Watch this Komodo dragon bring down a buffalo 20× bigger

The ground trembles as the Komodo Dragon charges forward, its long forked tongue flicking through the air. You know its bite won't kill you instantly, but if it sinks its teeth into you, it's game over. This predator doesn't need to catch you now, it just needs to wound you and wait. The Komodo Dragon is the largest living lizard in the world, a monstrous and voracious predator that will eat almost anything it encounters. On rare occasions, it's been known to attack and kill humans. And its method of delivering death is unlike that of almost any other predator. Biting, wounding, and waiting for the prey to succumb to death allows it to take down animals much bigger than itself. Things like water buffalo, an animal 10 to 20 times its size. Komodo dragons live on only five islands in southeastern Indonesia, Indonesia's four islands within Komodo National Park, and the island of Flores. These are islands of stark contrast. Much of the area is dry, rugged, and rocky, with thorny vegetation. However, there are also dense forests, mangroves, and patches of greenery, especially in the valleys and coastal areas. And in all of this, the Komodo dragon thrives. They can be found sunbathing on the jagged rocks, sleeping up in trees, and occasionally swimming between the islands. Scientists think Komodo dragons originated in Australia and migrated to Indonesia thousands of years ago. As larger predators went extinct, they became the dominant predator on these isolated islands. And for a long time, people in the western world considered them to be mythical creatures. For decades, stories of giant lizards inhabiting the Komodo Island circulated, making them seem like legendary beasts similar to the dragons in folklore. It wasn't until 1910 that Western scientists finally confirmed their existence. And though they might not be mythical dragons, they're a creature you would not want to contend with. Komodo dragons typically weigh about 70 kilograms or 155 pounds and measure around 2.5 meters long. But the largest verified specimen reached a length of 3.13 meters or 10.3 feet and weighed 166 kilograms or 366 pounds. But despite being a top predator, a Komodo dragon's bite force is relatively low. This might seem surprising, but a Komodo dragon isn't killing by crushing, it's killing by shredding. Despite what looks like a gummy smile at first glance, a Komodo dragon has 60 curved teeth, each up to an inch long. These teeth are razor sharp, serrated, and built for tearing flesh. The serrations along the edges help them saw through the meat efficiently, allowing them to rip large chunks from their prey. They might get damaged, but these teeth are constantly replaced throughout their lifetime. And if you look closely at their teeth, you'll notice the edge of them is orange. Scientists recently realized that the cutting edges and tips of the teeth have concentrated amounts of iron, which gives it that color. This thin coating of iron acts as a protective layer that keeps the serrated edges of their teeth sharp. These immensely sharp teeth can slash their prey's skin, muscles, blood vessels, and nerves. Often, this is enough to kill their prey instantly. For smaller prey up to the size of a goat, they can loosen their jaws like a snake and swallow it whole. They can eat up to 80% of their body weight in one sitting. That would be like me eating 150 quarter pounders at once. Because of their slow metabolism, large dragons only need around one meal per month. After eating this massive meal, the lizard drags itself into a sunny location to speed digestion. And then it does something exceedingly gross. After it's done digesting, the Komodo dragon regurgitates a mass of horns, hair, and teeth known as a gastric pellet, which is covered in a rancid slime. That picture doesn't look that bad, but trust me, it's wild. But for some of the Komodo dragon's other prey, eating it in one gulp is not possible. Water buffalo weigh around 550 kilograms or 1,200 pounds. No Komodo Dragon is even big enough to take one down outright. In fact, the Water Buffalo has a 100% escape rate from the Komodo Dragon after a bite. But here is where the Komodo Dragon mystery really begins. After the initial bite, the Water Buffalo will wander off and die a few days later. So how exactly is the Water Buffalo being killed? For years, scientists believed the Komodo Dragon's drooly mouth was full of nasty bacteria that would enter the wound of the prey animal, dealing the final blow. I know I was taught this. And in fact, when you try to do research on this subject, this is still often repeated. So the whole idea of bacteria as a weapon comes down to a 1980 book published by Offenberg. This is Brian Fry, professor of toxicology in the adaptive biotoxicology lab at the University of Queensland. in the book he describes seeing the occasional water buffalo