Geo-Joint: Australia’s Rabbit Proof Fence

Australia is a huge land, harboring many kinds of animals. But before 1788, rabbits were not among them. The initial group of boats that carried settlers from England to Australia, known as the First Fleet, brought domesticated rabbits along as a source of food. They were confined to the pens where they were raised. Wild rabbits were also brought to Australia, and in 1859, on Christmas Day, a group called the Victorian Acclimatisation Society had a bad idea. They thought they’d release a couple of dozen wild rabbits for the sport of hunting and to create a more familiar atmosphere for the far-from-home British settlers living southwest of Melbourne, in Victoria state. In a similar way, the Romans had introduced rabbits to Britain two thousand years earlier. Rabbits there took until the mid- to late 12th century to establish themselves in wild populations. In Australia, however, rabbits found not only freedom, but excellent living conditions. For lack of a harsh winter environment, they were able to breed all year long. Food was plentiful, and predators were present but not overwhelming. Escaped domestic rabbits established some feral populations, and the two species of rabbits cross-bred into a notably hardy strain. By 1886, the successful critters had spread beyond Victoria, and moved across New South Wales to the border of Queensland. As the 1900s dawned, they were into Western Australia and the Northern Territory. By the mid-1940s, rabbits had taken up residence in 4 million square kilometers of Australia, making their advance one of the world’s fastest by a mammal.

Compare this map to the detail below to see how much area the rabbits had occupied before the fence was started.

But once again, Australia is a big land, and though rabbits had established themselves widely, there was a good bit of the continent still untouched. Western Australia, a vast state, could see what was coming. In large numbers, rabbits are hard on a landscape. They mow down the vegetation and dig burrows, both of which can increase erosion which disrupts native plant growth and fouls watercourses with silt. The rabbits’ presence can attract predators (some themselves introduced) which may feed heavily on their abundant numbers. When the prolific rabbit numbers fall, however, these now-too-numerous predators turn to native prey and severely affect their numbers as well. Rabbits are indirectly blamed for the thinning or elimination of a number of native species in some areas. More distinctly, various species of bilbys and bandicoots, native marsupials, were driven to extinction as they were directly outcompeted for food by the rabbits. Similarly, rabbits ate the sprouting crops planted by farmers. The farmers of Western Australia did not want to suffer the fate of their more easterly countrymen, so the government came up with a plan.

Rabbit Proof Fence No. 1 crossed the country from north to south and became the world’s longest uninterrupted fence.

There was no possibility of hunting the rabbit population down to manageable levels given both its size and the size of the country. Not that they didn’t try—two million rabbits were shot or trapped in the ten years after their release, but it wasn’t enough. Their proposal set a gargantuan task of a different sort—to wall off the western part of the country with a 1,140-mile-long fence. Called the Rabbit Proof Fence, it was built, beginning in 1901, from the south coast at Starvation Bay, west of Esperance, to Ninety-Mile Beach, east of Port Hedland, on the northwest coast. It was an enormous feat, crossing vast stretches of difficult and inhospitable country over six years’ time. Hundreds of workers were set to the task, making fence posts of trees along the way, and running chicken wire between them, dug six inches underground. During its construction, in what must have come as a great disappointment, rabbits were found to the west of part of the fence. They had either breached the barrier or were already hopping beyond its limits before it was built.

Australians, however, do not give up easily. In April 1904, construction began on the Rabbit Proof Fence No. 2 (the first was now known as Rabbit Proof Fence No. 1, the longest continuous fence in the world). This one, when done, ran from Point Ann on the south coast, west (of course) of Rabbit Proof Fence No. 1, and very generally parallel to it, 150 miles to its west, curving east to connect with RPF No.1 at about the midpoint of that first effort (this is all much easier to follow on a map). Rabbit Proof Fence No.2 was completed by July of 1905, but for good measure, another short section (Rabbit Proof Fence #3, what else?) plugged the gap between the west coast and Fence No.2. All this fencing protected only a small slice of the west coast, but productive farmlands there were for a time spared the brunt of the rabbit influx.

The fences stretched through endless miles of Australian terrain.

The fences were effective in and of themselves, but they also featured “yard traps,” structures placed at intervals along the fence that caught inattentive rabbits in a sort of weir as they moved down the long wire barrier looking for a hole. Men were sent out on horse, automobile, and camel to check the many long miles of the fenceline for damage and to dispatch rabbits caught in the yard traps. The fences, along with poison and physically ripping out warrens, did a serviceable job for a few years. Even so, in the 1920s, Australia had an estimated 10 billion rabbits, and from then through the ’40s, the bunnies made their way even to the very far west. The science of pathology then came to the rescue as myxoma, a virus lethal to rabbits, was released into the environment. Brutally effective, (I’ll spare you the gruesome details of the disease’s progression), it sometimes reduced local populations by 99 percent. However, the mosquitoes that spread the disease were not plentiful enough in dry areas, and both the virus and the rabbits went through genetic changes that diminished the strength of the disease. Other viruses have been used since, with similar challenges of vector limitations and developing immunities. Clever science upped the role of technology in the competition against rabbits, but despite their low-tech nature, the Rabbit Proof Fences continue to have some usefulness, and parts are maintained to this day. Many sections, though, have been taken over by farmers to mark property lines, and much of the original fence is in disrepair.

A profusion of rabbits in Australia.

So fences and disease have worked together to slow the rabbit juggernaut, but like that famous battery bunny, they keep going and going and going……and it’s a pretty sure bet the Australians will continue to regret that Christmas Day rabbit liberation for many years to come.

As a postscript, it should be noted that the big fence of Western Australia is now called the State Barrier Fence and isn’t primarily meant to stop rabbits anymore. It includes parts of the old Rabbit Proof Fence, but also new sections, and plans are ongoing to upgrade it to keep out wild dogs (dingos and mixes), kangaroos, and emus, the large, flightless birds native to Australia. Farmers contend that the dogs attack domestic sheep, and the others decimate agricultural products, especially during large emu migrations. But this interruption of free passage has irritated environmentalists who point out that these animals once had free range and still attempt to migrate in large numbers, but are thwarted and sometimes harmed as they mass against the fence. That’s a debate too large for this article, but it’s clear that the fences of Western Australia are still in the news.


Get a feel for the desolate open spaces the Rabbit Proof Fence had to cross, with this National Geographic Physical Wall Map of Australia, available from Maps.com:

CLICK HERE TO VIEW THE MAP!


PHOTO CREDITS:

 

caption: Rabbit Proof Fence No. 1 crossed the country from north to south and became the world’s longest uninterrupted fence.
source: Wikimedia Commons: user 17177 (CC by SA 3.0)
caption: A profusion of rabbits in Australia.
source: Wikimedia Commons: unknown (Public domain)
caption: The fences stretched through endless miles of Australian terrain.
source: Wikimedia Commons: unknown (Public domain template PD-1996)

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