber-of-worldsnumber-of-worlds-1setworld-name(word"g"number-of-worlds".csv")export-worldworld-name]setlast-world-offsetlast-world-offset+original-number;-----ensuresworldfilesaren'toverwrittensetnumber-of-worldsoriginal-number;-----returnsworldcountsetyellow-handling-timeoriginal-handling;-----resetsyellowhandlingtimeendtoexport-lab-world;----------------exportspecificenvironmentforlabrecreationexport-worldexport-world-nameexport-view(word"view-"export-world-name".png");-----exportsimageoflandscapegeneratedendtodetermine-world;-----;-----------------forbehaviorspace:determinenextworldtoimportandrunletnum-test1000;-----startsveryhightoenurelastworldgeneratedisfirstletworld-test(word"g"num-test".csv")while[file-exists?world-test=false][;-----continuessearchinguntilfilenameexistssetnum-testnum-test-1setworld-test(word"g"num-test".csv")ifnum-test<0[error"Worlddoesn'texist"];-----indicatesnoworldlefttoimport

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]setworld-nameworld-test;-----setsworldnametoimportoncevalidworldnamefoundendtosetup-imported;-----;--------------forbehaviorspace:importnextworldandsetupclear-allreset-tickssetup-globalsdetermine-worldimport-worldworld-name;-----importsworldnamedeterminedfromdetermine-worldend;-----------------------------------------------settingvalues------------------------------------------------------------------------tofix-flower-count;-----;-------------forlabenvironment:makesuretotalflowercountiscorrectsetyellow-flower-counttotal-flower-count-blue-flower-countend;---------------------------------------------------setup------------------------------------------------------------------------------;-----;initializesbreedsandenvironmenttosetupclear-allreset-tickssetup-globalssettravel-distances[1];-----formonitoringdistancestravelled;-----;;callsetupfunctionssetup-patchessetup-flowersspace-flowerssetup-bees;setup-hives;-----hivesnotcurrentlyusedspace-flowersset-labelssetup-exportendtosetup-globals;-----addsinitialvaluestovariablesthatcan'tbeemptyatinitializationsetblue-search-mean1setyellow-search-mean1setyellow-handling-mean1setblue-handling-mean1setyellow-energy-mean1setblue-energy-mean1setsearch-threshold1setthreshold-switch-count0setdone-time?falsesetyellow-encountered1setyellow-accepted1setblue-encountered1setblue-accepted1setblue-ratio11setyellow-ratio11setseq-update?falsesetlandscapeIDrandom-float1end;----setup-patches----;makesthebackgroundgreentosetup-patchesaskpatches[setpcolor57]end

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;----setup-flowers----;initializescolor,shape,size,andlocationofflowerstospace-flowers;-----;;-------------adjustflowersintolab-environmentspacinggridaskflowers[ifelselab-flower-layout?=true[while[pxcormod5!=3orpycormod5!=0orany?otherflowers-here][setxyrandom-pxcorrandom-pycor];-----iflablayoutwanted,ensuresflowerplacedinavailablegridspots][while[any?otherflowersin-radius2=trueorany?hivesin-radius2=true];-----ifrandomlayoutwanted,ensuresflowersdon'toverlap[setxyrandom-pxcorrandom-pycor]]]endtosetup-flowers;-----createsfloweragentsset-default-shapeflowers"flower"create-flowersyellow-flower-count[;-----yellowflowerssetflower-type"f1"setxyrandom-pxcorrandom-pycorsetcoloryellowsetsize5setoccupied?truesetflower-nectar-contentyellow-energysetflower-handling-timeyellow-handling-time]setyellow-populationyellow-flower-countcreate-flowersblue-flower-count[;-----blueflowerssetflower-type"f2"setxyrandom-pxcorrandom-pycor;ifany?flowers-here[setxyrandom-pxcorrandom-pycor]setcolorbluesetsize5setoccupied?truesetflower-nectar-contentblue-energysetflower-handling-timeblue-handling-time]setblue-populationblue-flower-countend;----setup-bees----;initializescolor,shape,size,location,andvariablesofbeestosetup-beescreate-beesnumber-of-bees[setshape"bee2"setcolor45setsize4setxy0-20seton-flower?falsesettime-on-flower0;-----indicatesnotimehasbeenspentonflowertostartsethive-belongs-to1setbee-nectar-collected0setjust-landed?falsesetaccept-encounter?truesetflowers-in-viewflowerswith[self!=[last-flower]ofmyself]in-coneview-radiusview-degrees;-----addsflowerforinitialiationsetlast-flowerone-offlowers;-----choosesrandomfloweraslast-flowersovariableisn'temptyatstartsetchosen-flowerone-offlowerswith[self!=[last-flower]ofmyself];-----*chosen-flowersetnext-color[color]ofchosen-flowersetyellow-search-memory[10];-----addeddefaultnumbertolistssovariableisn'temptyatstartsetblue-search-memory[10];-----*setyellow-handling-memory[20];-----*setblue-handling-memory[20];-----*setyellow-energy-memory[10];-----*setblue-energy-memory[40];-----*setflower-landing-memory[1];-----*setlast-blue-time0;-----*setlast-yellow-time0;-----*setsampling?true;-----indicatesbeestartsinsamplingmodesetprey1blue;-----indicatesbeeconsidersblueasprey1tostartsetprey2yellow;-----indicatesbeeconsidersyellowasprey2tostartsetnextprey"both";-----indicatesbeecanvisitbothpreytypestostartsetPropNecBlue.5;-----50%nectarfrombluetostart

