Snakes

Many students seemed to be worried about our health and safety, for which we were grateful. However, we want to assure everyone that we are reasonably safe on BCI, probably safer than driving every day to work on a highway in New Jersey!

There are highly poisonous snakes on the island, such as coral snakes, which we see only occasionally. There are also many mimics of poisonous snakes, and they are often hard to tell from the real thing. We are very careful. The only case I know of someone being bitten by a coral snake on BCI was when a herpetology student decided to photograph a coral snake that he had caught and put in a cage. The snake tried to hide its head from the bright photographic lights and the big, scary man. The man poked the snake with his finger so that it would look up and make a better picture. The snake defended itself and bit him. A medical helicopter was called and the man was taken to a hospital in Panama City. He never showed any signs of poisoning, and it appears that the snake chose not to inject any venom. I have seen other people bitten by very dangerous sea snakes (not on BCI) with no ill effects except that the experience was really frightening! So being bitten by a snake is not necessarily the end. Most of the snakes on BCI are not venomous or only mildly so. There are vine snakes that look like green or brown vines and even move like vines shaking in the breeze. They are very well camouflaged. They eat lizards, especially anoles, and have a mild venom (not mild to the anoles!). I have been bitten by them and suffered no effect. The fangs are at the rear of the mouth, not the front. There are many other species of snakes including boa constrictors, rainbow boas, and Spilotes (big rat snakes).

Another highly poisonous snake is the Fer-de-lance. These pit vipers are much feared by field workers because they are cryptic, quick to bite, and deadly venomous. They are very common on the mainland of Panama, but have been considered extremely rare or even extinct on BCI. There were several times when I or other non-experts saw what we thought were Fer-de-lance, but the expert told us that they were no longer on BCI, that we must have seen a non-venomous mimic. Since we didn't bring any of these snakes back to the lab in our packs, we couldn't convince the expert that we had seen the real thing!

This is where good field guides (books that aid in species identification) are very valuable. I read very carefully on the subject of Fer-de-lance and how to identify them by their keeled scales (with little ridges on top) and their head shape, sensory pits, and pattern. I was convinced we had seen several Fer-de-lance, and decided to be very cautious in brush piles and other places where snakes like to live. One of the snakes we suspected was extremely large, over 2 meters in length and several inches in diameter, but it was still hard to see until I had nearly stepped on it. I think some of us became frustrated by the expert who never saw what we saw, and so wouldn't accept our observations!

In August of 1999, one of the field workers, Bonifacio, who knows wildlife very well, and had worked in the forests of Panama all his life, was working on a remote trail on BCI. He was kneeling on the ground, sorting fruits in a fruit trap, when he realized there was a Fer-de-lance coiled next to the trap. It was a great huge snake with a big triangular head, thin neck, and seven-inch thick middle. Bonifacio slowly backed away, convinced that this was the real thing. He found a stick with a forked end and carefully pinned down the snake's neck. The snake uncoiled its more than two meters of body and started thrashing around.  It was very strong and very dangerous. It's not permitted to kill anything on BCI without a good reason, and in this case Bonifacio felt he had a good reason: he was going to bring back this snake and make it very clear to all that we need to be careful when working in the forest. He wanted to settle this question of whether there are Fer-de-lance on BCI, but he wasn't going to bring this one back alive! So he killed the snake and brought it to the lab. And the experts have agreed that there was at least one Fer-de-lance on BCI. The rest of us figure that this snake probably has friends and family on BCI.

When I told of Bonifacio's encounter with the fer-de-lance in the Rainforest Connection reports, I received the following reply from my friend Leslie Z. Sokolow, who used to be a field biologist:

[The snake story] makes me remember my own experience with fer-de-lances in Brazil (the Brazilian species, Bothrops jararaca, is different than the Panamanian, B. asper). In the early 1980s, I was studying small mammals in a gallery forest near Brasilia. These forests are 1000-mile long fingers of the Amazon that stretch out into the open scrub cerrado of central Brazil.

These forests were little studied prior to my work there, primarily because of the great abundance of fer-de-lances. These forests were treated as taboo by the scientific community because these snakes were so feared. I was fascinated and mostly a bit paranoid by the reputation of this formidable beast--an aggressive, highly venomous rattle-less rattlesnake whose strong poison had no antidote.

