Wildlife at Estación Biológica Tamandúa

Up until now, our travel has mostly focused around culture, food and activities so Estación Biológica Tamandúa was the first place we went herping (looking for reptiles and amphibians) and wildlife watching properly. Therefore, here follows a blog post purely about wildlife!

Birds in particular, are extremely diverse in Central America. Unfortunately, Greg and I are not bird experts and our interests mostly lie in reptiles and amphibians. However, I think we both appreciate birds a lot more now. A common feature of Estación Biológica Tamandúa, was the hummingbirds which flittered around the flowers planted around the buildings. We did not realise how angry, noisy and territorial hummingbirds are. We would constantly hear angry squeaks and a sound like a hover craft and a pair of hummingbirds would chase each other through the room, close to colliding with our heads. The hummingbirds were also extremely inquisitive. They would fly towards us and hover at eye level for a few seconds, checking us out. They would also do the same thing with the bathroom mirror. Unfortunately this did result in one casualty which we found when we returned from the town. We watched with morbid fascination while the hummingbird was devoured by ants who tried to take it into their nest.

Cane Toad under the table

Another common feature, was the nightly influx of cane toads and Incilius into the main building while we ate dinner. As bugs are attracted to light, the toads were attracted to the bugs. Every evening we would be joined by toads of various sizes and would enjoy watching them eat huge beetles or miss their target and headbutt the wall with a load “thunk”.

Tamandua has a small resident population of Phyllobates vittatus, the Golfo Dulce Poison Frog. Recognised as “Endangered” on the IUCN Red List, P. vittatus occurs only in South Western Costa Rica and populations are extremely fragmented. At Tamandua, the frogs are regularly encountered next to a waterfall in a rocky cave, or on the hill side and can be heard calling. We encountered P. vittatus several times an on one occasion, I witnessed a pair under the bench, calling to each other.

Pair of Phylobates vittatus

Taking photos of frogs isn't always easy!
Phylobates vittatus escaping.

Another poison frog we encountered was the Rainforest Rocket Frog, Silverstonei flotator. This frog was extremely common along all the paths, although extremely fast! We also found its’ mimic the Striped Rocket Frog, Allobates talamancae, which looks very similar but cannot produce poison.

Contrary to our expectations, we did not see many snakes. Apparently, in this location, snakes are more abundant during the dry season. When the rainy season begins, the rivers begin to flood and the snakes move away from the rivers into the forest and are hard to find.

Silverstonei flotator- Rainforest Rocket Frog

Leptodeira septentrionalis
hunting Smilisca sordida (bottom)

Leptodeira septentrionalis, the cat eyed snake, however, was extremely abundant. If we ventured down to the river after dark, it was normal to find two individuals foraging for frogs and tadpoles.

They also ventured into the main building on a few occasions. One time almost ended in disaster as, unnoticed for a whole morning, the L. septentrionalis had taken refuge under a heavy table we had to move. Seeing the snake underneath as we moved the table, I assumed we had killed it and had about given up, when the snake crawled out onto the floor, unharmed but pretty pissed off! We also discovered a Yellow-belly Snake, Coniophanes fissidens passing through the garden one evening.

Coniophanes fissidens- Yellow Belly Snake

One of the snakes we expected to find lots of was Bothrops asper, the Fer de Lance. These are commonly found around the research station. However, in the entire 1.5 months we were there, we only saw 2 individuals, both juveniles. One we spotted in a tree about 6ft high above the path. B. asper in Costa Rica is commonly called Terciopelo but has many other names such as Fer de Lance and Barba Amarilla (in Guatemala). Having extremely toxic venom, a bite from a Bothrops can be very severe and causes necrosis, requiring rapid treatment with antivenom to prevent tissue loss or even death. Being so far from a hospital (probably more than 4 hours by foot, quad, boat), we had already made the easy decision to not handle any snakes which we could not identify first. We had also decided to minimise disturbance of snakes by not handling unless necessary. Most of the time, the best photos are in-situ and most snakes we found would freeze in position, allowing time to take photographs.

Juvenile Bothrops asper 6ft up a tree

On my birthday we decided to go out for a longer walk than usual to find waterfall number 4.

We walked our normal route beside the river and then continued past our normal waterfall. We climbed the side of the valley up a zig-zag path and reached the spine of the hill. We stopped to look at a frog which turned out to be a small Craugaster fitzingeri. We continued but a second later a spotted a snake moving rapidly across the path. Immediately recognising its diamond pattern, I shouted “Snake… Looked like a Bothrops!” Greg replied “It IS a Bothrops!” The juvenile Bothrops asper had moved off the path and taken shelter under a small pile of leaves, but still in plain site. I took some photos of it before we left it to continue on its way.

Juvenile Bothrops asper

Dermophis occidentalis

We didn’t actually make it to waterfall 4- the path had collapsed. On our return, we had just passed the place we saw the Bothrops, when Greg spotted something on the path. A caecilian! Unfortunately it was dead, however, it is very rare to find them as they are fossorial and are usually found when digging mud. We don’t know why this one was dead- there were no signs of trauma on its body. Even so, it was a very exciting sight for us as we have never seen a wild caecilian before.