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setPropNecYellow.5;-----50%nectarfromyellowtostartsetblue-accepted0setblue-encountered0setyellow-accepted0setyellow-encountered0setyellow-ratio11;-----indicates100%yellowencountersacceptedtostartsetblue-ratio11;-----indicates100%blueencountersacceptedtostart]end;----setup-hives----;initializescolor,shape,size,location...ofhivestosetup-hives;-----notincurrentuseifnumber-of-hives=1[;initializeallvaluesforasinglehivecreate-hives1[setshape"beehive"setcolor45setsize10setxy-500setheading0sethive-1selfsethive-nectar-content0]]ifnumber-of-hives=2[;initializeallvaluesforhive1create-hives1[setshape"beehive"setcolor45setsize10setxy5050setheading0sethive-1selfsethive-nectar-content0];initializeallvaluesforhive2create-hives1[setshape"beehive"setcolor45setsize10setxy-50-50setheading0sethive-2selfsethive-nectar-content0]]end;-------------------------------------------------------go-----------------------------------------------------------------------------------;setsthesimulationinmotiontogoifshow-radius?;-----debug:redrawrangeofdetect-flowerseachtimebeemoves[clear-patchesdraw-view]regenerate-flower-nectarmove-beesflowers-track-occupationset-labelstickifexport?[export-data];-----fordataoutput:exportdataifapplicablerequirementsmetendtodraw-view;-----;debug;drawsthebee'sviewrangeaskbees[askpatchesin-coneview-radius360with[distancemyself>(view-radius-1)][setpcolorgreen]askpatchesin-coneview-radiusview-degreeswith[distancemyself>(1)][setpcolorwhite]]endtomove-bees;-----;determineswhenbeesexecutecertainbehaviorsaskbees[ifon-flower?=false[bees-search-for-flower];-----;whilethebeeisnotonaflowercollectingnectar

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ifon-flower?[bees-collect-nectar];-----;whilethebeeisonaflower]endtobees-search-for-flower;-----;directsbeesearchingbehaviorwhilenotonaflowersetflowers-in-viewflowerswith[self!=[last-flower]ofmyself]in-coneview-radiusview-degrees;-----updatesdetectedfloweragentsetifchosen-flower=NOBODY[bees-decide-next-flower];-----;-----endof"ifchosen-flower=NOBODY"sectionifany?flowers-in-view=falseorchosen-flower=NOBODY;-----ifthebeeseesnoflowersitmovesforwardrandomly[forward1rightrandom30leftrandom30]ifany?flowers-in-viewandchosen-flower!=NOBODY;whenthebeeseesthechosenfloweritheadstowardsit[setheadingtowardschosen-flowerifon-flower?=false[forward1]]ifany?flowers-here;-----whenthebeereachesthechosen-floweritsetsthevariableon-flower?totrue[ifelse[occupied?]ofone-offlowers-here=true;-----iffloweralreadyoccupied,moveon[forward1][ifelseone-offlowers-here=chosen-flower[;-----ifbeereachedchosen-flower,startcollectprocedure,elsecontinuetowardschosen-flowerseton-flower?trueforward0][forward1]]]endtobees-decide-next-flower;-----beedecideswhethertoacceptthenextencountersetlast-color[color]oflast-flowerifelserandom-flower?[;-----ifbeeshouldchoosearandomflowerindetectedfloweragentsetifany?flowers-in-view[setchosen-flowerone-offlowers-in-viewifbee-decision-type="prey-model"[;-----prey-model:ifchosenfloweriscorrectpreytype,beewillacceptencounterifelse[color]ofchosen-flower=next-color[setaccept-encounter?true][setaccept-encounter?false]ifnextprey="both"[setaccept-encounter?true];-----ifbeeisgeneralized/sampling,ensureschosenflowerwillbeaccepted]ifbee-decision-type="PropNec"[;-----PropNec:ifchosen-flowercolorhashigher%nectar,ensureacceptance.Iflower%nectar,P(visit)=f1/f2%chanceifelsePropNecBlue>=PropNecYellow[ifelse[color]ofchosen-flower=blue[setaccept-encounter?true][ifelserandom-float1<(PropNecYellow/PropNecBlue)[setaccept-encounter?true][setaccept-encounter?false]]][ifelse[color]ofchosen-flower=yellow[setaccept-encounter?true][ifelserandom-float1<(PropNecBlue/PropNecYellow)[setaccept-encounter?true][setaccept-encounter?false]]]]ifsampling?[setaccept-encounter?true];-----ifbeeinsamplingmode,ensuresacceptance]][setchosen-flowermin-one-offlowers-in-viewwith;-----random-flower?isfalse:beeselectsclosestflowerindetectedagentset[color=[next-color]ofmyselfandself!=[last-flower]ofmyself][distancemyself]]

36

endtobees-collect-nectar;-----directsbeecollectionbehaviorwhileonaflowerletthis-flowerone-offlowers-herebees-determine-memory-values;-----calculatesearchtimesformemorystorageupdate-memory;-----adjustmemorylistsifapplicablesetNectarGatheredbee-nectar-collected;-----updatemonitorwithnewnectaramountheldbee-decide-prey;-----beeupdatespreydecisionssetseq-update?true;-----graph:updatesequencegraphsetjust-landed?false;-----endsone-time-onlyportionofcalculationswhenbeeislandedifnotaccept-encounter?[settime-on-flower[flower-handling-time]ofthis-flower+1];-----ifbeeacceptedencounter,itmustwaitatthislocationfor(handling-time)tickssettime-on-flower(time-on-flower+1)ifthis-flower!=chosen-flower[seterror-visit-counterror-visit-count+1];-----debug:ifthisflowerwasn'tthechosen-flower,trackerroriflast-flower!=nobody[ifelse[color]oflast-flower!=[color]ofthis-flower[iftime-on-flower>=[flower-handling-time]ofthis-flower+SwitchCostPenalty;-----switchcost:iflastvisitedwasdifferentcolor,increasedbeepausetimerequired[askthis-flower[setflower-nectar-content0];-----askflowertodepletenectarheldletthis-distancedistancelast-flowersettravel-distanceslputthis-distancetravel-distances;-----updatelistofdistancestravelledsetlast-flowerthis-flowersetlast-flower1last-flowerseton-flower?falsesetchosen-flowerNOBODYbees-choose-colorsetswitch-countswitch-count+1settotal-counttotal-count+1settime-on-flower0forward2]][iftime-on-flower>=[flower-handling-time]ofthis-flower;-----switchcost:iflastvisitedwassamecolor,lesspausetimewasrequired[askthis-flower[setflower-nectar-content0]letthis-distancedistancelast-flowersettravel-distanceslputthis-distancetravel-distancessetlast-flowerthis-flowerseton-flower?falsesetchosen-flowerNOBODYbees-choose-colorsettotal-counttotal-count+1settime-on-flower0forward2]]]endtobees-determine-memory-valuesletthis-flowerone-offlowers-heresetthis-flower1this-flowersetjust-landed?true;-----ensurescertaintasksonlyoccuronce,atlanding(addingtomemorylists,etc)iftime-on-flower=0andlast-flower!=nobody[ifelse[color]ofthis-flower=[color]oflast-flower;-----adjustscolorstreakmonitorvariables[setsame-color-inarowsame-color-inarow+1][setsame-color-inarow0]if[color]ofthis-flower=yellow[letlast-search(ticks-last-yellow-time);-----calculatestimesincelastyellowflowervisitifhandling-time-mode="mutually-exclusive"[;-----ifmutually-exclusiveprey-model:subtracthandlingtimesofvisitedflowersofotherpreytypefromsearchtimeletyellow-tempflower-landing-memorywhile[lengthyellow-temp>1=true][ifelsefirstyellow-temp<last-yellow-time[setyellow-tempbut-firstyellow-temp];-----iftimestampearlierthanlast-yellow,removefromlist[setlast-searchlast-search-blue-handling-time;-----iftimestampbetweenlast-yellowandcurrent,subtractfromsearchtime,removefromlistsetyellow-tempbut-firstyellow-temp]]]setyellow-search-memorylputlast-searchyellow-search-memory;-----addsearchtimetoyellowsearchmemorysetlast-yellow-time(ticks+yellow-handling-time);-----setnewlast-yellow-time,adjustforhandlingtime

