Over 60 per cent of Peruvian land is covered by the Amazon rainforest, and it’s there that you’ll find the most dangerous animals in Peru. If you’re planning to trek the Inca Trail or visit Machu Picchu, you should read this guide. Because, quite simply, Peru has animals that can kill you, including the most poisonous animals alive: poison dart frogs.
Known as la Selva (‘the Jungle’), Peru’s isolated rainforest region stretches from the eastern foothills (la Montaña) to the start of the Amazonian basin. In fact, east Peru’s Mantaro River, carrying meltwater from glaciers high in the Peruvian Andes, has recently been proved the true source of the Amazon.
So here, ranked in order of deadliness, are the all-time top 7 most dangerous animals in Peru. Maybe there’s still time to cancel your ticket…
The 7 Most Dangerous Animals in Peru:
Poison Dart Frogs
Carrying enough poison to kill up to seven grown men, poison dart frogs (or poison arrow frogs) are perhaps the most deadly animals on Earth. This is even more impressive when you realise that these frogs are tiny: the largest are no more than 6 centimetres long, and some are fully-grown at just 15 millimetres.
There are over 170 species of Dendrobatidae and, to our eyes, their stunning colour schemes are beautiful. But in nature, bright colours are often a warning sign, and the message here is clear: keep away. The poison produced by these frogs — batrachotoxin — is so potent that even in minuscule amounts it can cause paralysis and death if it enters the bloodstream.
This fact was not lost on rainforest tribes like the Emberá Chocó, who made small darts from slivers of palm wood and coated them with poison from the frogs, hence the name ‘Poison Dart Frog’. The toxin from the Golden Poison Frog, in particular, is 20 times more toxic than any other frog poison.
Fortunately, the Golden poison frog is only found in a tiny plot of rainforest on the Pacific coast of Colombia. Peru’s poison arrow frogs are less toxic, but the toxin can still kill. One example is Anthony’s poison arrow frog which carries epibatidine. According to a 1998 study, even minute amounts of epibatidine can cause severe brain and muscle damage. This can lead to respiratory paralysis, high blood pressure, seizures and death.
But it’s not all bad! Some species produce toxins that are useful for scientific research. For example, the toxin from the weirdly-named Phantasmal poison frog contains a painkiller 200 times more powerful than morphine.
Toxin from a poison dart frog can kill any animal, including us, in less than three minutes and there is no antidote. However, records up to 2019 show no published reports of human deaths from any poison dart frogs, including the golden variety.
The bullet ant (Paraponera clavata) shouldn’t really be on this list, as it’s not a killer. But we’ve included it for one specific reason: it has the most painful sting ever recorded.
There’s an official way of measuring pain, called the Schmidt Pain Index. On a scale that maxes out at 15, the bullet ant registers 15. Justin Schmidt, who created the index, describes it as “pure, intense, brilliant pain. Like walking over flaming charcoal with a 3-inch nail embedded in your heel”.
Bullet worker ants can grow up to 1.2 inches long, which in ant terms is massive. (Some websites mistakenly claim that the bullet ant is the largest ant on earth, however that honour goes to Dinoponera, the giant Amazonian ant, which can exceed 1.5 inches in length.)
Bullet ants can be ferocious, but they’re not instinctively aggressive. If disturbed, their first defence is to give off a stinky warning scent. At the same time, they will let out a shriek (yes, really!) to warn the nest. If the threat persists, the ants will bite and latch on to their attackers, and then sting repeatedly.
Their sting releases poneratoxin: a unique compound that disrupts synapses in the central nervous system. This confuses nerves and nerve endings, resulting in intense and all-consuming pain, emanating in waves from the area of the sting. Worse still is that the pain can last a full day, although over 12 hours is rare.
One amazing thing about the bullet ant’s sting is that there are no after-effects. This is because the injected neurotoxin, although it causes intense pain, is not physically dangerous. Moreover, after twenty-four hours, the toxin is entirely flushed from the body. According to adventurer and naturalist Steve Backshall, once the toxin is gone “you feel fantastic. You have such a massive overdose of adrenaline that you feel like a god. For a week afterwards, I felt like if I leapt off a cliff I could have flown.”
There are no scientifically documented reports of deaths, perhaps because, according to some estimates, it would take at least 250 stings to kill a 165-pound human.
The biggest cat in the Americas, the jaguar has a more powerful bite than any other big cat – strong enough to pierce a human skull. One of nature’s perfect killing machines, the jaguar is an apex predator built for elegance, speed, and deadly precision.
The name ‘jaguar’ (Panthera onca) comes from an indigenous Indian word and means “he who kills with one leap”. This is a fitting name, as the jaguar relies on stealth, speed, and that one single leap to catch its prey. Jaguars feed only on meat, and their diet includes over 80 different species, including capybaras, tapirs and turtles. To secure their prey, jaguars employ an unusual killing method. Using their powerful jaws, these big cats bite directly through the skull of their victim, causing irreparable damage to the brain.
