My final dissertation chapter explores the paradox of parasites on predators. Parasites likely decrease predator efficiency, which in turn decreases the level of vigilance in the prey, which in turn increases predator efficiency. Parasites are both good and bad for predators--is there an optimal level of parasites?
I modeled the dynamics, isoclines, and equilibria of the system in R with a Rosenzweig and MacArthur predator-prey model, using a Type I functional response. I used two implementations of prey vigilance: behaviorally fixed, where vigilance remained constant, and behaviorally flexible, where prey could adapt their vigilance to changing predator dynamics.