A Blog by Ed Yong

Meet the Agta, a tribe where a quarter of men have been attacked by giant snakes

When Thomas Headland first met the world’s longest snake, he was on the way to the toilet. He was living in the Philippine rainforest with a group of hunter-gatherers called the Agta. On the walk to the outhouse behind his hut, he stumbled across a reticulated python curled up on the trail. “The hairs on the back of my neck stood up and I shouted for help,” he recalls. At his cries, six to seven Agta jumped up from the surrounding bushes… and started laughing. Their new American neighbour had fallen for the old previously-killed-python-on-the-path gag. “I didn’t know what jokers these people were at the time,” says Headland.

Giant snakes frequently attack people in fantasy and science-fiction stories, but such attacks are not merely the stuff of fiction. Through his extensive work with the Agta, Headland has found that a quarter of all the men have been attacked by pythons.

Headland and his wife first arrived in the Philippines in 1962, three weeks after they had married each other in Minnesota. They lived solidly with the Agta for 24 years, and they still return to the forests every other year. “I’ve lived in the rainforest longer than any American scientist,” he says. “I’ve seen things out there that I saw in Tarzan movies when I was a kid.”

That includes plenty of giant snakes. “Three or four times, the pythons came into camp and killed chickens. One time, a man saw a snake coiled around his dog, and he killed it was a machete. My wife’s killed one python and I’ve killed one,” says Headland. The biggest he ever saw was a 6.9 metre monster, shot by his neighbour Kekek Aduanan (on the right in the photo). It was the third largest python on record.

The reticulated python is the world’s longest snake. Females typically weigh 75 kilograms (165 pounds) and grow larger than 7 metres (23 feet). The Agta, by contrast, are a small folk. Adults reach around 1.4 metres (4.5 feet) in height and weigh around 44 kilograms (97 pounds). For a snake that can swallow an entire pig, an Agta would make a mere medium-sized mouthful.

In 1976, Headland started formally interviewing the Agta about their encounters with pythons. The entire population includes just 600 individuals, and Headland managed to speak to 120 of them. To account for the possibility of tall tales, he asked careful, searching questions, and corroborated his data with different witnesses.

His survey, “encompassing approximately seven decades of memories” showed that 26 percent of the Agta men had been attacked by pythons, compared to just 2 percent of the women. After all, men spend more time out in the forest. Two unlucky men had been attacked twice, 15 had been bitten and 11 had substantial scars that recorded their encounters.

Mostly, the Agta fend off the serpents with machetes or shotguns. Only six people have actually been killed in the span of 39 years, including a man who was found inside a snake, and two children who were eaten by the same python on one fateful night. Without their iron weapons, the Agta would surely have lost more individuals to python coils.

But the Agta aren’t just victims. They’re proficient python-killers in their own right. All the men had probably killed smaller specimens at least once in their lives. After Kekek Aduanan shot the big python that Headland photographed, three hunters skinned and butchered the snake in under an hour (the skin’s being held out in the top photo).

Headland writes that reptile specialists have “long claimed that giant serpents eat humans only under exceptional circumstances”. But his study with the Agta – one of the few available for any hunter-gatherer groups – suggests otherwise. It shows that humans and giant snakes often come to blows. Headland thinks that the threat of pythons would have significantly influenced the lives of the Agta, especially before they made contact with Westerners and gained access to metal tools.

To see if serpentine threats were a common feature of our evolution, Headland contacted Harry Greene from Cornell University. Greene mined the natural history literature for encounters between serpents and primates, the group that includes ourselves, other apes, monkeys and lemurs. He found a laundry list of anecdotes. Snakes, both venomous and constricting, have attacked at least 26 species of primates other than humans. No living snakes specialise on killing primates alone, but many pythons, boas and other constrictors will attack them regularly.

But just like the Agta, primates often turn the tables, and many such bouts have ended in defeat for the serpent: a tarsier eating a coral snake; a patas monkey killing a mamba; a black lemur taking on a Madagascan boa; and more.  Humans, both prehistoric and modern, have eaten a variety of snakes – once spotted, they’re fairly easy to kill with simple weapons.

“These relationships have long characterized our joint evolutionary history,” says Greene, who points out that the giant constrictors diversified around 100 million years ago, around 20 million years before the origin of the major primate groups.

