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Dingoes have been largely eradicated in sheep lands, but are widespread and common in cattle country on the other side of the Dingo Barrier Fence. Pockets of dingoes, and/or their hybrids, survive in the Great Dividing Range and down to the coast in New South Wales and Victoria. Studies in central Australia demonstrate how rabbits are the dingo's main prey. That is so even in drought; but as rabbits become scarce, dingoes turn on red kangaroos as alternate prey. Populations of both species are suppressed at low levels by such predation for some time, even after good rains return. In other words, the dingo is on our side as a pest controller.
A Dingo Barrier Fence separates sheeplands in eastern and southern Australia from cattle country further west in inland and northern Australia. It was once c. 9,000 km long but was truncated in Queensland, and now is 5,531 km long. It also separates abundance of red kangaroos in the sheeplands from scarcity which begins immediately on the other side of the Fence. The highest density is in north-western New South Wales, measured in the 1970s at 12/km2, cf. 0.07 km2 across the Fence in South Australia. There are other disjuncts across the Dingo Fence. There are four species of kangaroo in New South Wales with only the red kangaroo in South Australia. Neither are there feral goats or pigs on the South Australian side.
A recent paper argues that other factors than dingo control lead to increased populations of red kangaroos in north-western New South Wales (Newsome et al. 2001). Analyses indicate insufficient rainfall to produce and support current red kangaroo densities. The causes are likely to be: increased run-off of rainfall from catchments due to over-grazing by sheep, rabbits and feral goats; the presence of a large geomorphic basin west of the Barrier Range in New South Wales which impounds most water shed from the Range.
That predation can suppress rabbit populations was tested at Yathong Nature Reserve, central New South Wales. Following good rains post-drought, very low populations of rabbits increased by up to c. 8-fold in one breeding season where foxes and feral cats were persistently shot. Rabbit numbers remained suppressed, however, where foxes and cats were not shot. Indeed, after two years of shooting, rabbits on the shot site were well on their way to another eruption, except that another drought intervened. Similar results emerged from persistent control of foxes around isolated rock wallaby colonies in Western Australia. Such colonies increased in numbers, while in one case with no such protection, the colony went extinct. Such studies have been followed by similar fox control experiments around remnant colonies of mala, bandicoots and bettongs.