Indicators of Catchment Condition in the Intensive Land Use Zone of Australia – Feral animal density

\n\nIt should be noted that this data is now somwhat dated!\n\nFeral animals impact on catchment condition by added grazing pressure,\ncompetition with native animals and by increased ground and water disturbance.\nFeral animals can also host and distribute diseases such as Brucellosis and\nmange. Rabbits and goats are renowned for their grazing impact, and including\npigs, can cause severe ground disturbance leading to erosion. Foxes and cats\nare predatory on many native species and also transmit diseases. Buffalo cause\nmuddying of waterways and can harbour Brucellosis. Buffalo, horses and goats\ncan also assist the spread of weeds.\n\nFeral animal density is an indicator of the extent to which Australia has been\ncolonised by a range of exotic fauna species. Native species numbers and\ndistributions have declined through direct predation, such as by foxes and\ncats, overgrazing by rabbits and goats to changing habitat conditions through\ncompetition for available resources. This issue is difficult to address at a\ncatchment scale due to animal mobility.\n\nRegional/national strategies are required (eg. use of calicivirus to wipe out\nrabbits). The main areas of Australia with relatively high feral animal counts\nare Gippsland and the mountains of southern NSW. The Victoria River Downs (NT)\nalso shows with high feral animal density. Moderate to poor condition is\notherwise indicated throughout most of eastern Australia and in the north of\nW and in the Northern Territory. Feral animal density is generally low in\nmost parts of Tasmania, South Australia, and Western Australia and in the\nRiverina District of New South Wales. The ABARES/CSIRO feral animal coverages\nwere used, which date from the late 1980s.\n\nThe scale of mapping is 1:25M. These maps give qualitative spatial\ndistributions for 22 feral species. Four classes of feral animal density were\ndefined (high, medium, low and none) and assigned a numerical value (3, 2, 1\nand 0). The density values for each species were added for all species, giving\na relative feral animal rating. Given the low resolution of the feral animal\ncoverages, only a broad regional picture is possible. Data reliability is\npoor.\n\nData are available as:\n\n * continental maps at 5km (0.05 deg) cell resolution for the ILZ;\n * spatial averages over CRES defined catchments (CRES, 2000) in the ILZ;\n * spatial averages over the AWRC river basins in the ILZ.\n\nSee [further metadata](http://data.daff.gov.au/anrdl/metadata_files/pa_iccilr9ab\n__07121axx.xml) for more detail.\n\n