Costa Rica, a biologically diverse jewel nestled between the Pacific Ocean and the Caribbean Sea, is home to a myriad of vibrant ecosystems from monkeys to marine turtles. Among the most captivating creatures that thrive in these habitats are lizards.
While over 5,500 species of lizards have been described by science. Of this, just 70 lizard species can be found in Costa Rica.
Costa Rican lizards come in a variety of shapes and sizes. Green iguanas can reach incredible lengths of over 1.5 meters while the many-scaled anole grows to just a few inches in length. Additionally, Costa Rica is home to the Green basilisk lizard, helmeted iguana, common house gecko, Central American whiptail, and banded gecko.
Lizards can be found throughout Costa Rica in a variety of different ecosystems. They have successfully exploited unique ecological niches, including our very own homes.
But before we dive into some of the lizards of Costa Rica, let’s first explore what a lizard really is.
What (Exactly) Is A Lizard?
Lizards, like snakes, belong to the order Squamata.
Lizards are often readily distinguishable from snakes due to the presence of legs, eyelids and external ear openings.
However, not all lizards follow this rule. Some, such as European slowworms, lack legs altogether and look more like snakes than they do lizards.
The highest diversity of lizards can be found in warmer regions of our planet, including Central and South America. However, Australia takes the number one position for the country with the most lizard species – a staggering 617!
Of all extant reptiles, lizards are by far the most diverse in body shape. Many species are decorated with throat fans (known as dewlaps). Some have spines. Others have horns and helmets on their heads. They truly are a wonderfully unique group of animals.
In Costa Rica, lizards inhabit a range of environments. Those, such as whiptails and anoles, are cryptically camouflaged to blend in with their forest floor habitat. Others, such as the casquehead iguana, are a uniform green colour, allowing them to remain undetected in the rainforest vegetation.
Read on to discover some of the lizards of Costa Rica.
1. Green Basilisk Lizard
Now, depending on who you ask, Jesus Christ could walk on water.
The scientist in me is sceptical of this statement.
However, and this has been confirmed by scientists and non-scientists alike, there is a species of lizard in Costa Rica that really can walk, or rather run, on water.
The basilisk lizard.
Unsurprisingly, this lizard is also referred to as the Jesus Christ lizard for its amazing aquatic capabilities.
Found throughout both Pacific and Caribbean Costa Rica, the green basilisk is often found on trees and vegetation near a water source. If threatened, the basilisk can make a swift exit from their arboreal perch, into the water below. Standing upright, they can run up to 60 meters and at a speed of up to 24 km/h across bodies of water.
However, this is no miracle. To make the impossible possible, the basilisk lizard has incredibly long toes with fringes of skin that can unfurl upon contact with water.
Long toes and extra skin increase the surface area, allowing them to spread an equal weight distribution to prolong sinking. The speed at which the basilisk slaps their feet down also influences sinking rates.
Churning legs and slapping feet create air bubbles that also prevent sinking.
Adults, being heavier than juveniles, can only manage a few meters, before sinking into the water. However, this doesn’t mean game over for the adult basilisk. Adults can stay submerged for up to 10 minutes. Or, if the threat is still persistent, they can swim to safety using their strong tail muscles.
The green basilisk is the only green basilisk species extant today. Males can be distinguished from females by the presence of large facial crests, as well as crests on their back and tail. To attract a female, size is everything – males with the bigger crests are often the most dominant and have better genes. Tough crowd.
2. Green Iguana
Costa Rica – the land where dinosaurs still exist.
Ctenosauras, or the black spiny-tailed iguana, literally screams dinosaur in their name!
But, we’re not here to talk about the black-tailed iguana – after all, they’re only the second biggest lizard species in Costa Rica. Pfft, losers.
The green iguana, though it may not have a particularly dinosaurian name, looks like a mini dinosaur. Weighing close to 5kg, and measuring just over 2 meters, the green iguana is the largest lizard in Costa Rica.
Despite their large size, they are predominantly herbivorous, feeding off a variety of leaves, flowers, and fruits. They have sharp, serrated teeth to strip and grind tough vegetation.
Like the basilisk, they can be found in lowland forests close to a water source. However, this species is more adaptable to habitat alterations. As such, they can often be found on forest edges in disturbed regions.
