Are snakes dangerous?
I not only have a personal interest in snakes, but a professional one. As such, I am always on the lookout for snakes, and whenever I do come across them, I count my blessings and take full use of the opportunity to observe and photograph these beautiful and elusive animals.
The fact is, however, to the casual observer, snakes hardly exist in the rainforest. Most snakes are secretive, shy and cautious animals. They are so well hidden and camouflaged in the bush, that it is almost impossible to see them unless one is looking carefully at the right place - either by accident or design - or it is moving quickly in an exposed area in view.
The tragedy of the situation is that, on those rare and blessed occasions where people do come across snakes, the knee-jerk reaction usually is to kill it. This behaviour is appalling. Snakes are as much part of the tapestry of life as anything else, and, play a very important role in tropical ecosystems. Moreover, the drive to kill the snake is completely unjustified, since the ignorant and flimsy excuse that the snake posed a threat is completely untenable. If left alone, the snake will leave you alone. Without exception. Most snakebites happen when people try to kill (or catch) the snake. In fact, many snakebites happen after the snake has been killed - the killers usually try and pick up or play with the carcass "trophy", without realizing that the snake's jaw and venom gland muscles can still be triggered to deliver a bite and inject venom.
Are snakes dangerous? Yes! Most certainly. They are wild animals. And like any creature - wild or domestic - they can potentially inflict damage of some sort on us. But they are by no mean crazed vicious killers driven to mindlessly slaughter poor unsuspecting humans without provocation. Is peanut butter dangerous? It can be if you try and stuff it up your nose. Anything can be dangerous if we do not understand it. Just a little bit of understanding of the world of snakes will go a long way in making things safer for both us and them (since the unfortunate consequence of a snake-human misunderstanding is almost inevitably the brutal death of the snake, whatever might happen to human afterwards, who usually gets away with little more than a moment of fear and a story to tell friends around some beer).
The most common question that I am asked regarding a snake is: "is it poisonous"?
This question, I find, largely misses the mark, for several reasons. To begin with, all snakes are venomous. Just like spiders, almost snakes produce a suite of enzymes or chemicals in one form or another in their mouths. Strictly speaking, all of these can be considered venomous, in that they attack tissue. However, the venom produced by a majority of snakes simply can have no serious effect on us, at least in the doses delivered by one or even several bites. In many cases, the worst effect would be a mild swelling around the bite. In the rainforests of Malaysia, snakes that can deliver venom of a quality and strength sufficient to endanger human life mostly fall into one of two groups - cobras (which include king cobras, black cobras, spitting cobras, kraits and coral snakes), and vipers.
In almost three years of serious frogging here in Malaysia, heading out about two or three nights week, I have yet to encounter a black, spitting or king cobra in the wild. This is probably because these alert and active snakes make their escape or hide long before I can stumble across them. To illustrate this, let me recount my experience with one member of the cobra family that I have encountered - the Red-headed Krait (Bungarus flaviceps). This is a truly majestic and magnificent creature, and measuring up to 2 m long, is impressive not only in its beauty, but its size. It is also extremely venomous. However, its main reaction when we came upon it - sitting on a log fallen across a creek - was flight. It was startled and very confused by our lights, and darted this way and that, up and down the log, seeking a safe exit, only to keep seeing our lights whenever it stuck its head out. Finally, it slipped away into a hole in the opposite bank of the stream. This reaction - i.e. flight - is going to be the typical reaction of any of the more active snakes that you happen to surprise, unless you overtly (whether deliberately or not) threaten or corner it. And, of course, if you do not surprise the snake, then it has ample time to make its getaway in secret, before you even knew that it was there in the first place.
Our vipers are even less of a threat. I regularly come across our arboreal vipers while frogging, usually coiled up and sitting perfectly still - so still that they are almost invisible - on some low branches or other vegetation. These snakes - largely sit-and-wait predators as opposed to the cobras, which are largely roving-predators - are so lethargic and dormant, that it takes a lot to get any reaction out them. You can walk right up to them, and as long as you do not venture into their "danger zone" they are quite happy sitting still where they are. This makes for some great photography, though sometimes I find it quite frustrating as I would like them to shift their pose to avoid some foreground clutter etc. I have no doubt that people get bitten by vipers in Malaysia, but I also have no doubt that it takes considerable and extensive provocation to get bitten. A typical scenarios is like that which was related to me by a logger. He was working away on a tree with a chainsaw, and, before he was halfway done, he apparently dislodged a viper from up in the tree crown. The viper bounced on top of him before landing on the ground. As the logger stumbled about in panic, he accidentally stepped on the equally-terrified viper. The viper struck him, sending him off to the hospital with a high fever for a couple of days. In circumstances like this, I submit that your housecat would be just as dangerous - put a cat in a box, shake the box vigorously while making a loud racket, then take the cat out and fling it at somebody: I think that the price to be paid there is going to be considerably more than few days of fever (in fact, if it is any of my cats, the human victim of this scenario is going to be shopping around for prosthetics of various sorts).