37

setyellow-encounteredyellow-encountered+1setyellow-ratio1yellow-accepted/yellow-encounteredifaccept-encounter?=true[;-----ifacceptingencounter:alsoaddcurrentflower'shandlingtime/energytomemorylistssetflower-landing-memorylputticksflower-landing-memorysetyellow-energy-memorylput[flower-nectar-content]ofthis-floweryellow-energy-memorysetyellow-handling-memorylput[flower-handling-time]ofthis-floweryellow-handling-memorysetyellow-acceptedyellow-accepted+1setyellow-ratio1yellow-accepted/yellow-encountered;-----updateaccepted/encounteredratioaftermemoryupdatesetbee-nectar-collected(bee-nectar-collected+[flower-nectar-content]ofthis-flower);-----addflower'snectarcontenttonectar-held]]if[color]ofthis-flower=blue[;-----repeatstimesincelastflowervisitcalculations,butforblueflowersletlast-search(ticks-last-blue-time)ifhandling-time-mode="mutually-exclusive"[;-----ifmutually-exclusiveprey-model:subtracthandlingtimesofvisitedflowersofotherpreytypefromsearchtimeletblue-tempflower-landing-memorywhile[lengthblue-temp>1=true][ifelsefirstblue-temp<last-blue-time[setblue-tempbut-firstblue-temp];-----iftimestampearlierthanlast-blue,removefromlist[setlast-searchlast-search-yellow-handling-time;-----iftimestampbetweenlast-blueandcurrent,subtractfromsearchtime,removefromlistsetblue-tempbut-firstblue-temp]]]setblue-search-memorylputlast-searchblue-search-memorysetlast-blue-time(ticks+blue-handling-time)setblue-encounteredblue-encountered+1setblue-ratio1blue-accepted/blue-encounteredifaccept-encounter?=true[;-----ifacceptingencounter:alsoaddcurrentflower'shandlingtime/energytomemorylistssetflower-landing-memorylputticksflower-landing-memorysetblue-energy-memorylput[flower-nectar-content]ofthis-flowerblue-energy-memorysetblue-handling-memorylput[flower-handling-time]ofthis-flowerblue-handling-memorysetblue-acceptedblue-accepted+1setblue-ratio1blue-accepted/blue-encounteredsetbee-nectar-collected(bee-nectar-collected+[flower-nectar-content]ofthis-flower);-----addflower'snectarcontenttonectar-held]ifaccept-encounter?=false[;-----debug:blueflowersshouldalwaysbeaccepted,ifnotthenerrorisloggedaskthis-flower[setcolorredsetsize10]export-interface(word"blue-not-accepted"bee-memory-length"-"bee-decision-type"-"random-float1.0".png")askthis-flower[setcolorbluesetsize5]]];-----endofsearchtimeadjustment/memorylistadditions]endtobees-choose-colorifnextprey="yellow"[ifelserandom100<resample-threshold[setnext-coloryellow][setnext-colorblue]]ifnextprey="blue"[ifelserandom100<resample-threshold[setnext-colorblue][setnext-coloryellow]]ifnextprey="both"[ifelserandom100<50[setnext-colorblue][setnext-coloryellow]]endtobees-deliver-nectar-to-hive;-----ifnectar-heldreachesbee-nectar-max,returntohiveandemptynectar-heldintohive(inactive)ifany?hives-here[askone-ofhives-here[sethive-nectar-content(hive-nectar-content+[bee-nectar-collected]ofmyself)setNectarGatheredNectarGathered+[bee-nectar-collected]ofmyself]setbee-nectar-collected0]ifhive-belongs-to=1[setheadingtowardshive-1ifany?hives-here=false[forward1]]ifhive-belongs-to=2[setheadingtowardshive-2ifany?hives-here=false[forward1]]endtoregenerate-flower-nectar;-----ifflowerunoccupiedandnectarlessthanmax,refillnectaraskflowers

