A Piece of Home in Paradise

By Michael R. Cornish

            Travel, travel we did. But before we did, we packed. We packed for a place I did not know, a place I could not imagine.  All we knew was that far up in the mountains near the continental divide, a man by the name Don Carlos ran a farm of some sort that was surrounded by preserve of dense, cool rainforest.  We were still in Palo Verde, a National Park in the province of Guanacaste, whose’ hot, humid air made it hard to image cool mountains.  Once packed, we loaded into the tube-shaped “coaster” bus and began our journey towards the province of San Jose.  Four hours pass; freshly-tilled rice fields with wood storks and rare jabirus looking for small fish and insects in muddy puddles, the pacific coastline of Guanacaste with large Dole container ships listing in the swell, and finally, the mountains of San Jose.  After a quick stop at the OTS headquarters, we departed for the preserve.  As we drove two more hours, the road took us up into the clouds. The mountains were shrouded in mist, concealing their immense height.  Unlike intrepid explorers, we dosed off, not knowing where we were nor where we were going.

            We awoke and got out of the coaster to a misty rain that made the cool air feel even colder.  The preserve was on a road to tight for the bus, so we walked the few kilometers down the its steep grade.  Eventually, we arrived; a building made of rough-cut logs fit together in a shingle-like fashion and covered in a steel corrugated roof had a sign labeled “Estación Biológica Cuericí”. We had arrived.

            The station, as expected, was surrounded by luscious forest with epiphytic plants draping the branches of the moss-covered leaves. A hike even had us see one of the only species of bird I had heard of before coming here, the resplendent quetzal.  All of these sights were astoundingly unfamiliar. This, however, was contrasted by what I least expected yet very familiar.

            Hailing from the green mountains of Vermont, cool, clear streams encased by coniferous trees are a familiar sight. And in the clearness of these streams, swam small trout that I enjoyed catching.  As we were given a tour of Cuericí by Don Carlos Solano and his daughter Ana (who now runs the farming aspect of the property), a series of pools of different sizes came into view that bubbled with the motion of hundreds of trout.  With the surroundings being so unfamiliar, the silhouettes of the fish and their conspicuous swimming patterns reminded me of home. This, however, proved to not only be a reminder of home, but also an amazing system that Don Carlos built.

            In a series of long, narrow pools, Don Carlos keeps the smaller fish that are still growing. With each successive pool, the size of the fish gets bigger. When nearing maturity, they are placed in a larger pond that is below those pictured.  This, however, is where it gets interesting; not only does Don Carlos raise trout but he also breeds them. When the fish would normally begin their migration up into smaller streams, Don Carlos opens up a small channel up which the breeding adults swim, thinking that it is a stream.  Eggs and sperm are then taken from choice fish and the fertilized eggs are placed into irrigated trays to develop and hatch.  The newborn fish (fry) go through a series of tanks as they grow, eventually to be placed into these pictured pools.  

            Once the fish mature and are ready for harvest, they are caught and put into pools that have especially clean water. This, Don Carlos says, improves the taste of the fish if they are kept there for a week or so before harvesting them.  The result of his efforts are large, beautiful, rainbow trout or in Spanish, “trucha”, like the one pictured below.

            Being able to see the system was a truly unique and amazing experience.  While our main interests in this course lie in natural systems, it was quite fascinating to observe one created and manipulated by the human hand in such a way.

Field Observations: A Return to Childhood

By Rowan Etzel

I've always loved spending time outside. As a budding scientist, I used to spend all my free time outdoors, sketching animals, mimicking bird calls, collecting insects, or simply watching the clouds change in the sky above me. In recent years, however, I've grown more distant from that part of myself, more caught up in the daily business of schoolwork and my various commitments and less connected to the world around me. I miss those days of immersion in the natural world, and one of my reasons for coming on this course was to regain that sense of immediacy and purpose.

On our first night at Palo Verde, I decided to take a walk down the road. Alone in the darkness, with just my feeble flashlight for guidance, I felt the forest come alive around me. Frogs were calling, bats swooping to catch the insects disturbed by my steps. The forest was teeming with life, and I felt present in a way that I hadn’t in a long while. At home and at college I love going on walks alone in the woods on a regular basis, but I’m so used to the woods of the northeast that they’ve lost most of their novelty to me, instead seeming more like a second home. There was such a distinct pleasure in walking outside to find a whole new ecosystem right there, and to be able to go access it whenever as part of the work for this course. I love writing field notebook entries, both for the simple organizational pleasure of ordering my thoughts as well as a physical chronicle of the creatures I see. Every day I’ve made it my goal to spend some time alone outside, taking some time to focus in on the butterflies, the ants, the birds, or just keeping my eyes open for whatever comes along.

