For Birds and Humans: Challenges and Benefits of Rat Eradications From an Inhabited Islands (Ventotene, Central Italy)

BACKGROUND: Rat eradication from islands is a very effective tool that can free entire ecosystems from the pressure of alienpredators. In this study we present the case study of Ventotene (Ponziane Archipelago, central Italy), which to date is the islandwith by far the greatest number of human inhabitants ever freed from the negative implications of rats. Rat eradication wascarried out in the framework of the Life PonDerat project, co-financed by the European Union. Besides considering the conser-vation benefits due to the removal of rats, we also considered the socio-economic and pathogenic impacts from introduced rats.RESULTS: The overall economic cost of the rats was quantified to be at least€18 500 per year to the residents of the island.Several zoonotic pathogens were detected in the rat population prior to eradication. A reduction in the rodenticide distributedover time on the island was also estimated. Identifying the origin of the rat population allowed for the development of moretargeted and effective biosecurity measures. The eradication effort was challenged by the presence of domestic animals andvariability in support for baiting in urbanised areas.CONCLUSIONS: The results of this study open up new perspectives on island restoration projects. We demonstratedthe cost-effectiveness of the action, including ecosystem restoration, reduction of rat impacts in agricultural systems, andimproving overall health and food safety. Ourfindings will have implications for similar interventions on other islands,potentially bringing significant benefits.