38

[ifcolor=blue[ifflower-nectar-content<blue-energy[setflower-nectar-contentblue-energy]ifflower-nectar-content>blue-energy[setflower-nectar-contentblue-energy]setflower-handling-timeblue-handling-time]ifcolor=yellow[ifflower-nectar-content<yellow-energy[setflower-nectar-contentyellow-energy]ifflower-nectar-content<yellow-energy[setflower-nectar-contentyellow-energy]setflower-handling-timeyellow-handling-time]]endtoflowers-track-occupation;-----ifanybeesonflower,setoccupied?trueaskflowers[ifelseany?bees-here[setoccupied?true][setoccupied?false]]endtoset-labels;-----debug:changeagentlabelsifelsebee-nectar-label?[askbees[setlabelprecisionbee-nectar-collected3]][askbees[setlabel""]]ifelseflower-nectar-label?[askflowers[setlabelprecisionflower-nectar-content3]][askflowers[setlabel""]]ifelsehive-nectar-label?[askhives[setlabelprecisionhive-nectar-content3]][askhives[setlabel""]]ifbee-label?[ifbee-label-as="blue-search-times"[askbees[setlabelblue-search-memory]]ifbee-label-as="yellow-search-times"[askbees[setlabelyellow-search-memory]]]endtoupdate-memory;;--------memory-lengthbasedupdate-memory-Activeaskbees[;ifbee'smemorylistshaveanewnectaraddedto1stlistindexandit'slongerthanallowed,lastvalueremoved(independentfromeachother)iflengthyellow-energy-memory>bee-memory-length[setyellow-energy-memorybut-firstyellow-energy-memory]iflengthblue-energy-memory>bee-memory-length[setblue-energy-memorybut-firstblue-energy-memory]iflengthyellow-handling-memory>bee-memory-length[setyellow-handling-memorybut-firstyellow-handling-memory]iflengthblue-handling-memory>bee-memory-length[setblue-handling-memorybut-firstblue-handling-memory]iflengthyellow-search-memory>bee-memory-length[setyellow-search-memorybut-firstyellow-search-memory]iflengthblue-search-memory>bee-memory-length[setblue-search-memorybut-firstblue-search-memory]iflengthflower-landing-memory>50[setflower-landing-memorybut-firstflower-landing-memory]ifnotempty?blue-search-memory[setblue-search-meanmeanblue-search-memory];-----updatelistaveragesforOFTthresholdifempty?yellow-search-memory=false[setyellow-search-meanmeanyellow-search-memory]ifempty?yellow-handling-memory=false[setyellow-handling-meanmeanyellow-handling-memory]ifempty?blue-handling-memory=false[setblue-handling-meanmeanblue-handling-memory]ifempty?yellow-energy-memory=false[setyellow-energy-meanmeanyellow-energy-memory]ifempty?blue-energy-memory=false[setblue-energy-meanmeanblue-energy-memory]setsearch-threshold((blue-energy-mean*yellow-handling-mean)/yellow-energy-mean)-blue-handling-meanifsampling?andlengthblue-energy-memory>=bee-memory-lengthandlengthyellow-energy-memory>=bee-memory-length[;-----ifbothmemorylistsfull,endsamplingmodeexport-sampling-filessetticks-at-sampling-endticksifelseblue-search-mean>=search-threshold[setspecialized-at-sampling-end?false][setspecialized-at-sampling-end?true]setsampling?falsesetthreshold-switch-count0;-----resetaccepted/encounteredmonitorsnowthatsamplingendedsettotal-count0setblue-encountered0setblue-accepted0setyellow-encountered0setyellow-accepted0setNectarGathered0askbees[setbee-nectar-collected0]];ifbeevisitedenoughflowerstofillit'slist,nolongersamplingsetsearch-threshold((blue-energy-mean*yellow-handling-mean)/yellow-energy-mean)-blue-handling-mean;-----updatesearch-thresholdwithnewmemoryvaluesifnotempty?yellow-energy-memoryandnotempty?blue-energy-memory[;-----PropNec:update%valueswithnewmemoryvaluesletyesmeanyellow-energy-memoryletbesmeanblue-energy-memory

