Night Hike in the Rainforest

Notice: No flash photos at night...

     This hammock feels good; this beer, even better. The air and the beer are warm, but that's something I've become quite accustomed to. Upon thinking about it, I might actually prefer the beer to be warm, at least the flavor of a familiar Imperial. Back in the United States with a Sierra Nevada, that's a different story. Anyways, aside from that brief mental tangent, it's not beer or hammocks that are on my mind. At this moment it is the multitude of frog calls that are serenading me from the nearby forest and stream- one of which, I'm pretty sure is a new species of transparent glass frog, is calling from somewhere quite close. Dik Dik Dik... he repeats. There is a tree, no higher than five or six meters tall, growing over the stream and crowning right next to a bridge...he must be there. That's my queue. The last ounce of warm beer disappears down my throat, my body rolls to the right, and my bare feet touch the gravel covered floor. Within ten minutes I have eaten an avocado, three tortillas with black bean spread, changed into my field clothes, and am once again in my knee-high green rubber boots. The sun has not yet completely set, but it is close. I am not used to so many different species of frogs calling so early. There are a few I can recognize, and a few that are a generic mystery "Quawk!" which are begging to be found.

     I head left from the cabina with the idea of hiking a short trail that borders a "lagoon", and from there working my way into a shallow, less than 10 meter wide river.The idea is that the lagoon trail should afford me the chance to find the calling tree frogs, and the river- the glass frogs.

Northern Cat-eyed Snake
Leptodeira septentrionalis

     On my way to the nearby trailhead I cross over a bridge. Just on the other side, to my right, there is a cream colored scaly belly making its way up through some vegetation. I grab the snake and immediately recognize it as a cat-eyed snake. A moment later, after a look at the snake's neck, I identify the species as a Northern Cat-eyed snake (Leptodeira septentrionalis). The snake is placed in a plastic bag which is tied closed, and then hung from my belt, as so many of you have seen me do before. Soon afterwards the trailhead appears on the right. I hop down on the trail and make my way around the perimeter of the lagoon. Before reaching the end of this trail, all of the usual suspects make an appearance. I hate to use the word usual (almost as much as I hate the word rare) because regardless of how commonly seen these species are, they are all nothing short of SPECTACULAR! Hourglass tree frogs (Dendropsophus ebraccata), Masked tree frogs (Smilisca phaeota), huge adult male basilisks (Basiliscus basilicus) sleeping overhead on cartoonishly thin branches, a juvenile Northern Cat-eyed snake (Leptodeira septentrionalis) which still has its bright white nuchal collar, a Spectacled caiman (Caiman crocodilus) its eyes reflecting back a glowing orange, plus a few more old friends.

A young Northern Cat-eyed Snake
(Leptodeira septentrionalis) showing
off a bright white nuchal collar

Upon first glance this
Dipsas was mistaken
for a Cloudy Snail-eater
Sibon nebulatus

     As this trail comes to an end, up and to my right is a black and silver snake called Sibon nebula-NO! I grab the snake, it's not even a Sibon! It belongs to a genus of snake that I have never had the privilege of seeing before. A Dipsas; what fortune! The exact species is Dipsas tenuissima. Like the members of the closely related Sibon snakes, Dipsas are specialized eaters of snails and slugs. They have modified teeth on their jaw that are used to extract the snails from their shells. Again I use the word- SPECTACULAR! The genera of Dipsas and Sibon are collectively referred to as the goo snakes, due to the contents of their stomachs (gooey snails, slugs, and frog eggs) when you try to examine what they've eaten. Finding a new species of reptile in Costa Rica is becoming harder and harder, much more so a new species of snake. He is bagged and hung from my belt as well, to be released the following day, but not before a photo shoot.

Upon closer inspection, the head of this Dipsas tenuissima
looks quite different than that of Sibon nebulatus

     Well, enough with the casual searching and the lucky finds. It's time to get down to business- the business of glass frogs. At once I jump down into the river, for the moment with the water level still below the tops of my boots. I turn off my lights to minimize the distractions, and shut my eyes- as if this matters in the pitch blackness. Yes, they are here, "all around". By all "around" I am referring to the three-dimensional world of a climbing rainforest organism. Sure he is calling from less than two meters to my left, but it also happens to be somewhere between one and thirty meters up in a tree...

