Frogs are a group of amphibians, often characterised by their smooth skin, and strong hind legs with webbed feet. Frogs can be found all across the wildlife of Costa Rica. Some species are very rare and only found in specific regions.
If you are an amphibian lover, one of the best places to see a large variety of frogs in a relatively small area would be the Costa Rican Amphibian Rescue Center, located in the Guayacan Rainforest Reserve, on the Caribbean slopes of Costa Rica.
Costa Rica is home to 149 species of frog, most of which are semi-aquatic. A range of tree, leaf, glass, and dart frogs can be found here. The red-eyed tree frog has a large geographical range throughout Central America. The Golfodulcean dart frog, can only be found in small pockets of land in localised regions.
But without further ado, let’s jump into some of the species of frogs you may see in Costa Rica.
1. Tree Frogs
There are thought to be 43 species of tree frogs in Costa Rica. However, none are as famous as the red-eyed tree frog and you can clearly see their colorings in the photograph above that I took myself.
With its bulging red eyes and vibrant colourations, this is a must-see of all Costa Rican frogs. Thankfully, they have a relatively wide-spread distribution across Costa Rica, and you will be able to spot them near water sources on both the Pacific and Caribbean sides of the country. For me, one of the best places to see the red-eyed tree frog is around Arenal, Alajuela.
With a lime-green back, blue flanks, and orange feet, the red-eyed tree frog is an unmissable site. I was so happy that I was able to capture the incredible colorations of this unique frog, as you can see in the photograph below!
However, unlike many colourful animals, they are not toxic. Instead, they display a behaviour known as startle colouration. If threatened, the red-eyed tree frog will show off all of its colours in a dazzling display, distracting and confusing a predator – at least for a few seconds whilst it can leap to safety.
The red-eyed tree frog is a nocturnal species. During the day, they remain concealed and hidden on the underside of leaves. Their eyes shut and legs pulled in close to their body, so as to not reveal an ounce of colour.
As soon as the sun sets, the red-eyed tree frog gets down to business – whether it’s to hunt invertebrates and insects around water, or search for a mate. Males shake leaves and wrestle one another to gain mating rights to a female. The winning male will fertilise any eggs a female may lay. The best time to see this behaviour is in the rainy season (May – November) of Costa Rica.
Another type of tree frog in Costa Rica is the spiny headed tree frog.
Remarkably different from the red-eyed tree frog, the spiny headed tree frog has light and dark brown markings across its back, legs, and flanks. They lack webbing between their toes.
This species of tree frog is primarily arboreal, living within bromeliads growing high in the forest canopy of Central Costa Rica, just below mountainous regions.
The spiny headed tree frog gets its name from the sharp appendages protruding from between their eyes, on the top of their head. These spines are thought to be an anti-predatory defence mechanism.
2. Leaf Frogs
There are just 6 species of leaf frogs found in Costa Rica. They are very closely related to tree frogs and behave in similar ways.
Perhaps the most famous is the lemur leaf frog. So-called after their large, lemur-like eyes, the lemur leaf frog has a bright green body with black spots across their back. The undersides and flanks of the lemur leaf frog are yellow, whilst the belly is white.
During the day, the lemur leaf frog remains motionless and undetected on the underside of a leaf, using their green colouration to blend into the vegetation. However, at night, when they are most active, their yellow-green skin turns brown. This is a form of camouflage, to avoid being detected by predators or prey.
The lemur leaf frog is critically endangered. It is thought that as much as 80% of its population has been wiped out. Now, they can only be found in a few sites across Costa Rica, Panama and Columbia.
If you’re wanting to spot the lemur leaf frog in Costa Rica, you’ll have to travel to the Caribbean side. Here, one of the best places to see lemur leaf frogs in the wild Fila Asuncion; an abandoned farm 15km from Limon. However, you may also be able to see this nocturnal species in the Barbilla National Park.
Costa Rica is also home to the blue-sided leaf frog. Found nowhere else on Earth, this frog is endemic to Costa Rica.
