Monday, May 14, 2012

Scully vs. Mulder: Do Giant Snakes Exist in The Wild?

This is part two of my post on the scientific accuracy concerning the legends of giant snakes in the wild. Part one was dedicated to laying out the ground rules on how to determine which species of snake grows to be the "largest", as well as documenting the largest snakes on scientific record. Part two will focus on the legends of giant snakes in the wild and will take a scientific look into the validity of such reports.

The world is divided into two types of people and only two: Fox Mulders and Dana Scullys. Yes, I'm referring to the X-Files. The Fox Mulders of the world believe in the strange and wonderful without evidence to back them up and, in some instances, despite the evidence against them. Fox Mulders are not necessarily wrong on their views and tend to have more faith to carry them through hard times when they need it. However, Fox Mulders are often led astray and can be blinded by their own faith in the unseen. Dana Scullys on the other hand are natural skeptics who believe only the scientific evidence they can observe for themselves. Stories and strange phenomena are no match for simple logic and accurate data in a Dana Scully's eyes. Dana Scullys are much safer investigators and don't fall prey to false data. However, Dana Scullys tend to turn a blind eye to events they cannot explain and can lose hope without a Mulder. As much as it pains me to say it, I am a Dana Scully. Plain and simple.

I feel very qualified to write a bias free post on something as controversial as the existence of giant snakes because I have, at different points in my life, held both viewpoints: that of the Mulder and that of the Scully. Having said that, zoology is a science and works off of data that can be verified and tested. It's from this point of view that we will examine the possible existence of giant snakes in the wild. Now it is important to understand, keeping with the World Conservation Society's definition, that the term "giant snake" is generally accepted as referencing a snake fifty or more feet in length. Such a snake has never been accurately documented or accepted by any zoological facility or organization as being real. This is not evidence against their existence but merely a starting point in understanding where we currently are in the search for giant snakes.

The idea of giant snakes reaching lengths of fifty feet or more is mostly restricted to the tropical regions of South America, though some reports of giant pythons do surface from time to time. Essentially, though the reticulated python is the longest snake officially on record, reports and legends of giant snakes seem to be centered almost entirely around the Green Anaconda. The idea of giant snakes is an old one to say the least. Indians of the South American tropics have long histories and stories of giant snakes and these stories are often woven into their religious beliefs. Among most tribes and villages, this supposed animal is referred to as "Sucuriju Gigante". It is believed by some native tribes and supporters of the giant snake theory to be either an extraordinarily large green anaconda, or an unknown subspecies of the green anaconda that enjoys such lengths as its average size. The idea of there being an entire undiscovered subspecies of anaconda is in itself a subject of debate, let alone whether or not such a snake would grow to such tremendous lengths. For now, let's treat the supposed Sucuriju Gigante as an extraordinarily large specimen of the green anaconda.

Though the earliest claims of giant snakes can be found in the religions practiced by various tribes of the Amazon region, I want to begin with reports of the early explorers instead. My reasoning here is that although the native Indians of those regions are more familiar with their homeland than anyone else, they are also incredibly superstitious and attribute supernatural powers to these snakes of myth and legend. In many of their tales, for example, this snake is a type of deity responsible for carving out the Amazon river as it slithered across the jungle. What I'm interested in is not legend, but finding perhaps what is the source of that legend. When dealing with these ancient tales, sorting myth from fact becomes impossible. When dealing with the reports of early explorers, while there may be just as much myth, it's easier to separate from the facts.

The most commonly cited report of giant snakes is the supposed encounter of Lt. Colonel Percy Fawcett, a British Royal Army officer who had retired to do survey work ("survey work" here refers to exploring uncharted territories in South America, not the typical road side survey work you might think of). This reportedly took place while he and a team of men were near the Bolivian/Peruvian border on a charting mission for the Royal Geographic Society of London in 1907. The only source of the report, despite the fact that multiple men supposedly experienced the incident, is Lt. Colonel Fawcett's diary. In his diary he wrote:

We were drifting easily along the sluggish current not far below the confluence of the Rio Negro when almost under the bow of the igarit'e [boat] there appeared a triangular head and several feet of undulating body. It was a giant anaconda. I sprang for my rifle as the creature began to make its way up the bank, and hardly waiting to aim, smashed a .44 soft-nosed bullet into its spine, ten feet below the wicked head."

