In this work, a simple Lotka-Volterra model of intraguild predation with three species is analysed, searching for the effect of the top predator on the coexistence with its prey-competitor species. Apart from the well-known result that the intraguild prey must be superior in the competition for the shared prey in order to make coexistence possible, the magnitude of intraguild predation and the form by which the intraguild predator makes use of the intraguild prey have important consequences upon the dynamics, extending or restricting the possibilities of coexistence. These results are easily obtained by nullcline analysis. Also, some interesting results are obtained for the same model but including saturating functional response.
Copyright 2002 Academic Press.