Growing problem: Camel numbers are increasing by up to 80,000 animals a year in remote parts of Australia.

Credit: Hans Boessem

SYDNEY: More than a million camels, the largest wild herd on Earth, are ravaging a vast and fragile desert region of 3.3 million square kilometres in the heart of Australia.

The camel plague is inflicting major damage on scarce water supplies, rare plants and animals, Aboriginal cultural resources and remote communities across the inland, according to an Australian government report released this month.

Pressure on scarce resources

"Because camels are cautious animals and beautifully camouflaged, and because these areas are sparsely settled, most people are simply unaware of the sheer numbers of these introduced pests - or of the extent of the damage they are causing," said Glenn Edwards a co-author of the report with the Desert Knowledge Cooperative Research Centre (DKCRC) in the Northern Territory.

"[However,] the longer we take to act, the more it will cost to manage and repair the negative impacts," he said. "We are very concerned that as the climate changes and the continent dries out further, the camel impact will worsen as they throw more pressure on scarce water resources."

The current camel herd - conservatively put at one million animals, but possibly much larger - is doubling every nine years and has the capacity to wreak havoc across the deserts. Camels are thought to inflict around A$15 million (US$ 10 million) in economic damage a year, over an area covering one third of the continent.

This area is spread across three states and the Northern Territory, with major hotspots where the borders of Western Australia, South Australia and the Northern Territory come together, and in the Simpson Desert.

Aboriginal impact

"In the environment we are seeing massive damage to mulga [acacia shrub] communities in certain areas, while camels may drive desert quandong [plants] to local if not regional extinction," he said. "Also they are emptying the precious waterholes and destroying wetlands on which native desert animals and birds depend for their very survival."

They animals are also having a major impact on Aboriginal cultural plants, bush foods and medicines.

Research in Aborigine communities by Petronella Vaarzon-Morel of the DKCRC and the Parks and Wildlife Service of the Northern Territory, has found that Aboriginal people are increasingly perturbed at the extent of camel damage to their country and cultural resources, fearful of personal danger and wanting something to be done about the problem.

Despite the damage they cause, camels have some positives, though, as a potential source of meat, tourism and weed control – and it is necessary to balance these considerations with the need to control them.

The new report advocates a risk-based approach to the camel plague, with the aim of managing their impacts rather than exterminate them, which is deemed an impossible task.

Reasonable limit on damage

The study calls for camel densities to be reduced to around 0.1 to 0.2 camels per square kilometre, which may involve removing an estimated 400,000 animals.

"Our overall aim is to get the population density down to one camel for every ten square kilometres eventually. This keeps the damage they do within reasonable limits. We can muster them for the meat, pet meat and leather trades, or we can control them by aerial and ground shooting," he said.

The camel herd may be larger than indicated in the report, as the last comprehensive survey was eight years ago. The authors now calls for a major new aerial survey to update estimates of the size and density of the herd.