Costa Rica (Aug 2025)
Tamandua mexicana
Guanacaste Province
Our exploration of Costa Rica actually started with one night at a hotel in Heredia Province. We hoped to walk its extensive gardens at night; unfortunately, it turned out it was closed overnight! We got up early the next day and spent some time photographing the wildlife there. After that, we had to move on.
We subsequently spent a couple of nights in the north, where while cruising we mostly encountered… mammals (see a couple below). Lots of them! The first night was extremely dry and the omnipresent dust made our hired car incredibly dirty. We found exactly zero snakes which didn’t put us in the greatest moods.
Common raccoon (Procyon lotor) and Central American agouti (Dasyprocta punctata)
The second night brought some rain and… one snake. A juvenile Boa imperator. Although it was a lovely individual, the amount of effort and time that went into that night made us hope for much more. Unfortunately, apart from some common lizards and more mammals, we didn’t encounter any other exciting finds.
In fact, the day walk we did before the second night was way more productive, especially in terms of invertebrates and more specifically arachnids, which made up a bit for unproductive nights.
After a couple of nights in the first location, we started moving east to Arenal which is where the real deal began. Frogs, snakes, moths and other critters were just awesome.
Drone view of the Arenal Volcano
But before we even got there, we saw a few cool things on the way, including crested caracaras (Caracara plancus), which were one of Artur’s bird targets. On top of that, a bunch of black vultures (Coragyps atratus) had a feast on, most likely, a deceased dog on the side of the road, which was a gruesome yet fascinating sight.
Caracara plancus
Black vultures (Coragyps atratus) doing what vultures do best.
We also have to mention crested guans (Penelope purpurascens), ancient looking birds that move like prehistoric raptors and are pretty good at climbing trees, which we saw after arriving to our destination in beautiful Arenal.
Penelope purpurascens
Our main target for that area were red-eyed tree frogs (Agalychnis callidryas) and they did not disappoint. These frogs are famous for their bright red eyes, which they use as a defence mechanism. When disturbed, they suddenly open their eyes to startle predators (a trick called startle colouration). How smart is that?!
This was also the area where Karolina saw her first glass frogs ever! Costa Rica is home to 15 species of glass frogs, and we were very lucky to encounter 7 species in just under 2 weeks.
Glass frogs belong to the family Centrolenidae. They have a distribution that ranges from southern Mexico, through Central America into the northern South America. Glass frogs are nocturnal and inhabit tropical and subtropical humid forest regions. The abdominal skin of some glass frogs is translucent, giving them their common name. They reproduce usually by attaching their eggs to the vegetation near streams and rivers (click for source).
Frogs were not the only animals we encountered in this part of Costa Rica though. It proved to be great for reptiles and not so bad for invertebrates either!
Artur was excited to see eyelash vipers (Bothriechis nigroadspersus). This species is famous for its incredible polychromatism: individuals can be golden “oropel,” mossy green, brick red, ghostly white, or even a mix of colours. No two ever look quite the same, which makes every encounter feel special.
We also saw our first terciopelo or fer-de-lance (Bothrops asper) there. The first individual was a juvenile climbing a small bush, the next one right after was an absolute monster waiting for prey by a small stream. This is one of the most iconic and feared vipers of Central America. Despite their fearsome reputation, they play a vital role in controlling rodent populations and maintaining ecological balance. We saw quite a few of them throughout the trip, some of a really decent size.
We enjoyed Arenal very much, with steady sightings, large diversity and incredibly easy terrain to walk during day and night. A small gallery of some other species we saw during just a couple of nights below.
And then there also were a few mammal species, with white-nosed coatis (Nasua narica) definitely in the lead for the cutest creatures. A huge group welcomed us on our very first day and, if approached slowly and from a lower ground, they did not fear humans at all, which allowed us to take great photos and videos.
Nasua narica
Spider monkeys (Ateles geoffroyi), on the other hand, showed us their darkest nature! We first bumped into them during the day, while walking a short trail near a stream, and one of them tried to assassinate Karolina by breaking and throwing large tree branches at her. We then most likely woke one up at night, and after a series of threatening screams, it threw… fresh poop at us! This species is now second only to macaques on our to-be-avoided mammal list.
