What do they look like? The Brush-tailed Rock-wallaby (BTRW) is a distinctively marked medium sized wallaby. It has a long cylindrical, untapered tail with thick, dark brown fur. The tail is a remarkable feature of this species with a prominent brush at the tip. The body is most commonly covered in dull brown fur, with grey fur on the shoulders and rufous coloured fur on the rump.
Where do they live? In Australia, there are at least 16 species of rock-wallaby inhabiting various geographical zones. It was formerly found along the Great Dividing Range from Nanango in southeast Queensland, through to the Grampians in western Victoria. The BTRW is now extremely rare and elusive in regions of southeastern Australia. As a result it has affectionately been named “The Shadow”.
What do they eat? BTRW feed mainly on grasses and forbs but also eat a significant amount of browse.
Behaviour: BTRW’s are nocturnal to crepuscular and spend most of their daylight hours sheltering or sunning themselves in steep, rocky, complex terrain in refuges, while ranging into surrounding terrain at night to feed.
Reproduction: BTRW’s are polygynous, with a male breeding with several females within his home range. The species displays social monogamy, with adult males and females forming relatively stable bonds. The gestation period is similar to that of other Rock-wallaby species at around 30 days. BTRW’s give birth to one young. Embryonic diapause is demonstrated by BTRW where by the development of a viable embryo is arrested at the blastocyst stage during lactational anoestrous. Development of the blastocyst is reinitiated once the pouch young has stopped suckling. The joey leaves the pouch at about 7 months of age and disperses from the mother between 11-15 months of age.
Threats: A number of factors appear to have contributed to the dramatic decline in the distribution and abundance of the BTRW’s. They include: predation, competition, land management between populations (including habitat modification/degradation), hunting, disease, climatic changes and stochastic events. In addition, fragmented BTRW populations with low genetic diversity may also have hampered the natural recovery of this species after significant declines in population levels.
Conservation Status: CWS is playing an important role in the conservation of this species and has been doing so for the last 10+ years. CWS has been an active member on the recovery team of this species to ensure the species continues to survive in the wild. Now that CWS has a facility to house the species our captive component to the program is to ensure the persistence of a population of Central ESU BTRW’s in ARAZPA institutions that can provide animals for release to the wild, as part of conservation-based reintroduction programs managed through the NSW Brush-tailed Rock-wallaby Recovery Team.
It is hoped that the animals that CWS breed will eventually be released back into the wild, provided that the treats that are causing their decline are removed. CWS staff will play an important role in the release and monitoring of this species once it is returned.