Yield, compensation and fertility control: a model for vertebrate pests

Abstract

A graphical and quantitative framework is described linking production yield, damage by vertebrate pests, their abundance and density-dependent responses to imposed sterilisation. Compensatory responses of yield to pest damage, and pest populations to fertility control are described as part of the modelling. The focal relationship is that between yield and the proportion of a pest population permanently sterilised, which is shown to be generally positive though the form of the relationship varies with differing assumptions. Compensatory responses to pest damage of production systems, such as crops, livestock, trees or fish, generate non-linear responses between yield and pest damage, and yield and pest abundance. Compensatory responses by a pest population generate linear or curved relationships between abundance and the proportion of females sterilised. The model is illustrated using data from empirical studies, especially of European rabbits in Australia and New Zealand. It is recommended that the framework be evaluated on wild populations of vertebrate pests.