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Biodiversity

Going, going … Brush-tailed Rock-wallaby
Protecting remnant bush

Going, going …
Brush-tailed Rock-wallaby
Petrogale penicillata

The Brush-tailed Rock-wallaby is listed as endangered in New South Wales, vulnerable in Queensland and nationally, critically endangered in Victoria and extinct in the ACT. The Brush-tailed Rock-wallaby (BTRW) is a small wallaby, weighing 5-8 kg. They are usually dark brown with a reddish-brown rump and grey on the neck and shoulders. Their most distinctive feature is their brushy tail. They live in rocky outcrops and rugged and precipitous terrain. They prefer cliff faces with numerous ledges, overhangs and tunnels.

These highly agile animals are able to move swiftly and confidently with precise bounds using their long flexible tail for balance and their short, well padded feet for grip. They live in small family groups, a number of which reside together in localised colonies. Colonies may be close together or hundreds of kilometres apart.
They forage at dawn and dusk, feeding on shrubs, grasses and ground cover plants. Daytime is spent in the shelter of caves, rock overhangs or areas of thick vegetation. The BTRW range extends from the Grampians in western Victoria to Nanango in south-eastern Queensland, roughly following the line of the Great Dividing Range. The species range is now highly fragmented and made up of small isolated populations, particularly in central NSW where they are under the greatest threat.

Numbers have declined significantly in the west and south of their range. In NSW, the colonies in the Shoalhaven and Warrumbungle Ranges are the most southerly and westerly known populations. Numbers are difficult to estimate due to the camouflaged nature of their markings, their ability to move quickly and silently through their habitat and the inaccessibility of their habitats.

Recent genetic research shows there are three distinct BTRW sub-groups:
* Northern group (in south-eastern Queensland and north-eastern New South Wales) - an estimated 10,000 to 20,000 animals.
* Central group (south of the Hunter River to south-eastern NSW) - an estimated 500 to 1000 animals.
* Victorian group (in East Gippsland) - fewer than 10 animals.
BTRWs are thought to be under threat from predation by foxes (and to a lesser extent dogs, cats, Wedge-tailed Eagles and Tiger Quolls). Predation has a serious impact on young animals searching for new homes or young just out of their mother's pouch. Other threats include competition with feral goats for food and habitat; weed infestation; loss of habitat due to land clearing; changes in the timing and intensity of fires; drought; disease; and, inbreeding.

BTRWs are at great risk of extinction from continued predation and habitat loss with suitable habitat becoming harder for them to find and many populations now existing in isolation from each other with little or no chance for re-colonisation from other colonies.
The NSW Department of Environment and Conservation (DEC) has introduced a recovery plan for the species aimed at increasing their long-term survival. Acting DEC Director General, Simon Smith, said, 'Our key action is fox and goat control. Brush-tailed Rock-wallaby protection is a key element in DEC's Fox Threat Abatement Program and goat control specific to Brush-tailed Rock-wallaby habitat is now being undertaken in Warrumbungles and Oxley Wild Rivers National Parks.,'
'We are working with the community to improve our knowledge of the species… with almost half of all Brush-tailed Rock-wallaby colonies in NSW found on private property, we need the support of landowners to let us know when they spot these animals and where they are.
Anyone who spots a Brush-tailed Rock-wallaby is encouraged to complete an online survey or pick up a survey brochure from NSW National Parks and Wildlife Offices.

Protecting remnant bush
REBECCA MOOY, Community Biodiversity Survey Project Officer, explains what you can do to help protect and manage remnant bushland.

The Frog and Reptile team looking over remnant bushland near Ulan, on the biosurvey held in November 2005. Photo: Phil Morley

Remnant vegetation or patches of bushland are areas containing native trees, shrubs and grasses that remain in our landscape. These patches of native bush can be found on both privately and publicly owned land. They are important habitat for native animals, providing food and shelter. Some animals move between different remnant bushland areas using them as a corridor. Why should remnant vegetation be conserved?

Weed infestation, overgrazing, clearing and dieback are a few of the reasons for remnant vegetation disappearing. Native bushland remnants are not only important as habitat for native plants and animals and wildlife corridors, they have many other values. Some of these include: helping to protect against salinity and soil erosion; maintaining water quality in creeks and rivers; enhancing property values; providing shelter for stock and crops on farms; and providing areas for recreation and education.

Through good management and planning these areas can be conserved. The Community Biodiversity Survey Manual is one tool that can assist land managers, farmers, community members, teachers and others to assess bushland health. Through the techniques used in the manual it is possible to develop a species list of the plants and animals using the bushland and determine the level of degradation. Healthy bushland is mostly free of weeds; has a range of understorey plants; regeneration of trees and other plants occurs; the trees have good foliage cover and do not show signs of dieback; some trees have hollows that provide homes for animals such as owls and possums; and there are fallen logs and timber on the ground providing hiding places for snakes, lizards and insects. In remnants where a large number of weeds are found to be competing with the native plants, different methods of bush regeneration can be used to restore the degraded plant community to health. Some of these methods include: removing the weeds; fencing around the remnant to control grazing of stock and feral animals; controlling erosion; planting native species around the remnant as a buffer from wind; and planting native species adjacent to and within the remnant to encourage wildlife to use it as a corridor.

A beautiful scribbly gum spotted during the November 2005 biosurvey. Photo: Phil Morley

Learning about biodiversity in these remnants
NPA is running workshops and biosurveys to train participants in the methods of native plant and animal survey. Would you like to register for a workshop? Need more information on how you can get involved with coordinating and participating on surveys? Are you thinking about hosting a workshop? Visit www.npansw.org.au/biodiversity or contact the NPA office on 02 9299 0000 for more details.
* Information for this article was adopted from NPWS Voluntary Conservation on Private and Public Land - Note 11- 2003