Cats and foxes were removed from Mt Rothwell over ten years ago. Their absence allowed other fauna populations to flourish, including rabbits and brush-tailed possums. The impacts of both of these species is visible with overgrazing of the grasslands by rabbits and damage to some old growth red box trees particularly noticeable. The ecosystem was out of balance.
It was proposed that introducing an apex predator would assist in controlling the growth of other fauna populations (specifically rabbits and possums), assist with disease control/prevention, ensure only the strongest native animals survived and provide balance to the overall ecosystem.
This led to the trial release of three male Spot-tailed (Tiger) Quolls Dasyurus maculatus in 2014. Staff and volunteers monitored the results. Many rabbit and possum carcasses with clear signs of predation by Spot-tailed Quoll, were located near den sites. No evidence of any carcasses of other species were found during this time. This was confirmed by scat analysis done by Conservation and Land Management students at The Gordon TAFE laboratory.
Two other quolls have since been released, with evidence of their successful activities still found. They are occasionally seen at night during field work activities.