The blue-sided tree frog has a unique appearance. Like the red-eyed tree frog, they have a green upper body. Their limbs and flanks are comprised of blue, pink and orange. Their extraordinary colour has made them a popular frog for the exotic pet trade.
Once common across the Central Valley, rapid urbanisation diminished their habitats. Now, the blue-sided leaf can only be found in fragmented populations in disturbed regions across the capital, San Jose – an unlikely place for an endangered amphibian.
If you mixed a tiger with a frog what would you get? Probably something like the splendid leaf frog.
This, well, splendid, species of frog has a green back (like most species of tree and leaf frogs). However, its flanks and legs are a vivid orange and decorated with black stripes, giving the impression of a tiger.
This medium-sized frog (approximately 7 cm), can be found in the primary lowland rainforests of Costa Rica.
3. Poison Dart Frogs
There are 175 species of dart frogs globally, however, just 7 species can be found in Costa Rica.
Although small, most species of which measure less than 4 cm, they pack a punch. Their skin is laced with potent toxins that could kill any animal that attempts to eat it.
Most of these toxins are synthesised from the dart frogs prey of ants, beetles, and mites.
Many species of dart frogs have unique parental care methods. After hatching, the male dart frog will transport the newly hatched tadpole to a water body within a bromeliad. The female then lays an unfertilised egg – or, a meal for the tadpole. This is a relatively unusual behaviour in frogs.
The most sought-after of the Costa Rican dart frogs is perhaps the blue-jeans dart frog. As the name suggests, the blue-jeans dart frog has blue legs, much like a dashing pair of skin-tight jeans. However, they are also known as strawberry poison dart frogs, as their red back is often covered in small black dots. They are relatively common and can be seen in a variety of locations including Arenal, Tortuguero, and Cahuita National Parks.
Another species is the Golfodulcean dart frog. This endangered amphibian is endemic to Costa Rica and can only be found in the Golfo Dulce region of Puntarenas. Despite being just 3 cm, their vibrant black, green, and orange skin stands out in the forest undergrowth.
The green and black dart frog can be found on the Southeast Pacific coastline. Although found mostly within the tree canopy, the frog will come down to the forest floor to migrate between trees. Its small size, smaller than 2 cm, means it cannot jump large distances. As the name suggests, this species is decorated in a green and black pattern of swirls.
4. Glass Frogs
Throughout Central and Southern America, over 100 species of glass frogs have been discovered. Of this, there are 13 described species in Costa Rica. Most of which are incredibly small, no longer than 2.5 cm.
Glass frogs thrive in rainforests in close proximity to mountain streams – an essential part of reproduction and tadpole development. They get their name from their translucent underside. Remarkably, when viewed from below, you are able to see the major organs within the frog. In other words, they have glass-like skin.
It still remains a mystery as to why such a physical characteristic exists, but scientists hypothesise that it has to do with camouflage. As there is no defined outline of the frog, they are able to blend more naturally into the surrounding environment.
The slope snouted glass frog has greenish-blue skin that blends perfectly into any leaf when viewed from above. This camouflage is taken to the next level with the addition of small yellow spots dotted across its back. The dots are thought to mimic the sunlight as it penetrates the rainforest canopy. Ingenious evolution for an animal not much bigger than a nickel.
Diane’s bare-hearted glass frog, the most recently discovered species of glass frog (2015), has a lime-green back and, like other species of glass frog, a transparent underbelly. It has a very generic, almost boring, body. However, it is the eyes of this species that leads to its nickname of the Kermit frog.
Diane’s bare-hearted glass frog has bulging white eyes with horizontally-shaped black pupils. This, almost comical, appearance has struck up an uncanny resemblance to Kermit the Frog – the much loved Muppet character.
Endemic to the Limon province of Costa Rica, the green striped glass frog wins the award for best parent.
When a female green striped glass frog lays her eggs on a leaf, the male will guard them with his life. Predators, such as wasps, make easy meals out of developing frog eggs, so males need to be vigilant with their guard duty. Their mottled yellow and green skin mimics that of a clutch of eggs, allowing them to hide in plain sight and remain close to their future offspring.
