Puff the Magic Dragon
The tense interplay between my love for snakes and the life-threatening allergic reaction to their venom had reached a tipping point. My allergy had become steadily worse, and with it was a reasonable assumption that I was now deathly allergic to all elapid snakes’ venoms. The real worry, however, was the untested potential for a cross-reactivity with other venomous snakes. As my previous research had shown, many of the components in elapid snake venoms were found in the venom of other types of venomous snakes. Not just the vipers, but also the various rear-fanged species I had been intensively researching. I was caught in the jaws of a life crisis. All my life had been about venomous snakes and I was now faced with that ending. It’s said that any crisis is not just about danger but also about opportunity. The danger was clear and apparent; the opportunity, however, was obscured in the mist.I packed up my field gear and headed out into the Western Australian desert with my mate and fellow researcher Chris Clemente. I had no particular research target. Chris was doing biomechanical research on the running ability of varanid lizards, so if nothing else, I’d have a chance to play with one of my all-time favorite animals. We picked a Toyota Land Cruiser and trailer from the Property & Facilities Department at the University of Western Australia, loaded it with the usual copious amount of gear and headed out on the highway with Airbourne’s song “Diamond in the Rough” banging out of the stereo. We cut inland, heading for Sandstone. Along the way, a beat-up ute passed us at high speed and then did a hairpin U-turn and skidded to a stop. A leather-faced man got out and flagged us down. It was my old friend Brian Bush. I had mentioned to him weeks earlier in an email that we would be heading this way, and the date we were leaving. He was waiting out in the desert to surprise us. Brian knows more about the desert of the Australian west and its scaly denizens than anyone: he is a wellspring of vital and obscure information. He also has an extremely demented sense of humor, so our trip was slightly delayed while he kept us laughing with twisted tales about his life well lived. The kind of life we should all aspire to!
Continuing on our way, we drove well into the night, camped for a few hours and then reached Sandstone the next day. As I was reversing the trailer off the dirt track, it jackknifed and there was a snapping sound like sticks being broken. Examining it, we discovered that one part of the hitch was being held together not with proper rustproof titanium bolts but cheap steel ones that had rusted almost all the way through. They could have snapped at any time, which would have caused a catastrophic accident if it had happened on the highway. Thoroughly unimpressed, we headed into the small town of Sandstone to see if there was anything we could scare up to fix the hitch. The local council handyman had a very well-stocked toolshed and was able to find the right parts to fit. He also knew a lot about the reptiles of the area and gave us some good local tips.
Back at the field site, we fixed the trailer, set up base camp, and got back to setting up the drift lines and funnel traps. As the name implied, the area had sandy soil with lots of small stones, so it was easy work to dig out a shallow trench to partially bury the over 330 feet of barrier fence that would guide the animals toward the traps set in pairs on either side every sixteen feet. The traps were a modification of the classic minnow trap, with a funnel pointing inward at either end. Any animal that went in would not be able to get out easily. We covered the traps with shade cloth since the sun was so brutally strong; by 7 a.m., it was already eighty-six degrees. During the midday heat, we just sat in the shade of our tents and suffered. It was well over 110 degrees, even in the shade. Our tents were warmer than they should have been, since they were exposed in the brutal sunshine. The only big tree in the area had a massive bull-ant nest under it. Lucky us. These ants are almost one inch long and extremely territorial. We only discovered them after pitching our tents in the shade and then being stung numerous times. Now it felt like we were camping on the surface of the sun. All we could do was remain motionless, other than drinking water and swatting off the countless flies that pestered us.
When it cooled down a bit in the afternoon, we got into the four-wheel drive and cruised the dirt tracks looking for life on the move. The shimmering heat caused the illusion of dark waves rippling along the track, so it took me a second to realize that one of them was solid, not made of ether. A goanna. A big one. We got out and quietly assembled the twenty-foot surf poles with nooses at the end. When the goanna stopped to look at me, I kept its attention while Chris did an exaggerated U-shaped walk to end up behind it. Slowly, quietly, he approached. Once he got close, he ducked down behind the scrub so that he was invisible. Hidden, he snuck forward, with only the surf pole visible, like an antenna from the world’s largest cricket. With me giving instructions in a barely audible voice, he lowered the rod tip until the loop was level with the goanna’s upright head and then brought it backward until it draped around its neck. Then, yanking back like he was setting the hook into a marlin, he drew the noose tight. I sprinted forward to dive onto the writhing five-foot-long lizard. My hands and forearms were protected by welding gloves from the large, sharp teeth of the carnivore and its long, recurved raptor-like talons. It was a desert yellow-spotted goanna—my first encounter with this species of varanid lizard. Its deep orange body was covered in yellow dots arranged in an intricate pattern, obviously an inspiration for Aboriginal dot painting. Its blue-grey head gaped and hissed at me while its long purple tongue flicked rapidly in and out in a decidedly snake-like manner.
