Exploring Indo-Pacific Snakes (Full Episode) | World's Deadliest Snakes | Nat Geo Animals

NARRATOR: To most of us, snakes shout danger! And that's a valuable instinct. Every year, they bite over five million people. Some have lethal venom, others primal aggression. A handful have both. Which snake is the most dangerous? It's the one in front of you. What are your chances? We'll tally them up and tell you. World's Deadliest Snakes. Australia. India. But first, Southeast Asia. A hot spot for some of the world's deadliest snakes. ♪ ♪ The humid tropical rain forests of Indonesia. A hunting ground for one of the biggest and most powerful snakes in the world. It's a reticulated python, longer than a London bus. No venom, but a bad temper, 350 pounds of it. Such a colossal predator requires a man-sized meal. Usually hunting at night, the python's reticulated camouflage allows it to move around the jungle unnoticed in the day. (screech) (whooping) Despite its enormous size, this giant is surprisingly active. Even primates are a welcome appetizer. In the wild it can hunt anywhere, but water helps support its massive bulk. It's capable of staying submerged for up to 20 minutes. You'll never see it coming. These jungle streams provide this giant python a direct express lane into human settlements. Southeast Asia is home to over 655 million people, and many communities border the python's rain forests. (dog barking) It's not unknown for pets to go missing, and sometimes children. Night gives the python the advantage. Cat-like eyes are optimized for night vision. And those pits along its snout detect the body heat of warm-blooded prey. (thump) (hiss) Once locked in its jaws, around 100 recurved teeth make escape near impossible. Squeezing so tight, it stops their blood flowing within minutes. By detaching its lower jaw, the python can spread its mouth wider than its skull. This meal is the size of a child. A serious problem when a hungry python ventures into a village. The reticulated python's fear and aggression factors are high, but it's all brute strength, without the venom. Bites are devastating, but rare. Unless you're a small child, your chances of survival are high. When it comes to snakes, you don't always have to be big to be deadly. India, China and Indonesia, famous for coffee, tea, and venomous reptiles. Hidden within the leaves are small, arboreal snakes that terrify local farmers. Green pit vipers. They don't mean to harm humans. It's a by-product of their incredible hunting prowess. Like the python, they use heat-sensing pit organs on either side of their heads to track warm-blooded prey like birds and rats. (squeaking) That wide head houses large venom glands and long, hinged fangs. Like other vipers, their mouths can open almost 180 degrees to strike. But their venom isn't the worst of them. Green pit vipers are dangerous because these tree-dwellers hunt and strike at head height. A mistaken bite on a human can cause bleeding and painful swelling, sometimes resulting in asphyxiation and death. They account for more snakebites than any other group in all of Southeast Asia. And they have another tag-team cousin at work below. There's a more venomous viper lurking in the leaf litter. A snake that's responsible for several hundred snakebites every year. The Malayan pit viper. Palm oil and rubber plantations pepper the jungles of Southeast Asia. Great places for a snake to hunt rodents. Its strategy is to bite immediately, injecting fast-acting, hemotoxic venom, which causes severe pain, extensive necrosis and massive internal bleeding. Its venom is so effective, its anticoagulant properties are being researched as potential treatment for stroke victims. While its cousins, the green pit vipers, take care of the trees, the Malayan pit viper covers the ground, lying in wait for rodents and frogs. Its pointed, leaf-shaped head and mottled markings help it blend perfectly into the leaf litter. Invisible. So easy to step on. These fangs can breach a rubber boot. Due to the lack of antivenom and hospital treatment in rural Southeast Asia, those that survive are often left with dysfunctional or amputated limbs, which is why it's locally nicknamed the "axe snake." It's time to tally up our first contenders for the title of the Indo-Pacific's deadliest snake. The pit vipers' venoms are potent enough to devastate limbs, and they're quick to strike. Yet, despite being responsible for hundreds of thousands of bites each year, only 2% are fatal. But it's more than enough to beat the giant python off top spot, for now. Home to four of the world's deadliest snakes and nearly 1.4 billion people. Over four times the population of the US, in a country smaller than the West Coast. A myriad of people and a host of dangerous snakes; a recipe for disaster. One of the most venomous is the common krait. It's small, slender and unassuming. Yet its venom, meant to immobilize prey, can cause respiratory arrest in humans. Just one bite can kill seven people. Shy, docile, and slow by day. (horn beeps) At night, the krait transforms into an alert and active hunter. During the rainy season, it enters homes in search of shelter, warmth, and reptiles. Rolling the