We should be careful before making specific claims about how snakes affected our evolution, since earlier attempts to address this question have been somewhat fraught. While some scientists have suggested that fear of snakes is innate, young babies don’t show such fears; they may, however, have the ability to spot images of snakes more quickly than other objects. Meanwhile, Lynne Isbell has suggested that the need to spot snakes could have driven the evolution of sharper eyesight among primates. This too is debatable, since the quality of a primate species’ depth perception is unrelated to its shared history with snakes or the odds of encountering a snake.

Headland and Greene don’t make any such claims. Their surveys of both the Agta and the scientific literature can’t tell us how snakes and primates have evolved together. Modern primates may have more run-ins with snakes than anyone had suspected, but it’s still not clear how our two groups have coiled around each other through our long mutual history.

Reference: Headland & Greene. 2011. Hunter–gatherers and other primates as prey, predators, and competitors of snakes. PNAS http://dx.doi.org/10.1073/pnas.1115116108

More on pythons and constrictors:

22 thoughts on “Meet the Agta, a tribe where a quarter of men have been attacked by giant snakes

  1. I think your link towards the end got messed up a bit. the “Spot Images of Snakes” link seems to point to a flu vaccine link on this blog?

  2. A quarter of the men? And only 2 per cent of the women? Really? And they all have caught fish “This big.” Good grief, what accurate science! Just because someone CLAIMS to have been attacked by a snake doesn’t mean he was. It probably is a matter of manly pride to have had such an encounter. Even if the men spend “more time” in the forest, it would probably only double the number of attacks…the women go in the forest too. Either that, or the men provoke attacks, are incredibly stupid, or are just lying because it makes a good story.

  3. Interesting to note that Flores Island, where the possibly-island-dwarf hominins were found, seems to be solidly within reticulated python range.

  4. Michelle, the very paragraph before the 26% figure is stated describes how the researchers accounted for the possibility of “tall tales”.

    Additionally, 11 of the men had visible scars. If we assume that about half of the 120 people interviewed were men, that’s about 15% right there, quite a bit more than double 2%.

    And since the relative amount of time spent in the forest by men versus women is not given, you have grounds to base your “probably only double the number of attacks” statement whatsoever.

  5. I’m skeptical, but not to the degree Michelle M is. Adult size in Retic populations, as I understand it, varies quite a bit geographically. If the pythons in this area frequently attain very large sizes then I don’t see how the 25% figure, after a lifetime in the forest, is totally unreasonable. Judging by the relative size in the photo, the hunters seem well within the prey size range for snakes that large. Of course it is pretty far out from any other reasably well validated accounts that I have heard about, such as Anacondas (which get bigger, mass wise) in SA or rockpythons in Africa – it is hard to get even a handful of cases where there is some sort confidence that a real fatal attack occured. The descrepancy is a bit worrisome.

  6. Good article. I think it would be better if we differentiate between predation by pythons, and attacks. The attacks may just be a natural reaction to someone stepping on or near the python, given that they are well-camouflaged and often wait opportunistically for prey to come to them. With this in mind a quarter of all men attacked over their lifetime seems reasonable. Many of them must literally run into large pythons at some point, which may sense them coming and be ready. Predation on children I can swallow, but the excellent photo nicely illustrates the challenge for pythons eating adults. Even allowing for the elasticity of the skull, the mans shoulders are maybe 3-4 times the width of the pythons jaws, and may well prove difficult to pass.

  7. Michelle,

    At least, per the article, the researchers tried to account for tall-tales to derive their number. Your “only double” estimate is completely unfounded and based on conjecture.

    I do not personally know the culture and seperation of gender roles within this given tribe, but if it is such that the women stay in the village they could well be spared from the snake hunting them.

    One could probably presume that if, as stated, the people hunt the snakes- they would be weary of attacking humans that are in numbers. The snake that only attacks solitary humans would live to breed- the snake that wildly attacks villages would die and not pass on the “reckless” genes.

    You can’t possibly suggest that men could only face at most double the risk without knowing their culture or the environment there.

    It is correct to be skeptical- but the claim from the researchers in question sounds very feasible.

  8. We are told, “The story has been taught for thousands of years as the sacred truth by our elders, and instilled into the minds of our children therefore it has to be true. ” I commend Bertrand Russell for giving us the insight to consider otherwise.

