Distribution and Conservation Status of the Black-Footed Rock-Wallaby, Petrogale lateralis (MacDonnell Ranges race), in the Northern Territory.

Abstract

The distribution and conservation status of the Black-footed Rock-wallaby Petrogale lateralis (MacDonnell Ranges race), in the Northern Territory were investigated to complement previous surveys in adjoining areas of Western Australia and South Australia. Historical data were collated and compared with recent biological survey results obtained between 1870 and 1999. From a total of 469 records, 400 were collated for the period 1975-1999. The species occurs over ten biogeographic regions, principally within the MacDonnell Ranges bioregion, but with many populations in the Burt Plain and Great Sandy Desert bioregions. It is widely distributed through pastoral, Aboriginal, conservation and urban land and, at present, retains much the same distribution as concluded from early records. Thirteen conservation areas and 30 pastoral leases currently support populations of the species. An unknown number of animals live in and about Alice Springs. Only two National Parks, the West MacDonnells and Finke Gorge, are considered large and diverse enough to ensure the long-term survival of P. lateralis. Measures of abundance are not available but numbers of animals in conservation areas are perceived to have remained stable or to have increased over the past 20 years. Surveys undertaken during the period 1975-1999 indicate that P. lateralis have disappeared from 21 of 400 sites. Petrogale lateralis were present on all major rock types, including many granite outcrops. They were most widespread and apparently abundant on major quartzite ranges such as the MacDonnells where steep cliff faces, gorges, scree slopes and fire shadow areas are common. The wide distribution of P. lateralis in the Northern Territory in comparison to other states may be due to a variety of factors: widespread, relatively contiguous and variable habitat, occupation of country north of the core distribution of Oryctolagus cuniculus and of Vulpes vulpes, the inability of Capra hircus to persist and thus to compete in rocky range habitat, and a government 1080 poisoning programme for Canis lupus dingo on pastoral land. There is however, concern for the survival of some populations on many small ranges and rock outcrops on the fringes of its known distribution where recent observations indicate that numbers of animals are low.