The Ups and Downs of the Brush Tailed Rock Wallbies

September is Biodiversity Month.  What does ‘biodiversity mean? It has been called the ‘web of life’.  It is the variety of living things or the different plants, animals and micro-organisms in the world. We depend on biodiversity for our sustenance, health, well-being and enjoyment of life.[i]

Spring is the perfect time to visit Jenolan, when biodiversity in a natural environment can be clearly seen.  When people think of Jenolan, they think of caves.  But Jenolan is located in a huge nature reserve, teeming with flora and fauna – the Jenolan Karst Conservation Reserve - which is part of the Blue Mountains World Heritage Area.  The area was declared World Heritage in 2000, because of its incredible diversity of eucalypts (91 different sorts). In addition, 10% (over 3,000 species) of Australia’s vascular flora are represented in the Blue Mountains World Heritage Area, plus many rare or threatened species.[ii]”

At Jenolan, if you explore one of our bush tracks (and you are patient and observant) you are likely to spot many birds and animals in the wild. In fact, in 2018, during a Jenolan Bioblitz, more than 200 different species of fauna, large and small, were spotted on a single weekend, including marsupials, reptiles, birds, invertebrates, spiders and insects. 

Jenolan’s colony of Brush Tailed Rock Wallabies is a good example of a rare species that lives wild in the Jenolan valley.  Brush-Tailed Rock Wallabies are small, with adults weighing only 6 to 8 kg.  Their greyish-brown fur makes them nearly invisible in their rocky environment.  They can be recognised by the light-coloured cheek stripes, black blaze on their heads and their distinctly bushy tails.  Extremely agile and sure-footed, they bounce effortlessly over the steepest and most rugged terrain. 

In the 1800s, the little Brush Tailed Rock Wallabies were a delightful attraction at Jenolan.  Tourists and staff loved hand-feeding the tame creatures. 

Unfortunately for the wallabies, although the spectacular caves were protected, wildlife was not. Hunting became a popular pastime, encouraged at Jenolan. To attract more overnight guests, ads were placed in newspapers enticing hunters to Jenolan, where they could thoroughly enjoy shooting literally any bird or animal that they encountered. 

In 1888, a Sydney Morning Herald article said, “Young fellows often bring their guns and try their inexperienced hands at lyre-bird, wallaby and platypus shooting, and find good appetites at any rate.”

In 1899 a decline in rock-wallabies was first observed.  By the 1920s, through the good work of Chief Guide, James Wiburd, all wildlife on the Jenolan Karst Conservation Reserve had become protected.  

In 1929, a Grafton Daily Examiner article, said “This taming of the wild has been portion of the life’s work of James Carvosso Wiburd, the snowy-haired, benevolent and beloved superintendent of the caves.  He is a second St. Francis of Assisi, and his tall, hatless figure is known to every bird and animal in the 36 square miles sanctuary which surrounds Jenolan, and which he persuaded the Government to declare a home for the birds, animals, reptiles and flowers he loves and protects.”

However, this protection also included feral animals.  By 1930, rabbits from the Jenolan Karst Conservation Reserve were driving local farmers crazy. And by 1960, foxes and feral cats had all but wiped out Jenolan’s colony of Brush-Tailed Rock Wallabies.

In 1965, to protect the wallabies from predators, a substantial electrified enclosure was built among the cliffs on the Reserve, away from the visitors.  Much of the work was done by cave guides, in their own time and at minimal government expense.  Thirty-five wallabies were placed in the enclosure. 

The population grew and between 1980 and 1988, groups of wallabies were released from the enclosure.  By 1988, the wallaby population in the enclosure had built up to 80. However, many were becoming sick, for reasons which were unclear - possibly from overcrowding or possibly from a disease called Lumpy Jaw.  Brush-Tailed Rock Wallabies eat mainly grass, although they can eat other vegetable matter if grass is not available (as seen after the recent bushfires). In 1988, although the wallabies were fed on a carefully planned diet, and visitors were asked to not feed them, Lumpy Jaw could have been present – a result of taking processed foods from the hands of doting tourists.  Because the wallabies were not thriving, a group of well-meaning environmentalists released the wallabies and destroyed the enclosure.  Unfortunately, in the wild, predators gradually reduced the wallaby population down to only seven. So in 1992 the remaining wallabies were captured and put back into the rebuilt enclosure. 

Since 1999, Jenolan’s Brush-Tailed Rock Wallaby colony has been monitored, using DNA analysis of faecal pellets, radio tracking and remote cameras, to monitor survival, movement and successful breeding.

In 2001, the National Parks & Wildlife Service (NPWS) started implementing the Fox Threat Abatement Plan, and Jenolan was a priority site for fox control.  The intensive fox control program was so successful that by 2007 the captive wallabies were released from the enclosure into a fox-free Jenolan Valley, where they have since thrived.  In 2010, several young captive-bred wallabies were introduced to the Jenolan colony to improve genetic diversity.

Today there are over 100 brush-tailed rock wallabies in the wild in the Jenolan Valley. The NPSW registers, tags and names all new joeys.  (At Jenolan, all wallaby names start with the letter ‘T’.) Also, they regularly catch, measure, weigh and examine the wallabies. Wallabies are no longer tame. All staff and visitors are asked to not approach or feed them, so that they learn to forage for themselves.

The old wallaby enclosure fence is still standing, and can be seen today. If you stroll along the shady McKeown’s Valley Track, you will spot an array of birds.  Don’t be surprised if you also spot a swamp wallaby or a brush-tailed rock wallaby, a kangaroo, lyre bird or an echidna. In summer, you are likely to spot Cunningham Skinks (similar size and shape to blue-tongue lizards), sunning themselves on the path.  

Bushwalking is more rewarding if you know where to look for the wildlife, so at Jenolan, we are working on a new guided bushwalk in the McKeown’s Valley.  On this guided walk, visitors are likely to spot native wildlife, learn about ‘karst’ environments and hear stories of the convict James McKeown, who hid in our valley years ago, and whose capture lead to the discovery of Jenolan Caves.  Please keep an eye on our website for more details.

Click here, to find out what you can do to help protect biodiversity wherever you live.