As I gazed upon it, I noticed something curious that had escaped my attention previously, despite my long history with varanid lizards in the wild and in captivity: there was a bulge running the length of its lower jaw, located in the exact same spot as the bulge on the lower jaws of the closely related venomous beaded lizards and Gila monsters. I could not recall ever seeing anything in the literature about this, and my scientific radar lit up like a Christmas tree. Could there be something to this? I spoke to Chris and he readily agreed that a couple of the lizards could be made available for my research purposes if we caught enough. Which we did. Over the next week in Sandstone we came across thirty-five of this species, as well as several other species, including the short-tailed monitor lizard, the smallest varanid lizard in the world: five inches of adorable toughness. In its mind, it was a twenty-three-foot giant. Intriguingly enough, all the species we caught had the same bulge on the lower jaw.
Monitor lizards are the ultimate predators. Never before had I encountered such perfectly adapted animals. They are powerful yet agile, and quick to accelerate to hit a very fast top speed that they can maintain for considerable distances. They have a special bone in their throat, called the hyoid bone, that allows them to turbo-pump air into their lungs, like the old-fashioned bellows used to kick-start a fire. Even the scales are reinforced with a piece of bone inside each, which has earned them the nickname osteoderms—“bone-skins”—and is about the only reason these beautiful animals have not been wiped out globally by the skin trade. The distances they cover in a day are astounding. One morning, at 8 a.m., we drove out in search of a diesel can that had fallen off the Cruiser during the previous night’s snake hunting. When we found it, we noticed the bird-like footprints of a large lizard, with the characteristic crescent moon marks left in the sand by the swinging tail. There were two sets of tracks, one approaching and one leaving. Clearly, this large lizard had detected the smell and had wandered over to examine the can. We drove across the red sand, following the parallel tracks. Two miles later, we came across the lizard. It was another large desert yellow-spotted goanna, one that had already walked four miles in the short time since daylight. We piled out and gave chase. Running at top speed, we chased it for 650 feet before diving on it just as it reached the entrance to its burrow. Chris and I were completely out of breath, but the lizard was obviously ready to go again.
We boxed up the lizards we needed, broke camp and headed out towards the town of Newman to ship them back to Perth. We drove at night to escape the heat, but this meant that instead of heat we had the pleasure of a kangaroo plague. These suicidally stupid macropods were in pandemic numbers, due to the artificial habitat improvement provided by the farmlands. Despite our best efforts, we hit six of them that night, including a couple with joeys. As we were deep in the desert far away from any wildlife rehabilitation facility, there was nothing to do but euthanize the joeys as quickly and humanely as possible before continuing on. It would have been cruel to leave them to die in the baking heat the next day and we certainly were not equipped to nurse them as we traveled. One large male kangaroo jumped into the side of the car at 2 a.m., giving us quite a scare as this face looking like the mask in the Scream movies suddenly appeared in the driver’s-side window before disappearing under the rear tires and then causing the trailer wheels to leap off the ground as they went over the mangled kangaroo.
Reaching Newman near first light, we went to the airport and dropped off the boxes before continuing on toward the Pilbara. At the Auski Roadhouse, we had our first shower in a week. We were as feral as a homeless person on a forty-day bender. The water stung like acid as our millions of tiny cuts were opened and cleaned out. Our clothes were disgusting beyond belief. We had stopped changing clothes several days earlier, based on the weird guy-logic that we were so dirty anyway, putting clean clothes on without washing ourselves first was just pointless. We just stopped wearing underwear, going commando to keep everything ventilated. Few tourists would ever have encountered two more filthy individuals walking through the desert with long fishing rods, looking like very lost dementia patients. We also removed carcasses of road-killed kangaroos from the road so that goannas or wedge-tailed eagles would not be car-struck while getting a free meal. But first, obeying the inscrutable exhortations of our demented senses of humor, we would draw a thick chalk outline around the body as though it were a crime scene, thus confusing any tourists even more.
The Pilbara has a certain prehistoric, harsh beauty to it. This oasis in the middle of the desert is carved out of black ironstone. During the day, we relished the novelty of swimming in the waterholes while still being in the boiling desert. The presence of the ironstone made night-time road cruising for snakes a low-yield venture. The ironstone’s density, which allowed the rock to retain heat longer than the road, made it a more attractive option to nocturnal snakes looking to warm up before going out hunting. We did come across a few Pilbara death adders away from the ironstone and in the sand dunes. Selection pressures exerted by predation resulted in the evolution of solid orange sand camouflage instead of black and burgundy bands.
After another half dozen days in the desert, we stopped at Shark Bay on the coast for a bit of beach time. While drifting on my back in the waters, I reflected upon the name. Sure there were plenty of sharks around, but so what? Every bay has sharks in it. There was nothing particularly special or noteworthy about this one to warrant such a name. What was special about it, however, were the stromatolites. Ten thousand years ago cyanobacteria (blue-green algae) began constructing these unique structures that are analogous to the earliest form of life on earth. The oldest such structures are 3.5 billion years old, and fossilized versions can be found in Marble Bay, Western Australia. It was only in 1956 that living versions were found in Hamelin Pool at Shark Bay, giving stromatolites the longest continual biological lineage. Perhaps this area should be renamed Stromatolite Bay to reflect its true uniqueness! While stromatolites are incredibly interesting from a biological perspective, from an adrenalin junkie perspective they are incredibly boring. Picture a bunch of black tar-like lumps, with the occasional bubble coming from them. That’s it. Nothing more to describe about their day-to-day, month-to-month, or even year-to-year activity.
