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HomeAnimalsTurrialba: Why the population explosion of Costa Rican snakes near people?

Turrialba: Why the population explosion of Costa Rican snakes near people?

PAVONES, Cartago — Minor Camacho was showing me around the Serpentario Viborana, an exhibit of venomous vipers near Turrialba, when a man pulled up on a bicycle and Camacho said, “That man has brought me a snake.”

The man got off his bicycle, greeted Camacho and his wife, Fanny Fuentes, and untied a bag that contained a large plastic soda bottle with a venomous, foot-long-plus hognose pit viper in it. Breathing holes had been burned into the bottle with a cigarette.

Minor Camacho holds a hognose pit viper on a snake hook.
Karl Kahler/The Tico Times

Camacho uncapped the bottle, shook the snake to the mouth, took it by the tail and pulled it halfway out.

“Son of a bitch, I wouldn’t touch it,” said the man, Manuel Antonio Mendoza Martínez.

Quoting something Camacho had just told me, I said, “You have to have more interest than fear.”

Minor Camacho holds a hognose pit viper by the tail.
Karl Kahler/The Tico Times

Mendoza said, “They know who’s afraid of them and who isn’t.”

“Can I touch it?” I asked. Camacho agreed, and as I stroked its smooth, cool body the snake whipped its head around and tried to strike, but the mouth of the bottle was too small.

Camacho pulled the snake all the way out and dropped it on the ground. I expected it to make a speedy escape, but it was more in the mood to fight than run. It coiled into striking position and vibrated its tail like a rattlesnake.

Camacho put his boot in front of it, and it struck repeatedly — leaving a tiny dark dot of venom on the front of his boot.

A hognose pit viper strikes at Minor Camacho's boot.
Karl Kahler/The Tico Times

Camacho gives locals a ₡1,000 tip for every live, venomous snake they bring him — just a tip, he stressed, as buying wild animals is illegal. He says sometimes people bring him a harmless snake, and he gives them their tip and then lets it go — “to teach people not to kill snakes,” he says.

He gave the man on the bike ₡2,000, because someone else caught it and he brought it here.

The new viper would be added to Camacho’s collection, which currently numbers only 25 or 30, but sometimes he has a lot more.

Hognose pit viper on a snake hook.
Karl Kahler/The Tico Times

“Do you have any boas?” I asked.

“Oh, yeah, up in the house,” he said. “Here we focus on venomous snakes.” I pictured Camacho and his wife sleeping with their pet boa curled around them.

“How many times have you been bitten?” I asked.

“Eight,” he said. By venomous snakes? Yes. There’s a hospital in Turrialba, 10 or 15 minutes away, in case of a serious bite. He could use antivenin, but he’s afraid that if he uses too much he’ll become allergic.

Minor Camacho points to the place on his hand where a venomous snake last bit him.
Karl Kahler/The Tico Times

His preferred antidote — though he stresses that this is NOT recommended — is to watch the bite for swelling, drink a couple of beers and go to bed.

Before Mendoza’s arrival, Camacho had already taken a hognose pit viper out of its cage on a snake hook, putting his hands perilously close to it — and it did strike at him, but he drew back fast.

Minor Camacho holds a hognose pit viper by the tail.
Karl Kahler/The Tico Times

He showed me how to catch a dangerous snake, pointing a finger straight at the back of its head and lowering it until he touched it — at which point the snake wrenched free and tried to strike again. I can’t wait to try this myself, next time I find one (yeah, right).

Minor Camacho presses his finger on the back of a hognose pit viper's head.
Karl Kahler/The Tico Times

Camacho brought out a couple of eyelash palm pit vipers, known for the strange skin formation above their eyes, and put them in a tree, where they coiled up peacefully until he got too close, and then they assumed a striking position.

Eyelash palm pit viper.
Karl Kahler/The Tico Times
Two eyelash palm pit vipers.
Karl Kahler/The Tico Times

“Do you have any rattlesnakes?” I asked.

“Sure.” He brought out a neotropical rattlesnake and dropped it in the grass. Again, it made no effort to escape, but it rattled its tail and assumed a striking position when he got too close to it.

Neotropical rattlesnake.
Karl Kahler/The Tico Times

“Do you have any coral snakes?” I asked. I was almost shocked when he said no.

Coral snakes can be extremely deadly, but he said, “You’re about as likely to be bit by a coral snake as to be repeatedly struck by lightning,” he said. “They’re extremely timid.”

I had been told there are two types of venomous snakes in Costa Rica: vipers, recognizable by their arrowhead-shaped heads, and coral snakes, recognizable by their red, yellow and black colors. Camacho said there is a third, a sea snake, but humans almost never encounter them.

