The Longest Fence in the World

The longest continuous fence on Earth stretches over 5,000 kilometers across the Australian outback, and it was built not to keep people out or in, but to separate one species from another. This episode of 99% Invisible, reported by Shirley Wong, traces the extraordinary story of the Dingo Barrier Fence—a piece of infrastructure that has literally split the Australian continent in two, creating entirely different ecological systems on either side. The episode moves from the fence's origins as a failed rabbit barrier to its transformation into a weapon against dingoes, and ultimately to the complicated moral questions about whether Australia's war on its native apex predator is still justified in a world where the wool industry has faded and the dingo itself has become a protected species.

0:00The Fence Begins in Jindawi

The Dingo Barrier Fence starts just north of Brisbane, on the outskirts of a small town called Jindawi. Jindawi has a hardware store, an accountant's office, a butcher shop, a beauty salon, and a small hotel on top of a pub—the kind of place where a meat tray raffle is a genuine attraction. But the town's real claim to fame is the fence, and the local pride is evident in the nearly seven-foot-tall metal sculpture of a dingo that stands outside the Jindawi Cultural Center. The sculpture is made from small pieces of metal welded together, depicting a lean, athletic animal with reddish-blond fur, a white belly, and pointy ears. Reporter Shirley Wong met Doug Henning, a former tourism officer, who agreed to show her the fence. Doug explained that despite the prominent statue, the people of Jindawi are decidedly not fans of the dingo. "There's not a lot of dingo fans in town," he said. The fence was built to keep dingoes out, and it runs from a cattle pasture just outside Jindawi all the way across the continent to South Australia. The fence itself is unremarkable—just a regular wire fence about six feet tall, designed to prevent dingoes from jumping over. But its scale is staggering: at over 5,000 kilometers, it is longer than the distance between San Francisco and New York City.

5:13The Invasion That Created the Fence

To understand why Australia built the longest fence in the world, you have to go back to the late 18th century, when British colonizers arrived and tried to make the continent feel like home. They brought with them the plants and animals of Europe, often for hunting or as pets. Ecologist Thomas Newsome explained that foxes were brought so people could hunt them, cats were brought as pets and established wild populations, and deer, pigs, goats, and other species were introduced for various purposes. Because of Australia's island geography, its native plants and animals had evolved in relative isolation, making them uniquely vulnerable to invasive species. Without natural predators, the European creatures ran riot. The most destructive invader was the rabbit. A man named Thomas Austin received 24 rabbits from England as a gift from his brother. Over three years, those 24 animals bred into thousands. The rabbits damaged crops, overgrazed grasses, spread diseases, and dug holes everywhere. In 1901, the government created a rabbit department and hired an inspector who realized that rabbits hadn't yet crossed into certain agricultural areas. His solution was a barrier. Rabbit-proof fences were built to seal off large portions of the continent as rabbit-free zones. Three different fences were constructed, but the rabbits found ways around all of them. The fences failed, and over time they began to disintegrate. But soon, another European animal would give those rusty fences a second life.

8:29Wool, Sheep, and the War on Dingoes

In the 1800s, wool was critical for the British textile industry, and Great Britain turned to its Australian colony to supply it. Historian Trish Fitzsimmons, co-author of *Unraveling the History of Wool and War*, explained that Lord Hobart, a British colonial administrator, encouraged colonists to develop fine wool for British manufacturers. By 1880, there were 100 million sheep in Australia—nearly 50 times the number of people. Australian wool became especially critical for the British military because it was waterproof and flame-resistant. During World War I, with 60 to 70 million soldiers in the field, each soldier needed something like 20 sheep per year to keep him alive and warm. World War I cemented wool as the foundation of the Australian economy. As the industry grew, farmers needed more land for grazing, so they bred sheep that could survive in the super-dry marginal regions of the continent. And there, the sheep met their great adversary: the dingo. For dingoes, the expansion of sheep into the interior was like a free buffet. Dingoes are highly effective pack hunters, and farmers would wake up to find dozens of their sheep killed or maimed. Environmental historian Dr. Justine Phillip explained that the wool industry was set up so that you couldn't have predators—it wasn't financially viable to supervise flocks of 2,000 to 100,000 sheep. Farmers wanted to eliminate the threat entirely. Australia went to war with the dingo. First, they created incentive programs that encouraged farmers to kill dingoes, with professional hunters and trappers paid bounties for every dingo they killed. After World War II, the assault ramped up. A 1946 newspaper headline read "D Day for Dingoes" above an article describing a plan to drop over 300,000 poisonous dingo baits across the landscape from airplanes that had returned from the war. At the same time, the wool industry developed a different strategy: take all those defunct rabbit fences and use them for dingoes instead. They joined the old rabbit fences together and raised them to a height that could keep dingoes out. The resulting fence was once 9,600 kilometers long; it is now still 5,500 kilometers long, cutting across scrublands and desert.

