Rewilding, the reintroduction of key species to restore ecosystem functionality, is a powerful tool used to curb the biodiversity crisis. Unlike most of the world, where iconic rewilding projects are being implemented, South America lags when it comes to restoring natural areas that have been degraded. In Argentina, however, we are effectively implementing rewilding activities using a model than includes acquiring and restoring large tracts of land, donating these lands to federal or state governments to create protected areas, and working with neighboring communities to develop an economy based on ecotourism. Currently, we work in four different locations in Argentina: the Iberá wetlands in the northeast, the dry Chaco forests in the north and the Patagonian steppe and coast in the south. To date, we have reintroduced three species and we are in the process of reintroducing 11 more. The former includes giant anteaters, collared peccaries and Pampa’s deer, whereas the latter includes jaguars, ocelots, giant river otters, guanacos, marsh deer, lowland pacas, coypus, Wolffsohn's viscachas, Red-and-Green macaws, Bare-faced curassows, Red-legged seriemas and red-footed tortoises. In Iberá, a 1.4 million-ha wetland, where the program is most advanced, preliminary research shows that reintroductions have reestablished several ecological interactions including jaguars preying on capybaras, giant anteaters feeding on ants and termites, Pampa’s deer grazing in open short-grass prairies and Red-and-Green macaws consuming and maybe dispersing native fruits and seeds. Despite this progress, the program faces some criticism from federal and state managers and often academics, who worried about the size of founding populations and their long-term viability, and environmental changes that might have occurred in the reintroduction areas compared to historical conditions. Other challenges include the impossibility to obtain, for most of the species, wild individuals for reintroductions; consequently, the program relies heavily on animals of captive origin, which are less fit for release. Moreover, Argentinean wildlife regulations, which were thought to fight wildlife trafficking, hinder rewilding activities, particularly the transportation of animals within the country and their importation from international donor institutions. Finally, ranchers argue that we are taking agricultural land out of production and reintroducing or boosting populations of species that would conflict with their activities. Despite challenges and delays, we have managed to secure and upgrade large tracts of land for conservation, begin to restore regionally and locally extinct species, and create an alternative economy that supports conservation work.