A hognose pit viper, recognizable by its triangular head.
Karl Kahler/The Tico Times

I said I was told at the Monteverde Herpetarium that sea snakes are a type of coral snake. Camacho pointed to a laminated poster of venomous snakes in Costa Rica and pointed out four species that many herpetologists today consider only two, saying snakes are constantly being reclassified.

For over an hour, Camacho gave me a personalized version of the charla, or chat, that he does for visitors. He said he has taught more than 10,000 children about snakes in the only program that exists in Costa Rica to enable basic prevention of snakebites for children.

Minor Camacho and Fanny Fuentes, the staff of two of the Serpentario Viborana in Pavones.
Karl Kahler/The Tico Times

“In Costa Rica, snakes have been studied for over a century,” he said. “But I personally consider that a very grave error has been committed: They’ve been studied only in laboratories. And so almost our total knowledge is of taxonomy — scientific names, families, etc. But this is repetitive. If you compare a book about snakes written in 1931, for example, and one written a couple of years ago, the content of the book is basically the same: repetitive descriptions of snakes. There’s a gap in the information about the natural history.

“A snake expert is incapable of finding a snake in the mountain unless it’s by accident. They just write their books and repeat and repeat. And a tour guide will see a snake and tell you, ‘This is a Bothrops asper [a fer-de-lance, or terciopelo]. To one of our campesinos, he doesn’t care about its scientific name, he wants to know why the terciopelo is killing his cattle, why it bit his grandson, why it’s getting into his house, why it killed his dog. That’s the information that doesn’t exist.”

Camacho, a soft-spoken but excellent storyteller, told a fascinating tale about the genesis of his interest in snakes. He was born in Turrialba, and at the age of 10 or 12 he started leaving the house to explore the mountains. At the age of 13, under an old bridge in a space between a bunch of rocks, he saw the tail of a snake.

“I was 13 years old and knew nothing about snakes,” he said. “So I did what I had to do: pull the tail. The snake turned its head and bit me right here [on the hand].

“Something told me it wasn’t important. So I kept going, carrying the snake in my hand, and I met a man working in agriculture, and I asked him, ‘Señor, what’s this?’ And he said, ‘Oh, you idiot boy, that’s very venomous. Kill it. If it bites you, you’ll die in five minutes.’ And it had bitten me one minute ago.

“At the age of 13, this was very bad news, right? I walked about another 100 meters, or 200, so he wouldn’t see me die, and with the snake in my hand, I found a semicircular boulder, and I sat down on the rock to wait for death.

“There was nothing I could do. I had two or three minutes. And I kept waiting for death, 13 years old, constantly checking myself to see if I was alive. And after about 30 minutes I understood that I wasn’t going to die. So I asked myself why the man who was working there told me this was venomous if it wasn’t. I came to learn this 50 years later: The man had no information, none.

“Today, 55 years after that, the people still have no information, at any educational level. We are a nation of people absolutely uninformed about snakes.”

After this experience, he kept exploring the mountains, and he found snakes “a thousand times.” He didn’t touch them anymore, but he became an expert at finding them.

In 1968 he started attending the University of Costa Rica in San Pedro, but his family was of modest means and had little money. One day he saw a sign saying, “We buy live venomous snakes.” It was for a national antidote program by the government of Costa Rica in cooperation with the U.S. Army.

“So every weekend, while my friends went dancing in the city, I went from San José to the mountains, and a couple of days later, or the next day, I returned with a bag of snakes under the seat of the public bus. There was enough venom in there to kill all the passengers on the bus like 10 times over. And I sold them to the university.”

Eventually he started working in the university’s herpetology program, milking hundreds of snakes of their venom in order to develop antivenin.

For financial reasons he was never able to finish his education and get a degree in biology. But in the mid-1990s he returned to the mountains where he was born and built this snake exhibit in Pavones (in Cartago, not to be confused with the surfing mecca on the south Pacific coast).

Needing snakes for his exhibit, he went out to find them.

“But the first week I learned something,” he said. “I was finding more snakes in 1994 than I found in 1968. I was finding them in greater numbers and in different places, in agricultural places, in plantations. … I started comparing a lot of places I knew, and quickly I learned that there was an increase in snakes.”

The biggest increase he saw was in three of Costa Rica’s most dangerous snakes — the fer-de-lance, the hognose pit viper and the eyelash palm pit viper.

Camacho wrote to various government official and institutions noting this increase in the snake population, saying this appeared to be a serious problem that would cause more dangerous snakebites in humans and cattle.