Jaguars are fiercely territorial, and adults meet only to mate and divide up territories – a single male will typically patrol an area of up to 3 square miles, and gets first refusal for any females in the area. Well adapted to swimming, his hunting ground includes both water and land. But even this apex predator has to be cautious, as anacondas have been known to attack and overpower fully-grown jaguars.
Each jaguar’s markings are unique. Whilst this is ideal for camouflage, it also makes these big cats prized targets for the fur trade. During the 1960s, more than 15,000 Jaguars were killed for their pelts every year. Poaching and fur-trading are now banned, but the Jaguar is still a threatened species.
Like most big predators, jaguars did not evolve with man as prey, and so we’re not on their ‘prey-radar’. In fact, experts have ranked jaguars as the least likely of all big cats to attack humans. Fatalities are rare, in fact in the last 20 years, only one death by jaguar has ever been reported throughout the whole of the Amazon basin.
More recently, proving that there’s no defence against stupidity, a woman stepped over a barrier at an Arizona zoo to take a selfie with a jaguar. Predictably, the big cat attacked: leaving the woman with deep gashes in her arms. She admitted that she was in the wrong but, in true litigious style, is also suing the zoo for having their barriers in the wrong place.
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Amazonian Giant Centipede
The Amazonian giant centipede (Scolopendra gigantea) or, to use its local name, the Peruvian giant yellow-leg centipede, grows up to 12 inches long, making it the largest species of centipede in the world. These native Amazonians aren’t insects: instead they’re myriapods, which is a group that includes centipedes, millepedes, and small translucent creatures called Symphyla.
They are voracious, predatory carnivores, and they will eat anything they can catch. This includes smaller prey, but also bigger creatures such as tarantulas, lizards, snakes, frogs and mice. Their first pair of legs have evolved into claws, which curve around the head and hold a toxin in a concealed gland. These centipedes are fast: they rush in, grab their prey and inject the paralysing toxin with lightning efficiency. Not many forest-floor creatures have been known to escape the Amazonian giant centipede.
Within the rainforest, you’ll find Amazonian giant centipedes hiding beneath rotten timber, leaf debris or under a rock, but they’ve also been known to reside in people’s homes: seeking out dark and moist hideaways. As with any venomous animal, Amazonian giant centipedes will bite to defend themselves or if disturbed. Bites on humans are rare, but reportedly very painful and can cause allergic reactions, fevers, and fatigue.
Only four deaths from centipede bites have ever been reported worldwide, and only one was due to the Amazonian giant. (Sadly, it involved the death of a 4-year-old girl, which happened in Venezuela in 2014). More recently, in October 2020, a former Thai boxing champion with diabetes died from blood-poisoning due to a bite from a Chinese red-headed centipede.
Brazilian wandering spider
The Brazilian wandering spider is the most venomous arachnid in the world. Its bite can deliver one of the most deadly toxins known to man, and until 1996 there was no antidote.
There are 8 species of Brazilian wandering spider, collectively known by their scientific name Phoneutria (which is Greek for “murderess”!) They’re also known as banana spiders, due to their occasional habit of turning up in boxes of shipped bananas. The most dangerous of this group – the Brazilian Huntsman (P. nigriventer) – is only found in Brazil, but two species are local to Peru, known as P. fera and P. reidyi.
P. fera is the larger of the two Peruvians and is the second-most toxic of all the wandering spiders, only beaten by the Brazilian Huntsman. Its diet includes large insects such as crickets, small lizards and mice, which it hunts for at night. This is why they’re known as ‘wandering spiders’ – other spiders generally wait for their food in a web or lair.
During the day, Mexican wandering spiders seek shelter and shade, which occasionally leads them to hide in dark corners of residential homes. In the rainforest, they’re wary of being easy prey for large birds and other predators, so they usually spend the daytime hidden in the leaf litter.
However, if disturbed they will bite (repeatedly), although their first instinct is to defend. They have a characteristic defensive stance in which they hold their front legs high above their head: this means their next move is to attack, so your best bet is to back away!
A bite from a wandering spider can be fatal, and some human victims have reportedly been killed in under an hour. Survivors aren’t much better off: the venom holds a potent neurotoxin which leads to respiratory paralysis, and also a very high concentration of serotonin which makes the bites excruciatingly painful. Bites can also cause priapism, which we’re not going to explain here.
Most wandering spider bites occur in Brazil, with roughly 4,000 cases per year, but less than 1% are considered severe. Since 1903, fifteen deaths have been attributed to Mexican wandering spiders. (In one case, two children who slept in the same bed, in a rural house on the Atlantic coast of São Paulo, were killed on the same night by the same spider.)
Jaguars may rule on land, but it’s black caimans that dominate in the water. They’re the largest predator in the Amazon River basin, they’re ruthless killers, and you won’t see them coming until it’s too late.
