Cheats and deceits : how animals and plants exploit and mislead

321 Pages·2016·39.23 MB·English

by  Stevens

CHEATS AND DECEITS

3
GreatClarendonStreet,Oxford,OX26DP,
UnitedKingdom
OxfordUniversityPressisadepartmentoftheUniversityofOxford.
ItfurtherstheUniversity’sobjectiveofexcellenceinresearch,scholarship,
andeducationbypublishingworldwide.Oxfordisaregisteredtrademarkof
OxfordUniversityPressintheUKandincertainothercountries
©MartinStevens2016
Themoralrightsoftheauthorhavebeenasserted
FirstEditionpublishedin2016
Impression:1
Allrightsreserved.Nopartofthispublicationmaybereproduced,storedin
aretrievalsystem,ortransmitted,inanyformorbyanymeans,withoutthe
priorpermissioninwritingofOxfordUniversityPress,orasexpresslypermitted
bylaw,bylicenceorundertermsagreedwiththeappropriatereprographics
rightsorganization.Enquiriesconcerningreproductionoutsidethescopeofthe
aboveshouldbesenttotheRightsDepartment,OxfordUniversityPress,atthe
addressabove
Youmustnotcirculatethisworkinanyotherform
andyoumustimposethissameconditiononanyacquirer
PublishedintheUnitedStatesofAmericabyOxfordUniversityPress
198MadisonAvenue,NewYork,NY10016,UnitedStatesofAmerica
BritishLibraryCataloguinginPublicationData
Dataavailable
LibraryofCongressControlNumber:2015944361
ISBN 978–0–19–870789–9
PrintedinGreatBritainby
ClaysLtd,StIvesplc
LinkstothirdpartywebsitesareprovidedbyOxfordingoodfaithand
forinformationonly.Oxforddisclaimsanyresponsibilityforthematerials
containedinanythirdpartywebsitereferencedinthiswork.
For Audrey and Samuel