I came to the field equipped with my snake guards, my metal-tipped work boots, my tourniquet, my nerves steeled, and began my field work. I was so jumpy those first few weeks as my first task was to bushwhack trails in a dense forbidding forest where no one had stomped around before. I remember consciously trying not to stoop too low, thinking I might get my chin bit by an enraged fer-de-lance. It took me a while to see my first fer-de-lance; they camouflage so well, one has to either develop a good search image or be right on top of one to see it. In fact, I rarely did see them. Either they were not as abundant as their reputation implied, or they were darn hard to see.

One day I came upon a huge fer-de-lance (over 6 feet long) basking right next to one of my live traps. I knew I had to kill it because I couldn't risk that this area where I traveled each day might be it's territory. I killed it with my small camping shovel, and being a girl, I had never killed anything so large and noble. I was surprised as how docile this deadly snake was that I had to kill. It must have taken me more than 5 full minutes to kill it and by the time it was dead, I was truly ambivalent about what I had done. This snake never assumed a threat posture towards me, even when I moved close enough to start pounding its brains out. Perhaps it was not the aggressive beast everyone claimed it was?

My suspicions were confirmed a few weeks later when walking along a narrow muddy trail, I missed seeing a big old fer-de-lance until, too late, I STEPPED on its tail end!! This snake had been snoozing in a shady spot but instead of whipping around to bite me (I certainly was close enough), it woke with a start and zipped away at top snake-speed. Instead of fighting, it fled! This was sufficient evidence of this creature's docile nature, its biggest secret as far as humans were concerned. After that episode, I packed my snake guards and work boots and wore comfortable sneakers the rest of my field days there. I saw many more fer-de-lances before finishing my field season but never did any show aggression to me.

Another fer-de-lance showed up on BCI in January of 2001. Some workmen who were constructing a new building called out to Greg as he was passing by, and pointed out a small snake coiled next to the foundation of the building. The snake was three feet long, dark brown, tan and cream, with a pattern like a Turkish carpet, and a triangular-shaped head. It was a baby Fer-de-lance, and a very poisonous snake. Its middle was all swollen, as it had recently eaten a meal, perhaps a small bird or lizard. When Greg leaned toward it for a better look, it reared up and struck out with open mouth and fangs exposed. The workmen clearly didn't want to be working around that site if the snake was allowed to remain, and insisted that it be taken away. Greg agreed that it should be moved.

He found a stick of the right size and shape, pinned the snake securely behind the head and then carefully transferred it to a sack. Then the sack went into a bucket with a lid. Now we had another problem: the workmen wanted the snake to be killed. They didn't want it to show up again; and this was understandable. More people die from fer-de-lance bites than from any other kind of snake in the New World. However, the basic rules of a preserve like BCI are that we do not annoy, harm, remove, or kill resident animals. On the other hand we are very lucky that there are not many more dangerous snakes residing on BCI. In some parts of Central America, one can see several Fer-de-lance or other poisonous snakes in one day. On BCI, it is an uncommon occurrence.

If someone on BCI were to be bitten by a Fer-de-lance, however, there might be a very strong opinion that the species should be eliminated. So Greg put the bucket in our office while we decided what to do with this snake. If it was to be released, no one would want it in his or her study area. These snakes have excellent camouflage, so they are usually not seen until very close, often too close. A botanist creeping around on the forest floor collecting seeds or measuring seedlings is very vulnerable. This baby snake needed to be released in a location removed from most human activities, where it could eat rats and grow up to live out its normal life as a predator of small mammals, and an important part of the natural ecosystem.

