The barba amarilla (Bothrops asper) is a formidable snake. Capable of exceeding lengths of over 2 metres (6ft) and armed with a powerful venom it is by far the most dangerous venomous snake found in Central America. They are commonly found around human disturbed areas such as corn fields where they prey on rats and other rodents. While this has some positive effects like keeping pest populations down it often brings agricultural workers into close proximity to these snakes.

Primarily for this reason the barba amarilla is the greatest cause of snakebite in the region.

One morning while on a walk through the forest around Estación Biológica las Guacamayas I was given a chance to see, or not, another reason that makes them so dangerous. A few metres behind me Cornelio, who works at las Guacamayas, spotted a young barba amarilla on the side of the path in the leaf litter. Only a few moments before I had looked at the area and seen nothing. Their camouflage is supreme, and their ambush hunting strategy relies on not being seen. Unfortunately this is another reason so many people get bitten by this snake, they simply are not seen as so they are stepped upon.

Bothrops asper

Bothrops asper has several common names depending on where you are in Central America. In some regions, including Guatemala it is called barba amarilla, or yellow beard, a reference to the yellow labial (lip) scales. In other regions, such as in Costa Rica, it is called terciopelo, or velvet skin, because of the velvety feel of its scales.

If this is not confusing enough there is a third name for this snake, the fer-de-lance, or iron lance, which is presumably a reference to the sensation one feels after being bitten. There are, however two other species of snake in the Americas that are commonly called fer-de-lance. They belong to the same genus as the barba amarilla, Bothrops. 

One of them Bothrops atrox is found on the Amazonian side of the Andes in South America. It is also known as the common lancehead. It is interesting that both of these snakes are found in former Spanish colonies and I find it odd that they have been given a French common name. So how did they get called fer-de-lance?

Bothrops lanceolatus

The third species might provide the answer. It is called Bothrops lanceolatus and is found on the island of Martinique, a former French colony. So it is probable that this is where the name originated.

A few days after our encounter with the barba amarilla, Cornelio and I were on another of our walks looking for reptiles and amphibians, as always. Cornelio gave another shout

“I found another barba amarilla”! I rushed over to where he was pointing. My first instinct was this was not barba amarilla but something else.

Xenodon rhabdocephalus

Almost before I had finished the thought the snake shot off into the forest with me closely behind. As it moved that feeling grew stronger it was not moving like barba amarilla, though it was moving too quickly to see for sure. After crashing through some spiky palm fronds I managed to get into a position to safely catch the snake.

Once I had the snake on my snake hook I took a closer look and found my instinct to be correct. It was a harmless, although mildly venomous, false barba amarilla (Xenodon rhabdocephalus), so called because they look almost identical to the real deal. With that firmly in my mind, it pays to be cautious in the tropics when out looking for snakes.

Xenodon rabdocephalus – False barba amarilla