wrong way could be fatal. NARRATOR: The common krait's bite is so small and painless, it feels like a mosquito bite. In a matter of hours, full-body paralysis sets in and maybe death. Many bite victims simply never wake up. The common krait is a problem in India, but there's an even more dangerous killer that haunts India's farmlands. (rooster crows) An ambush predator, known as the lurker. A snake that is near-impossible to see, until it's too late. The highly venomous Russell's viper. One of the most dangerous snakes in all of Asia. This large, stocky, slow-moving snake is a master of camouflage. Notoriously defensive, it often holds its ground and gets stepped on by accident. Not only do people not see it, but its strikes are so quick, there's no time to react. Its large, flattened head accommodates two long, half-inch, hinged fangs, which deliver huge doses of potent cytotoxic venom. A bite causes excruciating pain and begins destroying flesh. It's a predatory masterpiece, but what makes the Russell's viper so dangerous is its penchant for entering human settlements. Why? They're not malicious, they're just after rats. Out here, there are no hospitals, and antivenom, even if you can find it, isn't always effective. So, bites claim thousands of limbs and lives every year. Arch-enemy, or valuable service provider? Pest control. Rodents bite back, so the viper and its venom have a nifty plan. (squeak) Bite... ...and release. Large glands at the back of its head yield enough venom to kill over 600 mice from a single bite. The common krait and this, the Russell's viper, are considered two of the deadliest snakes on Earth. But how do they score against each other? The common krait is reluctant to bite, but when it does, it injects one of the most potently toxic venoms in the world. Found throughout India, it's responsible for tens of thousands of bites each year, and if left untreated, 80% of its victims die. But does the Russell's viper have the edge? Its venom glands are larger, injecting higher doses of lethal venom. And due to its wide distribution around India, and highly defensive demeanor, the Russell's viper is responsible for more snakebites than any other snake in the country, killing thousands every year. Despite its lethal potential, the common krait's small fangs and low venom yield cost it first place, making way for the Russell's viper to take pole position. To find a worthy challenger, we must travel to the country with the deadliest wildlife in the world: The land of sun, surf, and snakes. Here, there is a dangerous snake for every habitat, but one in particular is found all across Australia. NARRATOR: A snake so feared, it's simply called the death adder. And it's hard to spot. Its patterns and colorations mimic its surroundings; dry, arid deserts, or the undergrowth of Australia's woodlands. There it is. You only notice the death adder when it moves through the forest, crossing roads or entering people's backyards. The minute it stops, it vanishes. It can lie in wait, submerged in the leaf litter, motionless, for days at a time, primed for an explosive attack. But first, a trick. Is that a worm, or a tail? Once inquisitive prey is within range, this passive hunter unleashes the fastest strike in Australia, under a tenth of a second. What makes this efficient hunter so dangerous to humans are its defensive strikes on pets and people. Innocently lying in ambush, often stepped on by unwary hikers. Its large, quarter-inch fangs, swift strike and high venom yield can inflict serious damage. Potent, neurotoxic venom can kill a human within six hours. You may make it past them... (whimper) But dogs often don't, succumbing to bites in just 20 minutes, regardless of antivenom treatment. One bite from a death adder holds enough venom to kill over 18 people. And its strike is super fast and aggressive. But hidden in the wilds of Australia, hikers are the most at risk of stepping on one, and while many pets are killed each year, nearly all humans survive. The death adder is more defensive and potent than the pit vipers, but widely accessible medical care and antivenom costs it a higher ranking. Thousands of miles from the coast, deep in the outback of central Australia is a snake with a fierce reputation. The rare and reclusive inland taipan, the most potently venomous snake on the planet. Life out here is tough. To find food, this large, six-foot snake can't sit and wait, it must hunt. It carries highly specialized neuro- and hemotoxic venom. (hissing) If this rat gets away, it may not see another for days. To make sure, it can inject 40,000 times the amount of venom necessary to kill the rat. Awesome? Maybe not. Just one of those bites is enough to kill over 100 people. Prey suffer seizures, paralysis, and internal bleeding, all within seconds. And no chance of escape. This arid desert is no place to dawdle. With little shade, temperatures can soar over 100 degrees Fahrenheit, but the taipan has adapted by changing the color of its skin. They lighten in summer, so as not to overheat, and darken during the cooler months, to retain warmth. For shelter, the taipan makes good use of any unoccupied burrows and deep cracks in the dry plains. It's also the perfect place to hide eggs. Newborn taipans are five times smaller than the adults, but also deadly. Once free, they must fend for themselves, with only their venom to protect them. But there is one predator that's immune to even the taipan's bite. They call it the mulga. 