39

setPropNecYellowprecision(yes/(yes+bes))3setPropNecBlueprecision(bes/(yes+bes))3ifseq-update?=true[;-----graph:updatesequencegraphsifelse[color]oflast-flower=yellow[setlast-visit-yellow1setlast-visit-blue0setseq-update?false][setlast-visit-blue1setlast-visit-yellow0setseq-update?false]]]]endtobee-decide-preyifbee-decision-type="prey-model"[letyemyellow-energy-meanletyhmyellow-handling-meanletbemblue-energy-meanletbhmblue-handling-meanletlastpreynextpreyifelse(yem/yhm)>(bem/bhm);-----determinewhichflowercolorisprey1(bestchoice)[setprey1"yellow";-----ifyellowisprey1:setprey2"blue"ifelseyellow-search-mean>((yem*bhm/bem)-yhm);-----determineifbeeshouldgeneralizeorspecialize[setnextprey"both"][setnextprey"yellow"]][setprey1"blue";-----ifblueisprey1:setprey2"yellow"ifelseblue-search-mean>((bem*yhm/yem)-bhm);-----determineifbeeshouldgeneralizeorspecialize[setnextprey"both"][setnextprey"blue"]]iflastprey!=nextprey[setthreshold-switch-countthreshold-switch-count+1];-----ifgeneralize/specializechanged,increasethreshold-switch-countsetprey-1prey1setnext-preynextprey]ifbee-decision-type="PropNec"[;-----forPropNec:determinewhichpreytypehashigher%nectarinmemory,setasprey1letyesmeanyellow-energy-memoryletbesmeanblue-energy-memoryifelsebes>=yes[setprey1"blue"setprey2"yellow"][setprey1"yellow"setprey2"blue"]setprey-1prey1setnext-prey"NA"]endtosetup-export;-----createexportfileifonedoesn'texistsetsampling-file-name(wordexport-file-name"-sampling.csv")iffile-exists?sampling-file-name=false[create-sampling-files]iffile-exists?export-file-name=false[create-files]iffile-exists?export-file-name2=false[create-files2]iffile-exists?sampling-file-name=false[create-sampling-files]endtoexport-data;export-specific'foreverloop'procedure

