The Brush-tailed Bettong was almost lost from the whole of mainland Australia, after Europeans introduced cats and foxes from home.
As an ecosystem engineer (like the European Beaver in the UK) its absence has caused problems for the greater ecosystem as a whole. Looking like a cross between a rat and a kangaroo it eats a variety of fungi. When they dig up fungi and truffles, they spread fungal spores to the wind, as well as on their feet. without them many fungis may well disapear, leaving soils far less healthy.
40 were translocated, and the move has gone so well, that some of the individuals have already started dispersing into the surrounding area.