The sheer number of the animals I see here daily is astounding. There’s just so much going on in any tiny area of ground. A couple of days ago I was sitting by the side of the road, watching and taking notes. In just a few minutes’ time I saw so many things that it was hard to keep up in writing them down. Several dung beetles rolled their cargo by my feet, slowly zig-zagging their way across the road. A hummingbird whirred by to dip its long beak into a hibiscus flower a few feet from my face, its colors darkly shimmering in the sun. Two different types of wasp were digging into the mud of a drying puddle, and several types of butterflies floated in and our of the underbrush. A white-speckle-winged bird and I spent ten minutes watching each other, with the bird alternating between rustling around in the underbrush and jumping out to sit in the road and cock its head at me inquisitively, as if I were the one being observed.

In conducting field observations, I feel an unexpected return to my childhood, when I used to spend hours watching the world around me. I've grown to realize that my study of science and research is improved by cultivating that childlike sense of looking at the world, of observation and inference without judgement. Such an unfiltered outlook allows me to collect information more objectively, and removes some of the inhibitions I've gained over the years. What drew me to science in the first place was the joy of discovering the world we live in, and there’s a lot to unearth here in Costa Rica. 

Embracing Silence

By Anna Lee

The first time I stepped out on to the boardwalk overlooking the wetlands of Palo Verde National Park in Guanacaste, Costa Rica, I was met with silence. Not from the dozens of water birds strutting on the foliage or calling from the trees near shore, but instead, from my classmates. For once, this crew of extroverts had nothing to say. We were all so taken aback by the sudden appearance of acres of water and rings of mountains around us that we forgot to continue our conversation. For once, we weren’t asking each other questions or joking with people we had met only 72 hours before. We just listened to the world around. The overpowering natural beauty equaled us out as people. Nothing anyone said could have been as exciting as the stories unfolding all around. No one’s life was more colorful than the red, green, and purple dragonflies skimming the water or carefree as the spiny tailed iguana blocking the entire pathway. I think in that moment we all realized that no matter what brought us to Costa Rica, we  all arrived with the same purpose: to use our skills and passion to better understand and preserve the breathtaking landscape around us.

            While that silent moment didn’t last, I keep it as a reminder I’ll carry with me for the next 13 weeks as our program unfolds. Nature will not let itself be silenced by loud voices or careless conversation. Nature is not passive. It demands attention with grace. And when it is ignored, it has the potential to become violent. The day after my first encounter with silence in the wetlands, a classmate and I were walking along the shoreline completing an assignment. Suddenly we heard a splash, a snap, and alarm cries rise from the water. In the midst of our superficial discussion about our home universities, a crocodile had come up to eat one of the Northern Jacana birds that call the national park home. In seven seconds and without words, nature had told us a story of life and death more exciting than anything we could tell ourselves. Once again, nature reminded us of its power and at the same time, its fragility. When you fully experience the sights and sounds that exist in our world, there is no pressure to impress anyone. You never have to fight for a moment to speak, or make up a story to impress a classmate. It is time we all get used to never being the center of attention and let our world have the spotlight it deserves. While we all want our voices to be heard, sometimes you just have to embrace the silence and let Mother Nature speak for herself.  

Starting off at Palo Verde

By Finote Gijsman

It’s been two weeks since the start of the OTS Tropical Biology on a Changing Planet program in Costa Rica, and I can say that it’s already been quite a journey. The first field site we went to was the Palo Verde National Park in the Tempisque Conservation Area. Palo Verde is home to the endangered tropical dry forest ecosystem and a large marsh ecosystem that attracts many species of birds year-round.

On our first few days in Palo Verde, we familiarized ourselves with the park and its different ecosystems. Prior to the program, I didn’t really know much about the tropical dry forest, so it was interesting to learn about and experience it first-hand during our walks. Considering that this ecosystem is highly threatened due to habitat conversion by humans, I feel very privileged to have the opportunity to study one of the last significant fragments of tropical dry forests in Central America. This ecosystem is considered a “tropical dry forest”, because precipitation is highly seasonal and more limited relative to other wetter areas in the tropics. With long dry seasons that last several months, many plants shed their leaves to conserve water. We, however, were there in the middle of the wet season, so we were lucky to see many birds using the marsh. These included the green heron, boat-billed heron, and black-bellied whistling duck.

Later in the week, we hiked up to a lookout point in the park for the sunset. Along the way, we were greeted by a pair of white-headed capuchin monkeys. The two were resting in the canopy and did not seem too happy to see us, as they flared their teeth at us. Once we made it to the top of the hill, we were able to briefly watch the sunset over the wetlands, after which we rushed back to the station to avoid the evening showers.

