Great Walls of Australia (16 photos)
Few people know that at the beginning of the 21st century, Australia celebrated the centennial anniversary of the longest structure created in the entire history of mankind. Oddly enough, this significant event was not accompanied by pathetic speeches from politicians and did not receive widespread coverage in the international press. The fact is that this structure is just a fence stretching from south to north of the Green Continent.
Some disparagingly call it the Dog Wall, but many call it the Great Wall of Australia, proudly reporting that it is 5,323 kilometers long, almost 600 kilometers longer than the surviving Great Wall of China. The Great Australian Wall looks, of course, incomparably more modest than the Chinese one and is not of particular interest to tourists, since it is made of wire mesh with barbed wire on top.
As a matter of fact, there are now three “walls” in Australia. The first of them was created to fight rabbits. In 1859, a ship carrying twenty-four rabbits arrived from England to Australia. Released into the wild (the name of the person who committed this rash act is known - Tom Austin), these seemingly harmless animals, after 30 years, turned into a real disaster for all farmers. The rabbit population grew exponentially, the fight against them turned out to be ineffective, the fields and pastures of the Green Continent were rapidly turning into desert.
To avoid ruin, many kilometers of fences began to be erected around farms, which were initially created from various materials, mainly from various types of wood. Inspecting the condition of the fence at the beginning of the last century was carried out on bicycles, and the position of the chief keeper was called “rabbit inspector”. Termites unexpectedly took the side of the rabbits, and through their efforts the fences turned out to be very short-lived. Other “allies” of the rabbits were feral camels and local kangaroos.
Currently, this fence blocks the continent in half from north to south, its length is 3253 kilometers. This “wall” was built by 400 workers from 1901 to 1907. Despite best efforts, experts estimate that rabbits currently eat enough grass each year to feed 25 million sheep.
Even the “biological weapon” turned out to be powerless: the myxomatosis virus, which infected the captured individuals in 1950, and the calcivirus, introduced into their population in the 1990s. After the first (and very impressive) successes, individuals resistant to these viruses appeared, and as a result, the number of rabbits recovered quite quickly.
Australian sheep farmers, who found themselves in an even more desperate situation, had to seriously think about fences around their farms, whose herds were attacked by wild dingoes.
Interestingly, dingoes can be seen, but only in Australia, but also in Thailand, southeastern China, Laos, the islands of Indonesia, New Guinea and the Philippines. Moreover, the oldest remains of a dingo dog known to science were found in Vietnam: their age is estimated at about 5.5 thousand years. But Asian dingoes are smaller than their Australian relatives. It is believed that these non-barking, small wolf-sized predators descended from feral dogs brought to the continent from Asia more than three and a half thousand years ago by people who arrived from the islands of Southeast Asia (presumably Sulawesi and Kalimantan). That is, dingoes are secondary wild animals. The oldest remains of these dogs, found in Australia, are about 3,400 years old.
The usual color of these predators is red or grey-red, but there are groups with a gray or even black color. It is believed that this is a consequence of mixing dingoes with the settlers' domestic dogs. Dingoes quickly replaced the few local marsupial predators (their main competitor for a short time was the marsupial wolf) and began to live by hunting kangaroos, birds and reptiles. Later they included rabbits and sheep in their diet, but they can also kill a calf.
Moreover, sheep became the easiest and most desirable prey for dingoes. Having attacked a herd, in the excitement of the hunt, the dogs kill many more sheep than they can eat. One family of dingoes can kill a dozen sheep in one night. Dingoes usually do not attack people without provocation, but for Australian farmers this was little consolation. The fight against dingoes began back in 1788, when the first sheep were brought to the continent. The destruction of dogs was complicated by the nocturnal lifestyle of dingoes: during the day they hide in secluded places and go out to hunt only in the dark. Traps and nets were set for predators, they were shot and poisoned.
At the end of the 19th century, farmers in New South Wales alone spent several tons of strychnine annually on fighting wild dogs. For each animal killed, a premium of 2 shillings was paid. (Currently, payments for a dog killed within a fence can reach up to 100 Australian dollars). Large herding dogs imported from Europe successfully fought with their wild relatives. However, all these measures taken to combat the “red scourge of Australia” turned out to be insufficiently effective.
In a short time, the dingo population increased a hundred times, and there was a real danger of destroying the entire livestock population. In the 1880s Construction of a huge chain-link fence has begun in Southern Queensland. Other states followed the example of their neighbors and by 1901 the entire south-west of Australia was covered up and down with a wire net. In the mid-twentieth century, farmers and local authorities came to the conclusion that in order to more effectively combat predators, a chaotic network of different-sized fences needed to be replaced by a single fence, which would be maintained by royalties from the profits of ranchers.
As a result, in 1960, three sheep-producing states - Queensland, South Australia and New South Wales - combined their protective fences into a single wall of wire mesh, dug into the ground to a depth of 30 cm. Currently, this fence is 5,323 km long and height - 180 cm. It almost completely crosses the continent, only 180 km short of the western coast of the mainland.
The point, of course, is not the laziness of the Australians or the lack of funds, but the purely agricultural specialization of unfenced areas: dingoes simply do not go there. Some of its sections are already over a hundred years old. Others are newly built and have a repellent electric current generated by solar panels running through their wires. In areas where there are many foxes, the fence is cemented to prevent undermining. And in places where kangaroos gather in large numbers, the height of the stakes is increased. Maintaining the fence is not cheap: the states of Queensland, New South Wales and South Australia spend about A$15 million annually on this purpose.
The integrity of the mesh has to be restored quite often - floods and rains wash away the supports, and rust thins and destroys the mesh. In addition, it is torn by wild camels, kangaroos, emus, foxes, anteaters and wild boars. Many years of experience have shown that dingoes cannot break through the mesh, but they do not miss the opportunity to use any gap to enter the territory forbidden to them. That's why special caretakers inspect every kilometer of the fence every day, looking for damage to the mesh and underground burrows made by rabbits or wombats, and destroying dingoes that have penetrated the fence. Previously they rode camels, now they have powerful jeeps at their disposal.
The third Australian wall is not so large, only 44 km long, but quite high - 3 meters. It surrounds the Newhaven National Nature Reserve and protects its inhabitants from... feral cats. There are about 20 million of them in Australia, and, meanwhile, it is estimated that only 200 cats per year exterminate about 100 thousand rabbits, birds and small animals. It is estimated that wild cats kill more than 3 million birds, reptiles and mammals every day - about 2 thousand per minute! Australian authorities are planning to create a predator-free area of about 9,400 hectares.
Now in Australia they are rushing to build another barrier, this time to protect against cane toads. In Europe, these amphibians themselves are on the verge of destruction, but, carelessly brought to Australia and having no natural enemies there, they quickly multiplied, “colonized” the state of Queensland and are now moving to the northwest. The national park on the Cobourg Peninsula is in real danger. Scientists fear that if it is not possible to block the path of the toad hordes, many species of insects and small animals will be destroyed. A 9-kilometer fence that crosses the isthmus should stop the toads. Cane toads cannot jump, but they dig deep enough burrows, and therefore a concrete wall just over half a meter should be almost as deep.
