Abstract
Ecological theory suggests that predators should keep prey populations
healthy by reducing parasite burdens. However, empirical studies show
that predators often have minimal effects on, or even increase,
parasitism in prey. To quantify the overall magnitude and direction of
the effect of predation on parasitism in prey, we conducted a
meta-analysis of 50 empirical studies. We also examined how key
attributes of these studies, including parasite type, study design, and
predator interaction type (consumptive vs. non-consumptive) contributed
to variation in the predator-prey-parasite interaction. We found that
the overall effect of predation on parasitism differed between parasites
and parasitoids and that predator interaction type, and whether a
predator was a non-host spreader of parasites were the most important
traits predicting the parasite response. Our results suggest that the
mechanistic basis of predator-prey interactions strongly influences the
effects of predators on parasites and that these effects, while context
dependent, are predictable.