PARASITIC CASTRATION PROMOTES COEVOLUTIONARY CYCLING BUT ALSO IMPOSES A COST ON SEX

Implementing New Regulation Promotes Health but May Increase Inequality

Competition with a host nestling for parental provisioning imposes recoverable costs on parasitic cuckoo chick's growth.

Chicks of the brood parasitic common cuckoo (Cuculus canorus) typically monopolize host parental care by evicting all eggs and nestmates from the nest. To assess the benefits of parasitic eviction behaviour throughout the full nestling period, we generated mixed broods of one cuckoo and one great reed warbler (Acrocephalus arundinaceus) to study how hosts divide care between own and parasitic y...

Parasitic castration of plants by fungi.

If the production of genetically variable offspring is a mechanism of host defense against parasites, then parasites capable of suppressing sexual reproduction in hosts may gain a selective advantage over parasites that do not do so. Recent work has shown that a range of systemic fungi infecting plants sterilize their hosts, effectively preventing coevolutionary responses by host populations to...

The Coevolutionary Romance of Social Learning and Parasitic Behavior

Once an animal begins to acquire behavior by social learning, it may be seduced by parasitic parasitic, behavior that reduces the animal’s fitness and thereby increases its own spread. However, the animal’s psychology will coevolve, potentially limiting the influence and spread of parasitic behavior. I revisit prominent models of the evolution of social learning and introduce the possibility of...

Quantitative estimation of the cost of parasitic castration in a Helisoma anceps population using a matrix population model.

Larval trematodes frequently castrate their snail intermediate hosts. When castrated, the snails do not contribute offspring to the population, yet they persist and compete with the uninfected individuals for the available food resources. Parasitic castration should reduce the population growth rate lambda, but the magnitude of this decrease is unknown. The present study attempted to quantify t...