Long and “long”Long and “long” CoevolutionCoevolution –Arms race ParasitismParasitism MutualismMutualism Long-lasting interactions

The problem of exploitationThe problem of exploitation Oxpeckers & cattleOxpeckers & cattle –Birds defect Honeyguides & humansHoneyguides & humans –Humans ceased to benefit Stability of mutualisms

The behaviorThe behavior –Stations –Eat parasites, dead tissue Cleaners gain food, risk being eatenCleaners gain food, risk being eaten Clients may gain cleanliness, risk territories & mucusClients may gain cleanliness, risk territories & mucus Cleaner fish

Animals often provide mobilityAnimals often provide mobility Pollination and seed dispersalPollination and seed dispersal –Rewards are often required –Manipulation when possible “Ant plants”“Ant plants” Plant / animal interactions

The extended phenotypeThe extended phenotype The wasp and the spiderThe wasp and the spider Parasitic manipulation

The host’s survival / reproduction tradeoffThe host’s survival / reproduction tradeoff The parasite’s interestThe parasite’s interest –Castration –Behavioral castration In GammarusIn Gammarus …when parasites are transmitted horizontally

Intracytoplasmic parasites in eggsIntracytoplasmic parasites in eggs Feminization by WolbachiaFeminization by Wolbachia –In rolly-pollies –Increases transmission –Males prefer real females …when parasites are transmitted vertically

Trophic transmission to final hostTrophic transmission to final host GammarusGammarus –Polymorphus laevis Final host: FishFinal host: Fish Attracted to lightAttracted to light –P. minutus Final host: BirdsFinal host: Birds Swim near the surfaceSwim near the surface …when parasites have complex life cycles

1.Alters complex character 2.Favors infection in final host 3.Changes evolve more than once 4.Parasite benefits from change Proving manipulation

DefinitionDefinition –Care is exploited –Intraspecific –Interspecific Diversity: InterspecificDiversity: Interspecific –Slave-making ants –Maculinea –Fish –Birds Brood parasitism

Evolved independently several timesEvolved independently several times In cuckoosIn cuckoos –Specialist “gentes” Matched eggsMatched eggs –Rapid laying –Egg ejection –High begging rate Brood parasitism in birds

The host’s optionsThe host’s options –Incubate –Abandon (or bury) –Recognize and dispose Some hosts do discriminateSome hosts do discriminate Parasite’s options given recognitionParasite’s options given recognition –Switch hosts –Mimic the host’s eggs Do host defenses lag?Do host defenses lag? Or are they at equilibrium?Or are they at equilibrium? An evolutionary arms race

A test for equilibriumA test for equilibrium In native Africa, village weaverbirds reject cuckoo eggsIn native Africa, village weaverbirds reject cuckoo eggs 150 years after introduction to Hispaniola, no more discrimination150 years after introduction to Hispaniola, no more discrimination Ability regained shortly after shiny cowbird introductionAbility regained shortly after shiny cowbird introduction Mechanism: intrabrood variabilityMechanism: intrabrood variability Weaverbirds and cuckoos

Parasitism and sociality Horizontally transmitted parasites excel in group living hostsHorizontally transmitted parasites excel in group living hosts Free living parasites may be subject to dilution effectFree living parasites may be subject to dilution effect AllogroomingAllogrooming Group as quarantineGroup as quarantine