Brush-tailed Rock-wallaby (Petrogale penicillata)
This beautifully marked medium-sized wallaby is distinguished by its long, dark tail ending in a brush of coarse hair, a white to buff cheek-stripe and a black dorsal stripe along the head. The upper body is brown, tending to rufous on the rump and grey on the shoulders. The chest and belly are paler and the feet and paws are black. Males are larger than females and may weigh up to 11 kg.
Breeding occurs year-round in warm climates. Females reach maturity at 18 months of age and males at 20 months. There is a gestation period of 31 days after which the embryo is born and transfers to the pouch. Joeys remain about 29 weeks in the pouch. The joey gradually leaves the pouch but will continue to suckle for up to three months. The mother may hold another fertilized embryo and this will develop as sucking from the previous joey decreases.
A number of factors have contributed to the decline in distribution and abundance of Brush-tailed Rock Wallabies including hunting, competition with sheep and rabbits for food and predation by foxes and cats.
It has now evident that captive breeding programs and intensive management are vital to enhance the survival prospects of small isolated populations of Australian Mammals. A NSW and Victorian Brush-tailed Rock Wallaby recovery program concentrating on the viable populations is now in full swing. It includes trapping programs, captive breeding program and release targets.
Using informed well directed assistance it is possible to build up viable populations of this species in favoured locations. These populations must be large enough and genetically robust enough to resist further decline.
Yellow-footed Rock-wallaby(Petrogale xanthopus xanthopus and P. xanthopus celeris)
Formerly called the “Ring-tailed Rock-wallaby” this small to medium sized wallaby to about 6-11 kg inhabits the arid and semi- arid zones of inland South Australia, New South Wales and South West Qld. Their preferred habitat is rocky and boulder-strewn hills and ranges with close adjacent pasture areas. Colouration is striking, back is a fawn/greyish with a dark grey/brown stripe down the centre of the head and back, white and rufous on the belly. The Tail is rufous/yellow becoming ringed with rufous brown and grey, slightly bushy and brown or even white at the end. White blazes on cheek, flank stripe and haunches. Limbs and ears are rufous paws becoming dark grey at the extremities. This multi-colour pattern results in it being called the “prettiest” of wallabies.
They mate all year round with breeding rate mainly dependant on food and water supply. Gestation period is one month and the joey will remain with its mother for 8 months spending more time out of the pouch as it gets older. As with all macropods they can have an embryo in stasis in the uterus that will not develop until the older joey is weaned. This adaptation to drought allows them to quickly give birth to another joey when conditions improve.
Once widespread in the NSW, SA and SW Qld inland this animal was widely shot for its beautiful fur in the late 1800s and early 1900s. Skins were used domestically and exported. This and grazing of sheep was the main cause of its present restricted distribution.
Waterfall Springs maintains a healthy group of Yellow-Foots. Their placid and easily tamed nature is suited to hand rearing. Apart from participating in breeding programs to maintain gene pool and numbers Yellow Foot females are used in the cross fostering program to accelerate the breeding of the more endangered Central and Victorian Brush-tailed Rock-wallaby.