We returned the vehicle to UWA completely thrashed. We had committed slow-death vehicular manslaughter. Every reflector was broken, the paint was pockmarked with gravel chips, the transmission sounded like popcorn, all the panels were dented, and two of the windows were broken. This was pretty typical of how we treated rental vehicles but our innovation this time was to duct-tape to the bullbar a ram’s skull that we had named Wally. The vibrations of the next nine thousand miles of rough driving had resulted in it wearing two holes in the hood of the car—not just in the paint but almost all the way through the metal itself. But to us it was worth it, since the trip had been such a success and I had found a potentially exciting new path of research.
Upon my return to Melbourne, I set about in earnest to examine the monitor lizards for the possibility that they might in fact be venomous. Dissections of preserved specimens revealed a large macaroni-shaped hollow gland. Construction of cDNA libraries, as I had been doing with the venomous snakes, revealed that not only was there a diversity of proteins being secreted by the glands, but that some of them were in fact of the same type as classic snake toxins. I had goosebumps crawling across my body when I first examined this data; the purest and most intense feeling of elation. It suggested that not only were there more venomous lizards out there than previously recognized, but that snakes arose from these venomous lizards. This explained the curious frothy liquid coming out of the alligator lizard’s mouth as it chewed on my classmate back in third grade, and also why he bled so profusely. It also explained why I bled so much when the water monitor lizard clamped down on my thumb that time at Arun’s, when I was a university undergraduate.
This was as radical a reshaping of the view of reptile venom evolution as could be imagined. At the same time as I made this discovery, my good friend Nicolas Vidal made a startling discovery of his own. He had used new genes to assemble the first robust reconstruction of the organismal evolutionary history of the reptile lineages, placing snakes with anguimorpha lizards (a diverse assemblage including Gila monsters, monitor lizards, and alligator lizards) and iguania lizards as part of a new assembly. While snakes being close to anguimorph lizards was not a new idea, the closeness with iguanian lizards was very surprising. We examined the lizards and found that they also had protein-secreting glands. Freek Vonk did a sterling job on the histology for his Bachelor’s degree research project and this was an invaluable contribution to the overall research project. While these glands were in a much more primitive stage than those of snakes or anguimorph lizards, they secreted some of the same components. Nicolas, Freek, Holger Scheib, and I combined forces and submitted the manuscript to Nature, the most elite of scientific journals. In this paper we gave the new venom clade the name Toxicofera.
While the paper was under review, I was awarded a travel grant from the Australian Academy of Science, and it was back to Europe for the northern hemisphere summer, which coincidently was right when Melbourne was at its most suicide-inducingly grey and depressing. At the Swiss Institute of Bioinformatics (SIB) in Geneva, Holger and I got to work on a variety of computational projects. Our basic approach was to have a nice breakfast at a sidewalk caf?, get into the lab around 10 a.m., load a massive dataset on to the computer cluster, and then go for long walks around Geneva. I particularly enjoyed our afternoon walks through the old town, with its historic architecture and mysterious doorways. We would then stroll along the lakeshore, with the spray from the fountain forming fleeting rainbows in the summer sunshine. Geneva is a surreal world. It is like just the top 1 percent of a mega-city has been relocated as a beautiful lakefront small city. The sidewalks were even designed to glitter at night, as if they contained millions of tiny diamonds.
I nipped up to Zurich for a few days to milk the viper collection of my friend Marc Jaeger. He had the most impressive collection of tree vipers from all over the globe, including eyelash vipers from Panama and bush vipers from Kenya. Unfortunately, not long before, he had had a total system failure of the misting system, resulting in a number of the cages flooding overnight and a massive number of deaths. While this was a huge loss of precious life, it was also an opportunity to further study the genetics and morphology of these highly specialized snakes. I was going to take them down to Geneva to deposit into the local museum.
It soon became apparent that we did not have enough room in the white styrofoam boxes for the snakes as well as the icepacks, so I opted to leave out the icepacks so that I could fit in all the snakes. My delusional hope was that they would keep each other cold during the train travel back. Unsurprisingly, this did not work. We were not long past Solothurn when the stench of rotting snake started wafting through the first-class carriage. I had stored the boxes on the upper storage racks and concealed them with bags and jackets, so it was impossible for anyone else to tell where this evil smell was coming from. By the time we were halfway to Geneva the carriage was otherwise empty of passengers. It was another situation where my sense of smell, having been destroyed by the two Butler’s snake envenomations during my PhD days, came in handy.
Once at the museum in the lab of my friend Andreas Schmidt, we got down to sorting and cataloging the snakes and then storing them in formalin preservative. We were halfway through when I took a break to check my emails. To my great delight, there was an email from Nature, informing me that our paper on the single, early evolution of reptile venom had been accepted. I couldn’t breathe. The potential impact on my career prospects was quite staggering. Getting a paper into Nature is like winning a gold medal at the Olympics. While it does not mean “set for life,” it gives a massive momentum boost that can be used to keep a career moving forward for a very long time. I kept the news to myself for the rest of the day, avoiding Holger entirely. I didn’t trust myself to be able to keep a straight face. I had come up with a cunning plan for how to tell him. The next day, I was scheduled to give a seminar at the Swiss Institute of Bioinformatics about the lizard venom research, on which Holger and I were collaborating. I started my lecture by dropping the news about the paper being accepted. Holger’s face turned scarlet with the shock to his system, then white, then red again and finally into a wax dummy blankness. He did not hear another word of my entire lecture. That night, we celebrated properly in glittering Geneva. It was the best day of our academic lives.