10 feet long, 13 pounds in bulk, it's Australia's heaviest venomous snake. Hence its common name, the king brown. It's a hunter of snakes, with immunity to most of Australia's most venomous, including the smaller taipan. The king brown's venom may not be as potent as the taipan's, but what it lacks in quality, it makes up for in quantity, injecting up to six times more venom in a single bite; the largest venom yield ever recorded. Prey suffers hemorrhaging, paralysis and renal failure. Australia is home to some of the world's most venomous snakes, but how do they rate against the rest? The inland taipan is rightly feared. Its venom so potent that an untreated bite could kill you in less than an hour. But this shy serpent is relatively placid and would rather flee than fight, so, bites to humans are uncommon. Australia is home to over 25 million people, but 85% of the population lives within 30 miles of the coast, and the inland taipan hides out in the middle of the remote and desolate outback. Nearly all that are bitten have survived, thanks to quick hospitalization. Which means it may be the world's most venomous snake, but the inland taipan is far from being the Indo-Pacific's deadliest. Perhaps the king brown can kill you quicker? Its venom may not be as potent as the taipan's, but it has a savage bite and injects enormous amounts. And being the most widespread snake in Australia, bites are much more frequent. But thanks to localized antivenom, deaths are rare. Deadly enough to pip the taipans. The king brown is a heavyweight, but to find the true king of deadly snakes, we must travel to the jungles These are the hunting grounds for the longest venomous snake NARRATOR: The king cobra can stand up and look you in the eyes. Using up to 20 pounds of pure muscle to raise its body four foot off the ground. Like most cobras, it can flatten its ribs, extending the looser skin on its neck. This colossus can easily live for 20 years in the wild, growing up to 18 foot. Everything about the king is large, including its appetite and its venom load. One bite can kill an elephant in just three hours; a human, in 30 minutes. But there's a reason for its deadliness. It's a voracious hunter of other big snakes. While known to feed on small, venomous kraits and other cobras, they usually hunt down larger species, even giant pythons. This 10-foot rat snake is unaware it's being watched. Rat snakes often cloak themselves in the scent of their last kill, so other rodents are less likely to detect them; a scent the cobra can easily track. The king uses its lower jaw to detect tiny vibrations on the ground to home in on its target. It needs all the venom, power and size it can muster. Bad for the rat snake, and bad for us. 16-millimeter fangs, like hypodermic needles, inject 20 times more venom than most venomous snakes in a single bite. Within minutes, the neurotoxins stun the nervous system, paralyzing the body, shutting down lungs and damaging brain functions, while other toxins begin the digestion process, from the inside out. The cobra's backward-facing teeth help walk the meal down. A 10-foot rat snake fits nicely inside an 18-foot cobra. The king may be the biggest venomous killer around, but is it the deadliest to us? A single bite from a king cobra is enough to kill a human 20 times over. Yet, despite its size and reputation, it's not overly aggressive. But it doesn't hesitate to defend itself, biting tens of thousands of people each year, which, left untreated, kills thousands across the Indo-Pacific. The king competes with the deadliest on every level, but its more tolerant attitude and reluctance to bite costs it first place. If the king can't conquer top spot, what about an entire family of Asian cobras? There are 12 species of cobra found throughout the Indo-Pacific, and they exact a terrible toll on the people that live here. Some can spit their venom, while others rely on their size, cunning, and deadly bite. The monocled cobra is found across Southeast Asia, as far west as Thailand. This large six-foot snake hunts rodents around open fields and rice paddies, making human contact inevitable. With a short temper, it's aggressively defensive. It gets its name from the large circle on the back of its hood, and its highly potent neurotoxic venom is some of the fastest acting But one of Asia's Big Four is found throughout the Indian Subcontinent. It thrives along the edges of forests, fields and villages, especially near water. Not one, but two circles; the spectacled cobra. NARRATOR: The spectacled cobra is highly alert to movement, often striking out, and highly venomous. Its hood is deeply cupped. This cobra puts on a real show. Those spectacled eyes are distinct. Know your enemy. It's drawn to the edge of villages in its search for food. (clucking) A bite not only eats away at your flesh, but also causes full-body paralysis, crippling your ability