Black-footed rock-wallaby  (Petrogale lateralis)

The colouration of this shy, wary animal helps it to blend in with the background of rocks (3); it has dark to pale greyish-brown upperparts, a paler chest and dark brown belly (2). The dark face is marked with a white or sandy-coloured cheek stripe, and a dark brown to blackish stripe extends from between the ears to just below the shoulders. During summer these wallabies tend to become lighter in colour (2). The thick woolly fur is particularly dense around the base of the tail, the rump and flanks (2). The very long tail, which ends in a dark brush, is useful in maintaining balance when these animals jump from one rock to another (3). Furthermore, the soles of the feet are highly textured to prevent them from slipping (3).

There are four known subspecies of black-footed rock-wallaby and two geographic subpopulations (5), all of which differ in terms of their geographic range and fur colour (3). The distribution of the MacDonnell Ranges race, known locally as warru, has declined over most of its range. At present, it is found in the east and western MacDonnell ranges of the Northern Territory, in a few scattered populations in the Warburton area of Western Australia, and just one isolated small colony in north-western South Australia (5). The western Kimberley race is found only in the Edgar Range, Erskine Range, Grant Range and nearby parts of west Kimberley in Western Australia (5). The subspecies P. l. hacketti occurs on three islands (Mondrain, Wilson and Westall) in the Recherche Archipelago off the southern coast of Western Australia (1). P. l. lateralis is currently declining throughout its range. It was formerly found in suitable habitat in central and southern Western Australia, but now exists as just six populations in the Wheatbelt, and at Little Sandy Desert, Cape Range and Barrow and Salisbury Islands (2). P. l. pearsoni is restricted to Pearson Island (South Australia), with 300 individuals on the main island, 200 introduced to Wedge and Thistle Islands and 190 that were introduced accidentally to the south island (1).

Found amidst rock piles, steep cliffs, boulder scree slopes and granite outcrops, typically where there is some cover in the form of open vegetation (4).

This shy wallaby lives in groups of ten to one hundred individuals (3). They tend to feed at night in open areas on grasses, fruit, leaves and various herbs. They rarely drink, deriving most of the water they need from their diet (3). They also conserve water by taking refuge from the heat of the day in rocky caves (2). They are most active in the early evening when they leave their shelters (3).

Individuals typically reach sexual maturity at one to two years of age, after which time breeding can be continuous, but depends on the rainfall. Female black-footed rock wallabies show embryonic diapause, which means that the development of the embryo can cease temporarily until the environmental conditions become suitable for it to complete its development (2). The gestation period lasts about 30 days, and the newly born rock-wallabies, like most young marsupials, are initially very poorly developed and suckle for a time inside the mother's pouch (3). Other wallabies and kangaroos tend to stay with their young continuously until they have weaned, but black-footed rock-wallaby mothers often leave their offspring in a sheltered place while they go to feed. It is thought that this may be a safe option, considering the treacherous rocky terrain in which this species lives (3).

A major cause of the decline of these wallabies has been predation by introduced foxes, which is thought to be responsible for the extinction of several populations. Predation by feral cats, alteration of fire regimes and habitat damage caused by grazing sheep, goats and rabbits are also thought to have been problems (2) (4).

Various populations of black-footed rock-wallaby occur within protected sites. A recovery plan is currently underway, and much of the suitable habitat within reserves has been protected. Furthermore, fox control measures have been established at several sites (4).

For more information on the black-footed rock-wallaby see:

• Naturebase - Department of Environment and Conservation, Western Australia:
  http://www.naturebase.net/component/option,com_docman/task,cat_view/Itemid,1288/gid,372/orderby,dmdatecounter/ascdesc,DESC/
• WWF - Black-footed rock-wallaby fact sheet:
  www.wwf.org.au/publications/black-footed_rock_wallaby/

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk