Disease-induced stabilization of predator-prey oscillations.
Parasites are an integral part of virtually all food webs and species communities. Here we consider the invasion of a resident predator-prey system by an infectious disease with frequency-dependent transmission spreading within the predator population. We derive biologically plausible and insightful quantities (demographic and epizootiological reproduction numbers) that allow us to completely determine community composition. Successful disease invasion can have two contrary effects in driving its host population to extinction or in stabilizing predator-prey cycles. Our findings contradict predictions from previous models suggesting a destabilizing effect of parasites. We show that predator infection counteracts the paradox of enrichment. In turn, parasite removal from food webs can have catastrophic effects. We discuss the implications for biological control and resource management on more than one trophic level.
Hilker
Frank M
FM
Centre for Mathematical Biology, Department of Mathematical and Statistical Sciences, University of Alberta, Edmonton, AB, Canada T6G 2G1. fhilker@math.ualberta.ca
Schmitz
Kirsten
K
D000818:Animals; D003198:Computer Simulation; D020387:Food Chain; D008954:Models, Biological; D015233:Models, Statistical; D010272:Parasitic Diseases; D011156:Population Density; D011157:Population Dynamics; D011235:Predatory Behavior