Green Iguana (Iguana iguana)

Green Iguanas are the biggest species of lizards in the world, reaching lengths up to 1.5 meters including the tail. They are abundant in Costa Rican lowlands, and can be found in most of America’s continent, either naturally occurring or as established populations of escaped pets, as they are a very frequent target among pet lovers. They can be found in many beaches, around rivers, high in the tree canopy or walking slowly on the grass. Their diet is composed mostly of leaves, flowers and fruits, although some individuals have been observed eating insects and rodents.

Green Iguanas are not necessarily green in color, instead they have a lot of variability in their range. In some areas they are green, others brown or red, even blue in Peru. The back of the male is covered with spines, a defense mechanism to keep predators at bay, and they feature a dewlap, which is a fold of skin that starts at the front of the lower jaw and ends at the junction where the front limbs start. The dewlap is normally hanging, although it can be displayed as a sign of aggression.

The male Green Iguana is lighter in coloration than the female and has a heavier body. It also has a long dewlap that hangs from the throat.
A small green iguana resting on a green leaf, most probably waiting until its body is warmed up.

Smooth-head Helmeted Basilisk (Corytophanes cristatus)

The Smooth-head Helmeted Basilisk is a small lizard, measuring up to 11 centimeters in length, where most of this length is represented by its tail. It has the ability to change its skin color, ranging from green through brown and even black. Their skin is most normally patterned, with streaks of dark color breaking the light green overall coloration. Males have big crests on the head, while females do not posses them. Their fingers and toes are elongated. They inhabit tropical rain forests in the lowlands of Costa Rica, both in the Pacific and Caribbean sides of the country.

A small lizard clinging to a branch at the early evening. Lamps were needed to illuminate it for the picture.
A closer look at the lizard reveals an orange eye, with a big black retina that catches most available light during dark nights.

Spectacled Caiman (Caiman crocodilus)

Caimans are easy to confuse with crocodiles, however both belong to different families in the Taxonomic hierarchy. While each species in both families has its specific characteristics, there are a few physical traits that differentiate species from each family:

  • Jaws: The Crocodile has a V-shape, while the Caiman and Alligator have a U-shape. This can be seen most notably from above or the front, not so easily from the side.
  • Teeth: In Caimans, due to the way the teeth are placed, the lower jaw’s teeth are not visible when the mouth is closed. Crocodiles do show both upper and lower teeth at all times.

The Spectacled Caiman in particular has become established and common in Costa Rica. Like most reptiles, being cold blooded, they bask in the sun during the morning to warm up their bodies, before going for a day’s hunt. During that time, they may lie motionless in almost any place, like fallen trees, beaches and riversides. Adults have a length between 1.4 and 2.5 meters.

Caimans are definitely smaller than crocodiles, but their appearance is still fearsome for most of us.
Caimans inspire fear, specially after seeing such enormous teeth. Their biting force is tremendous as well.
This caiman was spending good time in the sun, warming up before going into the river for a full morning of hunting.

Plumed Basilisk (Basiliscus plumifrons)

The Plumed Basilisk, also known as the Jesus Christ Basilisk due to its incredible feat to run on water, is one of the four species of the Basiliscus genus and of three species to occur in Costa Rica. The similar Common Basilisk is brown with two yellow lines that run one through they, and a thicker one from below the eye, both ending in the upper portions of the back. The Plumed Basilisk is green, and the male has a big crest that protudes both on the head, back and tail. Most of its body is green with light blue spots around the back, a color pattern that lets it camouflage very easily in foliage and vegetation, particularly during the morning when they bask in the sun to warm up their bodies. Both their fingers and toes are very large, with scales that can be extended, increasing the effective surface area of their feet and enabling them to run over water for short distances, up to 20 meters.

The Green Basilisk or “Jesuschrist Lizard” resting on a rock, with the crests clearly visible on both the head, back and tail.
Note the bright yellow eye of the lizard. Its crest can be raised to signal that it is angry or is defending its territory.
A female basilisk, this time on the ground. It stayed there for a few minutes under the coverage of vegetation.

Common Basilisk (Basiliscus basiliscus)

The Common Basilisk, also known as the Jesus Christ Basilisk due to its incredible feat to run on water, is one of the four species of the Basiliscus genus and of three species to occur in Costa Rica. The similar Plumed Basilisk is green, and the male has a big crest that protudes both on the head, back and tail, while the Common Basilisk only has a crest on the head and a small ridge on the back. It is brown with two yellow lines that run one through the eye, and a thicker one from below the eye, both ending in the upper portions of the back; this color pattern lets it camouflage very easily, particularly during the morning when they bask in the sun to warm up their bodies. Both their fingers and toes are very large, with scales that can be extended, increasing the effective surface area of their feet and enabling them to run over water for short distances, up to 20 meters.

A brown, smaller version of the “Jesuschrist” lizard, known for its ability to run over water.