getting infected, and then that's the last you hear of it until the end of the book where he postulates this idea of bacteria being used as a weapon, but absolutely no data in between, nothing to support this. And it was seized on and ran from there. It became this enchanting fairy tale. But there's a very simple premise in science that extraordinary claims require extraordinary evidence. And bacteria being used as a weapon is as extraordinary of a claim as you could possibly make. Now, if you look at a dragon, and even in Offenburg's own descriptions, he describes the dragons as actually being quite fastidious in their eating, where after they've had a meal, they'll lick their lips and rub their head in the leaf litter and clean themselves up quite a bit. And then if you look at their mouth, the teeth are white and shiny and the gums are pink and clean. There's no rotting flesh hanging off of them. This is to say that Komodo dragons are much cleaner than you would think. And then there's the fact that potent antimicrobials have been isolated from Komodo dragon blood serum. So Komodos have actually a very powerful immune system. You can't have it both ways. You can't have them farming bacteria and also being highly resistant to bacteria at the same time. So it made no sense. So like on Rincha, for example, the water buffalo are localized to just a few small valleys and the only water source available to them are these rocky watering pools that for most of the year are stagnant. So they get filled with feces and then boiled in the tropical sun. And I remember the first time we went to the islands, I could smell these watering holes from like two to three or even 400 meters away. I mean, they reek. You know, they're basically sewage ponds. And I remember as we were going to them, I was like, oh, I've got some cuts on my legs, you know, from a little boating accident, you know, I better make sure to stay away from the water. And I had one of those little light bulb moments like, no, it can't be that simple all this time. So maybe the long fabled lethal Komodo dragon bacteria was really just poop water all along. And this makes sense, because anytime a water buffalo feels threatened by a predator, it bails into the water, hence the name. And normally this would be a better strategy for them, but water buffalo are not native to these small Indonesian islands. So in the marshes of Southeast Asia, the marshes are clean because the water buffaloes are living in these giant marshes and when they defecate, that just gets broken down by the plants and all the other processes in the water. So they flee into clean water. But in Komodo, they flee into water with these gaping wounds that they're fleeing basically into warm sewage. And any infection that's going to happen has nothing to do with the Komodos. It just has to do with the fact that, you know, the water buffalo is introduced to an island they don't belong to and encountering a predator that they didn't evolve with. So they do get occasionally infected, but that has nothing to do with the Komodo. And it's unlikely that the Komodos are intentionally using this to their advantage since water buffalo were only introduced to their habitat 300 years ago. It seems to just be incidental. and his colleagues even studied the bacterial load in the Komodo's mouth to quantitatively assess the possibility of the long-standing bacteria theory. So we studied a number of Komodos, including captive Komodos and including baby Komodos as they hatch from the eggs. The L.A. Zoo was super cool and let us sample the animals as they were hatching, swallowing their mouths before they even had their first drink of water. But what was fascinating about that study was that we showed that they have actually lower bacteria levels than a tazzy devil, a lion, or your average dog, or even your average, you know, three-year-old kid chewing on their classmate's ankle. But even so, you still see on nature documentaries, I'm talking about bacteria. Some of the guides in Komodo even still talk about bacteria, even though we disproved this, you know, over ten years ago. But what's particularly fascinating about everything was that Offenberg, in his own book, actually, without realizing it provides the first evidence for venom. Venom, could this actually be the Komodo dragon's secret weapon? And if so, shouldn't it be pretty obvious? So if you read the book, they did some horrible, absolutely despicable experiments that were getting thrown in jail nowadays where they tied goats to trees, let Komodo dragons tear into them, chase the dragons off, and then just sat down and watched what happens to the goats. And they described that even like with their intestines halfway hanging out, the goats were unusually quiet, you know, it seemed to be almost like they were sedated, rapidly went into shock, displayed gait problems, like they were dizzy or, you know, had