Australia Built a Giant Transcontinental Fence to Stop the Invasion of 10 Billion Rabbits

[00:00:03]Across the vast wilderness of Australia, a thin line of steel cuts through the desert, stretches across grasslands, and passes dry salt lakes, extending for more than 5,600 km, nearly the distance from London to New York. It has become one of the longest continuous fences ever built by humans. Yet, this enormous defensive line was not constructed to stop armies or people from crossing a border. It was built to keep out rabbits, wild dingoes, and other animals capable of turning a productive farm into barren land in a short period of time. So, how did Australia build and maintain this massive barrier? And why has a structure that helped save the country's agricultural industry also divided an entire ecosystem?

[00:00:50]In this video, join Mandarin Tech as we explore the super fence that changed the face of a continent.

[00:01:04]The story began on Christmas Day in 1859 at the Barwin Park estate in the state of Victoria. Thomas Austin, a wealthy settler from England, received 24 wild rabbits sent by relatives. He wanted to recreate the hunting pastime he had once enjoyed in his homeland in a new land half a world away from Europe. But when the cages were opened, what stepped onto the Australian grasslands was no longer just a handful of animals released for entertainment. It was the spark of a biological invasion. A female rabbit is pregnant for only about 30 days, and each litter can contain four to seven young. More frighteningly, their bodies barely need time to recover. Soon after giving birth, a female can become pregnant again. Under favorable conditions, a single pair of rabbits can produce hundreds of descendants in just about a year and a half. Australia also became the perfect breeding ground for this reproductive machine. The warm climate shortened the months when food was scarce. Vast grasslands stretched out like an endless buffet. The predators that had once kept rabbit populations under control in Europe were almost completely absent. [music] By around 1920, Australia's rabbit population was estimated to have reached 10 billion, creating an enormous grazing force across nearly the entire continent. Just 12 to 16 rabbits consumed as much food as one adult sheep. At that scale, their total appetite was equal to more than 600 million sheep feeding at once. They grazed vegetation to the ground, ate young shoots, [music] dug up roots, and destroyed newly sprouted plants, leaving little time for the land to recover. The damage was so severe that fewer than two rabbits per hectare could prevent shrubs and young trees from regenerating. Once the green cover disappeared, the top soil lost its natural protection and was quickly blown away by wind or washed into deep channels by rain. Grasslands that once supported thousands of livestock gradually became dry, barren ground. The livestock industry suffered immediately. Sheep lost weight, produced less wool, and many land owners were forced to reduce their herds or abandon their farms. The impact continues today with wild rabbits causing nearly 200 million Australian dollars in damage each year. A small animal had become powerful enough to wear away the land, livelihoods, and the foundation of an entire agricultural industry.

[00:03:39]At first, Australia placed its faith in gunfire. In 1866 alone, hunters shot around 14,000 rabbits at the Barwin Park estate. In many other places, people drove entire groups into fenced enclosures and removed thousands in a single operation. Yet the number of rabbits eliminated above ground never reflected the population still multiplying inside the deep burrow systems below. When hunting failed, the campaign shifted to steel traps. So many rabbits were caught that a processing facility in Capunda once handled around 6,000 a day. Cartloads of rabbits continuously left the grasslands, but the gaps they created were quickly filled again. The [clears throat] government then took the campaign to a more aggressive level. Poisoned grain and fruit were spread across the grasslands, turning the rabbit's own food supply into a weapon. Large numbers were removed, but poison could not cover an entire continent. It also harmed many native animals, while rabbit numbers fell only briefly before rapidly recovering. Even when people attacked the rabbits directly in their shelters, the results did not last. As long as a few burrows remained, the rabbits returned and continued spreading at a rate of more than 100 kilometers per year.

[00:04:58]In the end, the government was forced to change its strategy completely. [music] If the rabbits could not be eliminated, a massive steel barrier would be built to stop them. In 1901, surveyor Alfred Canning was assigned to map the route of rabbit proof fence no one. Over two months, his small team crossed almost roadless land using compasses, astronomical observations, and survey markers to define the route. The fence was planned from Starvation Boat Harbor on the southern coast to Wallal near 80m beach. Completed in 1907, it stretched about 1,834 km and became the world's longest continuous fence at the time. But length was not the only challenge. The fence had to stop animals that could jump, squeeze through gaps, and dig. Its wire mesh was about 1.07 metras high with openings no larger than 3.8 cm. Around 15 cm of the base was buried underground, while corner posts were reinforced against tension.

