Predation cues amplify the effects of parasites on the personality of a keystone grazer

1. Parasites can alter species interactions either by modifying infected host behavior or by influencing behavioral responses in uninfected individuals. Salt marsh ecosystems are characterized by a predator-prey interaction between the keystone grazer, Littoraria irrorata, and its main predator, Callinectes sapidus, both integral players in mediating the productivity of these habitats.
2. Littoraria also acts as the first intermediate host for at least four species of digenetic trematode. Parasite infection has been shown to decrease grazing and climbing in populations of Littoraria, though effects on infected host response to predators has not been investigated. Moreover, how infection might increase or decrease among-individual variation in behavior (i.e., animal personality) is still unknown. Here we ask how trematode infection affects the expression of boldness in the antipredator responses of L. irrorata in both the absence and presence of a predator cue.
3. We find that individua..., ,