some sort of neuromuscular issue. They said they bled much longer than we expected them to, more than you would expect from the mechanical damage alone. They just let the goats slowly bleed out over the next few hours. There was no clotting observed. So Fry's lightbulb went off again. These look like symptoms of envenomation. So with this hint, Fry and his team set out to look for the venom. So first they did an MRI scan on a Komodo dragon head. And they found what they identified to be venom glands in the mandible next to the mucous gland with one major compartment and several smaller compartments. They stated that the venom would travel through ducts and emerge at the base of the teeth. And as for the venom itself, Fry and his team looked at the DNA of the Komodo dragon and found genes that code for a whole suite of complex toxic proteins, a mixture as complex as that of venomous snakes. And when tested on rats, venom like this indeed caused hypotension, anticoagulation and ultimately death. We've discovered a number of potent hypotensive toxins that open up the aorta and like these kind of hypotensive toxins have been very well described from snake venoms where they help subjugate a prey long before death so it's like when you stand up out of a hot tub and you get dizzy you're not going anywhere quickly so long before you're unconscious if you're dizzy you can't flee and you can't avoid a predator from further attacks and komodo dragons do sustained attacks on prey around the 40-50 kilo range like pigs and deer. And then we've also shown a number of potent anticoagulant toxins from Komodo and other monitor lizard venoms. Great, so venom, not bacteria, is what the Komodo dragon uses in its hunt. That solves that then, right? Well, not exactly. Things got a little more confusing for me when I read several bite reports of Komodos on humans. A 2015 report describes a 34-year-old zookeeper being bit on the hand by a Komodo dragon. The wound showed no signs of envenomation and was treated with simple antibiotics. A 2022 report states a 43-year-old zookeeper was bitten on the leg by a Komodo dragon and suffered local tissue damage with no excessive bleeding or systemic symptoms to suggest envenomation. No specific therapy was administered other than local wound irrigation. And a 2016 report states a 38-year-old zookeeper was bitten on the hand, and her wounds healed normally. They say Komodo dragonbites are historically thought to be highly infectious and venomous. Based on a literature review, neither of these are likely to be true. Now I'm confused. After a bite from any related species that's venomous, like any venomous snake, you would definitely not be fine. You would need to be pumped full of anti-venom to be able to survive. Deepening my confusion is this letter from a prominent physician, Julian White, who is the head of toxinology at the Women and Children's Hospital in Adelaide, Australia. In the letter, he criticized the first of those bite reports for even describing Komodo dragons as venomous at all, stating that there's a lack of evidence supporting the use of venom by Komodo dragons in prey capture. Okay, now I'm even more confused. Fry's landmark study was done in 2009, and this This letter is done in 2015, so I reached out to Julian White to see if his opinion has changed since then. Stephanie, no, my opinion has not changed. I don't consider Komodo dragons, or any other verinid or agamid lizards for that matter, to be legitimately venomous. Therefore, I cannot comment on the clinical significance of Komodo dragon venom because, in my opinion, it is not venomous. He goes on to say Another animal whose bite can cause clinically significant local effects, with the potential for more widespread effects is Homo sapiens. Ask emergency physicians about bites by humans, and you will likely hear that they are amongst the most problematic to treat. Does that imply that humans are venomous? So a Komodo dragon is as venomous as a human? Listeners, if you're confused, believe me, so am I. And it turns out me researching any of this started tugging on a thread of a controversy that goes very deep. We had some zoos that not only refused participate in the study, you know, thinking that we were crackpots for even trying to disprove this bacteria idea, but they even actually contacted other zoos and told them not to participate with us. I won't name names, but it was, it was mind-blowing. They're like, oh, these guys are crackpots, you know, they think it's all venom, we know it's bacteria, don't let them near your animals, which is extraordinary, especially when you consider the fact that the moral justification for keeping animals in captivity at zoos is to to be involved in research and conservation. And the resistance to the idea went beyond just the zoos. And then when we tried to publish the results, we had a year long battle with one of the reviewers