Predicting the global economic costs of biological invasions by tetrapods

Highlights: • Global economic costs of invasive tetrapods conservatively sum to >US$55 billion. • Costs are predicted by species traits — longevity, female maturation age, diet and invasion pathway. • Directionality of predictions can differ between ecto- and endothermic invaders. • Significant discrepancies exist between databases documenting ecological and economic impacts. • Profiling of life history traits can help to identify and mitigate future costs. Abstract: Globalisation has 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 from 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 well-catalogued impacts and 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 invasion pathway traits, although the directionality in the association between impacts and these drivers varied 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.