Ateles geoffroyi
Time for inverts! Artur set up his moth light and sure enough, stunning moth species made their appearance.
Other invertebrates did not disappoint either. Costa Rica is an extremely diverse place and we just kept spotting incredible creatures, and they were just getting better and better.
Limón Province
After a couple of nights in Arenal, we moved to Limón Province.
While waiting for a night walk with the brilliant Stanley Salazar, we visited Frogs Heaven, where we mostly wanted to see Honduran white bats (Ectophylla alba). The place was quite nice but the frogs were often picked up by the guide so the visitors could have a better look at them, which didn’t leave us particularly impressed. The bats were lovely though, both Ectophylla alba and a small group of stunning sac-winged bats (Saccopteryx sp.). This is also where we saw the only sloth on this trip and a cute Beata sp. jumping spider.
Then came one of the best nights of the trip with Stanley. We drove to a remote area and entered a dense forest where we hiked all night, encountering an animal after another. Stanley is known for his extraordinary knowledge about habitats and behaviours, and was obviously very familiar with the rainforest too. Crazy as he is, he even climbed a tree to show us a shaman fringe-limbed tree frog (Ecnomiohyla sukia)! And he also disappeared a couple of times, frantically following the calls of coronated tree frogs (Triprion spinosus). He is very dedicated when searching for his guest’s targets so we just can’t recommend him enough. Below is a small selection of the wildlife we saw during our hike with him. This is from just one night…
Our next stop was Veragua, where we hoped to see the lemur leaf frog (Agalychnis lemur), which is successfully protected at the centre and is basically a guaranteed sighting. Unfortunately, this time we run out of luck, as weather conditions weren’t on our side. There was no rain for a few days, which we were told is extremely unusual for that area since they normally get some rainfall daily. With lemur frogs being highly dependent on humidity, we did not see a single one this time. This doesn’t mean our stay was entirely disappointing though; we discovered that Veragua is, for instance, a promising location for mothing and invertebrate activities and we did see a yellow Bothriechis nigroadspersus, known as "Oropel".
After Veragua, we drove back north but still stayed within Limón Province to explore it on our own. We were pleased to spot our first white-faced capuchins (Cebus imitator); they were not as pleased as us though and tried to scare us. We also had a close and rather special encounter with a stunning northern tamandua (Tamandua mexicana), a medium-sized anteater with a prehensile tail, small eyes and ears, and a long snout. Karolina really hoped to see one so she was over the moon. Such a special mammal!
Although herps were not abundant, we saw a couple of new snake species. A few jumping spiders hopped their way towards us too and we were treated to a hummingbird galore. Enchanting little birds.
Tamandua mexicana
Thalurania colombica
San José Province
After fruitful time in Limón, we moved to San José Province and spent the night and day with a wonderful host. His property lies in the perfect place, full of stunning birds and close to habitats of very vulnerable amphibians.
But let’s start with birds! The official bird list published by the Costa Rican Rare Birds and Records Committee of the Asociación Ornitológica de Costa Rica (AOCR) contained 948 bird species as of July 2023! Artur was absolutely mesmerised and woke up at 5 am to capture as many species as possible with his lens. Below are the results, and our favourite observation would probably be that of yellow-throated toucans (Ramphastos ambiguus), native to the tropical rainforests of Central America. These birds are highly sociable, often found in small groups, and are known for their distinctive calls that echo through the forest. Fiery-billed aracaris (Pteroglossus frantzii), also from the toucan family, were equally cool to observe, especially that there was a large resident group.
Atelopus varius
Birds weren’t the only treat nor were they the reason why we stayed in that area though! Our target was the variable harlequin toad (Atelopus varius). In recent decades, A. varius has become increasingly rare throughout its geographic range and is now classified as critically endangered. Rising temperatures across the tropics as well as the emergence of chytridiomycosis have been implicated in the declines of this and other Atelopus spp. We were very lucky to encounter two individuals of this species.
Another fascinating and rather unique observation was a Kiekie spider, from the Ctenidae family (wandering spiders), feeding on a frog! They are opportunistic predators with small vertebrates, such as lizards and treefrogs, as well as various arthropods on their menu.
Kiekie spider with its froggy dinner
Kiekie sp.
