Expedition: Costa Rica Part II

Costa Rica: Search for the fer de lance

Part II

La Selva

A red-eye tree frog (Agalychnis callidryas)

La Selva Biological Station, run by the Organization for Tropical Studies, is one of the most well known field stations in the world. Established in 1954 by Dr. Leslie Holdridge, La Selva has served as the base camp for thousands of scientists and researchers. The campus is lodged right in the middle of over 1,600 hectares of pristine, undisturbed rainforest.

La Selva Biological Station (Courtesy of Google Maps)

Having had no luck finding my fer de lance in Palo Verde, I entered the lush green jungle of La Selva with renewed hope.  Having heard from the locals and resident scientists that the fer de lance was a commonly seen snake at La Selva, I was excited to begin the next leg of my search.

Overlooking the river by La Selva Biological Station

The view I'm looking at

The jungle, filled with the dewy smell of freshly fallen rain, was alive with parrots, monkeys, and iguanas.

Scarlet macaws (Ara macao), the world's best alarm clock

Breakfast, usually at 8 am, consisted of a lot of protein and carbs, perfect for a long day of hiking in 95 degree heat and 90% humidity.

The thing that first struck me about La Selva were the epiphytes. I've read about these plants that absorb nutrients through the air, rain, and occasional debris that collect in the tree.  But I've never seen them up close in person.  The size, color, and majesty of these natural chandeliers are mind boggling. And they were everywhere.

An epiphyte growing in the branches of a tree

Aside from these plants, little poison dart frogs (Oophaga and Dendrobates spp.) were all over the forest floor.  Clearly aware of their toxicity, these brightly colored amphibians proudly hopped around, looking for little insects to snack on.

A "blue-jeans" frog (Oophaga pumilio)

And another one

Despite the wondrous sounds and sights of the rainforest, I had to focus on finding the ultimate snake.  Heading out each day at 6 am, I searched for a fer de lance. Day after day, I discovered many species that I've long dreamed about finding in the wild, but no fer de lance.

Check out the size of this banana tree!

A parrot snake (Leptophis ahaetulla) demonstrating a defensive display

A more relaxed parrot snake

At night, we would grab our headlamps and head out into the jungle to see what kinds of reptiles were out.  After many nights, we found a brown vine snake (Oxybelis aeneus).  This gorgeous, rear-fanged snake is one of the few snake species that have binocular vision.

A brown vine snake (Oxybelis aeneus)

The business end of a brown vine snake (Oxybelis aeneus)

 The brown vine snake hunts for lizards, frogs, and other small animals at night, using their rear-fangs and mild venom to immobile prey items.  While not dangerous to humans, this little snake can put on quite a show.

Croc Hunting

One night, myself and a small team headed out to explore one of the rivers that bordered the research station.  Wading waist deep at night in water that could contain piranha, American crocodiles, and a whole host of parasites was the only way to search for a very special kind of reptile. Related to the alligator, caiman have powerful jaws, excellent hearing and eyesight, and the instinct to survive. With close to ten different species, caiman can range from a mere 3' Dwarf caiman (Paleosuchus palpebrosus) to a whopping, 16' black caiman (Melanosuchus niger). On this particular night, we were searching for a spectacle caiman (Caiman crocodilus).  Using my tongs to steady myself in the river, I searched for a caiman in the darkness, hoping to spot the animal before it spotted me. Using our headlamps, we looked for the characteristic "eye shine"; crocodile eyes light up like glowing orbs when you shine a light at them.  After almost an hour of searching, BANG! We got eye shine.  Unable to tell exactly how big the animal was, we moved as quickly and quietly as humanly possible.  Moving ever so slowly, we got within a body's length of the croc. As I got closer, I could tell that this was a juvenile caiman around 3' long.  With one member of the team keeping watch, the rest of us got into position. BAM! The team leader jumped for the croc, securing his hands around its neck. After a quick tussle, we moved to shallower water to avoid attracting the attention of larger crocs in the area.  The caiman that we had caught was a gorgeous specimen.  Plump, healthy, and happy, this caiman had been feeding well. 