If a wasp ventures too close, the male will kick out, striking the wasp with its hind feet. This distraction allows the tadpole within the egg, if developed enough, to drop into the water below.
5. Forest Floor Frogs
Frogs can be found in just about all habitats across Costa Rica. However, many species can be found right below your feet. Some of these species are also known as rain frogs.
Cryptically coloured, and often incredibly small, these frogs often go unnoticed – especially when they’re competing with the dazzling colours of the red-eyed tree frog or blue-sided leaf frog.
However, staying invisible is a great way of staying alive.
The pygmy rain frog grows no larger than 2 cm and can be found on the lowland and montane forests of the Costa Ricans Pacific slopes. Their back is smooth, with yellowish skin.
Another similar species is the Chiriqui robber frog. As far as appearances go, the frog doesn’t look too dissimilar to the pygmy rain frog. They can even be seen in the same habitat. However, the Chiriqui robber frog has a darker brown colouration. Additionally, you can tell the two species apart by their eyes; the Chiriqui robber frog has large, amber eyes with a dark iris.
The brilliant forest frog is an anomaly within the rain frogs due to its size. Measuring up to 6 cm, they are one of the biggest frog species in Costa Rica. They have a pointed head, with a longish snout. The brilliant forest frog was once a common sight within Costa Rican forests. However, they have declined in much of their montane habitats.
Threats To Frogs
Frogs, as well as other amphibians, such as toads and salamanders, are perhaps the animal group most at risk of extinction. A staggering 41% of all known amphibian species are threatened with extinction.
As global temperatures continue to rise, the future of frogs remains uncertain. Already, a staggering 200 species of amphibian have become extinct – including Costa Rica’s very own golden toad.
Frogs face a plethora of threats, from climate change to pollution. However, one of the most distressing threats is the rise of a parasitic fungus known as, brace yourself, Batrachochytrium dendrobatidis. Or, Chytrid fungus, for short.
This infectious disease significantly impacts populations of frogs and amphibians all across the world. However, we’re not talking about just a couple of species. Oh no, the Chytrid fungus has been known to infect over 350 species of amphibians.
The fungus directly attacks the skin of the frog. And, seeing as the skin is an integral part of the respiration of a frog, this can have devastating implications. Many species infected do not survive.
There is a fear that climate change is accelerating the spread of the chytrid fungus. This parasite thrives in temperatures between 17 – 25 degrees Celsius. So, as our planet continues to warm, colder regions open up to novel fungal infections.
But the fungus has been made prevalent by the feverish spread of frogs and amphibians through the exotic pet trade.
However, the exotic pet trade isn’t just responsible for the spread of the fungus. It has also directly impacted frog populations – and Costa Rican frogs are some of the most sought after in the world.
With a demand for interesting, unique, or rare species, more and more individuals are being caught illegally. Many do not survive the journey. Those that do will struggle in captivity, as captive settings do not replicate the frog’s natural habitat.
But one thing is for certain, the exotic pet trade negatively affects wild frog populations all across the globe.
Habitat loss is also one of the driving threats towards frog populations. This is most notable in the tropics and neotropics. Frogs need clean, pollution-free water sources to reproduce. Without suitable habitat, they cannot survive.
However, habitat loss also increases the temperature on forest edges, which may cause their skin to dry up, affecting respiration.
However, many wildlife charities and organisations are working hard across Costa Rica, and the planet, to conserve frog populations and the habitats in which they thrive. The Costa Rican Amphibian Research Center is just one such organisation that researches and protects Costa Rican frog species.
Although we may not think it, frogs are an incredibly important part of rainforest ecology. They eat a wide range of insects, including harmful pests, and keep balance within the ecosystem. Without them, there would be dire consequences.
However, many species are at risk of extinction – with some species, such as the golden toad, already extinct due to a range of issues such as climate change, parasitic fungi, and habitat loss.
Without dedicated conservation, Costa Rican frog species, such as the blue-sided leaf frog and the Gulfodulcean dart frog (both of which are endemic to Costa Rica) may struggle to survive on our changing planet.