He said he received a reply that basically said, “We are the experts; you guys stop talking. You’re people from the country.” Many years later, he said, the same Costa Rican expert who wrote this letter was one of six herpetologists who published a paper saying there was a dangerous global increase in venomous snakes.

Camacho, who modestly says he doesn’t consider himself a real snake expert, is much less interested in the taxonomy of snakes than in their natural history. He says snake behavior and habitat has changed radically in the 500-plus years since Europeans arrived in the Americas and started planting crops — and he says climate change has played a major role in where they live.

As an example he cited Costa Rican plantations of macadamia nuts, imported from Australia, and he took an unshelled nut from his vest pocket that he said he’s had for 20 years. (“You haven’t eaten it?” I asked. “No,” he said, “because I need it.”)

In Australia, where rain in scarce, growers kept the ground clean so they could find 100 percent of the nuts that fell from the trees, he said. But in rainy Costa Rica, where the ground was full of grass and weeds, he said growers recovered only 70 percent of the nuts.

“So at some point, someone in the forest discovered this: ratones,” he said, meaning mice and rats. “It was new for them; they’d never seen it before.

“At first they played soccer with it,” he joked. Then he produced the empty half-shell of a macadamia nut from his vest. “But at some point some of them discovered this: that there was food inside. And this changed history because later, the mouse notices that there’s not only food, there’s lot of it. And that is the opposite of the forest.”

He cited three factors that control animal populations: predation, food sources and competition.

“Then the mouse notices that the plantation is an environment very different from the forest, where there are lots of enemies,” he said. “Here there aren’t. And with lots of food, competition disappears. So what happens? The mouse does this [whistles], and more mice come.”

Camacho mentioned a nearby place called Pacayas where carrots, tomatoes, potatoes and onions are grown.

“If you go and analyze the field when the workers have left, you’re going to find that what was left on the ground are pieces of potato, pieces of carrot, pieces of everything,” he said. “And if you come back at night, you’ll notice that the mice are drinking shots, singing karaoke and eating everything that the owner of the plantation left. And we return to our story: If there’s a lot of food for mice … in a few months, what’s the terciopelo going to find?

“Dinner is served. The temperature is ideal and there’s lots of food.”

As agriculture grew from a few isolated “islands” to connected “corridors,” Camacho said, snakes’ habitat completely changed.

“In time, the terciopelos will have young on the plantation that no longer belong to the forest,” he said. “They’ve never seen the forest. … And soon they’re going to find people.”

The other major factor that led to a major migration of snakes, he said, was climate change. In 1997-98, the “Super-Niño” weather phenomenon produced very little rain and a pronounced increase in temperature in Central America.

The terciopelo is most active at a temperature ranging from 21 and 24 degrees Celsius (70 to 75 degrees Fahrenheit), he said, and at higher temperatures it becomes inactive, like it’s asleep.

“Here where we are, that temperature is rare,” he said. “It only occurs in the evening and in the morning. So those times are when snakebites happen, morning and evening. But upon arriving at altitudes of 1,500 or 2,000 meters, you’re going to have that temperature all day long. And I think in those places they’ll be much more aggressive for more of the day than here. This suggests big problems in public health for people who live, for example, in Pacayas and Cervantes, the highlands.”

As temperatures increased, dangerous snakes began migrating from warmer and lower to higher and cooler places, using as highways rivers and creeks, where there was water and food. Along the way, they migrated through populated areas like Turrialba, biting people, dogs and cattle.

Camacho mentioned an 80-year-old woman in Santa Rosa, 3 kilometers north of Turrialba, who has been bitten by fer-de-lances three times in her own home. In fact, he said, almost one-fourth of all snakebites occur in homes.

So why do snakes come into homes?

Very simple: For snakes that are hot, thirsty and hungry, houses offer shade, water and food in the form of rodents attracted by leftovers thrown in the garbage.

Camacho said the world needs a new branch of science called “agroherpetology,” the study of snakes in the agricultural areas that they now prefer — not in primary forest, and not in university laboratories.

“What’s important to me,” he said, “is that knowledge of snakes is still in diapers.”


Getting there: Drive northeast from Turrialba on Highway 10 toward Siquirres about 11 kilometers until you come to a cemetery on the right; 500 meters beyond that is a small sign for Serpentario Viborana pointing to an unpaved road on the left leading downhill. A short distance down that road is another sign pointing uphill to the snake exhibit. (Four-wheel drive is not necessary.)
Admission: Ranges from a basic tour of ₡3,000 to more extensive tours costing $10 and $15.
For more info: Go to or

Contact Karl Kahler at


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