Ring-necked Coffee Snake (Ninia sebae)

Ring-necked Coffee Snake is a non-venomous species of snakes, although it does resembles the Coral snake due to its red coloration in most of the body. It lacks any ring patterns and is very slim, two traits that can help in identification. Its forehead is black, and it has a black mark on the back as well, just before the red body skin starts. It is found in Mexico and Central America.

Their red coloration still serves to warn predators not to come close. People ask me if this is a Coral or False Coral when they see the picture, but without any rings it only bears a small resemblance
With its elongated and thin body, one might think it is just a worm, were not for its bright skin color.
It wiggles around rather fast. In fact, the guide had trouble keeping it static on the same place during this photoshoot.

Rainforest Hog-nosed Pit Viper (Porthidium nasutum)

Rainforest Hog-nosed Pit Vipers are dangerous beauties. They can reach a size of 60 centimeters of length, which is rather small. According to the WCH assessment, their venom is not letal, but can cause uncomfortable symptoms including pain and swelling.

This species has two morphs, one with deep red-brown skin and another with brown-gray skin, both of which display small black markings from neck to tail. Each morph is found in different areas in Costa Rica, although being the same species, they can probably still mate and produce viable offspring.

Species having multiple morphs feature individuals with different appearances (usually different skin color or patterns in amphibians and reptiles), but each individual will normally only express one morph. While we talk about morphs, do you notice the split tongue?
I must accept I was tense during this photoshoot. While the snakes are handled with care, one always thinks of the worst possible consequences. A single bite might not kill a person, but the effects will be very painful and scary.
The nose of this pit viper looks very funny, just like its name would imply. It is very pointy indeed.
The guide sprayed water on the snake for a change, which makes the skin more reflective and deepens the brown tones.
A lower perspective brings us closer to a ground-level view. It looks very imposing in this posture.
The raised head in this shot of the Rainforest Hog-nosed Pit Viper makes for a more menacing look, although it remained calm and almost motionless for the most part.
The skin pattern of this snake is impressive to see from up close. The brown color lets it camouflage very easily in the forest floor.

Jumping Pit Viper (Atropoides picadoi)

The Jumping Pit Viper is another feared venomous snakes that occurs naturally in Costa Rica. They have a skin pattern similar to the Fer-de-lance, hence they might be confused on the field. Since both are dangerous, it is still a safe bet to stay away, whether the individual is one species or the other. The Fer-de-lance can be distinguished by the smaller head and ligher eyes; also the Jumping Pit Viper has solid brown triangles all along the body, while the Fer-de-lance features brown markings that are connected diagonally, but on the inside hey have lighter colors.

In spite of its common name, it is not more common for Jumping Pit Viper to jump on top of their prey than any other viper species. Their venom is very strong, so people are very cautious if they handle them.

By its name, it would seem like getting close to these is not a wise decision, however it is not common for snakes to jump onto people unless threatened.
Along with the Fer-de-lance, the Jumping Pit Viper is one of the most feared snakes species in Costa Rica. Its Spanish common name also refers to a “Eye of Round” beef cut, not exactly helpful if someone shouts “Mano de Piedra!”

Fer-de-lance (Bothrops asper)

Fer-de-lances are the most feared snakes in Costa Rica, even if they are not the largest species to be found here. They have grown a reputation out of casual encounters and deadly accidents. Part of the reason is that Fer-de-lances are more frequently found close to human settlements than other vipers, creating more chances to see them close. They normally do not display aggressiveness towards humans, preffering to stay concealed and motionless, however this very behavior make them hard to detect. It is common for people working on the field to tell stories of snakes passing through their legs; if not for that, they would have gone unnoticed. When a human is close, their usual reaction is to leave, but sometimes if they feel threatened, they will launch an attack, with potentially devastating consequences for the victim.

One of the most feared snakes in the country, you can tell I kept my distance when photographing this specimen. Special care needs to be taken when handling them, and as long as they don’t feel threaten, there should be no accident. I would never handle one of this on my own.
It has an habit for approaching homes, unlike many other venomous snakes that stay away. This increases the potential for accidents with unsuspecting victims, even in residential areas where one would not expect to find a venomous snake otherwise.

Eyelash Viper (Bothriechis schlegelii)

The Eyelash Viper is an arboreal venomous snake, found in Central and South America, with a diverse array of skin colors, with the yellow color potentially being the most impressive. It is called Eyelash due to the scales right on top of the eyes. They grow up to 82 centimeters in length, which is not very long between viper species. Its head is triangular in shape and its tail is prehensile, helping it grab branches to maintain its balance. They hunt by ambush, waiting in a spot for prey, particularly birds during the annual migration.

The bright yellow skin of this serpent is unmistakable. It coiled around the branch and used its tail tip as an anchor to maintain balance at all times.
This viper is found in many colors, including green, white and yellow like this individual. In this color, the common name applied in Spanish is “Oropel”, deriving from “oro” which means gold.
While the branches are straight, the body of this snake wrapped around them looks very curved, like a set of “S” shapes.
It does have a menacing look, specially from up close. One would think that the snake is angry given its face.