RATTLESNAKES!

By Acting Custodian T. O. Thatcher,
Lehman Caves National Monument, Nevada.

The buzzing sounded somewhat like the steady note of a cicada but lacked the dry, crisp character -- somewhat as if it were lightly muted. We stood motionless, my companion and I, straining to locate the exact source of the sound, for we had all intentions not to blunder onto the rattlesnake. Presently we saw it making its way over a small log. We both seized sticks and went after it, dragging it away from the bushes so we could get at it more easily.

"Wait! I'm going to take it back to the lab for a live specimen." I held the snake's head down with the end of my stick.

My companion looked doubtful. "What'll you carry it in?"

"I've got some paper sacks in my packsack. They'll do".

Out came the paper sacks and, taking the snake by the neck close behind the head, I lowered it into they smaller one and immediately twisted the mouth shut. The larger of the two sacks provided an outer covering and the top, twisted into a long neck, formed a handle which supplied the desirable element of distance between the rattler and my hand. I had captured my first live rattler.

Rattlesnakes belong to the group of reptiles known as the Crotalidae, or Pit Vipers, of which they form the type genus, Crotalus. The characteristic which gives this group of snakes its common name of Pit Vipers is the presence, on each side of the head, of a deep pit placed between the nostril and the eye. The object of these pits is not known but the presence of a large nerve connection at their inner faces indicates a sensory function and a theory has been advanced that these aid the reptile in directing its strike. Other characteristics are keeled scales; that is, each scale has a fine, sharp ridge lengthwise along the center, vertical pupils, and long, curved, movable fangs, which are held against the roof of the mouth in membranous sacs when not in use. The fangs are hollow with an oblique opening at the tip through which the venom is injected into the victim when the snake strikes, just as an injection is made with a hypodermic needle. To say that a snake strikes is apt indeed for there is very little of the biting action in the extremely rapid attack of a rattlesnake. In order to strike any distance, the snake's body must be in a series of S-shaped loops from which position the head is thrown forward by an abrupt straightening of the fore portion of the body. As the head comes forward, the mouth is opened to such an extent that the upper and lower jaws form an extremely wide angle; the fangs are thrown forward so as to stand at right angles to the upper jaw and are bared of the membranous sacs. Thus they are actually driven into the object struck. At the instant of impact there is a slight biting action which tightens the muscles about the poison sacs at the base of the upper jaws, forcing the venom out through the ducts and fangs into the base of the upper jaws and into the wound.

Though theories are numerous concerning the function of the rattles borne by the rattlesnakes, their purpose has never been actually determined. According to Dr. R. L. Ditmars, Curator of Mammals and Reptiles at the New York Zoological Park, who is one of the world's foremost authorities on reptiles, one of the most plausible theories is that they may serve as a call during mating seasons, for it is known that snakes, "particularly the Crotaline species, are highly sensitive to vibrations." "Again," Dr. Ditmars says, "it is possible the rattle may be employed to attract the prey."

I have found the much hated and feared rattlesnakes to be very interesting reptiles. After my initial experiences with them, prompted more by a spirit of bravado than anything else, I began to see in these snakes something which would make an interesting study as I settled down to observe their habits and reactions. Questions began to come to my mind. Why did these snakes have venom and a remarkably developed apparatus for injecting it? What was their food? How easily were they provoked into striking at a person? Did they always sound a warning with their rattles -- and many others. For the answers to some, I turned to observation and experimentation, for others to books, notably "Reptiles of the World", and "The Reptile Book", both by Dr. Ditmars. Both are excellent books, the first semi-popular and the latter technical. It might be well to state here that all my observations have been made on specimens of the Great Basin Rattler.

The question about the use of the venom was first answered by reference to the books, then by observation. The popular belief among the young fellows with whom I was associated when I began my studies was that the venom was used primarily or even entirely for defense or, as some people still believe, for attack on man. This, I read, was merely an incidental use, the chief purpose being the killing of prey. Later my observations indicated the same thing, for I found that hungry rattlers readily struck at live mice or rats put into their cages but showed considerable reluctance to making passes at an annoying human being. I am convinced that rattlesnakes, as a rule, are peace-loving, and would much rather run than fight; but if they are cornered, injured, or scared -- watch out!

