Nobody Tells You The Truth About Kangaroos

In 2022 in Western Australia, a pet kangaroo that its owner had raised from infancy, bottle-fed, and treated almost like a member of the family, attacked him and caused injuries that later proved fatal. This is an animal whose silhouette appears on the country's coat of arms, whose image is sold to tourists on magnets and t-shirts as a symbol of good nature and harmlessness. Yet it delivers a kick powerful enough to cause serious, sometimes fatal, injuries in a matter of seconds. At the same time, every year during mating season, dozens of male kangaroos face off in contests that look less like courtship and more like no-holds-barred fights. They box with their front paws to throw a rival off balance, then strike with their hind legs, the very kick that, in the wild, sometimes proves fatal. And at the very same time, this is one of the most refined locomotion machines evolution has ever produced. An animal that can move faster than a bicycle, that uses its own tail as a fifth leg, and that spends almost no extra energy to go faster. This efficiency is exactly what pushed Australia's kangaroo population to a scale that forced the government to legalize culling. And that decision has been the subject of fierce debate for decades. Here's the catch. We don't pick national symbols at random. They're supposed to represent qualities a country is proud of. Strength, forward motion, uniqueness. And the kangaroo became that symbol for Australia more than a century ago. But what happens when the very qualities that made an animal a source of national pride turn out to be the same qualities that make it a real problem for people, farmers, and the government itself? And there's a question here that applies to you personally, even if you've never seen a kangaroo in real life. All of us idealize things from time to time. An image, a symbol, a reputation, without noticing that a far more complicated, sometimes dangerous reality sits behind the pretty picture. And the kangaroo is a rare case where you can trace the entire path from national symbol to an actual animal capable of killing and see exactly where the image and the facts parted ways. To make sense of that, we first need to look at how the kangaroo ended up on the national coat of arms in the first place, and what that choice actually meant to the people who made it more than a hundred years ago. On Australia's coat of arms, the kangaroo stands to the right of the shield, balanced on the left by an emu, a large flightless bird, and another instantly recognizable symbol of the continent. The coat of arms, in its modern form, was adopted in the early 20th century, and the choice of that particular pair wasn't random, since both species are unique to Australia. Both are instantly recognizable, and both, according to a widely repeated explanation, are physically unable to easily move backward. The kangaroo, because of how its hind legs and tail are built, the emu because of its leg anatomy and the way its toes are arranged. And that detail became a convenient metaphor for a young country that wanted to present itself as a nation that only ever moves forward. From that point on, the kangaroo's image spread everywhere. On coins, on national sports team uniforms, on airline logos, on souvenirs bought by millions of tourists over the decades. And the kangaroo became a visual shorthand for Australia, an animal that a foreigner recognizes instantly, even if they've never seen one in person and know nothing about how it actually behaves. But there's an interesting shift in perception hidden in that history. The symbol on the coat of arms is static, heraldic, stylized. It stands upright on its hind legs, as if posing, holding the shield with its front paws, looking more decorative than threatening. And popular culture inherited exactly that image. Soft, friendly, almost cartoonish. The kangaroo in children's books boxes playfully. The kangaroo in advertising smiles. The kangaroo plush toy sits on a shelf next to teddy bears. And all of these images were built around the animal's silhouette, not around how it actually behaves. And this is worth connecting back to how this story opened. A pet kangaroo that its owner treated almost like family, and injuries that turned out to be fatal for a person. Between the decorative silhouette on the coat of arms, and the real animal capable of that kind of force, lies an enormous gap. One that's rarely noticed until someone runs into it directly. And to understand where that force comes from, and why it exists at all in a herbivore, we need to look at how kangaroos treat each other when there's no audience, and no coat of arms involved. During mating season, kangaroos engage in a ritual that observers have long called boxing, though it would be more accurate to compare it to mixed martial arts. Two males stand facing each other on their hind legs, using the tail as an extra point of balance, and trade blows with their front paws. Short, sharp strikes aimed mostly at the head and chest. And the goal of this phase isn't to cause serious damage, but to throw the opponent off balance, force him to back away, or make him lose his footing. The real danger starts once one of the rivals loses his balance, or leaves himself open. At that point, the kangaroo braces on its tail like a tripod, freeing up both hind legs, and delivers one powerful kick, sometimes a series of them, straight to the opponent's belly or chest. And the hind feet carry large, sharp claws, while the limb itself is capable of generating tremendous thrusting force, since it evolved for powerful jumps rather than delicate movement. Among wild kangaroos, these strikes during mating contests can cause serious injury, and in some cases, even death. Outcomes like that have been documented by observers, though most contests still end without any fatality, because the ritualized form of the fight is designed primarily to determine a winner, not to kill. That same body structure turns dangerous when a kangaroo uses it against a person, and this has nothing to