Population viability analysis of feral raccoon dog (Nyctereutes procyonoides) in Denmark

Abstract

To assess the effects of actions implemented by the Danish Action Plan (DAP) for eradication of the raccoon dog, the population dynamics of the raccoon dog in Denmark was simulated. A population viability analysis (PVA) was generated with the stochastic simulation program, VORTEX, based on population parameters of raccoon dog in other European countries (Poland, Finland and Germany), combined with statistics on dead raccoon dogs reported to the Danish National Veterinary Institute between 2008 and 2012. Simulations showed that the present feral population of raccoon dogs would expand markedly and reach an assessed carrying capacity of 30 000 individuals with no intervention within 10 years. Simulations of the current culling strategy showed that the raccoon dog in Denmark would reach the carrying capacity with only a few years' delay compared to simulations with no intervention. This indicates that more efficient and intensive actions are needed to reach the goal of the DAP, aiming at eradicating the breeding population of raccoon dogs in Denmark within 2015. Simulations suggested that around 950 individuals should be culled a year from 2012 to 2015. Sensitivity analysis that was performed showed that the only parameter that had a strong influence on the population dynamic was the first year mortality.