Back in Australia, the floodgates opened. I received in rapid succession a number of scientific awards based on the success of the Nature paper and the slew of follow-up papers. This included landing a new fellowship from the Australian Research Council. I was awarded the coveted Queen Elizabeth II (QEII) Fellowship—one of only sixteen given out that year and one of only two for Biological Sciences. The ARC wanted me at the grants announcement as the face of their fellowship scheme. There was one catch: Peter H?j, the head of the ARC, wanted me to bring a python into parliament, the seat of the Australian Federal Government. Naturally, I accepted this quite reasonable request and rolled up to Canberra with an over-ten-foot-long olive python named Ollie, who belonged to my mate Chris Hay. Despite prior arrangements, the parliament security services still had a total freak-out about the python. They even X-rayed it before letting it in. They were so distracted and concerned about it that they didn’t notice that the drill I was using for the screws that held on the wooden box lid was also a fully functional nail gun. So there I was in parliament with not only a very large python but also a lethal weapon. Naturally, I kept this to myself, and resisted the urge to shoot the science-budget-slashing Prime Minister John Howard repeatedly in the forehead, even though the ghosts of Australian native wildlife were telling me to do it.
However, it was Ollie that was in the true snake pit. Career politicians give off a very strange vibe. The Minister for Science at the time, Julie Bishop, freaked me out in particular. Once the cameras started rolling and she was posing with the python, she did not blink once during the ten minutes the cameras were focused on her. This, of course, prevents any one-eye-half-closed photos that make a person look like they are drunk, so fair call there, but the level of self-control this takes is eerie and not natural. She was as unblinking as the snake wrapped around her torso. I concluded that the only rational explanation was that she must be one of the Lizard Illuminati. She was definitely a kitten-eating evil reptilian humanoid from another planet. When Men in Black IV comes out, I expect to see her up on one of the big screens back at central office where they showcase aliens who have integrated themselves as prominent public figures.
Many other politicians and their staff enjoyed posing with the always-calm Ollie, to the point that he crowd-surfed around for over an hour while I stood back and watched with amusement. I then gave my presentation with Ollie twisting slowly around me, finishing with most of him balancing on my shoulders with the rest on the top of my head.
I was so happy with Ollie’s superstar performance that on returning to Melbourne we fed him a very large rabbit. A week later I received a phone call reminding me about my invitation to the Victorian State Parliament to receive another award and a nice big check to use for additional travel. So we packed Ollie back up and headed for the reception in Queen’s Hall. As we undid the lid from the box, a familiar smell wafted up, a smell that could mean only one thing: Ollie had crapped in the bag on the drive over and was now liberally coated with digested rabbit. I frantically and unsuccessfully tried to wipe him off as he came out. Which worked okay for the first three feet, but not the rest of him.
The Victorian Premier John Brumby wanted to pose with him, having seen the press of Ollie in Federal Parliament, so he put out his arms. Ollie slid across them and then wrapped himself around Brumby’s back. While the inevitable accompanying skid mark was hidden against the dark of Brumby’s suit, Ollie’s passing did leave quite a noticeable stench. Perhaps Ollie had cunningly planned this, one of the native wildlife getting their own back, since Brumby was as much an enemy of the environment as could be imagined. With friends like Ollie, who needs enemas?! I could see Tania Smorgon, the sponsor of the award, smirking a bit as she watched the scene unfold. I got the distinct feeling she wasn’t Brumby’s biggest fan. To her eternal credit, she rolled her sleeves back and posed with Ollie. Her unflappability may have had something to do with the fact that her two young sons had a pet python at home. Showing up Brumby was worth taking one for the team.
As they could not take the check back, I was off to Leiden University in the Netherlands the next week to examine the venom gland diversity of snakes and lizards using magnetic resonance imaging (MRI) with my friends and collaborators Rob Nabuurs, Wouter Teeuwisse, Louise van der Weerd, and Thijs van Osch. MRI is the non-invasive technique used for a diversity of medical exams such as scanning the brain for tumors. But we were going to use it for a rather different purpose: scanning the preserved head of a Komodo dragon I had on scientific loan from the Berlin Museum.
With the pragmatic approach to matters so very characteristic of the Dutch, we had approval from the Leiden University Medical Center to come in after hours and use the clinical scanners. Starting at 6 p.m., we worked until 3 a.m. to get the parameters right in order to get the highest resolution scans possible. It became readily apparent that the gland was not constructed of a single compartment with a single duct leading up to the teeth, but was actually extremely complex. There were six separate compartments, each with its own duct leading up to terminate between successive blade-like serrated teeth. It was clear that not only did Komodo dragons have venom glands, but that these glands were large and extremely intricate structures. Scanning Gila monster and beaded lizard heads showed that the Komodo dragon, and the variety of other varanid lizards we examined, had similarities yet also differences in their gland structures. Combined with our chemical analysis of Komodo dragon venom, we were quite confident in our conclusion that not only was the Komodo dragon the largest living venomous animal, but also that its extinct close relative Megalania was, at twenty-three feet, the largest venomous animal ever to have lived.