Even this little guy could deliver a nasty bite

Check out those gorgeous eyes!

After taking our data, we released the little guy back to his home in the river. Now came the tough part. Our tussle with the little caiman had created quite a commotion.  As crocodiles are attracted to splashing (signs of a distressed animal or, from the croc's standpoint, food), we were sure that we weren't the only ones in the river. While the caiman themselves present little danger, it is their bigger cousin, the American crocodile that can grow longer than 20" and have an attitude to match, that got us worried.  Using my tongs to feel underwater, I crossed the river as fast as I could. Half way through I heard someone yell.  I don't think I ever jumped higher.  I was expecting to feel the overpowering pressure of a croc's jaws around my waist.  I scrambled to the river bank, shaking furiously.  Suddenly, I heard laughing.  It turns out that one of my teammates slipped while climbing up the bank and smashed his elbow into a rock, and screamed.  Apparently, my reaction was worthy of Fail Blog.

Back on the trail of the fer de lance...

A few days went by without a sign of a single fer de lance. I was beginning to question the locals' claims that they were thick on the ground.  But La Selva doesn't let you mope for long and soon enough, we had another amazing find.

One of the most colorful snakes in the world is the golden eyelash viper (Bothriechis schlegelii).  These gorgeous vipers sit in flowers and trees, waiting for prey. Their size and coloration makes them incredibly difficult to spot. Ranging from yellow to orange to moss-green and ruby red, the eyelash viper is named for the scales that protrude over its eyes, giving the snake "eyelashes". The venom of this little viper is designed to immobilize small prey items, whether they be small birds or lizards. Bites from the eyelash viper are incredibly painful and cause massive swelling but rarely result in death.  Nevertheless, I still wouldn't want to get bitten by one.

The golden eyelash viper (Bothriechis schlegelii)

Another eyelash viper (photo courtesy of Rick Stanley)

Heading out on the longest night hike of the trip, a group of us wanted to find something exotic, something beyond any of our expectations. We decided that the only way to get a chance at finding something truly unique would be to go into an unexplored part of the rainforest. Trudging through the thick underbrush was difficult; the clay like mud stuck to our boots, making it hard to walk.  After three hours of searching, we decided to head back. After 10 minutes of hiking back toward base camp, we found one of the rarest snakes in La Selva, a tree boa (Corallus annulatus).  Check it out: 

I have read about and seen many photos of these snakes; I've even seen these in different pet shops and reptile specialty breeders around the country. But seeing one up-close in the wild was a completely different experience.

It was near the end of the expedition and I was beginning to fear that I would leave not having found my prized fer de lance. My professor, Jonathan Losos, Ph.D, and I decided to head out one last time to the arboretum, a hot spot for snakes.  

Professor Jonathan Losos and I on the hunt for a fer de lance

We searched long and hard for several hours. Even though the chance of finding a fer de lance looked slimmer and slimmer, my resolve did not wane. I continued to search, poking around with my tongs in hopes of finding a viper. Then BOOM! I lifted a fallen branch and there, curled up on the bramble, was a fer de lance!

At last! A fer de lance (Bothrops asper)!

Professor Losos ran over, camera in hand. The snake was a juvenile, perhaps only 1.5' long.  But it was a fer de lance nonetheless. Knowing the toxicity and temperament of the snake, I was more concerned with keeping my tongs between me and it rather than taking photos. My professor wanted to share the snake with the others.  But we both knew that by the time either of us got back, the snake would be gone.

Finally, I found a wild fer de lance.  The whole time we photographed it, it didn't move an inch.  But the moment we stepped away from it to leave, it darted back into the ferns, disappearing into the undergrowth.  As I headed back to base camp, I was both sad and ecstatic.  I had found the ultimate viper, a snake so legendary that its mere name sends chills down people's spine!  But I also knew that the expedition was coming to a close.  While packing my gear for the long trip home, I quietly reflected on my experience. Renowned geneticist, biologist, and historian of science, Professor Andrew Berry, Ph.D, once said, "It is not until you walk in the jungles of South America, swim in the reefs of Australia, or travel through the open plains of Africa that you will fully appreciate the grandeur of nature." Indeed.