do with aggression as a personality trait. It comes down to pure physical architecture, built for an entirely different purpose. In the 2022 case in Western Australia, a pet kangaroo that had grown up around people and hadn't shown notable aggression in daily life, at some point applied the same behavioral pattern wild males use against each other, and the body of the 77-year-old man wasn't built to withstand a strike that nature designed for a rival of the kangaroo's own species. And serious injuries from wild and captive kangaroos are documented regularly in Australia, though fatal cases remain rare. What emerges is a paradox. The very animal whose stylized silhouette represents good nature and national pride has one of the most powerful kicks of any herbivorous mammal on the planet, and that kick is a direct consequence of a much larger engineering feature of the kangaroo's body, one that under normal circumstances isn't built for combat at all, but for letting the animal move faster and more efficiently than almost any other land creature of comparable size. To understand where that force actually comes from, we need to look at the very core of what makes the kangaroo such a remarkable machine of nature, the way it moves. The way a kangaroo moves at high speed is fundamentally different from how most mammals run. Instead of moving its four limbs one after another, the way horses, dogs, or humans do, a kangaroo pushes off with both hind legs at once and lands on them together, using its tail as a stabilizer and balance point in the air. But the most interesting part isn't happening in the air at all. It's happening in the tendons of the hind legs at the moment of landing. A kangaroo's Achilles tendons work like biological springs. When the foot touches the ground, the tendon stretches, storing the mechanical energy of the impact. And then, as the animal pushes off again, that energy is returned to the body almost without loss, like a compressed spring snapping back. And that's exactly why kangaroos display a physiological trait that puzzled researchers for a long time. As their speed increases, their oxygen consumption rises far more slowly than it does in most other mammals of comparable size. In simpler terms, within a certain range of speeds, the faster a kangaroo hops, the less extra energy its body spends per unit of distance traveled. Because most of the work is being done not by muscle, but by the elastic recoil of the tendons. The tail deserves its own mention. For a long time, it was considered just a balancing tool. But research conducted in 2014 showed that during slow movement, when a kangaroo isn't hopping, but carefully stepping, for example, while grazing, the tail actually functions as a fifth limb, and the animal leans on it, pushes off the ground with it. According to those measurements, the tail does an enormous amount of mechanical work during those moments, by some estimates comparable to, or even greater than, the contribution of the hind legs. And in effect, a kangaroo has five points of contact instead of four, one of them a muscular tail capable of pushing the body forward just as well as a full limb. Combine all of these features, springy tendons, a powerful tail acting as an engine, and a highly specific hopping mechanic, and large red kangaroos, the largest species in the family, can reach speeds of roughly 37 to 43 miles per hour in short bursts, cover about 26 feet in a single jump, and leap to a height of nearly 10 feet. For comparison, that's faster than a city cyclist, and nearly twice as far as a world record human long jumper can manage. And a kangaroo can do it over and over without stopping to rest, because the mechanics of the movement itself conserve its energy. This remarkable energy efficiency explains exactly where the kick discussed earlier gets its power. Hind legs, optimized by nature for repeated powerful jumps, also happen to be a weapon of enormous destructive force. But that same evolutionary efficiency has another far less obvious consequence, one that shows up not in a single animal, but in how quickly the species as a whole can reproduce once conditions turn in its favor. To understand how that grows into a genuinely controversial issue in modern Australia, we first need to look at what happens to kangaroos during the rainy season. To understand how evolutionary efficiency turned into a demographic problem, we need to look at how kangaroos reproduce. And here they have another trait every bit as remarkable as an eight yard jump. A female kangaroo can pause the development of her embryo for an indefinite period, a phenomenon biologists call embryonic diapause. If conditions are unfavorable, drought, food scarcity, the stress of already having a joey in the pouch, the fertilized egg stops dividing at a very early stage, shortly after fertilization, and stays in that frozen state until conditions improve. And as soon as favorable conditions arrive, heavy rain after a drought for instance, which turns desert and scrubland green almost overnight, the embryo's development resumes and within a few weeks a new joey is born. This means kangaroos are evolutionarily wired to respond to rainfall almost instantly on a biological time scale. In dry years, the population can stay stable for a long time or even shrink because reproduction is effectively on hold. But once several seasons of heavy rain arrive in a row, and that's exactly how the climate behaves across much of Australia, alternating long droughts with sudden wet periods, the kangaroo population starts growing explosively because females already have a batch of embryos on standby waiting for their moment. Add to that the absence of natural predators capable of keeping the population in check today. The large predatory marsupials that once hunted kangaroos went extinct either before European arrival on the continent or shortly after. And what you get is a species evolutionarily equipped to sharply increase its numbers within just a few years, the moment conditions allow it. This hidden demographic spring, combined with the