Exotic pest animals have major economic, environmental and social impacts across Australia, a study investigating threats to biodiversity in the Northern Territory has found.
The study, financed by the National Heritage Trust and implemented by NRETA, identified feral animals, weeds, fire, land clearing and pastoralism (grazing), as being the greatest environmental threats.
The severity and extent of each threat was examined in the study, with one of the highest ranked relating to large feral herbivores.
NRETA, with economic input from Dr Adam Drucker of Charles Darwin University’s School for Environmental Research (SER), submitted a draft report to the NT Government that was accepted in March 2008, recommending aerial culling of feral camels, horses, donkeys and buffaloes. The proposal involved an initial cull of 600,000 animals in the first year, 250,000 in the second year, and 30-35,000 a year thereafter.
Estimated population numbers of these animals in the NT exceeds 930,000 and continues to grow.
A cost-benefit analysis found that the net benefits of controlling the feral animal population were likely to be large, “as cattle properties may well benefit from reduced competition between livestock and large herbivores”, Dr Drucker said.
Significant cultural and biodiversity conservation advantages also were expected to flow from feral animal control.
A final report will be presented to the NT Government at the end of 2008.
In a separate study, Professor Stephen Garnett, Director of the SER, identified additional environmental benefits from feral animal control in the form of reduced methane emissions in the large feral herbivore population.
“Feral animal emissions of methane constitute over four per cent of the annual greenhouse gas emissions of the NT,” Professor Garnett said.
“A feral animal control program also has potential for Indigenous employment, as well as health benefits for people working on country.”