If threatened, they too can leap into the water and evade predators by propelling themselves with their powerful tail.
The tail of a green iguana is dual-purpose. Not only does it aid the reptile with swimming, but it can also be used as an anti-predatory whip. Imagine a meter of pure muscle being whipped at high speeds at you. It would cause some pain. If tail thrashing isn’t effective, they’re not afraid to bite.
As a last resort, the green iguana can detach their tail completely from their body. The wriggling mass of muscle distracts predators for just enough time for the iguana to escape. Severed tails can heal fast at no detriment to the lizard.
Once common in Costa Rica, they were readily hunted for their meat. They are becoming rarer to see, however, strong populations of green iguanas can still be found in National Parks on both Pacific and Caribbean slopes, such as Arenal, Tortuguero, and throughout Guanacaste.
You may even see them basking when you’re least suspecting – such as mounds of rubble on the outskirts of a construction site. Very natural.
Green iguanas have a menacing display of spines running down the ridge of their neck, back, and tail – just another anti-predator adaptation. These guys obviously took no chances when it came to defence.
Mature males have large dewlaps (the dangly throat skin) as seen in the photograph I took down below.
These throat fans can make the iguanas appear larger, allowing them to warn predators or warn potential rival males. Again, female iguanas are likely to choose the males with the biggest dewlaps.
3. Helmeted Iguana
If you cross a basilisk lizard with a green iguana, you’ll probably get something that resembles the helmeted iguana.
If you’re picturing a small lizard with a biker helmet on, I hate to disappoint you. The helmet refers to the large, bony crest on the lizard’s head. In zoology, we refer to this helmet as a casque. The posterior region of the crest is serrated, perhaps a way of breaking up the solid outline for more efficient camouflage.
Both sexes have this crest but, surprise surprise, the male uses his larger crest to win over a potential female mate.
Despite the name, the helmeted iguana is in fact a species of basilisk lizard.
However, this basilisk cannot run on water. Instead, it relies on a superpower to evade predators – invisibility. It does this in two ways.
Firstly, like a chameleon, the helmeted iguana can change the colour of its skin. By concentrating melanophore cells (cells responsible for changing pigmentation), the helmeted iguana can appear darker – a perfect way to blend into the dark forest understory.
However, the helmeted iguana takes camouflage one step further; by actually becoming a living jungle ecosystem.
In 2003, a team of researchers discovered a fungus-like organism, Mycetozoa, growing on the body of the helmeted iguana. The organism showed no parasitic tendencies, and could in fact aid in the prolonged survival of the iguana.
As the helmeted iguana remains motionless for long periods of time, the body provides a suitable substrate for the Myxomycetes to mature.
4. Common House Gecko
We have an intruder in our midst.
Unlike the other lizards on this list, the common house gecko is not native to Costa Rica. In fact, it’s not even native to the continents of the Americas.
The common house gecko is native to South and Southeast Asia!
Thought to be a stowaway on trading ships in the early 21st Century, the common house gecko soon became established as one of the most widespread and dominant lizard species in Costa Rica.
Research is just beginning on the effects of the common house gecko in Costa Rica. However, they are an invasive species and may cause the spread of zoonotic diseases. They may be responsible for the decline in local insect and native gecko populations.
These gray geckos, which measure between 4 – 6 inches, are found everywhere. And I mean everywhere.
Although they can be found in National Parks across the country, such as Tortuguero and Manuel Antonio, the best places to see the common house gecko is near a light source in any house, apartment, or hotel. Now the name makes sense.
Inside or out. On the ceiling or on the walls. In the bathroom or in the bedroom. They are everywhere. An age old question is just how these house geckos are able to stick to walls and ceilings.
Originally, it was assumed they secreted a sticky, mucus-like substance. However, this is not the case.
Scientists discovered that the house geckos have toe-pads covered in many miniscule hairs (very different from your hair), known as setae. Although setae can be used as a sensory organ, the main function is adhesion. Okay, brace yourself, for things are going to get technical.
The tiny hairs, or setae, are made of keratin and are naturally strong. Through a process known as the van der Waals force, the setae on the toepads interact with whatever surface they are walking on. Now, this has to do with the spread of polar and non-polar molecules. Pretty technical stuff for an animal that licks its own eyeballs.
