How to effectively manage invasive predators to protect their native prey

Invasive predators can have substantial effects on their native prey and often there is a need for rapid action to quell this impact. Conservation action is often employed on behalf of the native prey by means of predator removal or birth control. The decision to employ such actions is often based on the outcome of a population viability analysis (PVA) or similar method aimed at reducing the predator population. These models typically focus on one species and ignore the effects of that species’ interaction with others. Thus, there is inherently a disconnect between what is being managed (the predator population) and the desired outcome of the management (the persistence of a prey population). We built stage-based, stochastic matrix models of an invasive generalist predator and its native prey and coupled these using a functional response. We generated management recommendations based on the number of times the prey population persisted, and considered a range of life history types for predators and prey. We compared the results of our model to those generated by a traditional elasticity analysis commonly used in PVA. Recommendations from our model disagreed with those made by traditional elasticity most often when considering management of short-lived predators, and showed complete agreement between methods when considering long-lived predators. We illustrate that traditional PVA approaches to managing predators for the benefit of prey can provide inefficient control recommendations. Our coupled predator–prey model provides a flexible yet comprehensive approach to exploring management actions designed to benefit native prey species, including the option of ‘do nothing’.