Of course, any laboratory finding must be backed up with studies of the natural history of the animals themselves and the role venom plays in predation. So I was off to Komodo Island with an Animal Planet film crew. Joining us was Kevin Grevioux, the creative genius behind the superb werewolf versus vampire Underworld movie franchise. While I am an adrenaline junkie, I am also a complete geek for this movie genre, so I considered it a great privilege to be on camera with Kevin. We flew first through Bali, Indonesia, and then onwards to Flores. Indonesia was very much the modern day crashing upon the rock of antiquity. Trash was strewn everywhere, with sea garbage washing up on otherwise pristine shores as the modern intruded upon the ancient.
As it was the dry season, we didn’t have to worry too much about mosquitoes transmitting diseases such as malaria or dengue, but the heat was extreme. At the Ranger Station on Rinca Island we filmed the large Komodo dragons that were hanging around waiting for an opportunistic feed on leftover food. Not long after, we left the station and headed up the large hill nearby, where we came across a large Komodo dragon on the path in front of us. Then we noticed there was one behind us and two more to our right. Our large, slow-moving group had attracted considerable attention from these formidable predators. The two largest started coming towards us with a deliberate gait that reminded me a little too much of a shark on an approach trajectory, so we dropped the gear to lighten our load and hasten our departure. We headed straight up the hill for about 750 feet before we turned to check behind us. The three largest dragons were still determinedly following us. Kevin asked, “What happens if they catch up with us?” to which I gave the concise reply, “If they do, it will be like the werewolves feeding in your movie. … All that will be left of you is a stain on the grass!” Our speed instantly increased. We walked for nearly half a mile before the last of the dragons dropped off the hunt. Using binoculars, I could see that all three had taken up a strategic position in the shade of the trees near the path to await our return. This displayed a level of predatory foresight that was chilling and amazing at the same time.
In order to avoid the awaiting dragons, we took a different path down via the steep side of the mountain, which was devoid of thick vegetation that could conceal a large Komodo dragon. From there we traversed the island over to the watering holes. Six hundred and fifty feet before we got to them, I could smell the stench of sewage-filled water on slow boil in the tropical heat. Komodo dragons had long been thought to use weaponized bacteria to kill their prey. But there is a simple saying in science: extraordinary claims require extraordinary evidence. The use of killer bacteria as a hunting weapon was as extraordinary a claim as had ever been put forward. The evidence for it was startlingly lacking. Despite this, it had long been a staple item staged in nature documentaries, resulting in a penetration into the popular consciousness far exceeding any other “fact” about these magnificent animals.
In fact, the primary role of toxic bacteria in debilitating and ultimately killing Komodo dragon prey was entirely speculative. Popular reports of bacteria festering on chunks of flesh remaining in the serrated teeth, or on gore around the head area, is in conflict with the documented behavior of Komodo dragons, who lick their lips and scrape their mouths to remove any gore remaining from their meal. This behavior result in the known characteristic of healthy Komodo dragons having clean mouths, pink gums, and white teeth that lack retained prey item flesh. The bacterial hypothesis is also in conflict with the preference of Komodo dragons for fresh prey over rotting corpses. The voluminous references in regard to bacteria ultimately rely on a book published in 1981 by Walter Auffenberg. However, when this primary source is examined, it is merely stated as a tenuous hypothesis that the gum and blood “combination may have some significance as a bacterial culture medium.” Despite a conspicuous lack of support from quantitative data, this single statement is later extrapolated by Auffenberg to “unsuccessful attacks often lead to a bacteraemia in the prey that eventually results in their becoming food for the ora population.” In other works, this is repeated as dogma. Thus, without any supporting evidence, a strong association was put forward between bite wounds and severe wound sepsis and septicemia. In short: scientific voodoo.
The one study that later looked at the contents of Komodo dragon mouths found the same sort of bacteria expected to be found in the mouth of any reptile or the typical gut contents of a mammal. The one quasi-pathogenic species (Pasteurella multocida) was found in only two out of the twenty-six wild dragons. Further, no single species of bacteria was found in all wild dragons. The variability was quite profound. This points toward transient, environmental sources for any bacteria present in the dragons’ mouths—not a scenario that would be evolutionarily favored for use as a weapon. Rather, a typical scenario for any carnivore.
Komodo dragons evolved in Australia, not Indonesia, and are by no means the biggest to have roamed. At least two (now extinct) larger varanids existed to predate on megafauna. The second largest, at over fifteen feet, radiated to the island of Timor, while the Komodo dragon radiated to Flores and other nearby islands. The largest species, Varanus (Megalania) priscus, remained in Australia and reached well over twenty-three feet. The situation today is that the Komodo dragons have three mammalian potential prey choices: deer, pig, and water buffalo. Deer and pigs are within the natural prey size (ninety to one hundred pounds) that Komodo dragons would have evolved to eat in their native Australia, while the water buffalo are dramatically larger. Field observations by others and myself showed that when Komodo dragons attack such prey items as pigs or deer, 70 percent die in the first thirty minutes. These deaths are from the profound mechanical damage wrought by the shark-like teeth, with the animals dying from severe blood loss. A young boy was killed in this way at one of our field sites on Rinca Island. A large Komodo dragon attacked him from behind while he was squatting and defecating. The initial attack sliced his femoral artery all the way through, resulting in several massive blood spurts, each to a shorter distance than the one before as the boy’s blood pressure dropped substantially due to the loss of blood volume. He was dead in less than two minutes.
