Invasive species, such as rats, are one of the most severe agents of global change, which threatens the planet’s biodiversity. Since man has sailed the seas 40 millennia ago, rats have been stowaways on boats that reached the most remote islands, where there were no predators to contain their great ecological opportunism. The changes that rats have generated are very important, since, by breaking into simple and vulnerable systems such as insular ones, they alter the entire ecosystem. Rats have been the cause of the extinction of many endemic organisms, unique to these islands, such as invertebrates, reptiles and birds. On the island of Dragonera, the presence of the rat dates back to the arrival of man, approximately 4 millennia ago. Since then, the island’s biodiversity and its ecological processes have remained altered, and only now, after an innovative and successful rat eradication action carried out in 2011, can the island regain its original ecological dynamics.
This project, funded by BBVA Foundation, aims to evaluate the effects of rat eradication on fauna and vegetation taking into account their trophic and competition interactions. We will study how resilience mechanisms have operated, that is, the processes that buffer disturbances to minimize damage and resist impacts. No project has so far been carried out throughout the Mediterranean on this scale, on an island on the surface of Dragonera, of more than 350 hectares. The work team is made up of ecologists, physicists, mathematicians and geographers who will approach the project from a transdisciplinary and holistic perspective, considering the island a unique system where processes occur in a linked and complex way. It is from this perspective that we will be able to better understand how the resilience of ecosystems operates, and how they recover after halting anthropogenic impacts.