He continues...

"We stepped ashore and approached the reptile with caution. It was out of action, but shivers ran up and down the body like puffs of wind on a mountain tarn. As far as it was possible to measure, a length of forty-five feet lay out of the water, and seventeen feet in it, making a total length of sixty-two feet. Its body was not thick for such a colossal length-not more than twelve inches in diameter-but it had probably been long without food. I tried to cut a piece out of the skin, but the beast was by no means dead and the sudden upheavals rather scared us. A penetrating foetid odour emanated from the snake, probably its breath, which is believed to have a stupefying effect, first attracting and later paralyzing its prey. Everything about this snake was repulsive."

Fawcett's description of the snake is interesting to say the least, especially considering that he positively states the snake was an anaconda. Though in fairness, Fawcett was a military officer who served with distinction and was known by close friends and colleagues as a meticulous recorder of facts, I am convinced that this incident is something less than accurate.

Both species of anaconda, the green anaconda and the smaller yellow anaconda, are both extremely thick and heavily proportioned to their length. Fawcett states that the snake in question was no more than twelve inches in diameter. I'm sorry, but even a 16 foot anaconda will have a body diameter pushing nine or ten inches and a twenty foot anaconda, though extremely rare and for the most part, poorly documented, will easily beat a twelve inch diameter. Fawcett does act surprised, stating that perhaps the snake had "been long without food". However, even allowing that a snake could somehow reach the incredibly length of 62 feet as Fawcett claims, no amount of starvation would cause it's body size to shrink down to a diameter of 12 inches. The body proportions that are possessed by the green anaconda, as well as the smaller yellow anaconda for that matter, would dictate that a 62 foot specimen would have to be several feet in diameter at the very least, even despite it's best attempt to play Gandhi. As Dana Scully would put it, "A sixty-two foot specimen of a green anaconda with a twelve inch diameter just isn't possible, Mulder!"


(Even this anaconda specimen held by snake researcher Jesus A. Rivas and associate,
despite being only around the twelve foot mark, has a width pushing ten inches)

The reason that no zoological facility has yet to accept claims of a giant snake is because no documented specimen has ever been brought to light. Like the many instances before and since where supposed giant snakes are concerned, Fawcett was unable to accurately measure the specimen with any real degree of certainty. He states very clearly that it was difficult to measure and that half the body lay in the water. Although it is possible for estimates under such conditions to be correct, it is not likely and certainly not substantial evidence. This leads me to my next point: Fawcett himself.

Lt. Colonel Percy Fawcett was a man of exaggerated ideas. Even Agent Mulder would raise an eyebrow at some of the Lt. Colonel's claims. It's important to understand that Fawcett was well aware of and very educated on the folklore of giant snakes. He believed whole heartedly in these stories before ever setting foot into the Amazon jungle and it isn't unreasonable to suspect or even suggest that he let these beliefs influence his judgment. In addition to this giant snake incident -I say "this" because there was supposedly another- Fawcett also made claims of finding giant spiders the size of dinner plates capable of killing a human victim with one bite and turning their blood black. While, just like the anaconda incident, the spider itself may very well be an actual documented species such as the Goliath bird eating spider (a tarantula subspecies that grows the size of a dinner plate), Fawcett greatly exaggerates the attributes and characteristics of those animals based upon myths told in native South American communities. And as I mentioned above, there is something that most people are not aware of concerning Fawcett's snake adventures: the other snake incident. In Fawcett's writings, he tells of finding yet another giant snake in the jungle, only this snake was supposedly 80 feet long and made what Fawcett described as a loud roaring noise. While the size that a snake may attain is certainly debatable, the simple fact is that snakes are not equipped with vocal cords that would allow any vocalizations that could be described as a roar. The only snakes that produce audible noises or, more specifically, vocalizations, are the rattlesnakes and cobras, respectively. Rattlesnakes obviously produce their trademark sound by rapidly vibrating the excess skin that forms the rattle at the end of the tale and do not actually produce "vocalizations". The cobra on the other hand merely hisses at an elevated volume, producing a sound similar to a deflating tire. Being that all snakes are deaf, both of these noises are used specifically to warn predators and alert large foraging mammals to the snake's presence, allowing the snake to avoid being crushed (as opposed to being used for communication between members of the same species as in other animals). An eighty foot anaconda would not only lack the biological requirements for such vocalizations, but would have no biological need to develop such an adaptation in the first place. The simple fact of the matter is that Lt. Colonel Percy Fawcett greatly exaggerated in the majority of his claims and because of this, neither giant snake story can be taken as much more than that, a story.