Despite their superhero-like abilities to walk upside they do, like the best of us, embarrass themselves occasionally. With a dull thud, I’ve witnessed a gecko or two just suddenly drop from the ceiling above me. Sheepishly, they scurry off soon after, seemingly unharmed (besides their dignity).
5. Slender Anole
This small reptile, measuring no more than 5 cm in length, is one of the most commonly sighted lizards in Costa Rica.
The slender anole is active by day and night and can be found on and around the forest floor, where their cryptic brown hues help them blend into the leaf litter or tree stumps.
At first glance, they really are quite inconspicuous. No flashy colours to promote. No ornate casques.
However, just pause and watch one for a while (and this applies to most anole species).
You may notice that the anole might start bobbing its head up and down, as if doing a little dance. Well, this is a dance of sorts – a courtship display.
By bobbing its head up and down, the male is able to extend his dewlap. What was once a small, barely noticeable lizard, is now this frantic, and colourful, trying his luck for a mate. The dewlap is often red, rimmed with yellow. Sometimes, males flash their dewlaps at one another to settle territorial disputes – the larger the dewlap, the more likely the male is to dominate.
6. Central American Whiptail
Most of the lizards on this list so far haven’t been the most spectacularly coloured – after all, most decide to go down the route of inconspicuousness.
However, the Central American Whiptail lizard is the exception.
As juveniles, the long tail of this lizard is a bright, metallic shade of blue. It is thought that the tail is brightly coloured to divert the attention from their more vulnerable regions. If a predator succeeds in grabbing the lizard by the tail, the whiptail can simply detach their tail.
As they mature, the blue tail fades. However, they are still easy to distinguish among Costa Rican lizards. Adults have a prominent cream-coloured stripe running down the back of their body. Their brown flanks are speckled with white spots.
Another distinctive characteristic is the presence of long toes on their hind feet. The toes are thought to be able to get a good grip on the substrate where they live – be it leaf litter or loose soil – and they can reach maximum speeds of up to 17 mph.
The Central American whiptail is present throughout the Caribbean and Pacific slopes (though more commonly sighted or the Caribbean slopes), where they can be seen foraging for insects on the forest floor. They are not particularly fussy when it comes to dinner – they’ll eat pretty much any invertebrate that fits in their mouth.
7. Central American Banded Gecko
As far as lizards go, I would say this guy is really cute.
There are no dinosaur-like qualities to the Central American banded gecko. Instead, it looks more like a cuddly toy you may find in a museum or zoo gift shop.
This species of gecko, found in semi-arid and humid forests of Costa Rica, is ornately decorated from head to toe in eccentric swirls and bands of cream and brown. However, their psychedelic patterning is limited to just their back; their underbelly remains a plain cream colour.
The Central American banded gecko is typically crepuscular, coming out when the sun starts to set – this is the optimal time for spotting them, as I discovered whilst in the hills of Turrialba, Cartago. This is when they most often hunt for small invertebrate prey. During the day, they stay hidden within small burrows in the ground.
Although they can be somewhat skittish towards humans, the Central American banded gecko has soared in popularity as an exotic pet. The demand for this lizard has seen wild populations starting to decline.
Whether you’re traipsing through the foothills of Arenal National Park, or staying in a hotel on the outskirts of the capital, San Jose, the likelihood of you spotting a lizard in Costa Rica is quite high.
Many species of lizards found in Costa Rica are highly adaptable, and can thrive in an array of different habitats. Some lizards live near rivers and lakes, such as the basilisk lizard, whereas others, like the Central American banded gecko, are confined to underground burrows most of the time.
Some move slowly through the undergrowth and display cryptic colouration to avoid predation, whereas others rely on their speed and agility to race across bodies of water.
Such diversity of body types and appearances have allowed lizards to thrive on our changing planet for millions of years. However, a fresh wave of threats, such as the exotic pet trade, casts shadows of doubts on the future of this ancient group of reptilians.
If you want to learn more about the animals that live in Costa Rica then you may want to check our articles on the terrestrial mammals of Costa Rica, as well as different types of frogs and types of Macaws!