On two occasions, scared rattlers furnished me with very interesting experiences. The first occurred one day while I was driving down a narrow desert road in my car when suddenly I came upon a small rattler in the middle of the road. It was impossible to stop the car before the snake had been passed and as I wanted it for a specimen, I straddled it with the wheels of they car. As soon as the car stopped, I jumped out and ran back. The snake was still in the middle of the road, apparently thoroughly confused and scared by the sudden passage of the car. Before I got closer than five feet to the snake, it began to strike wildly in my direction, though being only two feet long, it had no chance of hitting me.

READY FOR ACTION.

The second incident happened as my wife and I were driving over a mountain road at night. We were proceeding slowly when the headlight beam revealed a good-sized snake on the road. I stopped the car so that the snake was still in the light about twenty feet ahead of the car, took my flashlight and went to capture it. By diverting the snake's attention with the light, it was a simple matter to seize it behind the head and lift it clear of the ground. The snake thrashed vigorously and began to spray me with musk. I immediately tossed it back to the road a few feet distant and wiped the musk from my hand and clothes, then went after the snake again. The snake, somewhat dazed and frightened, had thrown itself into tight loops and as I came close, it followed the flashlight intently. I held the flashlight, which was a long one, by the end and thrust it at the snake which immediately struck and missed. Several times more the performance was repeated, each time the snake striking below the light. Each time the snake's head passed through the beam of light when it struck at right angles to my line of vision, I could catch a glimpse of the fangs and the widely opened mouth. At the end of this performance, the snake seemed suddenly to become completely confused and struck, first directly away from the light, then wildly in any direction even when the light was held motionless. After several such strikes the snake settled back into its guard position and I stepped away and turned out the flashlight to let it calm down. In a short time it began to crawl away so I stepped over, placed the light on its head, picked it up and letting its tail drag on the ground just enough so it wouldn't thrash about, took it to the car and dropped it into a burlap sack which I carried for the purpose.

Persons unfamiliar with the handling of venomous reptiles should never attempt to catch them without first using some device by which the snake's head can be securely held without danger of getting bitten. The wisest procedure for those unfamiliar with reptiles is to avoid handling rattlesnakes under any circumstances.

And now a word about the musk mentioned above. The substance is, as nearly as I can tell, a transparent fluid and is released through the anal opening. I thought at first that it might be feces but subsequent investigations indicate that the fecal matter is opaque and of a rather pasty consistency and lacks the extremely obnoxious odor characterizing the musk. As compared with the odor of a skunk, I find the snake musk to be much more objectionable. This occurrence has been noted on a number of specimens but as yet I have found no reference to similar observations in any of the books to which I have had access.

The food of rattlesnakes consists of small rodents which are hunted chiefly in the evening and night, and possibly an occasional bird. The assumption that birds may form a small part of the diet is based on one laboratory observation which took place while I was going to college. In the zoological laboratory we had a pen of rattlesnakes and one day one of the students brought in a live mature English Sparrow which was placed in the snake pen. At first the bird flew wildly about, then settled down on the floor of the pen. The snakes had watched it closely and soon after the bird settled, one of them proceeded to glide slowly towards it, keeping all the time very close to the floor. Several times the bird moved and each time the snake changed its direction, cautiously stalking its victim. Finally when its head was within six inches of the bird, the rattler slowly formed into its loops and with startling suddenness lashed out to seize the bird. It did not let go and immediately draw back into the loops as is the habit when striking a mouse or a rat, but clung tenaciously to the sparrow as if sensing that it would fly away and be lost, if released. When the sparrow died, the snake started to swallow it but was disturbed by a group of students coming in for classes, whereupon it dropped the bird and refused to have anything further to do with it.

The fact that rattlesnakes destroy many harmful rodents and the statement that a rattler is a more efficient mouser than the best cat, give rise to a question about their status -- are they good or bad? The answer can become very involved but the simplest statement would be, "It depends upon where they occur." In an area frequented by many people, the snakes must be classed as undesirable, for they are dangerous. On the other hand, in areas where human occupancy is at a minimum, the rattlesnake may be classed as beneficial or at the very least, neutral.

Observations made in feeding penned snakes showed many times that they would miss when striking at a running mouse, and from the same observations, I have concluded that a man can move his hands, about as fast as a rattler can strike--but don't try to find out! Because these snakes feed very reluctantly in captivity, force feeding is sometimes necessary to keep specimens alive. I have done this by using polished wooden forceps to push strips of flesh from a freshly killed rabbit down the snake's throat. But even this is not always successful for some individuals react unfavorably to such handling and subsequently die.