[00:06:01][music] In 2026, building a long fence might depend on drilling machines, off-road trucks, and satellite navigation. But in the early 20th century, almost everything had to be done by hand.

[00:06:15]Workers first cleared scrub, leveled rough ground, and opened tracks for carts. A narrow patrol road, and temporary supply stations gradually appeared beside the route. Around 400,000 wooden posts along with thousands of tons of galvanized wire and fine mesh had to be transported hundreds of kilometers. Horsedrawn carts handled easier sections while camels carried materials deep into the interior.

[00:06:41]Workers broke the hard ground with picks and crowbars, [music] dug holes, raised the posts, tightened the support wires, attached the mesh, and buried its lower edge to stop rabbits from digging underneath. Every step required precision. Loose mesh could be pushed aside while excessive tension could make it break [music] as temperatures changed. All of this took place in heat approaching 50° C amid dust, wind, and severe water shortages. They were not simply building a fence. They were stitching a line of steel across the desert.

[00:07:16][music] But the race had already been lost before the final sections of steel were closed. While construction crews were still moving northward, the first groups of rabbits had already appeared on the far side of the planned barrier. Even after the entire line was connected, the fence remained under constant pressure.

[00:07:36]Flood water eroded the ground around the posts. Falling trees tore through the mesh. Sand piled up into natural ramps, and rabbits could dig beneath sections weakened by erosion. A structure stretching for thousands of kilometers only needed one weak point to lose its effectiveness across a vast area.

[00:07:55]Western Australia was forced to move its defensive line farther inland. Fence [music] no two about 1,166 km long was built farther west followed by fence no [clears throat] three which extended for about 257 km. Together, the three barriers formed a network of more than 3,200 km, like several layers of doors erected after the first had already been breached. Even so, the system could not eliminate the rabbits.

[00:08:25]What it did achieve was to slow their advance, giving weak growing regions more time to strengthen production and organize more effective control measures.

[00:08:37]As rabbit populations gradually came under control, these fences were reinforced and extended to deal [music] with an even greater threat to the livestock industry, dingoes. Dingo had lived in Australia for around 3,500 to 4,000 years, serving as top predators and helping control kangaroos, rabbits, and many smaller animals. But as sheep farms expanded, they quickly became an economic threat. Sheep are slow, live in groups, and are almost unable to defend themselves. Once dingoes entered a farm, the sight of a panicked flock could trigger them to keep chasing and attacking even after they had enough food. For this reason, farms began building their own fences in the early 20th century. But dingoes were more intelligent than rabbits. They could follow the edge of the mesh, search for [music] gates, dig underneath, or go around the end of the barrier. Short sections of fencing only forced them to change direction. By the 1950s, state governments decided to connect many separate sections into one unified system stretching from Queensland through inland New South Wales to South Australia.

[00:09:50]However, stopping a predator that was strong, fast, and intelligent enough to search for weak points required a far stronger barrier than the earlier rabbit fences. Most sections of the dingo fence were about 1.8 metras high using heavy steel mesh fixed to strong posts. The bottom was buried or weighted with rocks to prevent digging while electric wires were added in vulnerable areas. The greatest challenges were gates, road crossings, and seasonal waterways. Gates had to allow farm vehicles through without leaving gaps, while drainage channels needed to carry flood water without becoming routes for dingoes. One design failure could weaken an entire section. Maintenance became a permanent battle. Wind loosened the mesh, sand formed natural ramps, and flash floods could pull posts from the ground. Patrol teams therefore traveled constantly in off-road vehicles, checking tracks, filling holes, tightening wires, and replacing broken posts. The fence was strong, not because it never failed, but because every gap had to be closed before a dingo found it.