Continuing back, we started our descent along the steep zigzag path, when Greg saw a snake shoot out from the undergrowth and freeze just off the path. This enabled me to get some good photos and we identified the snake as Mastigodryas melanolomus, a species found throughout Central America.

Can you see it?

Mastigodryas melanolomus Salmon-bellied Racer

All in all, my Birthday was an exceptional day for herping!

With not much to do, and generally using candle light after dark, our circadium rythums kicked in and we got into a routine of feeling sleepy after dark. Unfortunately, herping is best after dark and this meant we didn’t get out as much as we had expected.

One evening, we were feeling a little tired and decided to take a short walk along the path by the river to the river crossing to the rest of the trails. We walked steadily, looking at frogs and Greg clambered down into the river to look for the giant Savages Bull Frogs that live in holes along the river. Just before we reached the crossing, I looked down and spotted a snake in the undergrowth. I recognised the extremely thin body and bubble-like head with large eyes as a member of the Imantodes genus (Imantodes inornatus). We had encountered Imantodes in Guatemala a few years before and knew from experience that these are extremely cool, calm snakes. I shouted to Greg, who attempted to climb up an 8ft bank out of the river. Thankfully, the snake was perfectly happy slithering around the knee-high vegetation and showed no signs of stress as we took photos of it.

Immantodes inornatus- Western Tree Snake

On our final week, we decided to go out for our last long night walk. Taking a path we had only walked in the day, the Camino Publico, we headed up the hill, away from the river. Continuing along the path slowly, we kept an eye out for any odd shapes or reflections that could indicate an animal. Looking up suddenly, I saw a bright object in a tree above our heads. It turned out to be Bothreichis schlegelii, the Eyelash Viper, one of our target species that we most wanted to see. As it was about 8-9ft above the path, we didn’t get great photos. This was a brilliant, positive note to finish our trip on!

Bothriechis schlegelii- Eyelash Viper

Finally, thank you to Estación Biológica Tamandúa for the brilliant opportunity and experience we had. If anyone else fancies seeing any of the cool animals we saw, check out their website and book a trip!

Thanks for reading!

Bryony

Total species list

35 Herps in total!

Amphibians

Frogs and toads- 18 species

Agalychnis calidryas Red Eyed Tree Frog

Craugastor crassidigitus Slim-fingered Rain Frog

Craugastor fitzingeri Common Rain Frog

Diasporus diastema Common Dink Frog

Engystomops pustulosus Tungara Frog

Espadarana prosoblepon Emerald Glass Frog

Sachatamia albomaculata Cascade Glass frog

Hyalinobatrachium valerioi Reticulated Glass Frog

Teratohyla pulverata Dusty Glass Frog

Hypsiboas rosenbergi Gladiator Tree Frog

Incilius aucoinae Pacific Forest Toad

Leptodactylus savageii Central American Bull Frog

Phylobates vittatus Gulfo Dulce Poison Dart Frog

Rhinella marinus Cane Toad

Silverstonei flotator Rainforest Rocket Frog

Allobates talamancae Striped Rocket Frog

Smilisca phaeota Masked Tree Frog

Smilisca sordida Drab Streamside Tree Frog

Salamanda- 1 species

Bolitoglossa lignicolor Wood-colored Webfoot Salamander

Caecilian- 1 species

Dermophis occidentalis

Reptiles

Lizard- 9 species+

Basiliscus basiliscus Common Basilisk

Holcosus leptophrys Delicate Ameiva

Holcosus quadralineatus Four-lined Ameiva

Mabuya unimarginata Central American Mabuya

Leposoma southi Northern Spectacled Lizard

Norops biporcatus Giant Green Anole

Norops limifrons Slender Brown Anole

Norops polylepis Jumping Anole

Sphaerodactylus graptolaemus Costa Rica Least Gecko

Snake- 6 species

Bothrops asper Terciopelo/ Fer de Lance

Bothriechis schlegelii Eyelash viper

Leptodeira septentrionalis Northern Cat-eyed Snake

Immantodes inornatus Western tree snake

Mastigodryas melanolomus Salmon-bellied Racer

Coniophanes fissidens Yellow-belly Snake

Bolitoglossa lignicolor, Wood-colored Webfoot Salamander

Metamorph glass frog sp.

Hyalinobatrachium valerioi Reticulated Glass Frog

Leposoma southi, Northern Spectacled Lizard

Sachatamia albomaculata, Cascade Glass frog in amplexus

Leptodeira septentrianalis eating a toad (likely Incilius aucoinae)

Hypsiboas rosenbergi Gladiator Tree Frog

Teratohyla pulverata, Dusty Glass Frog

Teratohyla pulverata eggs

Leptodactylus savageii, Central American Bull Frog