energy efficient movement described earlier, which lets kangaroos cover enormous territories at minimal energy cost, is exactly what led to the situation discussed next. One modern Australia has had to manage for decades. According to estimates from Australian government environmental agencies, during periods of favorable climate, the total population of several major kangaroo species across the continent can exceed 50 million animals, meaning it can at times be noticeably larger than the human population of Australia itself. And these estimates are revised regularly because the population swings dramatically. After severe droughts, the count can drop by tens of millions, and after several wet seasons it can surge again, following the exact mechanism described in the previous section. This dynamic creates a whole knot of problems. Farmers complain that large mobs of kangaroos trample and graze down pasture meant for sheep and cattle, competing with livestock for the already limited grass and water in dry regions, while ecologists point out that at excessively high population density, kangaroos can degrade the pastures and fragile ecosystems themselves, and recovery from overgrazing can take years. Animal welfare advocates insist that kangaroos aren't pests, but part of the continent's unique wildlife, and that culling them on a mass scale is immoral and inhumane, regardless of the economic arguments involved. For decades, the government's response has been a system of regulated commercial culling, in which individual state governments set annual quotas for harvesting a certain percentage of each kangaroo species population, based on aerial population surveys. Officially, this system is meant to keep numbers under control, while also supporting a legal industry built around kangaroo meat and hides that has existed in Australia for many years, and supporters argue that regulated culling with quotas is more humane than allowing the population to grow so large that animals start dying en masse from starvation and disease during drought years, meaning that controlled human intervention, in their view, prevents a far larger and more agonizing natural catastrophe for the kangaroos themselves. Opponents of the practice point to the other side of the issue. Trapping and killing methods don't always meet stated humane standards. Joeys left without a mother often die slow deaths, and the quotas themselves, according to some ecologists, are set more based on the economic interests of agriculture than on strict scientific calculations of sustainable population levels, and debate around this issue periodically draws international attention, including protests and petitions calling for a full ban on commercial kangaroo hunting. What's particularly striking about this story is that both sides of the debate are, at their core, working from the same set of facts. The extraordinary energy efficiency of kangaroo movement, which lets them occupy enormous territories, and embryonic diapause, which lets the population rebound explosively after every drought. And these same biological features, which a few chapters earlier looked like a marvel of evolutionary engineering, turn out to sit at the center of one of the sharpest, still unresolved ecological debates in modern Australia. Now it's possible to return to both questions raised at the very start of this story. The first question was about what happens when the qualities that made an animal a national symbol turn into a real problem, and here's the answer this story gives. A kangaroo's strength and energy efficiency are a very concrete engineering outcome of springy tendons, a powerful tail acting as an engine, and a highly specific jumping mechanism, not just decoration on a heraldic image. The symbol on the coat of arms shows the silhouette of that mechanism, but doesn't tell you what that force was actually built for. Extremely efficient movement across the continent, and when necessary, winning a contest against another male of the same species. When that force is accidentally directed at a person, the result can be tragic, as the case in Western Australia showed, and the kangaroo's body was always built exactly this way. What happened was that same physical architecture being applied to the wrong target, not some sudden uncharacteristic burst of aggression. The second question was personal. How often do we idealize an image without noticing the more complicated reality behind it? And the kangaroo story shows that even the most seemingly harmless familiar symbols, coats of arms, logos, cartoon characters, grow out of real living organisms with their own evolutionary logic. One that was never designed to please people or look cute on a souvenir t-shirt. The explosive growth of the kangaroo population and the government measures that followed are a story about what happens when a species biological success collides with the limited resources of a landscape that people have already reshaped for their own purposes. Farms, pastures, fences, and roads. And it isn't a story about some bad animal at all. The kangaroo remains Australia's national symbol because the image on the coat of arms only tells part of the story. The part where the animal represents forward motion and the continent's uniqueness. And the rest of the story, the force of that kick. The population booms after rain. The disputes over culling rarely makes it onto a souvenir magnet. But it's exactly that part that makes the kangaroo a far more interesting and far more real creature than the stylized silhouette holding up a shield on a government emblem. If the story about the force of that kick and the paradox of a national symbol is the one that got you, let me know in the comments. Had you heard about cases of kangaroo attacks on people before this? And if the story about culling and the population explosion is what interested you more, hit like and share your take. Should the government manage wildlife populations this way or should other solutions be found? I read every comment and I'll respond to the most interesting opinions.