A dead possum has been found on the side of the road on the usually possum-free Aotea Great Barrier Island, Stuff reveals. But how it got there or who killed it is a mystery. There has never been an established possum population on the island. The island is mostly predator-free and has no stoats, hedgehogs, deer or some species of rats. Department of Conservation operations manager Kirsty Prior said while DOC thinks the possum came from off the island, staff are taking the discovery very seriously.