Chapter17BehavioralEcology2Behavioriswhatananimaldoesandhowitdoesit.Everybehaviorresultsfromacombinationofgenetic(“nature”)andenvironmental(“nurture”)influences–Instinctivebehavior–Learningisalsoconsideredabehavioralprocess.–Behaviorsareadaptive,theyaretheresultofalongevolutionaryprocessReedwarblerCuckooAspeciesinteractionthatnicelyillustratesmanyaspectsofanimalbehavior...InstinctsallowreedwarblerstobuildnestsandtolayeggswithoutlearninghowtodosoEvenso,nestingbehaviorsonlyoccurwhentheappropriateenvironmentalcuesarepresent,andtheyimprovewithexperience(throughlearning)ReedwarblerchicksinstinctivelybegforfoodCuckoosremoveahosteggandlayoneoftheirowninanestCuckoosinstinctivelyparasitizereedwarblers’nestsCuckoochicksinstinctivelyremovereedwarblereggsandyoungCuckoochicksinstinctivelyexploittheinnatefeedingbehaviorofthereedwarbleradultFemalecuckoochicksbecomeadultsthatinstinctivelyparasitizereedwarblernestsTheaforementioned,specificbehaviorsareinstinctiveadaptationsthatarosethroughevolutionbynaturalselectionAssuch,eachrequiresanenvironmentalcontextandcanbemodifiedbyexperienceandlearningHybridlovebirdsprovideanotherexampleofthedualnatureofbehavior(combininggeneticandenvironmentalinputs)…Hybridlovebirdsprovideanotherexampleofthedualnatureofbehavior(combininggeneticandenvironmentalinputs)…Hybridlovebirdsprovideanotherexampleofthedualnatureofbehavior(combininggeneticandenvironmentalinputs)…Hybridlovebirdsprovideanotherexampleofthedualnatureofbehavior(combininggeneticandenvironmentalinputs)…Hybridbehaviorhaselementsinheritedfrombothparents,andcanbemodifiedbyexperienceandlearningEverybehaviorhasbothproximateandultimatecausesProximatecausesor“how”,questionsaboutbehaviorfocusontheenvironmentalstimulithattriggerabehavior.Aswellas,focusonthegenetic,physiological,andanatomicalmechanismsunderlyingabehavioralact.EthologymainlyconcernsproximatecausesThreeethologistssharedtheNobelPrizein1973:KarlvonFrischKonradLorenzNikoTinbergenEverybehaviorhasbothproximateandultimatecausesUltimatecausesconcerntheevolutionarysignificanceofabehavior;i.e.,thebalancebetweenfitnesscostsandbenefitsthatselectivelyfavorsthebehaviorBehavioralecologyattemptstounderstandbothproximateandultimatecausesProximatecause:daylengthchangestriggerthereleaseofhormonesthatstimulateanest-buildingresponseUltimatecause:Thefitnessbenefitshaveoutweighedthecostsduringtheevolutionofnest-buildingbehavior17.3Instinctandlearning•Instinctivebehavior(本能行为)•Learnedbehavior(学习行为)InnatebehaviorInnate(instinctive)behaviorsdonothavetobelearned;theanimalperformsthemcorrectlywithnopriorexperienceAsimplekindofinnatebehaviorisafixedactionpattern(FAP)inresponsetoanexternalsensorystimulus(asignstimulus)•LorenzandTinbergen(1938)examinedegg-rollingbehaviorinthegreylaggoose.–Iftheeggslippedaway,shecontinuedthemotion.–Oncestarted,thebehaviormustbecompletedinaspecificway.•StereotypicalbehaviorFixedActionPatterns•Afixedactionpattern(FAP)isasequenceofunlearned,innatebehaviorsthatisunchangeable.–Onceinitiated,itisusuallycarriedtocompletion.FixedActionPatterns•AFAPistriggeredbyanexternalsensorystimulusknownasasignstimulus.–Theegg,forexample.FixedActionPatterns•Inmalesticklebacks,thesignstimulusforattackbehavior,istheredundersideofanintruder.(a)Amalethree-spinedsticklebackfishshowsitsredunderside.FixedActionPatterns•Whenpresentedwithunrealisticmodels,aslongassomeredispresent,theattackbehavioroccurs.•Noattackoccurswiththerealisticmodelthatlacksred.MalesticklebacksusesimplecuestorecognizeothermalesTinbergenshowedthatvariouslyshapedmodelscouldstimulatetheresponsejustaswellasrealmales,supportingthesign-stimulushypothesisMalesrespondedtored-belliedmodelsMalesdidnotrespondtorealisticmodelsthatlackedredbelliesFixedActionPatternsHumanbabieshaveaninnatedivereflexWateronthefaceisthesignstimulusClosingthemouth,holdingbreath,andkickingconstitutethefixedactionpatternTinbergenalsoshowedthatgullchicksbeginresponsetoanappropriatelycoloreddotAnappropriatelycoloreddotisthesignstimulusBeggingisthefixedactionpatternLearningcanmodifyinnateresponsesparrotControlofBehavior•Biologistsstudythewaysbothgenesandtheenvironmentinfluencethedevelopmentofbehavioralphenotypes.•Behaviorthatisdevelopmentallyfixediscalledinnatebehaviorandisunderstronggeneticinfluence.TheGeneticsofBehavior•Hereditarytransmissionofbehaviorisoftencomplex.•Occasionally,abehaviorwillfollowMendelianrules.TheGeneticsofBehavior•“Hygienic”beesuncaphivecellsandremoverottinglarvae.–Controlledbytwogenes.–Homozygousrecessiveindividualsshowthetrait.Learnedbehavior•Learnedbehaviorsarethosethathavebeenmodifiedbyexperience•Learnedbehaviorsrangefromverysimpletoverycomplex.Habituation适应:ananimalignoresaninsignificantstimulustowhichitiscontinuallysubjected,examples:wildanimalslosetheirfearofhuman.Valuablelearning:helptonotwasteenergyandtimebyrespondingtounimportantstimuliWequicklyhabituateto“background”noisesLearnedbehaviorHabituation(习惯化)Asanimalsbecomeaccustomedtoastimulus,habituationmayoccur.Imprinting–isatypeofbehaviorthatincludesbothlearningandinnatecomponentsandisg