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Parasites in Ecological Communities
From Interactions to Ecosystems
Interactions between competitors, predators and their prey have traditionally
beenviewedasthefoundationofcommunitystructure.Parasites–longignored
in community ecology – are now recognised as playing an important part in
influencingspeciesinteractionsandconsequentlyaffectingecosystemfunction.
Parasitism can interact with other ecologicaldrivers,resultinginboth detri-
mental and beneficial effects on biodiversity and ecosystem health. Species
interactions involving parasites are also key to understanding many biological
invasionsandemerginginfectiousdiseases.Thisbookbridgesthegapbetween
communityecologyandepidemiologytocreateawide-rangingexaminationof
howparasitesandpathogensaffectallaspectsofecologicalcommunities,enab-
lingthenewgenerationofecologiststoincludeparasitesasakeyconsideration
in their studies.
This comprehensive guide to a newly emerging field is of relevance to
academics, practitioners and graduates in biodiversity, conservation and popu-
lation management, and animaland humanhealth.
melanie j. hatcher isVisitingResearchFellow,SchoolofBiology,Univer-
sity of Bristol, UK, and Senior Research Fellow, Institute of Integrative and
ComparativeBiology, University of Leeds,UK.
alison m. dunn is Reader in Evolutionary Ecology, Institute of Integrative
and Comparative Biology, Faculty of Biological Sciences, University of
Leeds, UK.
ecology, biodiversityand conservation
SeriesEditors
MichaelUsher UniversityofStirling,andformerlyScottishNaturalHeritage
DenisSaunders FormerlyCSIRODivisionofSustainableEcosystems,Canberra
RobertPeet UniversityofNorthCarolina,ChapelHill
AndrewDobson PrincetonUniversity
EditorialBoard
PaulAdam UniversityofNewSouthWales,Australia
H.J.B.Birks UniversityofBergen,Norway
LenaGustafsson SwedishUniversityofAgriculturalScience
JeffMcNeely InternationalUnionfortheConservationofNature
R.T.Paine UniversityofWashington
DavidRichardson UniversityofCapeTown
JeremyWilson RoyalSocietyfortheProtectionofBirds
Theworld’sbiologicaldiversityfacesunprecedentedthreats.Theurgentchallengefacing
the concerned biologist is to understand ecological processes well enough to maintain
theirfunctioninginthefaceofthepressuresresultingfromhumanpopulationgrowth.
Those concerned with the conservation of biodiversity and with restoration also need
to be acquainted with the political, social, historical, economic and legal frameworks
within which ecological and conservation practice must be developed. The new
Ecology,BiodiversityandConservationserieswillpresentbalanced,comprehensive,up-to-
dateandcriticalreviewsofselectedtopicswithinthesciencesofecologyandconservation
biology, both botanical and zoological, and both ‘pure’ and ‘applied’. It is aimed at
advancedfinal-yearundergraduates,graduatestudents,researchersanduniversityteach-
ers,aswellasecologistsandconservationistsinindustry,governmentandthevoluntary
sectors.Theseriesencompassesawiderangeofapproachesandscales(spatial,temporal
andtaxonomic),includingquantitative,theoretical,population,community,ecosystem,
landscape, historical, experimental, behavioural and evolutionary studies. The empha-
sis is on science related to the real world of plants and animals rather than on purely
theoretical abstractions and mathematical models. Books in this series will, wherever
possible, consider issues from a broad perspective. Some books will challenge existing
paradigms and present new ecological concepts, empirical or theoretical models and
testablehypotheses.Otherbookswillexplorenewapproachesandpresentsyntheseson
topicsofecologicalimportance.
EcologyandControlofIntroducedPlants
JudithH.MyersandDawnBazely
InvertebrateConservationandAgriculturalEcosystems
T.R.New
RisksandDecisionsforConservationandEnvironmentalManagement
MarkBurgman
EcologyofPopulations
EsaRanta,PerLundbergandVeijoKaitala
NonequilibriumEcology
KlausRohde
TheEcologyofPhytoplankton
C.S.Reynolds
SystematicConservationPlanning
ChrisMargulesandSahotraSarkar
LargeScaleLandscapeExperiments:LessonsfromTumut
DavidB.Lindenmayer
AssessingtheConservationValueofFreshwaters:AnInternationalPerspective
PhilipJ.BoonandCatherineM.Pringle
InsectSpeciesConservation
T.R.New
BirdConservationandAgriculture
JeremyD.Wilson,AndrewD.EvansandPhilipV.Grice
CaveBiology:LifeinDarkness
AldemaroRomero
BiodiversityinEnvironmentalAssessment:EnhancingEcosystemServicesforHumanWell-being
RoelSlootweg,AshaRajvanshi,VinodB.MathurandArendKolhoff
MappingSpeciesDistributions:SpatialInferenceandPrediction
JanetFranklin
DeclineandRecoveryoftheIslandFox:ACaseStudyforPopulationRecovery
TimothyJ.Coonan,CatherinA.SchwemmandDavidK.Garcelon
EcosystemFunctioning
KurtJax
Spatio-TemporalHeterogeneity:ConceptsandAnalyses
PierreR.L.Dutilleul
Parasites in Ecological
Communities
From Interactions to Ecosystems
MELANIE J. HATCHER
UniversityofBristol,UK
ALISON M. DUNN
UniversityofLeeds,UK
cambridgeuniversitypress
Cambridge,NewYork,Melbourne,Madrid,CapeTown,
Singapore,Sa˜oPaulo,Delhi,Tokyo,MexicoCity
CambridgeUniversityPress
TheEdinburghBuilding,CambridgeCB28RU,UK
PublishedintheUnitedStatesofAmericabyCambridgeUniversityPress,NewYork
www.cambridge.org
Informationonthistitle:www.cambridge.org/9780521889704
#M.J.HatcherandA.M.Dunn2011
Thispublicationisincopyright.Subjecttostatutoryexception
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noreproductionofanypartmaytakeplacewithout
thewrittenpermissionofCambridgeUniversityPress.