(The popular sketch of Fawcett's supposed encounter with a 62 ft. anaconda)

While there are many more stories and reports of giant snakes, in all likely hood they suffer from the same exaggerations as the Fawcett incidents or were simply distorted by poor observational skills and inaccurate estimates concerning weight and length. Guessing the length of an object alone is very difficult to do. Consider that I spent six years living in my current house before my front porch was added. I had seen the front of my house every day for six years straight and estimated it to be 20 feet from the corner to the front door. When it was finally measured to build the porch, that distance turned out to be 27 feet. After seeing that section of my house every day for six years, I had missed my estimate by nearly 25%. Don't think for a second that one glance at an unfamiliar animal such as an anaconda or reticulated python as it moves through the water or dense undergrowth of a tropical jungle will yield a perfect estimate. Consider that the professional reptile keepers at the Pittsburg Zoo inaccurately estimated the length of their largest python Colossius, who they cared for and observed on a daily basis for several years, by nearly eight feet.

Not only is there a severe lack of proof for the existence of giant snakes, but there is what I believe to be substantial evidence against their existence as well. As Bill Nye The Science guy would say, consider the following...

(1) Though supposedly residing in the Amazon for thousands of years, not a single snake carcass has been recovered measuring even half the supposed length of Sucuriju Gigante. I understand that in the hot tropics of the Amazon jungle anything that gives up the ghost is soon decomposed by scavengers and high levels of humidity. But to suggest that not even one of the 400 vertebrae or pairs of ribs that would be possessed by not just one, but each individual representing an entire population of giant snakes mind you, would be discovered after so long is somewhat impractical. Researchers discover countless species measuring mere centimeters living in the dense rainforest every other day, and many of them are discovered by complete chance. How is it that researchers are completely unable to find any remains of an 80 foot snake when they are specifically searching for it?

(2) Anacondas have a variety of prey to choose from in the dense tropics and wetlands of Central and South America including capybara, caiman, and even turtles. A typical anaconda will eat a small meal about once every week or a large meal once every month or so. As with all animals, the larger the snake, the more energy it requires and therefor, the larger or more abundant it's food suply must be. An anaconda measuring fifty feet would need to consume a prey animal as large as a small to moderate sized cow on a monthly basis. It would be nearly impossible for a 50 foot anaconda to attain a constant food suply of this type in the wild, let alone an 80 foot anaconda. This leads me to my next point.

(3) The largest snakes that have been reliably documented are those in captivity, the largest of which was Samantha, the 26 foot reticulated python housed in the Bronx Zoo until 2002. I mentioned above that it would be very unlikely that a snake could find sufficient amounts of prey in the wild to attain and then sustain a length of fifty feet. On average, animals in captivity attain a larger size and greater weight than specimens of the same species in the wild. Considering that captive snakes that are well fed on a regular schedule and receive quality medical treatment to ensure their survival will rarely reach a length of 20 feet and are not known to exceed 26 feet, it is highly unlikely that a wild specimen that might fall victim to disease, drought, predators, and a lack of food would live to grow three times that length.

(4) Anacondas are, of course, reptiles. As with any reptile, anacondas grow relatively slowly. Unlike many reptiles however, snakes are relatively short lived and usually have a maximum life span of 20 years. Keep in mind, that's a maximum life span for captive anacondas that receive the free food and expert medical care I mentioned above. Not only do anacondas reach greater lengths in captivity, they reach a greater age too. My point here is that anacondas in the wild will generally live less than 20 years and this is not nearly enough time for said anaconda to reach even half the supposed length of the mysterious Sucuriju Gigante.