Intriguingly, another 20 percent of attacked pigs or deer continue to bleed profusely and without clotting, and die of blood loss within three hours. During this time, the pigs or deer appeared sedated, walking slowly and with an unsteady gait, and go into shock long before they should from blood loss alone. Ironically, Auffenberg himself recorded similar observations in his book, thus inadvertently providing the first evidence for the dragon’s use of venom. Our laboratory work had identified in their venom toxins that prevent blood clotting while also precipitously lowering blood pressure. These chemicals are consistent with the signs and symptoms observed in the field.
The outcome of attacks on water buffalo was dramatically different. The buffalo would get away every time, but with deep wounds to the legs. They ran to safety, ending up standing in feces-filled waterholes, thus facilitating dramatic infections—not from the dragon’s mouth, but rather from an environmental source. A deep wound in such water is a perfect scenario for the flourishing of bacteria, particularly the nasty anaerobic types. Thus, the sampling of Komodo mouths that purported to show them harboring pathogenic bacteria neglected to sample the real source of any infection to the water buffalo: the waterholes. It has been an artificial scenario all along that has nothing to do with the evolution of the predatory ecology of Komodo dragons.
Water buffalo are an introduced, feral animal on the islands. Any interaction is unnatural, even if Komodo dragons had evolved on the islands, rather than being Australian in origin. In their native habitat in south-eastern Asia, water buffalo live in large, clean, free-flowing marshes. Thus any feces are carried away, diluted, and broken down. However, on the rocky islands they share with Komodo dragons, the only water sources are backyard swimming pool–sized stagnant watering holes that rapidly become choked with sewage. Ultimately, these disgusting waterholes are the source of any infection the water buffalo suffer after a Komodo bite. Therefore, we concluded that any infections that do occur are inadvertent, and that the idea of using bacteria as a weapon has as much to do with reality as the sun orbiting a flat earth.
Returning to Flores at night, a week after we left, we had to unload the mountain of gear from the boat. As I was stepping onto the slippery steps exposed by the low tide, a sneaker wave hit the boat sideways, sending me tumbling off the boat. I flung up one hand to grab a rope I could just make out in the flat light of dusk, caught it, but then, swinging sideways, smashed against the pier with my left side, with my knee bearing the brunt of the impact before I went into the dank harbor water. The crew pulled me out and laid me flat on the pier walkway. A crowd quickly gathered, giving me a suffocating feeling as I writhed in pain. Kevin channeled his character Raze from Underworld. Baring his fangs, he roared for them to stand back and give me air. Even if the locals did not know what he was saying, they got the point from the intimidating posture of three hundred pounds of ebony-skin-covered muscle.
I was transported to the local medical facility, which consisted of a single concrete room with bare light bulbs illuminating the geckos running across the paint, which was peeling like a skin-cancer-inducing sunburn. It was only slightly more hygienic than the pollution-filled water from which I had just been pulled. My knee looked like hamburger meat, and the side order of chips was the abundant bits of barnacle shell sticking out of my flesh in random directions. The young doctor was partially blind, due to a cataract that caused one eye to look like that of a dead fish. He recognized me from television and seemed more interested in posing for pictures with me than attending to my considerable injury. He poked half-heartedly around the wound before sewing it using the needlecraft of a drunken housewife. Even though he used half the number of stitches it required, this took my career tally to four hundred stitches.
We flew out the next morning to Bali and checked into a hotel in Ubud. By evening, my knee was hot and inflamed. I watched with alarm as over the next several hours jagged red triangles shot up the leg. By three in the morning, the angry redness had reached my crotch and I was as delirious as a college student with a spiked drink. My last coherent action was to bang on the door of director Rachel Maguire. The crew raced me to the Bali SOS clinic; upon arrival I passed out and remained unconscious for the next five hours. The “doctor” in Flores had done a shockingly poor job of cleaning the wound before sealing the flesh with the tight stitches, creating the perfect environment for the most lethal types of anaerobic bacteria. Untreated, this would have surely killed me. I reflected upon the irony of debunking Komodo dragons using bacteria as a weapon, then almost dying myself from infection.
Once I was up and hobbling around on crutches, we completed the filming by going to the superb Rimba Reptile Park. There we went into the enclosure of the giant captive-born-and-raised Komodo dragon named Monty. This leviathan really drove home to me just how intelligent these animals are. When I gazed into his eyes, he gazed back with brown eyes filled with sentience. He also, however, took an unsettling interest in my leg, obviously smelling the blood that lay beneath the bandages, so as soon as my portion of the sequence was complete, I wisely removed myself from the enclosure and chatted in the sunshine with my British friend Jon Griffin, who lived in Bali and ran a reptile export business with our mutual friend Duncan McRae.