But the animal with the worst venom that will kill you fastest and deadest (if it ever bites you and chews on you enough to inject the venom) is the coral snake (Micrurus nigrocinctus). I had a collision with one on the trail one morning! I was walking along, gazing up at treetops and looking for monkeys when I felt something lash at my boot. I knew SNAKES and levitated forward at warp speed. When I came down and looked around, I saw the snake zooming off at least as fast in the opposite direction. It moved so fast it was a blur of colors that blended into a bright, almost fluorescent orange. The snake stopped and looked back at me with his tiny little eyes and tiny little head. He was about two feet long and was banded with red, cream, and black, in the usual pattern for real coral snakes (as opposed to those that are false corals, or mimics, and not venomous). He quickly found a hole in the ground and zipped down it before I could start up my camera. I'm sure his version of the encounter was much more exciting after all, he had my boot come down on top of him!This is the first coral that I'd seen in about three years, and nobody on BCI has ever been bitten by one unless they pretty much put a finger in the snake's mouth! It's really quite safe in this forest. Some rainforests have bushmasters and many fer-de-lance, and that's another very serious problem. But not on BCI. This place is not a tropical paradise, what with the ticks and chiggers, but it's also not dangerous. No one has ever died on BCI and the worst illnesses and injuries were appendicitis and some broken ribs when someone fell out of a tree and landed on a boat.

Greg and I had a friendlier encounter with a snake back at camp in our room. One morning when we were getting ready to go out and check the traps, Greg noticed a snake in the room, with its body coiled against the door and its head underneath the door. Since it wasn't moving, he worried that he might have squished it when he came in the night before. He recognized that it was the same snake he had seen on our steps two nights ago. Not just the same kind of snake, but the same individual, because it had a distinctive scar on its tail, and the tail seemed to be partially paralyzed.

Now it wasn't moving at all, so we thought it was dead, even after we cautiously opened the door and tried to move the body. It was such a pretty snake.  It was about twenty-two inches long with a slender body and a long, somewhat pointed snout, brown with black saddle markings on its back, and a row of dots below the saddles.

But it was alive! And now it wanted to hide somewhere. So it slid back under the door. We peeked around to see where it would go, but it wasn't visible on the other side of the door!We were trying very hard not to catch a part of the moving coils of snake in any part of the doorway. It took us a while to figure out that the door is hollow and the snake was moving upwards into the interior of the door (I said it was a slender snake). We quickly took photos on our digital camera, and went to the laboratory where there's a photo collection of BCI snakes. We found a matching picture. It looks like Leptodeira annulata, a frog-eating snake.

The book said that they hunt around frog ponds, but we don't know of any near our room. A friend said that he heard they eat the tadpoles of red-eyed tree frogs. We wonder if this one eats geckos from our room instead of frogs.

We saw him again on other nights, when he came out to hunt at about 9 pm, and sometimes again at dawn when he came home again to the hole in the door. Perhaps his tail injury was from the door closing on him. We put a sign on the door to warn other people to be careful.

My friend Pat Detamore (who also had the pet sloth) wrote about an experience she had with a snake many years ago, while she was living in the former Panama Canal Zone:
 


Alfred's Story

By Patsy C. Detamore

A friend and I were exploring a small island in Gatun Lake when we came across a large boa constrictor (about 6 ft. long and unusually fat) lying on the ground. Although we had spent a lot of time in Panama's forests, we had seen very few snakes, as they usually hide when they hear human footsteps approach. This one just lay quietly as we stood over it, and my friend suggested we take it home and eat it. (He had just been through a course at the Jungle Survival School and wanted to demonstrate to me that it was possible to live off the land if one were willing to eat some unusual foods.) Besides, he said, snake meat really is delicious. He sent me to cut a forked stick with my machete while he watched the snake.

As I turned away, my movement made the snake decide it ought to leave as well and it began to slither down a hole under some leaves. "Hurry up,"  my friend called, "its getting away!" He grabbed the tail and held on while I searched frantically for a branch of the right size. (I want you to know that this happened many years ago, before I learned about conservation of our environmental resources, or even about avoiding danger in the jungle. I wouldn't agree to removing a snake or any other wild creature from the rainforest now!)

By the time I got back with a forked stick, the snake had turned around in the burrow and poked its head out to see what was holding its tail. My friend, unwilling to let go of the tail, now grabbed the snake's neck with his other hand so as to keep from getting bitten. The stick was no longer necessary, and we put the snake into a large cloth bag that we always carried in case we found something we wanted to carry home.