PREFACE
Most of us will have encountered one form of deception or another in the
naturalworld.It’shardnottobecausedeceptioniseverywhere.Itrangesfrom
therelativelyfamiliarsightofacaterpillarcamouflagedonatree,totheway
that some orchids elaborately mimic the smell and appearance of female
insects. But what’s often less well appreciated is the intricacy, extent, and
sometimestheextremityofdeceitandmanipulationusedbyanimals,plants,
andevenfungi.Thisisperhapspartlybecausedeceptionoftenoccursinmany
habitats that we are somewhat less familiar with (such as the deep sea or
tropical rainforests), and because it frequently occurs in sensory modalities
thatwearelesswellattunedto(suchasultravioletlightorultrasonicsounds).
Inshort,themorewelookfordeceptionandtrickeryinnature,themorewe
find it. I have spent most of my career working on various aspects of
deception, from camouflage in crabs through to mimicry by cuckoos, and
the extent that organisms go to in order to manipulate one another still
astounds me. In some regards it shouldn’t, because biologists have long
appreciatedthat being successful, in evolutionary terms,is about passingon
your genes to the next generation, and if that means tricking and exploiting
otherstodoso,thensobeit.Itis,however,thesophisticatedadaptationsand
intricacy involved in many forms of deception, and the number of forms of
deceptionthatexistinnature,thatneverceasestoamazeme.
Thisbookisaboutwhatweknowregardingdeceptioninnature(andwhat
wedon’t).Itisaboutthetypesofdeceptionthatexist,howtheywork,andthe
historical context and significance that deception has had, and continues to
have, in understanding evolution and adaptation. It is also very much about
the modern scientific work that has sought to investigate and understand
vii
PREFACE
deception across a wide range of organisms. Each chapter discusses one or
twomaintypesorfunctionsofdeceptionbroadlycoveringthreemainareas:
obtainingfood, avoidingbeing eaten, andreproduction. Withoutwishing to
give too much away, Chapter1 focuses on a couple of specific examples
(especiallyhowsomecaterpillarstrickantsintolookingafterthem)tointro-
ducesomekeyideasandconceptsinthestudyofdeception,andtoillustrate
justhowsophisticateditcanbe.Chapter2discusseshowanimalsmimicother
species,oraspectsoftheenvironment,inordertostealfoodfromothersand
tocapturetheirprey.ThisthemeiscontinuedintoChapter3,whichdiscusses
thewaysinwhichmanyspecies(especiallyspiders)usedeceptivecommuni-
cationsignalsandstimulitoactivelylurepreytowardsthemthroughavariety
ofapproaches.Thebookthenturnstohowanimalsusedeceptioninorderto
avoidbecomingamealthemselves,startingwithvarioustypesofcamouflage
(Chapter4), followed by how harmless animals mimic other dangerous spe-
ciessothatpredatorsavoidthem(Chapter5),andthenhowotherspeciesuse
suddenstartledisplaysandotherdeceptivetacticstocausepredatorstofleeor
ignorethem(Chapter6).Chapters7and8moveontothewaysthatanimals,
plants, and fungi trick and manipulate individuals of the same and different
speciesforreproduction.Westartwithhowbirdsandinsectsdupeothersinto
rearingtheiryoung,beforemovingontohowindividualsmanipulatepoten-
tialpartnersandrivalsinmating.Chapter9thenbringsthingsbacktogether
to highlight some of the key areas and concepts of deception, and looks
forwardstowhatwestillneedtounderstandanddiscover.
There are several processes that are thought by scientists to drive the
evolutionofdeceptioninnature.Definingkeyconceptsinasubjectlikethis
isimportantifwearetobeclearaboutwheredifferentprocessesoccur,and
how the type of deception discussed actually works and evolves. However,
whileimportant,thereisariskthatformaldefinitionscanbecomeoverlydry,
andIdidnotwanttointerruptthestoryofhowdifferenttypesofdeception
worktoomuchbyintroducingsemanticsfromtheoutset.Instead,Ihavetried
to find a balance between discussing the varied types and examples of
deceptionandhowtheyworkwithoutbeingtooformal,whilestilloutlining
what the key concepts are. Beyond the brief description that follows here,
viii
PREFACE
I have generally introduced key terms, including when they may occur in
nature,wheretheyarefirstrelevantinthebook,ratherthanadoptingamore
formal set of definitions and concepts from the very outset in Chapter1. Of
these, perhaps the most familiar type of deception is mimicry. Here, an indi-
vidualresemblesanotherspeciesinsomeway,suchthatitcandeceiveothers
into considering it as the ‘wrong’ object type. For example, some species of
harmless snake match the banding colours of venomous species to avoid
predators—something called Batesian mimicry. Conversely, aggressive mimicry
occurs when mimicry is used in an antagonistic way. For example, some
insects resemble the colour and shape of flowers to avoid being recognized
and avoided by their prey, which frequently visit real flowers. Camouflage is
also a widespread and intuitive idea (though much more complex and intri-
guingthangenerallyrealized).Frequently,camouflageinvolvesmatchingthe
appearanceof theenvironment, orsome specific objectin it (such as adead
leaf), sothat apredator(or preyitem) fails todetectorrecognizeit.Thereis
one other key concept worth highlighting here too: sensory exploitation. This
occurswhenanindividualproducesacommunicationsignalthathasevolved
tobehighlyeffectiveinstimulatingthesensorysystemofanotheranimal(of
thesameoranotherspecies).Indoingso,theindividualmakingthesignalcan
elicitagreaterbehaviouralresponsefromitstargetthanmightotherwisehave
been the case. For example, some frogs produce mating calls that have
evolvedspecificsoundpropertiesthatstronglystimulatethehearingsensitiv-
ity of females, and in doing so increase their chances of mating. Sensory
exploitation seems to be a common way that deception arises and works
innature.
Inprinciple,thisbookcouldhavebeenorganizedbyanothersetofideasor
subjects, and we should not think of the topic(s) of each chapter and the
notionsdiscussedasisolatedfromoneanother.Onthecontrary,Ihavetried
throughout to indicate common concepts and theories and attempt to link
them together. Nonetheless, the main themes of each chapter seemed to be
the most logical way to organize things; being the broad types of deception
that exist and what ultimately they achieve. It should also be said that the
comparativelengthofcertainchaptersandextentoftheideasdiscusseddoes
ix