    An interesting fact related to the frustration of hunting for glass frogs: Human ears are placed more or less symmetrically on our heads, whereas an owl's ear openings are offset- one being higher than the other. This affords them, while limiting us, the ability to determine the vertical location of a sound. As humans we are really only efficient at determining a sound's origin on a horizontal plane.

If you want a true account of what it's like to search for glass frogs in the rainforest READ THIS!
http://amphibios.org/blog/glass-frogs/
While you're at it, read every entry on this page. It was created by my very good friend Tim Paine (T-Paine!). He is an accomplished photographer, a talented biologist, teacher/mentor to many, friend and inspiration. And that's not even his day job...

Searching around the river yielded eggs
 of the glass frog Teratohyla pulverata

     By this time, a light rain had started, though it's more snow flurry-like than rain. The water has since entered my boots- owing to an encounter with a medium sized Spectacled Caiman, Caiman crocodilus (the caimans in these parts are comparable to a slightly smaller alligator). In my spotlight, reflecting back at me was a pair of bright, and what appeared to be frog eyes, coming from the river bank. After a few quick steps, I was upon the 3.5 foot "frog", with a snout full of pointy teeth. As is typical, the caiman made a lunge to escape into deeper water in the opposite direction. As is also typical, I followed. Now I'm up to my waist in the river, holding this crocodilian, and there's no one around to share the moment with.

     A few minutes later I found myself balancing on the top of  a fallen tree that was across the river, holding a stick, stretching up as far as I could, trying to get a better look at some overhead leaves from which a glass frog was calling. Then it hit me. I sat down on the log, turned off my light again, and I thought:


"...you are walking around in a deep rainforest, somewhere far from home, you are soaked, wading through a stream in the rain, it is dark all around you with mysterious sounds making your mind wonder “what is out there”, and you realize you are doing all of this to look for little green frogs with clear bellies. What the hell am I doing? You think – this is weird. “I’m weird”. Life is good!" - Tim Paine

Teratohyla pulverata gets it's name from the fine
white flecking on the frog's back.
"Pulver" comes from the Latin word for dust.
Many other languages also share some form of
the word "pulver" meaning powder or dust.

PURA VIDA

-Don 

A weekend back up at Rara Avis

*Disclaimer- The narration in this one is pretty weak, so I'm going to load you up with frog pictures to make up for it. Enjoy :-)

Spined Glass Frog, Teratohyla spinosa
Central America's smallest species of glass frog 

    Friday morning at 7:30am Rachel and I board a bus that is bound for Puerto Viejo de Sarapiqui. Our stop is the little rural town of Las Horquetas de Sarapiqui which lies about twenty kilometers to the south. The bus breaks down less than five minutes after we leave the station. Fortunately, still being so close, we are shuffled onto a new bus within ten minutes, and we continue on our way. One of my favorite drives through the country is the portion of this route that takes us through Braulio Carrillo National Park. The road cuts through the rainforest covered mountains, with one side usually a steep drop off, and the view out of the other side a sheer wall of rainforest that quite often has waterfalls appearing out of nowhere, and then disappearing down under the highway. It really is a beautiful (if not sometimes unnerving) drive. We made our normal stop at the junction of highway 4 and highway 32, at the rest stop across from Rancho Robertos, at which point we grabbed a breakfast of gallo pinto, plantains, and maybe the best chicken empenada that I've ever had. Within 30 minutes after our breakfast we pulled the cord and got off the bus one stop too far, which only meant that we had to walk down the highway for about five minutes to reach the street that the Rara Avis "office" is located on. Agro Sarapiqui (hardware store), Aguila Oro (liquor store), Tica Linda (favorite restaurant owned by my "Tico family"). Already the emotions are welling up. Not in a bad way, or even a sad way, but something extra is there.

