ビッグボーイと遊ぶ: 大型ヘビ類のハンドリング

Last year, a 19-year old man was killed in New York City while preparing to feed his 13-foot Burmese python. In January 1994, a 6 foot python escaped from its owner in Santa Rosa, California, by crawling down the toilet, causing a panic among residents in the apartment building. In July 1993, a 15-year old boy in Commerce City, Colorado, was attacked and killed by an 11-foot Burmese Python. In June 1991, a nine year old boy in Long Beach, California, was bitten on the foot and coiled by a 12-foot pet python. In August 1984, a large python escaped its cage in Solvay, New York, causing a panic for nine days before it was found in the ceiling. In November 1980, a seven-month old girl in Dallas was killed when the family's 8-foot python escaped its cage and crawled into the crib, smothering the infant.

Every time an incident like this occurs, the consequences for herpetoculturalists are severe. The fear and misunderstanding which surrounds reptiles (and their keepers) is increased, authorities become more likely to pass uninformed laws in an attempt to "do something" about the "problem", and the efforts of responsible herpers to educate the public about these animals are undermined and crippled.

The problem of fatalities and attacks by captive snakes is very small, but is growing steadily. Between the years of 1978 and 1988, according to the American Federation of Herpetoculturalists, there were four reported instances of amateur keepers killed by their snakes, and only one of these involved a Burmese python (the others involved Reticulated pythons). A check of the New York Times index between 1970 and 1992 turned up only one report of a fatality involving a captive python. In the five years since then, however, at least two deaths and a number of attacks have been reported, nearly all involving Burmese pythons. This appears to be a direct result of the growing popularity of captive Burms. Inexperienced snake keepers and large potentially aggressive constrictors make a particularly dangerous combination. The sad fact that many thousands of hatchling Burmese pythons have been purchased in the pet trade--most of them by people who are inexperienced and unprepared to deal with them once they reach a large size--means that the number of incidents involving these snakes will only increase in the future. Everyone who has or who may obtain in the future one of the large constrictors, therefore, must be aware of all the safety precautions that are necessary to keep these snakes, and must practice all of these safeguards until they become second nature.

Only five species of constricting snake get large enough to pose a serious threat to human life. These are the Reticulated Python (Python reticulatus), the Amethystine Python (Morelia amethistina) , the Green Anaconda (Eunectes murinus), the Indian Python (Python molurus--the Burmese python P. m. bivittata is a subspecies of the Indian) and the African Rock Python (Python sebae). Only two of these, the Burmese and the Reticulated, are commonly found in the pet trade. The Reticulated python can reach a maximum length of over 30 feet; the Burmese python can reach lengths up to 20 feet. The common Boa Constrictor (Boa constrictor) has never been demonstrated to have ever killed a human being, but it can reach adult lengths near ten feet and can sometimes be difficult and unsafe to handle. For purposes of this discussion, then, any constricting snake that reaches an adult size of eight feet or more should be considered potentially dangerous.

Because Burmese pythons are tough and undemanding snakes, and are reliable feeders, they are sometimes recommended as "good snakes for beginners". The fact is, however, that they are large and powerful animals that grow quickly, reaching a potentially-dangerous size of eight to ten feet and a weight of fifty pounds within two years. Some people have attempted to control the snake's growth by feeding it only a limited amount of food--a practice that is harmful to the health of the animal, and also produces a snake that is always hungry and sometimes aggressive. Despite what you may hear, Burms are not suitable for beginners, and should not be kept until you have a few years of snake keeping experience to your credit.

The first priority in keeping large constrictors is to make sure they are under strict control at all times. Housing for a big boid is a much more complicated affair than it is for a corn or king snake; it is more akin to the requirements for keeping a venomous snake. The enclosure for a boa or python must be spacious and extraordinarily strong. Large snakes are immensely powerful and can push their way out of all but the strongest cages. The cage should be locked at all times, and if possible should itself be within an escape-proof room that is also locked. Very large snakes can be kept in a room of their own, or a walk-in closet which has been converted into a snake cage. These must be kept securely locked at all times. Be aware that boas and pythons can push their way through windows or screens and escape.