Upon returning to Australia, I wrote up a Komodo dragon venom evolution paper that was accepted for publication by the esteemed scientific journal Proceedings of the National Academy of Science. My transcriptome analyses had shown that the venom was as complex as that of the Gila monster. In addition, my students worked in the laboratories of collaborators Paul Monagle and Wayne Hodgson to demonstrate the venom’s effects of blood coagulation blockage and blood pressure lowering—effects entirely consistent with what I had observed in the field.
While there had been certainly no small amount of controversy when the first paper on the single, early evolution of reptile venom came out in Nature, nothing prepared me for the reaction to the Komodo dragon–specific study. This was best captured in an article by the esteemed science writer Carl Zimmer in the New York Times of May 18, 2009:
Chemicals in Dragon’s Glands Stir Venom Debate
The Komodo dragon is already a terrifying beast. Measuring up to ten feet long, it is the world’s largest lizard. It delivers a devastating bite with its long, serrated teeth, attacking prey as big as water buffaloes.
But in a provocative paper to be published this week, an international team of scientists argues that the Komodo dragon is even more impressive. They claim that the lizards use a potent venom to bring down their victims.
Other biologists have greeted the notion of giant venomous lizards with mixed reactions. Some think the scientists have made a compelling case, while others say the evidence is thin.
Biologists have long been intrigued by the success Komodo dragons have at killing big prey. They use an unusual strategy to hunt, lying in ambush and then suddenly delivering a single deep bite, often to the leg or the belly. Sometimes the victim immediately falls, and the lizards can finish it off.
But sometimes a bitten animal escapes. Biologists have noted that the lizard’s victims may collapse later, becoming still and quiet, and even die. For decades, many scientists have speculated that the dragons infected their victims with deadly bacteria that lived in the bits of carrion stuck in their teeth.
Yet others have always been skeptical of the bacteria hypothesis. “Your average lion has a much dirtier bite,” said Dr. Bryan Fry, a biologist at the University of Melbourne. “It’s complete voodoo.”
Dr. Fry suspected that Komodo dragons were using venom instead. In 2006, Dr. Fry and his colleagues published evidence suggesting that some lizards share the same venom genes as snakes. They concluded that venom evolved about two hundred million years ago in the common ancestors of the lizards and snakes. Studying an Australian lizard called the lace monitor, Dr. Fry found proteins in its mouth that were produced by those shared venom genes. When he tested the proteins, he found that some could cause a rapid drop in blood pressure and that others stop blood from clotting.
Komodo dragons, like the lace monitor, are closely related to snakes, which suggested to Dr. Fry that the largest of all lizards might be venomous too. To test his hypothesis, Dr. Fry climbed into a Komodo dragon’s cage at the Singapore Zoo. “I dangled a rat above it and got it really excited,” he said. As mucus drooled out of the lizard’s mouth, he used a test tube on a pole to collect it.
Dr. Fry did not find any venomlike proteins in the mucus, but later he realized mucus was the wrong place to look. Studying other lizards, he discovered that the proteins were coming from a separate set of glands in their mouths.
A medical disaster offered Dr. Fry a chance to take another look at the Komodo dragons. During a mysterious outbreak at the Singapore Zoo, most of the Komodo dragons died. Dr. Fry and his colleagues were given permission to dissect jaw tissue from a terminally ill lizard and preserve the heads of two dead lizards for later study.
The researchers found the second set of glands in the Komodo dragon heads, and inside they found venomlike proteins. Tests showed that one protein keeps blood from clotting. Another one relaxes blood vessel walls. “It drops the blood pressure like a stone,” Dr. Fry said.
He argues that Komodo dragons depend on these venoms for their success. A Komodo skull is light, so it cannot generate a powerful bite or hold down a struggling victim, the way alligators do. “You’d expect them to be strong, but they’re not,” he said.
Instead, Dr. Fry argues, Komodo dragons slice open their victims, adding venom to the open wound. “If you keep it bleeding and lower its blood pressure, it’s going to lose consciousness, and then you can tear its guts out at your leisure,” he said.
Some experts praised the new study, which is published this week in the Proceedings of the National Academy of Science. “This paper clearly demonstrates that the Komodo dragon is a venomous predator,” wrote Nicolas Vidal, an evolutionary biologist at the National Museum of Natural History in Paris, in an e-mail message.
But Kurt Schwenk, an evolutionary biologist at the University of Connecticut, is not so impressed.
Dr. Schwenk finds the new mouth glands intriguing, but he considers most of the evidence for venom in the study to be “meaningless, irrelevant, incorrect, or falsely misleading.” Even if the lizards have venomlike proteins in their mouths, Dr. Schwenk argues, they may be using them for a different function.
Dr. Schwenk also doubts that venom is necessary to explain the effect of a Komodo dragon bite. “I guarantee that if you had a ten-foot lizard jump out of the bushes and rip your guts out, you’d be somewhat still and quiet for a bit,” he said, “at least until you keeled over from shock and blood loss owing to the fact that your intestines were spread out on the ground in front of you.”
During my undergraduate education, my Scientific Philosophy honors thesis examined how individuals respond to major paradigm shifts. My basic conclusion was that those who did not shift their view in light of new data had the same basic psychological mindset as religious adherents who felt challenged—they displayed defensive behavior, rejecting all new arguments without assessing them with due diligence. That certainly was the case here. The article quoted Kurt Schwenk, an evolutionary biologist at the University of Connecticut, who had no experience in venom research or with Komodo dragons. I found his stark statement that the evidence for venom was “meaningless, irrelevant, incorrect, or falsely misleading” as unprofessionally unscientific as it was deeply offensive. By rudely saying the evidence was false and misleading, he was effectively accusing me and my co-workers of scientific fraud. He displayed a fundamental lack of toxicological understanding in his statement that venom wasn’t necessary to explain the effects of a Komodo dragon bite.
Our central point, which he clearly did not get (either willfully or through simple ignorance), was that the teeth were the primary weapons and the venom was there in a supporting role, to potentiate the blood loss and shock-inducing effects—something that was well supported by our high-quality, peer-reviewed data showing venom components with exactly these toxic effects. I felt it was telling that he could not come up with a criticism of the data itself and seemed instead to be simply making an argument from authority—despite not having any venom research expertise. I tried to be philosophical, but at the end of the day I was extremely offended.
The bizarreness of unscientific, emotional responses took on a surreal quality when, in collaboration with the University of California, Los Angeles bacteria specialists Ellie Goldstein, Diane Citron, and Kerin Tyrrell, we reinvestigated the mouths of Komodo dragons. These are the people who had done the seminal studies of bite-wound bacteria, ranging from bites in prison to bites from wild animals. If indeed Komodo dragons were cultivating bacteria, their mouths should have higher levels than ordinary carnivores, regardless of whether they were captive or wild. In other words, they should be selectively causing microbial blooming. The Los Angeles Zoo and Honolulu Zoo were particularly supportive of the research and let us take samples from their prize animals, for which we were extremely grateful. This is, of course, the ethical justification for keeping animals in captivity—for the intellectual and social benefit. The Los Angeles Zoo even gave us access to hatchling dragons only hours old that had not yet eaten or drunk anything: the most crucial sources of data.
However, other zoos were not so supportive (I will not name or shame them, despite really wanting to). Some ignored our request, while others flatly turned it down and, most staggering of all, some even went as far as ringing other zoos to try to convince them not to be a part of the study. When we submitted the paper, we had the most incredible battle with one of the reviewers, who could not make a coherent scientific case against our data or interpretations, but still stridently argued for its rejection. Once the paper was accepted, we assumed we were home free, but then the journal sat on the paper for an entire year. Only after we had sent many emails showing how annoyed we were was the paper released. I was gobsmacked. This was a subject for which we were providing the first solid evidence to debunk a cherished and long-held belief that had never been supported by evidence. Yet, unlike the issue of climate change, there were no economic interests being threatened. Collectively, this was as irrational a reaction to science as I had ever encountered. Between Schwenk’s unprofessional response and the zoological institutions’ illogical reactions, I was quite cynical by the time the dust settled. My academic conclusions in Scientific Philosophy as an undergraduate did not prepare me for the reality.
Not long after this, I was cleaning out the cages of the pair of Bell’s phase lace monitors that were part of my collection of sixty giant lizards. My attention was distracted by the male when I absentmindedly made a small jerking action to flick away a fly, so I didn’t see the female sprint across the cage. She latched on to my hand and jerked her head back, just like a Komodo dragon would with a deer leg. As the teeth cut my flesh to the bone, they made the ratcheting sound of a steak knife being dragged across a T-bone steak. Crimson ejaculations of arterial bleeding from my right index and middle fingers rhythmically painted the wall like a Jackson Pollock artwork. Having had many flesh wounds in my life, my first thought was, “Ah well, at least it’s not a death adder bite. How bad can it really be?” It turned out I had grossly underestimated the gravity of the situation. In both fingers the tendons, nerve bundles, and arteries had been completely severed. All that was securing the two digits were the small ligaments on the side, where the finger bones met.
Upon arrival at the hospital, I had to explain how I came to be presenting at 7 a.m. on a cold, rainy, Queen’s Birthday holiday in Melbourne with a hand destroyed by a large tropical lizard. I tried to convince the Indian locum to simply send me straight to surgery; that if I unwrapped the towels from my hand and unclenched my fist, I would unnecessarily start bleeding. He climbed up on his high horse and said in a thick Delhi accent, “I am the doctor here and you follow my instructions!” “Fine,” I thought to myself. “If I’m going to bleed, you’re going to suffer too.” So I unwound the towels and unclenched my fist with my fingers spread, palm facing directly at him. Twin spurts of blood lasered out like Spider-man’s web streams and splattered all over his shirt and face. He picked the wrong day not to be wearing a lab coat.
As predicted, off to surgery I went. It took a pair of plastic surgeons four hours of microsurgery to put my hand back together. In order to keep the tendons from pulling apart during the long healing process, my hand was in a brace and strapped to my chest for the next two months. During this time I had to do everything with my left hand, which drove me nuts. For example, learning how to wipe my bum with my left hand was a messy exercise in frustration. One-handed typing also took on a whole new meaning. I went through the swearing-in ceremony to receive my Australian citizenship with my arm still in the sling, my right hand resting above my heart. At least I looked patriotic during the anthem.