     Rach and I reached the office and it was just like old times. Berny is there, Danilo arrives shortly afterwards, and Diego is waiting for us with the horses... We have our greetings and brief small talk with the guys, change into our boots (Oh how I missed wearing my boots!) and without wasting another minute of our Rara Avis weekend, we mount up on the horses and start our 15km (10 miles) trek through pastures, secondary forest, and eventually, rainforest. In all of my time spent up there I have never taken a horse. I always see people when they arrive at El Plastico by horse, and do they ever look worn. But in reality it was actually pretty fun! We had to wear helmets, which was nice for me, as my bald head did not get sunburned, but Rachel however, complained that the helmet was too small or her head and hair was too big..something like that :-) Honestly though, she looked pretty cute!

     We made it to El Plastico in pretty good time, a little faster than the tractor would of done it, and we manged to stay dry. Ya, like there was any chance of that lasting. Both Juan and Miriam were down the mountain, so it was just us, the dogs, and Ghandi "my" cat up there. After a short rest, we started our hike, all prepared for the inevitable rain, which could later be described as spiteful and unforgiving...or just as a normal afternoon up at Rara Avis :-) We arrived late for lunch, my M.O., and soaked through and through. But we there- back at Rara Avis.

Brilliant Forest Frog, Lithobates warszewitschii.
This common frog of the forest floor has red
thighs with bright yellow spots.

*On the way up from Plastico I got to play my favorite rainforest game with Rachel, many of you have played it with me before- Spot the venomous snake you just walked right passed. We found an eyelash viper (Bothriechis schlegelii) on the side of the Atajo Trail. It was one of four for the weekend.

     We had some lunch, drank some amazing and well deserved coffee, and studied Adilio's toothy grin. Aside from a few physical changes- new signs, the removal of the hummingbird feeders to up the lodge's CST rating (ok, that will be the only political reference for the rest of the blog), Rara Avis was still Rara Avis. We passed the rest of the rainy afternoon in the hotel and around the clearing. There was a gap group up there and an older Italian couple staying as well. The Italians were very interested in frogs. Nelson introduced us, and from then on we spent meal times and photo times with them. After dinner we geared up and went out on a night hike. I had considered taking the group out with us, but in the end I decided to enjoy some personal time with the forest. We were targeting glass frogs and rufous-eyed stream frogs (Duellmanohyla rufioculis) that night. We were successful, only failing to find one of the glass frog species. This was also the first time I got to use my new headlamp- Fenix HP-11. After the caminata noctura, we returned to the dining room for a few minutes before heading to bed.

Photo by: Rachel Clarkin-Breslin

     After breakfast we lazily got back into our field clothes and started on a short, but extremely slow-paced hike. We made our way to the mirador, where there was another eyelash viper; a brown one that I've known for more than a year. I always make references to animals being old friends, this one surely was. We sat there for a while talking about the forest, mainly me rambling on with stories from my time spent up there. We decided to continue down the Catarata Trail (Waterfall Trail) for a little longer. We stopped by the Vantanea and the old tree house. If there was a place where I was going to get  emotional, this was it. The rest of the hike was nice, slowly making our way down to the first drainage basin of the trail and then back again. Lunch was typical- good food and the onset of the day's rain. After lunch we invited the Italians up to shoot the catches from last night. A lot of photographing and a little more hiking around the clearing pretty much sums up the rest of the afternoon. After dinner we decided on another night hike, but unfortunately things were just against us for that night. I changed the batteries on my brand new headlamp, and it stopped working. Just like that. I got to use it for only one night. At the same time, Rachel started not feeling too well, so we decided to spend that night inside.

Eggs of the Spined Glass Frog,
Teratohyla spinosa, are laid on
the undersides of leaves, overhanging
small fast-flowing streams. Upon
hatching, the minute tadpoles slide
 off the leaf and into the stream below!

Spined Glass Frog, Teratohyla spinosa

    


                                





    





*In this blog I though it would be nice, or maybe interesting, to post some behind-the-scenes shots of the photography. Many of you reading this have spent time with me in the forest, and have already seen the process, but a few of you, who always say such nice things about my photos- Tony, Reebes- might like to see how it's done. I'll load up the end of the post with all the pictures.