of the paper at the journal, where it took us a year to get the paper through the review process, even though they weren't arguing anything on the scientific side of it, where they couldn't go after us on the science. You know, they're arguing on ideological grounds and then the journal even sat on it for six months. You know, they're not actually going to let go of their position ever, despite evidence. And that is behaving like a religious adherent, not as a dispassionate scientist. So the bacteria side of it is already very illuminating about how people view dragons and how they get emotionally threatened by any data that challenges that viewpoint. I cannot wrap my head around why. Well, but look at people arguing against climate change. We have people arguing against science all the time. But there's no financial incentive to deny venom like there is to deny climate change, so I don't fully understand. So Fry goes on to explain to me that a lot of this could come down to social and interpersonal reasons. And then there's probably no small contribution by jealousy because we've gotten worldwide press on this. We've had David Attenborough comment about my research in a documentary. I've done a lot of filming on Komodo. It's certainly increased my stature on filming in the documentary world. My diplomacy is definitely my weakest skill, so I've no doubt have rubbed it in a couple of people's faces who have made comments along the way, and I've just cheerfully pointed out where they're wrong. But regardless, there's no scientific argument that can be made against it. So it seems like Fry's studies could simply be disruptive to the status quo. Doctors and scientists who for years espoused the bacteria bite theory would have to admit that they were wrong before. But isn't that just how science works? Fry speculates that part of the problem is that careers could suffer. People who were at the top of Komodo dragon science would have to take a step back and egos could certainly suffer. But Julian White seems to take some issue with Fry's study. I followed up with him again, asking about that study specifically. He says the paper makes the assumption that the mandibular glands are venom glands, rather than just structurally complex salivary glands. And that saliva is a fluid designed to assist breakdown of food items, the first point in the normal digestive pathway, and to achieve this usually contains numerous molecules are toxic or enzymatic. He also says that most venom toxins have evolved from existing molecules, often, but not always, derived from digestive tract secretions, so finding DNA coding for similar molecules does not equate to the animal being venomous. Ultimately he says that this all remains contentious within an unresolved debate, and more research needs to be done. Plus, there are some semantics getting in the way too. The opponents of Fry state that Komodo Dragon venom is not as potent as those in truly venomous animals like snakes or cone snails, meaning the Komodo Dragon's bite does not fully rely on venom to incapacitate prey. I think where a lot of the misunderstanding comes from is that the venom is there in a supporting role. It's not the primary weapon like it is for a snake, where they inject it into these tiny little insignificant mechanical damages, you know, just little holes or little scrapes in the skin, you know, trivial, not going to affect the prey at all. But that, you know, that's one extreme. The other extreme, you know, mechanical damages is something like a shark that just, you know, takes a leg off. Komodos are somewhere in between, where the teeth themselves are incredible weapons. They're serrated on both the front and back edges. They're even reinforced with, you know, titanium and other metals. and they bite, and then they pull back, each tooth cutting in succession, leaving four very deep wounds in the prey. Now, this can be alone enough to kill. So in our field observations and those of other people, about 75% of successful prey attacks, the prey bleed out in the first few minutes, so from something like a severed femoral artery. So this shows, from a mechanical perspective, how formidable Komodos can be. But with these field observations, it's shown that another quarter of the prey bleed out over the next two to three hours, with the Komodo biting them repeatedly and more and more blood happening, but no coagulation occurring. And the animals being weak, from hypotensive, unable to run away because of the neurotoxins. So the venom is there to add another quarter percentage of successful predation. And this takes the Komodos now into super predator range, where they have a successful predation rate of about 90%, which is much higher than that of like a lion or a shark. So they are an extraordinarily efficient predator. So we've never said that the venom is the only thing in town, but it's certainly there. I think