Firstpublished2011
PrintedintheUnitedKingdomattheUniversityPress,Cambridge
AcataloguerecordforthispublicationisavailablefromtheBritishLibrary
LibraryofCongressCataloguing-in-Publicationdata
Hatcher,MelanieJ.
Parasitesinecologicalcommunities:frominteractionstoecosystems/Melanie
J.Hatcher,AlisonM.Dunn.
p. cm.– (Ecology,biodiversityandconservation)
ISBN978-0-521-88970-4(Hardback)–ISBN978-0-521-71822-6(Paperback)
1. Parasites–Ecology. 2. Parasites–Behavior. 3. Host-parasiterelationships.
4. Parasitology. 5. Bioticcommunities. I. Dunn,AlisonM. II. Title. III. Series.
QL757.H342011
577.8057–dc22
2010050212
ISBN978-0-521-88970-4Hardback
ISBN978-0-521-71822-6Paperback
CambridgeUniversityPresshasnoresponsibilityforthepersistenceor
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Contents
Acknowledgements page xii
List of abbreviations xiv
1 Introduction 1
1.1 Concepts from epidemiology 5
1.2 Concepts from community ecology 9
1.3 Parasites 12
1.4 Aims of this book 17
2 Parasites and competitors 20
2.1 Introduction 20
2.1.1 Parasitism in modules of competition 21
2.2 One-host–one-parasite systems 22
2.2.1 Population dynamics 23
2.2.2 Competitive release 30
2.3 Apparent competition 32
2.3.1 Baseline theory 32
2.3.2 Implications for biological control 37
2.3.3 Empirical evidence for apparent competition 39
2.4 Parasite-mediated competition 49
2.4.1 Specialist parasite-mediated competition 49
2.4.2 Shared parasite-mediated competition 50
2.5 Parasite-modified competition 56
2.6 Examples from conservation and management 59
2.6.1 Red squirrels, grey squirrels and poxvirus 59
2.6.2 Grey partridge, pheasants and nematodes 63
2.6.3 White-tailed deer, moose and brainworm 66
2.6.4 Red grouse, deer, mountain hare, sheep and
louping ill virus 68
viii (cid:2) Contents
2.7 Competition between parasites 72
2.7.1 Competition for resources 77
2.7.2 Apparent and host-mediated competition 78
2.7.3 Coinfections and trait-mediated indirect effects 81
2.8 Conclusions 86
3 Parasites and predators 90
3.1 Introduction 90
3.1.1 Overview of predation modules 90
3.2 Parasites of prey with specialist predators 92
3.2.1 Baseline theory 92
3.2.2 Empirical examples 100
3.3 Parasites of prey with generalist predators 104
3.3.1 Baseline theory 104
3.3.2 Empirical examples 107
3.3.3 Evolutionary dynamics and predation 115
3.4 Parasites of predators 118
3.4.1 Baseline theory 118
3.4.2 Empirical examples 119
3.5 Parasites of predators and prey 123
3.5.1 Patterns and evolution of manipulation and
trophic transmission 124
3.5.2 Theoretical impacts on populations and
communities 126
3.6 Applications: predator control and harvesting 129
3.6.1 Do predators keep the herds healthy? 129
3.6.2 Biological control 133
3.6.3 Harvesting infected populations 135
3.7 Conclusions 138
4 Parasites and intraguild predation 141
4.1 Introduction 141
4.1.1 Parasitism and IGP 142
4.1.2 Predictions from basic IGP theory 143
4.2 Ecological significance of IGP 145
4.3 IGP as a unifying framework for competition and
predation 149
4.4 Parasites intrinsic to IGP 151
4.4.1 IGP in trophic transmission 152
4.4.2 Parasites and IGP in biological control 155
