Evasive invasive species: Bioeconomic modelling of adaptive wild pigs

Wild pigs are considered one of the most successful invasive species due to their adaptability and range of damage to agricultural crops and natural ecosystems. The lack of natural predators and high reproductive rates have led to their population explosion. Pigs are intelligent, exemplified by the fact that survivors of culling attempts learn to avoid future culls, making control efforts more costly and ineffective. This study extends current bioeconomic invasive species modelling to incorporate different levels of species adaptation to control measures and refine the revenue and cost functions of the decision maker. In the suggested model, avoidant behavior is assumed constant and incorporated as a culling response parameter at various levels featured in the cost function. In addition, our model includes crop prices, yields, replanting and recovery cost variables by non-culled pigs, which has not been considered in the previous literature. Our results suggest that with higher levels of avoidant behavior, producers are unable to keep the wild pig population at sufficiently low levels and remain economically viable. Without an accurate assessment of revenues and costs of depredation, policymakers may fall short of the optimal culling strategy, as well as inadequately informing and supporting local producers and communities. The tradeoff between economic viability for local producers or communities and population control is complex. This analysis addresses the influence of one of those complexities, the ability of the targeted species to avoid culling attempts.