Under absolutely no circumstances, however, should a large constrictor ever be allowed to free roam in a room that is occupied by humans. Even though a snake may have been around humans since its birth, it is still a wild animal, with all its natural behaviors and instincts intact. If, for whatever reason, the snake suddenly feels threatened, or if it momentarily confuses its keepers with food, it can attack suddenly and unpredictably.

A number of rules must be followed in order to safely handle large constrictor snakes. While most boas and pythons are not usually aggressive, they are potentially lethal animals whose power and strength must be respected. No one should ever attempt to handle a large snake (eight feet or more) by himself. This includes even such routine tasks as changing the water or cleaning the cage. A rough guide recommended by most experienced snake keepers is to have one handler for every five feet of snake (every three feet is suggested for nervous or aggressive species such as Reticulated Pythons or Anacondas).

When handling a large constrictor, never allow any of the coils to wrap around your torso or your neck. Boas and pythons are extremely powerful animals, and can cause problems for you even if they are not attempting to constrict, simply by hanging on. If startled or frightened, the snake's reaction will be to tighten its grip--which can present immediate and serious problems if the snake has you coiled in a vulnerable spot.

Feeding time is an especially dangerous moment to be near a large constrictor snake. Although Burmese pythons are not aggressive animals, they are very eager feeders, and will often strike and constrict potential prey that is obviously too big for them to swallow. Because they have poor vision, snakes distinguish prey almost entirely by scent, and can easily confuse prey and keeper. As far as the snake is concerned, if you are moving and have the odor of food on or near you, you are probably food. The feeding response is largely reflexive, and the snake, if it thinks you are a potential meal, will instinctively constrict and kill you before realizing that you are too big to swallow. By the time the snake realizes its error, it will be too late for you. Nearly all fatal accidents involving large constrictors are the result of unsafe feeding procedures, known to experienced snakers as "Stupid Feeding Errors (SFE's)".

For this reason, great care should be taken to avoid confusing the snake during feeding time. Do not ever approach a large constrictor after having handled any potential prey animal (live or dead) or if any potential prey animal is in the area. Potential prey animals that may trigger a feeding response include virtually any warm-blooded creature, such as dogs, cats, rodents, birds and rabbits. In general, live prey animals should be avoided, and large snakes should be fed pre-killed prey exclusively. Dead prey animals intended as food should never be handled with the bare hands. Instead, keepers should use tongs or long-handled forceps to offer prey animals from a safe distance. It is a good idea to wash your hands thoroughly with soap before handling a large constrictor, to remove any trace of prey scent, and to never attempt to handle a large snake that is in a feeding mood.

Potentially dangerous species of snakes should be obtained when they are still very young. This allows the keeper and the snake to learn each other's habits and idiosyncrasies. At this stage, the keeper can learn to handle the snake and avoid Stupid Feeding Errors while risking nothing more serious than a few bites and puncture wounds. Snakes that are regularly and properly handled when young are less apt to be nervous and defensive when older.

Some experienced snake keepers suggest a routine of moving your snake to a different cage for feeding, the theory being that if the snake is always fed in the same cage, it will learn to associate the opening of the cage door with food, and may go into "hunting mode" whenever the cage is opened, striking at the keeper by mistake. In my experience, however, this has never been a problem. Since the cage door must be opened regularly for such non-feeding tasks as cleaning and watering, most snakes will not come to associate cage-opening with feeding. In addition, the "feed in another cage" strategy is not workable for very large constrictors, who should not be handled more than necessary and definitely not when they are hungry. Mistaken attacks on the part of the snake can usually be avoided if you use long-handled tongs for feeding and do not allow prey scent to get on you or your clothing.

Even if you do not intend to feed the snake, you should carefully watch its body language if you must go near it. If the snake begins to approach you stealthily, with tongue flickering and his eyes riveted on you, he is looking for prey and may be potentially aggressive. If, on the other hand, he draws back and pulls his neck in an S-shape, while hissing or breathing heavily, he is afraid and may strike at you in self-defense. Most large snakes will only use their coils to constrict a potential food item--in self-defense, they will strike with the teeth in the manner typical of all snakes. A bite from a large boid is an intensely painful affair, however, and is nothing to trifle with. Moreover, once the snake has struck, he may be enticed into a feeding response and begin to throw coils around you, especially if you begin to struggle.

In short, a number of simple but vital rules can be laid out for keeping a large boa or python: