Agalychnis spurelli : A personal excerpt by Andres Jimenez

This blog piece was taken and translated directly from Osa Conservation’s Wetland Program Coordinator, Andres Jimenez, and his very own personal blog.


While I wait here for the fog on my camera to evaporate, and while the few clean clothes I have left are drying, and while none of my shoes are fully covered in mud, here I am dedicating myself to editing photos and writing this blog! Little did I imagine (although one always has hopes) that on a rainy night…wait…let me correct myself – during the deluge, where for a few moments I envisioned myself constructing a small boat in order to begin having to collect two of each kinds of species like Noah himself – I would come across an explosive reproductive session of these wondrous red-eyed frogs in the middle of the day!

Agalychnis spurelli - the gliding tree frog.

Agalychnis spurelli – the gliding tree frog.

The previous night I walked something like 6 hours with a great report of local creatures including: two vipers, one anteater, an armadillo, and countless horned spiders, but then again this experience also left me (as my misfortune would have it) with a camera lens completely and utterly fogged – an issue that will become ever so relevant when I later arrive to the focal point of the swamp in this mentioned tale. Anyways, I don’t want to distract you all with the tales of my night-time adventures, lets get directly to the frog; or better said, the avalanche of frogs. Agalychnis spurrelli, also known as the gliding tree frog, is a beautiful and rare frog that, prior to this tale, I had only managed to see in the wild twice in my life. This particular tree frog is about 40 mm by 70 mm, that is to say it has some 7 cm from its mouth to its anus, which in reality is quite large for a frog species. For those who are not so familiar in the ways of amphibians, that measurement is for this frog’s body size, the legs, that are often rather much larger and longer, are not included in this measurement. This frog species tends to live on the canopy of a tree, and it often moves as though walking on a tightrope, placing one hand in front of itself, followed closely by his feet: a feature I would like to add this is very popular on all TV channels.

It’s very likely that you have before seen, or perhaps are aware of, some of the cousins to this wondrous frog – maybe you have even caught glimpses of them on TV. Agalychnis spurrelli cousin frog has a red body, red eyes and specks of colors running around it side. Clearly our Agalychnis spurrelli and its cousin are very spectacular creatures, and I would imagine that this often results in people  wondering what the thought process behind their given common names is, being that the names are so unique as the frog themselves. According to many biologist, and as it was reported by Savage 2002, this “gliding tree frog” has the capacity to jump in a “parachute” style giving rise to it’s common name. You see, after the frog jumps, it positions it’s body with a 45 degree angle, maintains both it’s legs straight, outwards and parallel to the ground, and this enables the frog during it’s descent, (or in some cases ascent) to use it’s suckers, more commonly referred to as it’s digits (that are extremely sticky) and anchor itself to the vegetation in one spectacular and graceful jump; it goes without saying that the jumps can be very wide, and inclusively the frog is furthermore capable in using it’s webbed digits to execute large spins in the air.

Enough with side notes and distractions – back to the main story at hand: at my arrival to the earlier mentioned swamp, where my colleagues already prepared their photography equipment for shots of the area, what called my attention at that movement was the strange movement in the trees that was on the other side of a marshy swamp. Sheer curiosity willed me to pull my binoculars expecting to observe a bird, but to my great fortune (finally!) I couldn’t have been more wrong. The movement in the branches continued, and it was low and high, far and wide, it was thousands and thousands of frogs that were jumping from tree to tree, branch to branch, in a spectacular display that made this self-proclaimed amphibian lover go running through a swamp with little precaution for the vipers near my feet…I know what you’re thinking…I’m not exaggerating.

An explosive reproductive session.

An explosive reproductive session.

At this point I took out my camera, prepared the camera lens, hung the camera strap around my person, and jumped into the swamp. A swamp -like the majorities of open water – is stagnant water covered in vegetation…so sometimes they are deep…and other times they are not…the point is it can often be hard to tell. But in any case, here I was in the water, and I begun to approach the frogs little by little, inch by inch, I was more nervous than I thought I would be, that’s for sure. With one wrong movement, I could jeopardize my hopes of this anticipated photo. I approached a little bite more, and at this point the water was creeping into my boots, and starting to rise quickly (at this moment I had to remind myself that this was my last clean pair of pants….err…my last cleanest pair of pants….). With the water officially up to my waist I suddenly recalled… my camera lenses I realized was completely fogged up! Clearly the previous nights adventure had cost me dearly! Only some 20 photos after initiating my photographic campaign came through, and my camera decided to not recuperate from the previous nights tryst. The irony! One photo would be produced foggy, I’d clean the lenses, take anther photo, and it would be foggier than the first! I’d change to another lens I had, still foggy. I’d clean the lens once more, everything seemingly according to plan…and then the inner camera would fog up…it was a nightmare ! I wasn’t able to capture a single worthwhile photo during the whole moment.

When I had given up on everything a ray of sun emerged; and I’m not being metaphorical. There was a sliver of light permeating through the forest – I was swift to head in it’s direction and there, finally, I was able to detach the len and allow them to dry in the light. After a few long, torturous, and endless few minutes (that I of course spent enviously looking on to the frogs jumping in bliss) one of the lenses finally decided to cooperate – my hopes were answered…. or were they? The sun quickly disappeared once more and now the problem was another: there was no light; it was totally dark, and how was I to capture this moment without the right amount of light? Those of us who have taken photos within the forest without sun know that pictures will come out totally dark. But I was fortunate in one thing, there was a bat biologist, Melkin, who offered to let me borrow his flash and once readied onto my camera I once more jumped into the swamp.

In the process of being lugged around - a lazy male is carried by a female to the site of her choosing to deposit her eggs.

In the process of being lugged around – a lazy male is carried by a female to the site of her choosing to deposit her eggs.

We return then to the swamp: behind the lenses of my camera an Agalychnis spurelli walks through the leaves carrying a male on her back. These frogs prefer to reproduce at night in ephemeral puddles off water, like swamps, that have some foliage to cover the water. They only reproduce during the rainy season, where the males look for a perch to call out to the females on. In the majority of the cases the swamps tend to have several couples, that after their initial courtships ritual, will situation themselves on a leaf. Following the females deposit of egg on said leaf, a male will then fertilize said eggs. What is particular about these frogs is that, generally speaking, before they deposit their eggs on to the leaf, the male will embrace the female, (the male is about twice her size) and then the female will carry her partner to the site of her choosing for depositing her eggs. As you will see from my photos, the loafer males are so huge that they even apparel to be asleep while the poor female lugs him around doing all the work! Well then, now that we are clear on the basic of reproduction of this species we ask: what set apart this morning from all the others? The serious response: thousands of frogs reproducing at once in the same place at the same time, in the day. What many will deem “and explosive reproductive session” that occurred in the middle of the day! Imagine how much it must have rained for these creatures, who primarily reproduce at night, would willingly decide to reproduce during the plain light of the day! A great moment to have to pulls one’s camera and take an image that is worthwhile, right? The previous night it had rained so much that the ambient condition for these frogs was so perfect that the previous nights frog orgy lasted well into the morning of the following day. We biologist arrived, as my mother would have said, with milk and bread, just in time to take a few photos of the previous nights partners. I leave you with photos and history. Now you know: next time that you are in the low parts of the Caribbean or the Pacific and you should have rainfall to rival that of the deluge, take a camera, and looks for a swamp in which to enjoy the great reproductive explosion of amphibians (if you’re lucky).


“If you would like to see more of Andre’s photos please click on the following link to check out his personal blog about his wondrous adventures with the Agalychnis spurelli .”

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