The readiness of these snakes to rattle or to strike at a person, varies greatly with individuals and species. One time I was hunting and stopped close to a sagebrush to turn and watch some game. Looking down a moment later, I found a rattler resting between my feet! It must have been my lucky day for I hadn't stepped on the snake and it made no indication of striking nor had it rattled. On another occasion merely jumping across a bush in the bottom of a small wash set a snake hidden under it to rattling vigorously. This specimen struck the moment a stick was brought close to it. Here the often repeated story of being chased by a rattlesnake might be aired. Calm reasoning based on a knowledge of the snake's habit of running for cover if threatened, will give this tale a different aspect. In all probability the snake in its rush for cover has accidentally started in the direction of the observer who has promptly left for other territory.

This habit of running can be used to advantage in capturing specimens in open territory by stepping alongside the running snake which has its head close to the ground, and swinging the arm down to seize the snake close behind the head. If a person misses, the arm can readily and speedily continue its swing. This method is not to be recommended, however, particularly for snakes more than three feet long. The most preferable method is to go into the field armed with a forked stick previously prepared with a running noose in the fork, to be controlled from the handle.

In conmon with most reptiles, rattlesnakes like warmth but cannot stand too much of it. Have you ever seen a rattler basking in the direct glare of the noonday desert sun? Neither have I, and this is the reason: The snakes have no means of controlling their body temperature, so it fluctuates with the temperature of their surroundings and should that become too high, the reptile's blood literally boils and death results. That rattlesnakes apparently like to be handled after becoming used to it, is probably due to their liking the warmth of a person's skin. Often they have flattened themselves on my bare arms just as if basking.

MILKING.

Now back to the venom and its place in the modern world. This deadly substance is now produced commercially for use in making anti-venine, discovered by Dr. Albert Calmette of the Pasteur Institute, to combat the effects of snake bite. Since this discovery, anti-venine institutes have been created in most major countries where poisonous reptiles present a problem, and rattlesnake farms have sprung up in a number of places in the United States. Antivenines are specific; that is, to combat the venom of a particular type of snake, anti-venine made from that type venom must be used. The process by which the venom is obtained is known as "milking". A vial is prepared by stretching, not too tightly, a piece of tough dental rubber over its mouth. Then the snake is taken, immediately behind the head, and the covered mouth of the vial touched against its lips. Usually the snake responds immediately by sinking its fangs through the rubber and shooting streams of venom from them. The fangs are usually worked independently of each other after first sinking through the rubber, alternately being driven out and down to get a deeper, better hold. With the fangs through the rubber, the snake is "milked" of all possible venom by pressure of the handler's fingers at the base of the upper jaws. The venom is a rather oily acting, slightly cloudy, amber liquid which forms long needle-like crystals when dried on a glass plate. In action it destroys the red corpuscles of the blood and causes dehydration. It is so virulent that three drops directly in the blood stream is sufficient to kill a healthy man. I have seen a three-foot specimen give one cubic centimeter of venom, approximately ten drops, at one time.

Of course no one wants to be bitten, but if anyone does have that misfortune, the only thing to do is to follow drastic first aid measures, and then get to a doctor in a hurry. In rattlesnake country, it is always well to carry a snake bite kit. High boots are an added protection, but the first line of defense must always be caution, for though the rattlesnake is not vicious, it certainly requires treatment with respect. The first rule to observe, if you are bitten, is don't get excited. A tourniquet should be applied between the bite and the body: above the elbow, in bites on or near the hand or forearm; and just above the knee, in bites on the foot, ankle or lower leg. The tourniquet should not be twisted too tightly; just tight enough to obstruct the superficial circulation but not the deep circulation. The tourniquet should be loosened for one-half minute every ten minutes or so, to prevent gangrene complications. A rubber tourniquet is supplied with most outfits but if it is not available, a string or shoelace can be used. The bitten part should be cleaned with antiseptic material, if available. The suction device supplied with some of the well known kits can be brought into use after an incision with a clean razor blade or knife, treated with antiseptic, is made of each fang mark. The incision of the two fang marks should be connected. If the suction devices are available they can now be applied and in extreme situations the mouth might be used if there are no abrasions or sores whereby danger might be attached to such sucking effect. Repeat the suction effect even over a period of several hours. This is highly important because a life may be saved even if only a drop of venom is extracted. If there is excessive bleeding, a new cut close by might be made. If an anti-venom is available it can be injected at once above the tourniquet, the amount of the dose depending upon the size of the snake. When a doctor is reached his attention should be directed to the measures already taken.