The Greater Bilby (Macrotis lagotis) is a solitary, omnivorous marsupial endemic to Australia occurring in semi-arid and arid regions of the mainland. Once widely distributed, this Vulnerable species (IUCN 2016) has gone extinct throughout much of their range with natural populations now reduced to 20% of prior occupancy and only occurring in isolated parts of Western Australia, the Northern Territory and a small area of southwest Queensland. The Bilby is listed and classed as Vulnerable under Schedule 1 of the Environment Protection and Biodiversity (EPBC) Act 1999, protected under law by CITES (Appendix 1) and in all states and territories within its natural distribution.
Since European settlement the range of Bilbies dramatically declined as a result of habitat modification for agriculture and mining, inappropriate fire regimes, introduced herbivores and predators. Losses caused by introduced carnivores such as Red foxes and cats are of particular concern. An ongoing national recovery effort spanning several decades has resulted in successful reintroduction of the Bilbies to various parts of their former range including South Australia (SA) and New South Wales, utilising fenced areas subject to predator removal and control. Thistle Island, SA is the only area outside of their natural range the species has been introduced to, and was undertaken as part of that conservation action.
Habitat requirements of Bilbies are not clear, but presence of soil types that enable construction of burrows is seen as a critical factor, supporting important aspects of their biology and behaviour. Burrows serve as the sole form of shelter - as retreat from predators and environmental extremes – but also for reproduction, being necessary for mating and rearing of offspring.
Climate modelling was used to predict potential range of the Bilby in Tasmania. The cold, humid climate of Tasmania is vastly different to arid conditions the species is adapted to. CLIMATCH analysis combined with species-specific habitat modelling suggests poor prognosis of establishment in this temperate island. Survival would be strongly impacted if unable to construct burrows fitting soil and aspect requirements necessary for refuge, reproduction and retreat. Bilbies’ well documented susceptibility to land clearance and predation by cats, which are widespread throughout Tasmania, also suggest this species would not be able to persist in the landscape.
The risk assessment determined that the Bilby is not dangerous to humans, has a moderate establishment risk in Tasmania and moderate consequences if establishment should occur. By taking these factors into account, the assessment concluded that the risk posed by importing Bilby into Tasmania is moderate.
Following the initial risk assessment, the Department considers permitting the importation of animals assessed as ‘moderate risk’ into the State as long as appropriate mitigation measures, enforced through a wildlife exhibition licence, can be identified and applied.
Mitigation options to reduce the risk associated with importing Bilby include:
1. Limiting importation to registered wildlife parks or zoos to ensure the holding facility meets the stringent keeping standards Tasmania applies to all institutions.
2. Requiring any wildlife park or zoo to submit a Bilby species management plan (including enclosure details) prior to import.
3. The wildlife exhibition facility can clearly demonstrate they have proficient keepers for that particular species.