They may have provided transport for the Three Wise Men delivering presents to baby Jesus, but camels are being held in rather less esteem by Australian farmers and conservationists this festive season. While the Three Wise Men brought gifts of gold, frankincense and myrrh, Australia's rapidly expanding feral camel population is leaving a legacy of fouled water holes, broken fences and trampled vegetation. Conservationists say Australia is home to between 600,000 and 750,000 dromedaries, which were introduced in the 19th century to carry supplies in the Outback. With the advent of railways and the motor car they were no longer needed, and were set free. The animals, which are native to the Middle East, have adapted so well to Australia's desert regions that the population is doubling every eight years. In some areas, camels may outnumber Australia's largest marsupial, the red kangaroo, by 100 to one. The 'big red' is an iconic species in Australia, used by national carrier Qantas as its emblem and renowned for its speed and ability to live in arid conditions. Glenn Edwards, of the Northern Territory Parks and Wildlife Service, said widespread culling of camels was urgently required. 'If we don't start managing camels they're going to get away from us,' he said. 'The longer we leave it, the more expensive it will be.' About 60,000 camels need to be culled each year just to keep the population stable. Culls are normally carried out by trained marksmen operating from helicopters. Dr Edwards told a conference, held by the University of New South Wales and the Australian Mammal Society, that the estimates of the camel population were based on an aerial survey of central Australia held last year. 'You couldn't look outside the window of the plane without seeing camel tracks all over the dunes,' he said. 'They're encroaching a lot more on pastoral lands and on to roads.' Aside from the increased danger of collisions with vehicles, wild camels also damage a lot of farm fences. The Department of Agriculture in Western Australia said: 'Camels batter fences down by leaning on them until they collapse, and will often demolish long lines of fence for no apparent reason.' They can also behave aggressively towards sheep and cattle, sometimes depriving them of feed or water. And they carry diseases which can be transmitted to livestock, including tuberculosis. Although their soft, rubbery pads make them less destructive than cattle, sheep or other introduced herbivores such as donkeys and wild horses, camels can cause damage to delicate desert plants. Australia's camel population is one of the largest and healthiest in the world. Around 12,000 animals were imported between 1840 and 1907, along with their handlers, from India, Afghanistan and Baluchistan. Half the present population is found in Western Australia, with 30 per cent in the Northern Territory, 18 per cent in South Australia and the rest in western Queensland. While 5,000 camels are captured each year and sold for their meat to countries in the Middle East, the trade makes little dent in the species' burgeoning numbers. Used extensively by 19th century explorers such as Burke and Wills, camels are now a popular tourist drawcard. Several Outback operators run camel safaris, venturing into the desert for days or even weeks at a time.