By the time we reached home, it was too late in the evening to prepare the snake for cooking, so we put it alive in a box, which we stored in another friend's basement. (Neither my friend's wife nor my husband was willing to play host to that snake overnight!) Unfortunately, the other friend's wife had no idea there was a snake in the box in her basement, and opened the lid when she went down to do her laundry the following morning. Imagine her astonishment (and horror) when she was greeted by a squirming mass of, not just one large angry snake, but also 52 baby snakes as well!The poor woman slammed the lid down on the box and went screaming down the street, barefoot and still in housecoat and curlers, to a neighbor's house.

When my friend and I came to collect our snake, we discarded the idea of eating it after all, you can't eat a MOTHER. Instead, we gave the big snake to a small zoo that the United States Army used to show newly arrived soldiers what they might find in the jungle, and tried to find homes for the babies.

Each of the baby snakes was about 18 inches long. (Many snakes lay eggs, but boas give live birth. )We found homes for most of the babies, but my friend kept three of them and I was able to convince my husband to let me keep one. I named him Alfred.

I kept Alfred for three years. In that time he grew very rapidly because I fed him much more than he would have found to eat on his own in the jungle. He outgrew first one cage, then another. Eventually, at nearly eight feet long, he lived in a cage in my back yard until someone opened the cage and let him go. I never found out whether he had been set free or if he had been stolen to become someone else's pet.

I learned a lot about snakes from Alfred. But I also learned something first from his mother. I hadn't known that boas have a musk gland that can put out a really powerful scent. After my friend and I had handled her, our hands had a very strong, unpleasant odor for DAYS. No amount of washing seemed to take it away until it just wore off naturally. I have no idea what that musk is used for, but if I had been an animal looking for an easy snake meal, that smell certainly would have turned me off!

The first thing I had to learn with Alfred was what and how to feed him. Having had no experience at all with snakes before, I talked to a biologist friend who told me that it was important that Alfred's first meal be alive, but small enough to swallow easily and not so lively that it would bite him. If it bites him before he's had a chance to eat, it may frighten him so that he will never eat, he told me. He recommended baby mice that were too young to have teeth, a meal that would most likely have been his first meal in the forest. The lab where the man worked was able to supply me with all the mice Alfred could eat, and he learned to love his once-a-week mealtimes.

I also learned that snakes have a pretty good memory. Alfred's first cage was a box with plastic window screen for the sides and part of the lid. One night he found a small tear in the screen on the lid and got out. I found the cage empty in the morning, but had no trouble finding Alfred, as he was busy trying to get into the mouse cage nearby. After repairing the hole, I put Alfred back in his cage and he immediately stretched himself up the wall looking for that hole!

Much later, after Alfred had outgrown that cage and another one besides, I had to be gone from home for several weeks. Although I had learned from books that snakes, boas included, can live for more than a month without eating, I did not want Alfred to go hungry. So I asked my daughter to see that he got his usual once-a-week meal of six full-grown mice. My usual method of feeding him was to give him one mouse at a time, making sure that he ate it before putting another in the cage. (I had been told that if a captive snake does not eat the mouse in his cage, the mouse may bite him and cause at the very least, a skin infection. But my tender-hearted daughter could not bring herself to watch the snake kill and eat a mouse, so she just put all six in the cage with him.

Poor Alfred! He got so excited at having so many choices he couldn't decide which mouse to eat first. (Imagine yourself in a candy store and being told you could eat anything you wanted, but had to do it quickly!) As the mice wandered around the cage (no one had ever told them that snakes could be dangerous to their health), Alfred grabbed one in his mouth, but threw a coil around a different one. The mouse he had in his mouth squirmed around and bit its attacker on the nose. Alfred was so shocked that he dropped both mice and rushed over to soak his nose in his water dish, then curled up in a corner with his head tucked under a coil, hoping all those nasty critters would go away. He stayed that way until my daughter took all the mice away.

She offered him a single mouse later on that day, but he went back into his corner and wouldn't touch it. He reacted the same way the next day, and for all the days I was gone from home. In fact it was a full THREE MONTHS before I could get him to eat again! I put a mouse in his cage every week during that time, but he refused to eat until hunger finally overcame his fear and he again began to eat quite normally again.