  9. Oh, and wonderful article. This is the sort of thing that remiinds us our only ‘priveledge’ in nature is that we’re kind of smart—a two-edged tooth, certainly, when considering the full gamut of our behaviour—up to and including our geopolitical repetoire

    To find us living in a state of nature is so rare; in this sense we are perhaps the most endangered species of all

  10. “The attacks may just be a natural reaction to someone stepping on or near the python, given that they are well-camouflaged and often wait opportunistically for prey to come to them.” – I bet deer say the same thing.

    “but the excellent photo nicely illustrates the challenge for pythons eating adults. Even allowing for the elasticity of the skull, the mans shoulders are maybe 3-4 times the width of the pythons jaws, and may well prove difficult to pass.” – I agree that the vast majority of adult people are too big for the vast majority of even large snaked to swallow, However, I don’t think that the exceptionally large snake in that photo would find it unusually difficult to swallow the (apparently rather small) people in that photo.



    Even if the shoulders were a problem, a snake would likely not recognize that ahead of time, so it probably wouldn’t effect the predation (or attempted) predation rate.

  11. Let’s not forget that pythons are entirely capable of eating and swallowing antelope and other large, horned animals. Humans – who are basically medium-sized sausages – couldn’t really be more suitably shaped.

  12. On human predation by large snakes – taking on board the comments on what National Geographic show and on humans resembling sausages – one crucial fact remains. The number of verifiable instances of large constructing snakes killing and swallowing humans is miniscule. Almost zero. Some dodgy youtube videos. It is an extraordinarily rare occurrence, that almost never happens, whether reticulated pythons, anacondas, or african or asian rock pythons. It could happen in some of the more remote tribes such as the Agta (who say this happens to 1 person every 6 years). But if it did happen these days, where modern technology is nearly everywhere, you can bet it would be all over the internet. It’s an order of magnitude down even from predation by great white sharks, whose statistics are very low to start with.

  13. just wondering if there are still wild reticulated python nowadays as big as the one in the picture=) so far the biggest iv’e seen is around 18feet=) its a female, caught by hunters here in southern mindanao, and ate it, eggs are seen inside its tummy=(

  14. There are still many wild reticulated pythons in the Philippines as long as they are far from the cities. Filipino males look on them as prime food for increasing vigor and health accompanied by alcoholic beverages. Caves inhabited by bats are often the home of really big reticulated pythons. The only problem is people have the bad habit of seeking them out for food and boasting rights. So the days we can see or hear about really big ones may be numbered.

    I have been to Aurora Baler, where some of the isolated Ilongot tribes still do headhunting. According to their stories, an island in Casiguran has gigantic snakes. How big? I couldn’t tell, but from their descriptions – really big enough to swallow a man with wide shoulders.

    They also have tales of giant bighead catfish that can swallow a man whole. This they say is the reason most of the Ilongots do not dare bathe in deep waters deep in the jungles. They describe meter long catfish as the babies of a big momma. The majority of the Ilongot lands are unexplored except by the Ilongot tribes on the fringes of their tribal territories.

    No military or communist rebels dare to venture deep in their territories. Headhunting season or not, unwelcome strangers in deep Ilongot tribal lands often end up missing. The Agta tribal lands are also near Aurora, Baler. Both tribes tell tales of big gigantic snakes, strange sights deep in the jungles of their tribal territories. People would speculate that they tell tales but they also are very honest people, lying is actually a modern “civilized” city dweller habit to them.

    A scientist would probably keep their minds open to the possibilities until more conclusive hard material evidences show up. Often we forget that just a century ago people had a ridiculous belief that to go past 65 kilometers per hour would kill a person.

    Not seeing proof does not necessarily mean that it does not exist. Seeing proof also does not necessarily mean we are right. The Earth for example seems to our eyes to be stationary with the Sun revolving around it but that does not mean it is the truth.

  15. Really interesting article and bearing in mind the record of the largest reticulated python – 33 feet I believe – the claims seem plausible. To all you doubting Thomases, I can only say, Absence of evidence is not evidence of absence.

  16. Experts on big snakes doubt the posibility of big snakes swallowing adult men based on the breadth of our shoulders.For the cases of the kids its highly possible,but remember that nommatter how big constrictors grow their heads tend to remain small in relation to their body size.One would argue that they are able to dislocate their jaw bones and expand the breadth of their mouths,but our shouders are just too wide.Im from Western Uganda in east Africa and we do have wild pythons.A fefteen year old boy was strangled by one in 1995.It was a whooping 17 and a half feet but it died trying to swallow him.his shoulders were just too wide.

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