Once widespread across Europe, wild European bison were driven to extinction in the early 20th century by hunting and habitat loss. Starting in 2014, Rewilding Europe and WWF-Romania’s ongoing bison reintroduction programme has become the largest ever attempted in the Southern Carpathians. As a so-called keystone species, the reintroduced bison are having an increasingly influential impact on their local environment. Through their grazing, wallowing, trampling and fertilising, the burgeoning bison herds create conditions that allow a diverse range of plant and animal species to thrive.