a lot of the times what the opponents of venom point to is that when people get bit in like a zoo or whatever, the people get treated with antibiotics and the wounds heal somewhat normally. So that makes me ask the question, does envenomation always happen? Well, that's exactly right. It would be like in Australia, our most dangerous snake, the Eastern brown snake, doesn't envenomate in the majority of the cases. The majority of the cases are dry bites. So you could say, oh, look, nothing happened here. So clearly the snake is not venomous. So in a zoo environment or in any other kind of captivity, most of the bites are just quick little nips, just quick little get away from me nips. They're not actual predation bites. You know, they don't clamp on and give a good chew. But there have been cases, there has been one case report reported where the person had low blood pressure, they had persistent bleeding, and that was where a Komodo clamped on and gave a good chew. And certainly with other monitor lizards too, most of the other monitor lizard bites are just quick little nips, but there are a number of reports of other monitor lizard species producing effects, including ones that I've had where they've clamped on, gave a good chew, and then I've had persistent bleeding, I've had muscle aching, I've had dizziness, and other people have reported the same thing. So they're taking absence of evidence as evidence of absence when these are not feeding bites. There's a difference between a defensive bite and a feeding bite. The only other thing that I can think of that might cause such a profound misconception is their conspicuous drool. It certainly looks like it could be dangerous. what's in it, and is it in any way full of bacteria like the original researchers thought? So they've got two types of glands. So they've got the venom gland, and then they've also got these big mucus lobules, which is what the drool is. So the drool's not the venom. These are separate liquids. So in the case of the drool, it comes down to their predatory ecology, and that's that they overwhelmingly feed on furry animals, so they need a lot of lubrication to get them down their throat, just like pythons put out an extraordinary amount of mucus when they're swallowing a deer or another furry, because you need to lubricate. And also, Komodos are unusual in that they dismember their prey. So they take animals and then they tear it apart and swallow it. So they need a lot of lubrication to get these big chunks of meat down their throat. Or they can eat up to 80% of their body weight in a single go, but they're eating that piece by piece. So it'd be like us trying to swallow a grapefruit-sized chunk of a cow, including the fur. You know, we need a bit of lubrication to get that down." So as menacing as their drooly mouth looks, it serves a pretty simple purpose. So the Komodo dragon debate really comes down to how venomous is defined. If an animal must inject venom like a snake, then Komodo dragons don't qualify. However, to Fry and lots of other herpetologists, if something has toxic venom and uses it in prey capture, it seems pretty ridiculous to not call that thing venomous. And while this debate seems perhaps semantic in nature, or too wrapped up in egos or something, there are still many mysteries to uncover in this incredible animal. For example, we're just now understanding how smart these reptiles can be. They're like cattle dog level intelligence. They are extraordinarily clever animals. Komodos in captivity learn to recognize different trainers, they can actually be trained, click training to do certain tasks. They're even smart enough to have a dislike. One of them, Monty, who is this amazing Komodo dragon, he's unfortunately passed now, captain born and raised, lived his natural life in the Bali Reptile Zoo, and he was smart enough that he actually had a dislike to a particular trainer. A particular keeper he just would charge every time that person came through, but then he would have ones he was all right with, and then then he would have favorites. So, you know, smart enough to have likes and smart enough to have dislikes. That's wild. I even read some stories about how they might engage in play. Yeah, that's been documented. I forget which zoo it was. I want to say Bristol in the UK, where they observed a Komodo actually playing with like a soccer ball and other toys that they left in there. Things that weren't predation, they just put something in, it would explore, it was curious, and then it would actually, you know, bat it around and do that several times a day. So it shows that they need that kind of same habitat enrichment that you would with a mammal. This in particular blows my mind. You never think of lizards as being particularly intelligent and it likely plays a role in their super predator status. There's nothing else in the world quite like a Komodo dragon.