Abstract

Omnivory is defined as feeding on more than one trophic level and is ubiquitous in most natural communities. We investigate a three-species nonlinear response omnivory model incorporating stage structure in the top predator. The model consists of four coupled ordinary differential equations involving fourteen parameters. As estimates from natural systems the parameters are subject to natural intrinsic variability and measurement error. To determine how infinitesimally small changes in the parameters affect the model solution, we derive sensitivity equations and numerically solve for the sensitivities. Our performance measure of the sensitivities shows that the mortality and search rates are the most sensitive parameters with conversion efficiencies at intermediate values. The resource enrichment rates and handling times are the least sensitive.