(5) Any debate student can tell you that an obvious hoax, however elaborate, is not proof against the existence of a mysterious animal. However, I believe that in this instance, one specific type of elaborate hoax can actually serve this purpose. At the very least, it serves as the catalyst for what I believe to be the false rumor that is Sucuriju Gigante. In many parts of the world, constrictors such as anacondas and pythons are hunted for their meat and skin. While the meat is consumed, the skin is sold and highly prized as decoration. As with most products, the larger the skin, the higher the cost. Generations of fur trappers and skinners from around the world have made an honest living from their trade, no doubt. But I can only imagine the temptation that came with the discovery of that most unusual and highly lucrative property of snake skin: it stretches. I don't mean it slightly stretches, or it stretches a few inches. I mean you can take the skin of a 15 foot anaconda and stretch it an additional 10 or 15 feet, nearly doubling the size of the original skin without any distortions. This is a common practice anywhere the skins of large constrictors are sold and it has been happening since the first day an anaconda skin found it's way into the local market and fetched a price. It's not unreasonable at all to suspect that this form of hoax is not only responsible for helping spread the rumor of the giant snake, but partially responsible for starting it as well.


(Snake skins, like this green anaconda skin, are easily stretched during the
tanning process and are not sufficient evidence of giant snakes)

Since I proposed that I would write this article from an unbiased view point, it's only fair to mention what is thought to be proof for the existence of giant snakes. Having already discussed the most common citation of evidence, which is eye-witness testimony, I will focus here on the remaining two pieces of often cited evidence: photographs and unusually large snake spoor. I'll begin by discussing the latter.

People native to the regions that make up the habitat of the green anaconda often sight unusually large spoor (tracks) of snakes that measure several feet in diameter. This would be the correct size for a snake measuring fifty feet and would certainly serve as a form of physical evidence, if not for one detail. Although it cannot be proven that these tracks do not belong to the supposed Sucuriju Gigante, they can't be proven to belong to the mysterious giant either. While venomous and non venomous snakes go about killing their prey differently, all snakes consume their prey the same way: swallowing the animal whole, usually head first, by stretching their incredibly elastic jaws and inching their mouths over their prey. This allows snakes to consume prey animals many times the size of their head and girth of their body. The reason that such large snake spoor is insufficient evidence for the existence of giant snakes is because an anaconda measuring 20 feet can consume prey as large as caiman and in some rare instances, deer. A twenty foot snake, having eaten a sufficiently large prey animal will bulge in the middle during the digestion and leave a track at the widest point of its body. A 20 foot snake that has consumed such a large animal would easily leave a track two or more feet in width and would likely be the source for the supposed giant snake spoor.

Photographs of giant snakes do surface from time to time and while some are certainly fakes, models, or photoshopped, some do show real anaconda and python specimens. Unfortunately for those who believe in the existence of giant snakes, none of these photographs offer any means of scale. A snake shown in a photograph may appear to be quite large, but if there is no scale of comparison, it is impossible to determine the size of the animal shown. While there are many reports of supposed giant snakes, no suitable photographs exist. I say "suitable" because there are two regularly cited photographs of supposed giant snakes.


(A supposed 60 ft. anaconda)

The first photo shows what is reported to be a 60 foot anaconda that was shot in the water. Although the photo is genuine in the sense that it was not tampered with and certainly shows a genuine anaconda specimen (most likely dead at that), there is no scale of comparison. This snake could be sixty feet long. It could also be sixteen feet long. Or six feet long. There's no way to know for sure.



(This snake was supposedly shot by a military squad in South America in 1948 and was
reported to be 115 feet long)

The other photo also shows what I believe to be a genuine anaconda specimen, but unfortunately the scale of comparison in this photo is precisely what leads me to believe the snake, though genuine, is not nearly the size it was reported to be. Three men are shown behind the snake at what is clearly a distance and different level of height. The snake is in focus and the men behind it are not, which, as any photographer will tell you, is typical of a camera's inability to capture clear images of multiple objects at different distances. This photo shows little more than a normal anaconda on an elevated platform with several men positioned rather far off behind it.

Although the idea of giant snakes will always exist and continue to intrigue people around the world, it is unlikely that it will ever come to be more than just that: an idea. Evidence is a stubborn thing and is completely indifferent to either side of an argument. It is what it is.

Of course, let's not let the idea of a giant snake spoil us. Anacondas and pythons have been well documented at over 25 feet in length. These snakes are true giants of their species and are just as fascinating as any mythical creature. Let's not allow our interest in the unseen to destroy our love and fascination for the incredible creatures we do have.

It looks like Dana Scully was right on this one, Mulder. Now what is this about a "fluke man", you say?









No comments:

Post a Comment