High Quality Content by WIKIPEDIA articles! In Australia, rabbits are the most serious mammalian pests, an invasive species whose destruction of habitats is responsible for the extinction or major decline of many native animals such as the Western Quoll. Annually, European rabbits cause millions of dollars of damage to crops. Since their introduction from Europe in the 18th century, the effect of rabbits on the ecology of Australia has been devastating. Rabbits are suspected of being the most significant known factor in species loss in Australia. The loss of plant species is unknown at this time. Rabbits often kill young trees in orchards, forests and on properties by ringbarking them.