40

;ifticks=1andcurrent-iteration=1[create-files];createoutputspreadsheet,addvariablenamesanddefinitiononceperexperimenttrial;ifticksmod(sim-iteration-length-1)=0[export-files];outputtotalvariablesattheendofeachiteration(totalnectargatheredbyhive1,etc)if(ticks-ticks-at-sampling-end)mod(sim-iteration-length-1)=0[export-files]endtocreate-files;initialoutputheadersandrelevantvariablesettingsatthestartofeachtrialletspacer","file-openexport-file-namefile-print(listspacer"Outputname:"spacerexport-file-namespacer"Date+TimeStarted:"spacerdate-and-timespacer)file-print(listspacer"NectarGathered"spacer"total-count"spacer"bee-decision-type"spacer"threshold-switch-count"spacer"yellow-energy"spacer"blue-energy"spacer"yellow-handling-time"spacer"blue-handling-time"spacer"yellow-flower-count"spacer"blue-flower-count"spacer"bee-memory-length"spacer"yellow-encountered"spacer"yellow-accepted"spacer"blue-encountered"spacer"blue-accepted"spacer"handling-time-mode"spacer"search-threshold"spacer"specialized-at-sampling-end?"spacer"world-name"spacer"landscapeID"spacer"ticks"spacer"ticks-at-sampling-end"spacer)file-closeendtocreate-files2;initialoutputheadersandrelevantvariablesettingsatthestartofeachtrialletspacer","file-openexport-file-name2file-print(listspacer"Outputname:"spacerexport-file-namespacer"Date+TimeStarted:"spacerdate-and-timespacer)file-print(listspacer"blue-handling-time:"spacerblue-handling-timespacer"yellow-handling-time:"spaceryellow-handling-timespacer"blue-energy:"spacerblue-energyspacer"yellow-energy:"spaceryellow-energy"yellow-flower-count:"spaceryellow-flower-countspacer"bee-memory-length:"spacerbee-memory-lengthspacer)file-print(listspacer"Blue-flower-count"spacer"Blue-search-mean"spacer"inequality"spacer)file-closeendtoexport-files2letspacer","letinequality(((blue-energy-mean*yellow-handling-mean)/yellow-energy-mean)-blue-handling-mean)file-openexport-file-name2file-print(listspacerblue-flower-countspacerblue-search-meanspacerinequalityspacer)file-closeendtoexport-files;-----attrialend,exportlistedvariablesintoanewspreadsheetrow,setnext-run?trueifnext-run?!=true[letspacer","letActualPVL(total-count-switch-count)/(total-count+1)letMeanTDmeantravel-distancesifelse[sampling?]ofbees=false[file-open(word"sampling-"export-file-name)][file-openexport-file-name]file-print(listspacerNectarGatheredspacertotal-countspacerbee-decision-typespacerthreshold-switch-countspaceryellow-energyspacerblue-energyspaceryellow-handling-timespacerblue-handling-timespaceryellow-flower-countspacerblue-flower-countspacerbee-memory-lengthspaceryellow-encounteredspaceryellow-acceptedspacerblue-encounteredspacerblue-acceptedspacerhandling-time-modespacersearch-thresholdspacerspecialized-at-sampling-end?spacerworld-namespacerlandscapeIDspacerticksspacerticks-at-sampling-endspacer)file-closeexport-interface(word"results"bee-memory-length"-"bee-decision-type"-"random-float1.0".png")ifexport-memory-lists?=true[export-lists]setnext-run?true]endtoexport-lists;-----exportentirememorylistsinseperatespreadsheet,ifneededifnext-run?!=true[letspacer","file-open(wordexport-file-name"-lists.csv")file-print(listspacerbee-decision-typespacerbee-memory-lengthspaceryellow-handling-timespacerlandscapeIDspacerworld-namespacer([blue-search-memory]ofbees)spacer)file-close]endtocreate-sampling-filesletspacer","file-opensampling-file-nameendtoexport-sampling-files;-----exportvariablesatsamplingendtoseperatespreadsheet,ifneededifnext-run?!=true[letspacer","file-opensampling-file-namefile-print(listspacersampling?spacerbee-memory-lengthspacerbee-decision-typespacerNectarGatheredspacertotal-countspaceryellow-encounteredspaceryellow-acceptedspacerblue-encounteredspacerblue-acceptedspacerthreshold-switch-countspaceryellow-energy-meanspacerblue-energy-meanspaceryellow-search-meanspacerblue-search-meanspacersearch-thresholdspacerspecialized?spacerlandscapeIDspacerworld-namespacer)]end

41

toupdate-label;changethebee'slabelduringthesimulationwiththedrop-downmenu'bee-label-as',allowsreal-timediagnosingifelsebee-label?[ifbee-label-as="blue-search-times"[askbees[setlabelblue-search-memory]]ifbee-label-as="yellow-search-times"[askbees[setlabelyellow-search-memory]]][askbees[setlabel""]]end