[00:10:56]>> [music] >> By 2018, more than 2/3 of South Australia's dingo fence, about 1,600 km, had been standing for over a century.

[00:11:08]The steel had become brittle, posts were leaning, and some sections were so badly worn by sand that a strong impact from a kangaroo or feral camel could tear them open. Australia could no longer keep patching a structure that was decaying kometra by kometra. In May 2020, South Australia launched a reconstruction program worth about 29 million Australian dollars to replace 1,600 kmras of the fenc's two 100 km route.

[00:11:39]Crews reserveyed the ground, adjusted the alignment, replaced sections overtaken by the landscape, and strengthened the structure. By June 2025, more than 1,070 km had been completed. 225 kilometers were under construction and contracts had been awarded for the rest. Extreme rainfall and contractor shortages delayed completion until mid 2026. At the New South Wales South Australia border, a 32 km gap was also closed after 18 months, joining two separate systems into one continuous fence about 2,700 km long.

[00:12:21]Although the fence can be rebuilt with new steel, the market is left on nature cannot be replaced. By removing dingoes from vast areas, it triggered a chain reaction powerful enough to reshape the desert. In one study along the fence, scientists recorded 3,245 kangaroos, but only one dingo on the side where dingoes were rare. On the opposite side, they found 85 dingoes and only eight kangaroos. Without predation pressure, grazing animals multiplied and repeatedly ate young vegetation before it could recover. The effects reached far beyond plant numbers. With less ground cover, the soil held less moisture and contained lower levels of carbon, nitrogen, [music] and phosphorus. After rare rainfall, vegetation recovered more slowly on the dingo free side. An analysis of 32 years of LANCAT satellite images showed that the dividing line was visible from space. In the Strleki Desert, the change even altered the landscape where dingoes had been removed. Woody shrubs trapped more sand, making many dunes taller and rougher. On the other side, predators kept grazing animals under control, creating a clearly different surface.

[00:13:39]From an economic perspective, the dingo fence has fulfilled the task it was built for. It keeps wild dogs out of sheep farming regions, reduces the risk of livestock attacks, and allows many grazing areas to remain productive. In South Australia alone, the barrier is protecting a livestock industry worth about 4.3 billion Australian dollars.

[00:14:01]Economic analyses estimate that rebuilding the fence and reducing losses caused by wild dogs could deliver net benefits of between 56.4 and 112.9 million over 20 years. But the fence was built to protect sheep, not to preserve the entire ecosystem. As pressure from dingoes declined, red foxes and feral cats gained more space to hunt, becoming serious threats to marsupials, ground nesting birds, reptiles, and many small native species.

[00:14:32][music] Each year, feral cats in Australia prey on more than 1.5 billion native vertebrates and around 1.1 billion invertebrates. They have contributed to the disappearance of more than 20 mammal species and threatened over 200 species currently under conservation protection. The fence has protected sheep flocks, but many smaller creatures have paid the price.

[00:14:57]This paradox forced Australia to change the way fences were used. Instead of building enormous steel barriers across the continent, conservationists began creating enclosed areas where feral cats, red foxes, and rabbits could be removed before native species were brought back. At New Haven Wildlife Sanctuary, a fence 1.8 metas high and 44 km long surrounds an area of 9,400 hectares. Once the enclosure was sealed, control teams used traps, trained dogs, and sensor cameras to remove any remaining invasive animals. Only after the area was confirmed, safe were native marsupials released back into the wild.

[00:15:39]These protected zones became mainland islands where native animals could breed without being hunted by introduced predators. By May 2024, Australia had established 26 fenced areas free of feral cats along with 120 islands protected from these predators.

[00:15:58]Australia's story shows that a solution can save an entire industry while still creating consequences that no one expected. Humans can build fences to divide land, block wild animals, and protect their own interests. But nature is an interconnected network. When one link is changed, the entire system responds. Perhaps the greatest lesson is not whether the fence succeeded or failed, but how carefully we consider the cost of every intervention. In your opinion, is this an engineering achievement or a warning from nature?

[00:16:31]Leave your thoughts in the comments and subscribe to Mandarin Tech to discover more extraordinary structures around the world.