13:48Life Along the Fence

Australia still spends $10 million a year on the fence, funded through state and local governments and a fence tax on sheep and cattle farmers. A team of patrolmen divides up the length, each taking care of a section. Walking along the fence with Doug Henning, Shirley Wong saw holes that had been patched over—evidence of animals digging underneath. Large dents in the wire showed where kangaroos had run into the fence hard enough to cave it in. But the damage the fence does to animals is far greater than the damage animals do to the fence. The fence interrupts migration patterns and prevents animals from moving around in search of food or water. Emus, kangaroos, and wallabies all get stuck behind the fence. Some of these creatures play important ecological roles transporting seeds, so the fence has impacted plant diversity as well. The biggest effect, however, has been removing the dingo from a massive chunk of the continent. As Australia's apex predator, the dingo kept other animal populations in check. When the dingo went away, it set off a cascade of ecological consequences. Ecologist Thomas Newsome explained that without dingoes eating them, kangaroo numbers have exploded. There are now too many kangaroos in Australia—so many that some vegans make an exception for hunting them to control the population. The excess kangaroos overgraze the landscape, taking away food and shelter for small mammals, birds, and reptiles. The populations of red foxes and feral cats have also increased in the absence of dingoes, driving native species like bilbies and bandicoots to near extinction. The fence has created two entirely different ecological universes on either side. On the dingo side, there are more grasses and leafy ground cover; on the side without dingoes, there are more dry, woody shrubs. Scientists can see the effects of the fence from space, both in vegetation and in changes to dune morphology. On the dingo side, the land is looser, with dunes that shift in the wind—closer to how the landscape looked before colonization.

17:45The Political Third Rail

The wool industry is no longer the backbone of the Australian economy, which raises the question: why does Australia still maintain the fence? Dr. Justine Phillip said the fence is a hotly debated topic among scientists and people running livestock operations. But it would be very difficult for a politician to come out and say they want to tear it down. "It's considered political suicide to talk about removing the dingo fence," she said. The fence is a symbol of Australia's agricultural heritage, and for politicians who want to show support for farmers, the fence must be upheld. "To suggest even that you take it down is considered very un-Australian." This struck Shirley Wong as ironic, because the dingo itself is also iconic and uniquely Australian. But the general public hasn't always seen the dingo that way. For a long time, people thought dingoes were just regular domestic dogs that had gone wild. Even Justine Phillip admitted she used to believe this. People didn't start to appreciate the dingo until the 1960s, when scientists—including Thomas Newsome's father, Allen—began conducting in-depth research on how unique the dingo truly was. Dingoes are hard to classify. Experts say they are descendants of a primitive Asian dog that came to Australia either with seafarers or by land bridge somewhere between 4,000 and 10,000 years ago. This has led to debate about whether they should be considered native. But the fact is, dingoes evolved in Australia and became genetically distinct from their ancestors—the modern dingo has never lived anywhere else. Before colonization, dingoes had deeply intimate relationships with Aboriginal people, serving as partners in hunting and water finding, and often residing in camps as protectors or companions. As the scientific consensus shifted, a new generation of dingo fans emerged, including Justine Phillip, who did her PhD on the misrepresentation of dingoes. "They were such beautiful creatures," she said. "It seemed really strange that they had been greatly misrepresented."

