Predicting the global economic costs of biological invasions by tetrapods

Abstract

Globalisation has steadily accelerated rates of biological invasions worldwide, leading to widespread environmental perturbations that often translate into rapidly expanding socio-economic costs. Although such monetary costs can be estimated based on the observed effects of invasions, the pathways that lead invasive species to become economically impactful remain poorly understood. Here, we implement the first global-scale test of the hypothesis that adaptive traits that influence demographic resilience predict economic costs, using invasive terrestrial vertebrates as models given their rising impacts and well-catalogued characteristics. Our results reveal that total global costs of invasive tetrapods are conservatively in the tens of billions of dollars, with the vast majority due to damage costs from invasive mammals. These monetary impacts are predicted by longevity, female maturation age, diet and invasional pathway traits, although the directionality of predicted economic impacts also varied by trait across classes. Alarmingly, costs remain unknown for >90% of recorded established alien tetrapods worldwide, and across the majority of invaded countries. These huge socio-economic costs demonstrate the necessity of mitigating tetrapod invasions and filling knowledge gaps. Effective identification of traits predictive of costs among and within these groups can facilitate the prioritisation of resources to efficiently target the most damaging existing and emerging invasive tetrapod species.