to breathe, within hours. With food on tap in and around human dwellings, the spectacled cobra is a familiar face. (squawk) This cobra is so feared, it's worthy of Hindu deity. But is it deadly enough to take top spot? The monocled and spectacled cobras have bites to match their barks. And death comes quickly. They are intolerant and strike on movement, but what makes them really deadly are their numbers. Unlike the king, they are found all across India and Southeast Asia, living among billions of people, which makes them responsible of bites each year. And with limited antivenom and hospital care, many tens of thousands of their victims die. Making the monocled and spectacled cobras the deadliest snakes in Asia... for now. It will take a serious contender to knock the cobras off the top spot. But maybe the second most venomous snake in the world could do it. Down under, many of the deadliest look alike. Taipan? Mulga? No. This is an eastern brown. Responsible for more snakebite fatalities in Australia than any other. Like the taipans, their venom has evolved to kill fast-moving prey quickly. They, too, are very fast, actively chasing down their prey. But what makes this snake so dangerous is that it thrives in towns and cities all across the east coast, in the most populated areas of Australia. It can squeeze its narrow, five-foot, slender body through tiny gaps in doorways of homes and sheds. Like many others on the leaderboard, they're only here for the rats, but that often means they face us. If disturbed, it reveals a calling card: a signature "S" for maximum strike force. That strike comes at 40 miles an hour, often with a gaping mouth to compensate for its short, fixed fangs, which usually means a painless bite and one that's difficult to see. Yet each bite delivers a small but deadly venom cocktail, causing progressive paralysis and uncontrollable bleeding. Victims can collapse within minutes, and if left untreated, they could be dead in under half an hour. The eastern brown's venom is so toxic, not even antivenom can reverse the effects. It has a short fuse and attacks with little warning, making it responsible for thousands of bites every year. In the last decade, 60% of Australia's snakebite deaths were attributed to them. They have the venom, the defensiveness and the opportunity, but thanks to quick hospitalization, they just miss out on the lead. NARRATOR: To be the deadliest, a snake needs aggression, a deadly bite, opportunity, and human vulnerability. For that, we need to return to India. India is home to nearly one and a half billion people. (horns beeping) Many of which live and work in the densely populated rural districts. Men, women and children share this open farmland with four of the world's deadliest snakes. We've met three of them. And each year, close to 50,000 people die here from snakebites. That's the equivalent of a town being wiped out every year. And most of those deaths are from the fourth. (rustling) The saw-scaled viper. Many snakes offer a clear warning to stay away, but this one is a born deceiver. At only 12 inches long, the saw-scaled viper may be small, but it packs a serious punch. Its venom is many times more potent than any cobra. And being highly aggressive, it strikes readily. Lightning-fast, again and again. When disturbed, they coil up into strike position, rubbing their tough, keeled scales together to create a sawing sound, hence the name. Ignore it at your peril. The strike comes quick, and venom soon after. But what makes this snake a problem is its proximity to humans. The saw-scaled viper is found across India and Pakistan, living amongst highly populated and remote rural farmlands. Out here, there is limited access to hospitals and victims often rely on ineffective traditional remedies. Globally, the saw-scaled viper is responsible for more human deaths than all other snake species combined. Many of which are children. The viper's small size and excellent camouflage makes them hard to see under leaves and grass. And unlike the Russell's, they don't try to flee, or mock-charge like the king. Instead, the saw-scaled stands its ground, biting at anyone and anything that comes too close. BOY: Ah! NARRATOR: Within minutes, the victim's limbs start to swell as the necrotic venom breaks down blood vessels and muscle, often leading to unavoidable amputations. If left untreated, the excruciating pain is followed by organ failure and quite easily, death. It's not the biggest or the fastest, or even the most potent, but it lives on our doorstep, it's notoriously aggressive, and it strikes with relish, which all stacks up to make the saw-scaled viper the deadliest snake across the Indo-Pacific. These snakes have a bad rap, but their bites are in defense. Humans aren't prey and snakes don't actively set out to harm us. A life without limbs has armed them with an arsenal of alternative skills to master their environments: chemical weaponry, highly evolved senses, and incredible muscle power. Without them, rodents would run riot, agriculture would be plagued, and our homes would be infested with disease. As much as we may fear them, a world without snakes would be a far more dangerous place.