Puntarenas Province
Our second to last stop was in Puntarenas Province, where we spent time with Laurent, Diego and Cesar. We had a great time together; it’s always fantastic to surround oneself with like-minded people. We explored a variety of habitats, including Laurent’s lush garden, as well as pristine rainforests and streams, encountering a whole plethora of incredible creatures. We finally saw a pecari and the top mammal of the trip - A BABY AGOUTI (D. punctata)❤️.
Central American agouti (Dasyprocta punctata)
Yawning kinkajou (Potos flavus)
A small selection of herps from that leg of the trip below, with the most notable being a special glass frog species, poison frogs and a unique observation of an ornate cat-eyed snake preying on a glass frog - more on each under the gallery.
Hyalinobatrachium vireovittatum was the most precious glass frog observation, as there are fewest reports on them in Costa Rica since it’s currently only known from nine locations in the central and southern Pacific (Vargas et al. (2025). Hyalinobatrachium vireovittatum en Costa Rica) AND we have a record of a male guarding the eggs.
There are 7 species of poison frogs (Dendrobatidae) in Costa Rica, and thanks to Stanley Salazar and César Barrio Amorós, we saw 4 of them. Dendrobatidae are diurnal frogs found near streams. Some species exhibit extremely bright colouration deriving from their diet of ants, mites and termites, and it's correlated with their toxicity. A couple of species, which we have not seen, eat a much larger variety of prey and have more cryptic colouration. You can see Dendrobates auratus, Oophaga granulifera and Phyllobates vittatus below. The fourth species we encountered, Oophaga pumilio, was in Limón.
And finally, an ornate cat-eyed snake (Leptodeira ornata) with its emerald grass frog (Espadarana prosoblepon) dinner. Ornate cat-eyed snakes prey on amphibians, particularly frog and toad eggs as well as adult frogs. As rear-fanged snakes, they deliver low-toxicity venom that paralyses their meal-to-be before it gets swallowed. Rest in peace, little frog! It's the circle of life.
We didn’t forget about inverts, of course! We were lucky to be able to set up the moth light and some cool species made their appearance. Both day and night walks were very productive too. Being in a new country is always an exciting experience because most, if not all, species are new and many are a living proof of convergent evolution, a truly fascinating phenomenon. It just shows how efficient mother nature is, repeating successful solutions in different corners of the world, no matter how distant.
One of the most interesting observations was a tailless whipscorpion Paraphrynus laevifrons with parasitoid eggs on its abdomen. It is believed that eggs of the parasitoid chloropid fly (Pseudogaurax sp.) are laid on the eggsacs of female Amblypygi and the fly larvae consume the Amblypygi eggs upon hatching. The larvae then pupate on the female’s opisthosoma before emerging (source). Sick!
Paraphrynus laevifrons with parasitoid eggs on its abdomen
Forest symphony at dawn. Sound on!
Alajuela
Our last night was with @Estebanherpingwildlife, with Bothriechis nigroviridis and Bothriechis lateralis being our main targets. The weather conditions were rather harsh, it was extremely windy and wet. We started at a lower elevation where we found a gorgeous blue-sided leaf frog (Agalychnis annae) and a stunning side-striped palm pit viper (Bothriechis lateralis). We then drove and hiked up, in hope of finding Bothriechis nigroviridis but, sadly, we could not spot any this time. On the way up though we saw the second species of salamander on this trip, Oedipina uniformis. Costa Rica has over 50 (!) species of salamanders within its relatively small land area. All of Costa Rica's salamanders belong to the family Plethodontidae, or lungless salamanders, and they occupy a variety of habitats, from sea level to the highest mountains.
Throughout the trip, we saw a couple of Oedipina species, which are often called "worm salamanders" due to their slender bodies, tiny legs, and long tails. They are secretive and mostly fossorial, living on the forest floor under leaf litter, logs, and rocks.
This was an amazing continuation of our Galapagos adventure, although we must say we did not fall in love with Costa Rica as much as we thought we would. One definitely cannot question its phenomenal biodiversity, but the reality of travelling across the country is much different than what online videos tend to show. There’s a lot of destroyed habitat and although the diversity is huge, the density not so much in many areas. Nevertheless, we’ll surely come back one day to explore the south!
Special thanks to all people mentioned above as well as Jesse whose extensive knowledge of the region made this trip possible.
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