Of course, there is also the Malayan Pit Viper, Calloselasma rhodostoma, known as the "MPV" to friends. This species is, as Peter Paul points out, responsible for many deaths in mainland Southeast Asia, "mainly rubber-tappers stepping on them, as they [the MPV's] do not move away from disturbances". Unlike the arboreal pit-vipers, its venom is extremely potent. Peter Paul was telling me of an acquaintance who was struck by a Malayan Pit Viper. The snake is question was a juvenile, and the strike was merely a glancing blow with one fang to the side of the finger. Today, the acquaintance's finger is still blackened and twisted. Be that as it may, a very, very simple precaution can avoid a lot of trouble. Peter Paul was telling me of some of the conclusions of a talk on snakebite given at the 2001 World Herpetological Congress. The majority of snakebites to humans occur on the feet or ankles. The Malayan Pit Viper is a ground/leaf-litter snake, unlike the arboreal pit-vipers discussed above. The most likely way you are going to provoke one to attack you (and note, the only way that it will attack is if you provoke it, whether by design or by accident) is to step on it. Simply wearing good foot protection will really take care of this. Shoes, or better yet, boots will go long way to making your time in the bush safer and more comfortable, with regards to snakes or anything else (ants, rattan, etc.). Cast aside your pretension to hippie-dom, do away with your sandals while in the bush, and wear shoes!
Another thing to remember with venomous snakes is that venom is metabolically expensive. And so the snakes would prefer to reserve it for prey capture, where the cost of expending the venom is balanced by the energy gains of the prey acquisition. Therefore, many defensive bites are so-called "dry" bites, with little or no delivery of venom, unless the snake is extremely threatened, stressed or provoked.
The other, and more concerning, problem with the question, "is this snake poisonous?", is the implied assumption that a "poisonous" snake is dangerous while a "non-poisonous" one is not. As we have seen above, venomous snakes are not as dangerous as they are made out to be. And the fact is that non-venomous snakes are more dangerous than commonly thought.
Pythons, for example, are probably, to many people, the most familiar non-venomous snake. I personally would far rather be bitten by one of our arboreal vipers than a python. Pythons are normally considered sluggish snakes. They can be at times, but be under no illusion - when they strike, they strike so blindingly fast that sometimes your visual system cannot register it. When they do bite, they clamp down hard on you and do not let go. Depending on the size of the python, it may take anywhere up to half a dozen or more people to get it to release the bite. To begin with, the python must be forced to unlock its coils and then stretched out, and kept stretched out until its bite can be released. This requires a considerable feat of strength. Furthermore, getting the python to release its bite is no easy task. Pythons, like all snakes, have extremely flexible jaws that consist of several independent parts. What this means is that, when a python does bite, you have to independently pry off each segment of jaw and stick a metal plate underneath (between the jaw and flesh) to prevent it from reattaching as you move on to work on another jaw segment. After the python has been removed, you are left with some savagely damaged flesh - the pythons jaws are filled with sharp, recurved teeth that can wreak fearsome havoc. Furthermore, like all snakes, the python's mouth is festering with many, many kinds of pathogenic bacteria - the wound is almost bound to develop a very nasty infection.
Snakes in the Field
So, we've seen that, while snakes are not mindless killers, venomous and non-venomous snakes alike should be treated with respect. In fact, I think that "respect" is the prime operative tactic to be employed when dealing with any element of nature. When encountering a snake in the field, observe and appreciate it - you are witness to a very shy and elusive creature that not many people get to see in the wild.
It would help to know the temper of the snake. Some species have a very bad temper, while others are extremely gentle. For example, the Yellowbellied Water Snake, Enhydris plumbea, is definitely one of the most vicious-tempered animals that you will encounter in the Malay Peninsula. In contrast, the Sunbeam Snake, Xenopeltis unicolor, has one of the sweetest and most gentle dispositions that I have seen in any creature, snake, human or otherwise.
However, the temper of the snake should not really be of a concern if you stick to the second rule (the first being to respect the snake), which is simply: Do not attempt to catch, pick up, handle, or provoke the snake. There is simply no reason of you to do so. Observe, enjoy, appreciate, and learn - from a suitable distance. And do not forget to wear shoes!