26:56The Island Where Dingoes Roam Free

There is another place in Australia where anyone who wants to see dingoes is likely to find them: an island once called Fraser Island, now known by its Indigenous Butchulla name, K'gari. The island is covered in tropical rainforest with long white sand beaches and spectacular freshwater lakes. It is home to a small population of dingoes that have evolved in isolation from the mainland animals. When K'gari was named a UNESCO World Heritage site in 1992, the dingoes were officially named an indigenous species and given legal protection, meaning they are allowed to roam free. The Butchulla Aboriginal Corporation hires rangers to deal specifically with dingoes, which they call wangari. Tessa Wiya, an officer for the Butchulla Aboriginal Corporation, works with park rangers to educate people on how to be safe around dingoes. The tips are directly informed by traditional practices: if a dingo gets too familiar, you make it know that the camp is your territory by shouting and yelling. "He will know because that's you being the dominant one," she said. "And he will just watch from afar because he knows he's not welcome in there." Tessa believes humans and dingoes can live alongside each other on K'gari peacefully, just like in the past. But there are real obstacles, including the sheer volume of tourists. Hundreds of thousands of tourists visit K'gari every year, many coming specifically to catch a glimpse of a dingo. Tour operators use the dingo as a cute mascot to advertise their services. Butchulla elder Boyd Blackman, who worked for 30 years as a ranger, recalled seeing a tour bus with a cartoon dingo wearing a party hat, sunglasses, sneakers, and a Hawaiian shirt, with the slogan "Come party with me." Advertisements like this give tourists the wrong impression. Sometimes tourists get too close or try to take selfies with dingoes. "The dingo, he's not a party animal," Boyd said. "These are naturally wild animals." The volume of tourists has caused some of K'gari's dingoes to become habituated to humans—they eat from trash cans and hang around tourist campsites. This has led to serious problems. In 2001, a young boy was killed by dingoes while camping with his family. After that tragedy, the government culled dingoes and fenced in some of the largest townships on the island. But tourism has only increased, and dingo attacks have been happening more and more in recent years. The Butchulla Aboriginal Corporation wants the government to restrict tourism or even close the island during times when dingoes are particularly active, but so far this has been a non-starter.

31:48Tragedy on K'gari

Just as the episode was being prepared for publication, a tragedy occurred on K'gari. A young Canadian tourist named Piper James was found dead on the beach. Her body was discovered surrounded by a pack of dingoes with significant bite wounds. The exact cause of death was unclear—an initial assessment suggested she drowned, but also that she had been bitten by dingoes before she died. Shirley Wong called Tessa Wiya back to see how the community was responding. "The community is very shaken up," Tessa said. "It's quite heartbreaking." Tessa said she wasn't surprised that dingoes might have been involved. The Butchulla Aboriginal Corporation had been telling the government for years that something like this might happen. "We've been actually telling the government that there needs to be a cap on the visitor numbers," she said. "And then they want to say, 'Oh, are we so shocked?' Well, no, you were warned." The tragedy made international news and sparked fierce debates about how to respond. The government decided to euthanize the pack of 10 dingoes that had been found near the body, arguing it was necessary for public safety. But several scientists questioned that decision, arguing that previous dingo culls have not made the island safer. There are somewhere between 70 and 200 dingoes left on K'gari, and scientists argue that killing any of them reduces critical genetic diversity and makes the population more vulnerable to extinction. The Butchulla Aboriginal Corporation said they were not consulted about the decision to cull the dingoes. When Tessa found out the animals had been killed, she was devastated. "To the Butchulla people, the wangari are their family," she said. "They're like their brothers, their sisters. These wangari, they're punished for doing what they do naturally. It's not right."

Conclusion

This episode leaves the listener with a profound sense of the unintended consequences of human infrastructure. The Dingo Barrier Fence was built to solve a problem—first rabbits, then dingoes—but in doing so, it has reshaped the entire ecology of a continent. The fence has created two different Australias, visible from space, and the decision to maintain it has become a political third rail, even as the industry it was built to protect has faded. The tragedy on K'gari underscores the difficulty of coexistence. The Butchulla people showed that humans and dingoes can live together, but that requires respect, knowledge, and restraint—qualities that are hard to sustain in a world of mass tourism and political expediency. The dingo is both an iconic Australian animal and a dangerous predator, and Australia has never quite decided what to do with that contradiction. The fence is a monument to that indecision, and to the enormous, lasting power of a simple wire barrier.

Key takeaways

• The Dingo Barrier Fence is the longest continuous fence in the world at over 5,000 kilometers, stretching from Queensland to South Australia.
• The fence was originally built as a rabbit-proof barrier in the early 1900s, but the rabbits found ways around it and the fence failed.
• After World War I, the fence was repurposed to keep dingoes out of sheep-grazing areas, as the wool industry became the foundation of the Australian economy.
• The fence has split the Australian continent into two distinct ecological zones, visible from space, with different vegetation, animal populations, and even dune morphology on either side.
• Without dingoes as apex predators, kangaroo populations have exploded, and populations of foxes and feral cats have increased, driving native species like bilbies and bandicoots to near extinction.
• Australia still spends $10 million a year maintaining the fence, funded by state and local governments and a tax on sheep and cattle farmers, even though the wool industry is no longer economically dominant.
• On K'gari (formerly Fraser Island), dingoes are a protected species, but increasing tourism has led to habituation and attacks, including a 2023 tragedy in which a Canadian tourist died.
• The Butchulla Aboriginal Corporation argues that humans and dingoes can coexist, but that requires capping visitor numbers and respecting traditional management practices—recommendations that have been ignored by the government.