Captive breeding has helped revive wildlife such as the Eurasian beaver, the cheetah and the Arabian Onyx. Several species have been reintroduced into locations in order that the ecological balance is restored. When herbivorous bandicoots were set free in the wild, they dug the ground and redistributed dry leaves and branches, reducing the chance of bush fires. But some predators may overhunt or threaten other vulnerable species. _____________