Mammals

Mammal – Marsupial, Family Macropodidae
The Brush-tailed Rock-wallaby sports a distinctive bushy black tail that’s 60cm long and has dark brown fur on its back shading to red on the rump. Their face has light coloured cheek stripes and a thin black dorsal stripe runs between the eyes to the back of the head. An adult male weighs up to 11kg and is 55cm tall, while the smaller female weighs up to 8kg and stands 50cm high.

Conservation Status:
This once abundant species of rock wallaby claimed rocky areas throughout south eastern Australia, but since European settlement their numbers and range has undergone significant reduction. A federal listing as “Vulnerable” indicates Brush-tailed rock wallabies are still sighted in parts of NSW and Queensland, but they are now “Critically Endangered” in Victoria where less than 10 individuals are believed left in the wild. The ongoing extinction of small and isolated regional populations, such as their recent disappearance from the Grampians, is due to a combination of factors. Catastrophic events, like the drought and bushfires experienced by the Gippsland rock wallabies in 2002-3, have a massive impact on the overall population size when there are so few colonies left. Re-colonisation is unlikely due to the fragmentation and isolation of populations. Predation by foxes is a major reason why numbers declined initially and studies show that feral cats take a high proportion of juveniles. Competition with feral grazers like goats and rabbits, as well as domesticated stock, lowers the carrying capacity of the rock wallabies’ habitat and further decreases population numbers. It is also believed that Brush-tailed rock wallabies have been poisoned with 1080 carrot baits laid for rabbits. Two feral diseases also cause mortalities in this marsupial, including Toxoplasmosis that is carried by cats, and Hydatidosis with foxes, dogs or sheep as hosts. Historically, there was unrestricted hunting and thousands of rock wallabies were shot for their fur and because they were considered an agricultural pest. Furthermore, habitat loss and changes in the vegetation have forced rock wallabies into suboptimal areas, with steep rocky escarpments becoming their last true refuge from the feral predators.

Habitat, Diet & Breeding:
Brush-tailed Rock wallabies live on cliffs and rocky escarpments in sclerophyll forest, where crevices, ledges, or caves provide protection from predators and the weather. They prefer to inhabit rocky slopes with a northerly aspect, so they have ample opportunity to sun themselves during the day. Little is known about their ecology, but they have been found to forage over a home range of about 15ha. This herbivore has a broad diet, eating a variety of plants including grasses, orchids, ferns, shrubs and trees, as well as flowers and some fruits. Capable of breeding all year round and after a gestation of 30 days, Brush-tailed Rock-wallabies give birth to a single joey. It remains in the pouch for 6 – 7 months, suckling from 1 of 4 nipples. Young are sexually mature at 18 – 24 months and they can survive for up to 15 years.

Interesting Facts:
The introduction of Brush-tailed Rock-wallabies to Mt Rothwell in July 2004 was the culmination of a long journey. Due to their rarity in Victoria, animals had to come all the way from New Zealand. Back in the 1860s the then South Australian Governor, Sir George Grey, introduced this species along with three other kinds of wallaby to Kawau Island in NZ. Later, the NZ government planned to cull what they rightfully considered to be a feral species on the island. Mt Rothwell managed to offer a safe home back in their own country and 8 Brush-tailed Rock Wallabies were released onto the sanctuary’s granite outcrops, and have since grown to a population of over 30.