     We were scheduled to leave after breakfast the next morning, but Rachel had gotten sick during the night, so we decided that a horse ride down the mountain might not be the best thing for today. We ended up staying another night, and spent the rest of that day just hanging out on the balcony of the hotel, and taking short walks around the clearing. While on a short hike back down the Catarata trail ( I lost something on the trail earlier) I did manage to find an oddly colored specimen of Drymobius melanotropis. It was grayish-blue on the back, and bright orange/red on it's venter. Normally these snakes are a beautiful green color. Twan has also found a specimen of this snake up at Rara Avis that was not green, but a darker, red/brown color.

Lighting issues ruined what could
have been a great shot.

*At this point my photography took a turn for the worse as I became extremely frustrated with the lighting while photographing a Yellow-spotted Tropical Night lizard (Lepidophyma flavimaculatum), so I resigned to just taking voucher shots of the snake. I believe Rachel got some good photos of the snake though.

Yellow-spotted Tropical Night Lizard
Lepidophyma flavimaculatum

      We ended up leaving on the following day, Monday. It certainly would of been much better if Rachel had not gotten sick, and if my headlamp wouldn't have broken, but we made the best out of it. To be optimistic, it was kind of nice to have a "reason" to stay back at the lodge, take it easy, and drink our body weight in coffee. If not, I know I would have spent the majority of the days out in the forest pushing myself, and not just enjoying being up there once again.

PURA VIDA!

-Don

Golden-groined Rain Frog,
Pristimantis cruentus,
Take a close look at those eyes!

Rufous-eyed Stream frog

Duellmanohyla rufioculis  

This species is restricted to small rocky streams
in mid-elevation premontane rainforests.
While their numbers at Rara Avis appear to be stable,
suitable habitat in the rest of the country is becoming
harder and harder to find.

This frog was placed in a clean drinking
glass in order to show the eggs inside.

This shot required using an off-camera flash that was held by
Rachel. From behind the leaf, she pointed the flash at the frog
and camera. The result was this silhouetted image.

Behind the Scenes:

Here you can see our temporary studio.
I often use empty beer bottles
 to hold branches and leaves in place.
This leads to one of the MANY weird
looks I receive when I first come to a
new station. Tables covered with plastic
bags full of snakes and frogs, alongside
multiple beer bottles and coffee glasses
all with flower stalks and leaves sticking
out of them!
"Us weirdos gotta stick together"- Rachel Clarkin-Breslin

Rachel holding the Drymobius "still".
What you can't hear is my steady stream
of profanity directed towards the camera
and the snake.

The setup for the shot

The glass frog, Teratohyla spinosa, was placed on a thin branch supported horizontally by two water filled drinking glasses. The glasses eliminated any shake that would of been present by hand-holding the branch. The idea was to shoot the frog up close with flash and no immediate background, effectively isolating the subject and causing the the background to appear black. The effect of the black background is called flash falloff, it's a neat trick when you want to isolate your subject, or give the illusion of a photo taken at night- which in this case would be natural, as glass frogs are nocturnal.

Glass frog natural habitat?

The shot

This little guy stayed still on the branch just long enough to snap off a couple of shots with different settings. Notice the difference between the first two photos in regards to how much of the frog is in focus. The second picture shows the subject's legs a little more clearly than the first. This was accomplished by using a higher F-stop than the first photo. As to which is better, it is completely a matter of opinion. I personally like the first shot more, as having the legs out of focus helps to draw attention to the frog's head and eyes.

1st photo- f/16,  1/250

2nd photo- f/32, 1/125

The third photo, of just the frog's eyes, is the result of some major cropping of the original file. Cropping to this extent severely reduces the image's quality, making it unsuitable to print (in my opinion), however for the purpose of blowing up the frog's eyes to take a closer look, it's kinda fun :-)

The frog's cooperation and patience only lasts for so long.
After a few poses for the camera, he made a break for it.