The black caiman is the largest of all the alligator family with adult males averaging 13 to 15 feet in length (huge 20-foot caimans have been reported, but not confirmed). They’re only found in the Amazon, living in freshwater lakes, slow-flowing rivers, and the seasonally flooded savanna.
Like their crocodile and alligator cousins, caimans have walked this earth for millions of years. In 2005, Peruvian scientists discovered the fossilized remains of a giant, 46-foot-long crocodile deep in the rainforest. It had been laying there for over 15 million years, and some experts see it as proof that the Amazon was once a huge inland sea connected to the Caribbean.
The black caiman is an apex predator, and will attack any animal that ventures into its territory, including unwary humans. With acute sight and hearing, it prefers the cover of night to hunt its prey. Its dark colouring means it’s hard to spot in the dark, which makes stalking easy. As with all crocodilians, a caiman’s teeth are designed to grab but not chew, so they generally try to swallow their food whole after drowning or crushing it.
Although they have no natural predators, attacks on caiman can happen. Anacondas have been known to crush and consume young caiman, and there are several records of jaguars taking down small adults, including one that measured 12 feet. No-one has ever seen a caiman take on a jaguar, although animal behaviourists all agree it’s a likely scenario. As to who’d win in a jaguar vs caiman fight to the death, our money’s on the caiman.
According to CrocBITE, between 2010 and now (December 2020) there have been 74 recorded black caiman attacks on humans, of which 17 were fatal. The last was in May 2019, when a 53-year-old Brazilian fisherman, possibly drunk, was snatched from his canoe. Of the 74 reported incidents, the vast majority were in Brazil – only six attacks happened in Peru.
It’s been claimed that almost half of the people who have ever lived have died from a mosquito-borne disease. That’s over 50 billion people. In la Selva and the major cities, regrettably, you’ll meet a lot of mosquitoes. Potentially, this makes them the most dangerous animal in Peru, and certainly one to be wary of.
As most websites will tell you, mosquitoes don’t actually manufacture the disease, but they do carry and ultimately transmit the infectious pathogens and parasites that cause illness. And, as they are the only animal involved, it’s fair to rate them as dangerous and indeed deadly.
In 2017, Peru’s capital city Lima saw a rise in mosquito populations. This included the most dreaded species – the Aedes aegypti, a carrier of various diseases including dengue fever, Zika virus, chikungunya and yellow fever. Malaria, also famously carried by mosquitoes, is only a problem in the rainforest – according to official sources, there is no malaria risk for travellers visiting popular tourist spots like Cusco, Machu Picchu or Lake Titicaca.
You’ll hear this a hundred times if you decide to go to Peru, but we can’t stress it enough: buy insect repellent! You should also make sure you get a yellow fever jab a good few weeks before travelling. That, and judicious use of mosquito netting, will usually keep even the most persistent mozzies at bay. Here’s a link to the CDC’s advice on the best repellent spray for mosquitoes.
Mosquito-borne diseases account for more than 17% of all infectious diseases, causing over 700,000 deaths every year (some experts put this at over one million). Malaria, transmitted by Anopheline mosquitoes, is the biggest killer by far: there are an estimated 219 million cases globally, and more than 400,000 deaths every year.
Dengue fever, the next most deadly infection, is carried by Aedes mosquitoes. There are an estimated 96 million symptomatic cases per annum, resulting in over 40,000 deaths every year.
And so there it is: our all-time top 7. We hope you enjoyed our article, and if we’ve managed to increase your knowledge of dangerous animals in Peru, then our work here is done! And we’d love a little something from you in return, so why not drop a comment in the comments box or connect with us on social media. Thanks!
Frequently Asked Questions
What animals live in Peru?
There are over 3,000 different species of animal living in Peru, of which roughly 180 are endemic. That makes Peru one of the greatest biodiverse countries on the planet. The numbers of animals can be broken down as follows:
Mammals: over 500 species, such as the apex jaguar and the elusive sloth, and not forgetting the llama and the alpaca! Birds: over 1,800 species, the second-highest of any country in the world. Reptiles: roughly 300 species, including anacondas and black caimans. Amphibians: about 400 species, with at least 380 of them frogs, including the poison dart frogs.
What big cats live in Peru?
Jaguars and cougars are the only big cats that live in Peru — both are over a metre in length, which is the accepted big cat group entry requirement. The jaguar, at up to 2 metres long, is the largest big cat in the whole of South America and the third biggest worldwide. The cougar is slightly smaller, at 1.6 metres, but it’s still classified as a big cat.
What is the most dangerous animal in the forest?
The most dangerous animal in the Amazon rainforest is the mosquito. Responsible for over 700,000 deaths per year – mainly from malaria and dengue fever and other diseases – it’s the most dangerous animal in the world. Here’s a grim statistic: if you total the human deaths from every other animal (roughly 620,000 fatalities per year), mosquitoes are still the biggest killers.