In the evening, we got a talk by one of the researchers at the station, Davinia Beneyto, who is studying the crocodile population of the Tempisque River basin. The male: female sex ratio of American crocodiles in this region appears to be very male biased, with approximately 3.4 males for every female. The cause for this skewed sex ratio has not yet been determined, but Davinia and her colleagues suspect that the use of a hormone, 17α-methyltestosterone (MT), in nearby tilapia farms may be the reason. Tilapia farms around the national park are known to raise fish using food that is laced with the hormone to convert females into larger, more profitable males. With these crocodiles being apex predators, it may be that fish from the nearby tilapia farms are being eaten by the crocodiles at the Palo Verde National Park and in turn affecting the crocodiles’ endocrine system. Such findings may have large implications for the vulnerable American crocodile population at the Palo Verde National Park and possibly even Costa Rica as a whole. The biased sex ratio may be even more startling, because climate change is predicted to affect the crocodile sex ratio in the opposite direction, by favoring females. Crocodile nests are known to be temperature sensitive, with the sex of the baby crocodiles being determined by the temperature of their nests and not genetically. Hormones may therefore be driving a major shift away from what is naturally predicted by regional warming at Palo Verde.

I personally found this crocodile research program fascinating. I had never really heard about temperature dependent sex determination, but to learn that what was being observed was the opposite of what was expected with climate change, was even more appealing to me. Being a plant biology major, I have mainly been exposed to the way research works within that field of study, so I came into this program hoping that I would get to explore other fields in biology and learn about how the research methods within them. While the program has been field-work intensive, I have really enjoyed getting to branch out and learn about other systems. It has been very refreshing to get out of the organized lecture/classroom setting and be able to interact closely with professors specializing in many different subjects.

Catching Túngara Frogs in Palo Verde National Park

By Genevieve Valladao

Up until a week ago, I had never touched a frog. I prefer big predators – jaguars, sharks, crocodiles – organisms that humans aren't able to just grab and play with. So, when I found out that one of the first research projects I was going to be working on in Costa Rica involved trapping frogs I was a little nervous. The project was designed to test for effects of Belostomatid (Lethocerus annulipes) predators on site selection of prey Túngara frogs (Engystomops pustulosus). It involved capturing Túngara frogs at ten different sites, marking each of them individually, applying a treatment of Belostomatid chemical cues to half of the sites the next day, and then checking the sites the next night to see how the dispersal patterns of the frogs were impacted. Túngara frogs mate in small pools of water, so the study sites for our experiment were large puddles along the dirt road outside of the Palo Verde Research Station. Our program was split into two groups, each going out to catch frogs a different night and I was assigned to the second group.  

Photograph courtesy of Ray Hopkins

            Group one caught 48 frogs individual frogs the first night of the project, but also came back covered in mud and mosquito bites. Their complaints made me even less excited to go out the next night. But when night rolled around the following day, I put on my rain gear, rubber boots, headlamp, and face mosquito net, and headed out. I was unsure of what to expect. “Okay,” Brian said about 100 meters from the station, as we came up on our first puddle and he handed each of us a small plastic bag. “This is our first site.  Surround the puddle, grab as many frogs as you can, and drop them in your bag.”  Before I could question how I was even supposed to catch a frog, Brian and the rest of the students were along the edges of the puddle, shining their lights in the water.  Two frogs were caught at our first site.  As Brian tagged and documented one of the frogs, I watched the way he held it by the back leg.  “Can I hold it?” I asked - I did not want the first time I had to hold a frog to be one that I was trying to catch for our project.  I was not at all confident that I would be able to hold it without either hurting it or letting it go away.  Brian handed the small frog off to me and I got to get a good look at it - it was a male so its throat was stretched out from calling to females, which was amazing.

Photograph courtesy of Milena Cambronero

            We didn’t catch many frogs the rest of the night, possibly due to the puddles being small from a lack of rainfall.  And I stayed in the back of the group when we would approach a site, so the few frogs that we caught had already been captured by the time I came up on the site.  Sometimes, after a frog had been tagged and released, I would try to recapture it for practice.  Sometimes I would be able to catch it, and other times it would slip through my hands. I was relieved coming up on the last site – I hadn’t been the first to spot any frog so I hadn’t had the pressure of catching one.  But as I ran my headlamp over the puddle, my light illuminated something in the water – a Túngara frog.  I palmed it, just as Brian had instructed, and was able to pass it off to be marked.  I had caught my first frog for our project!

            The day after our experiment was supposed to be finished, it poured rain.  Frogs love rain.  So Brian asked for volunteers to go out one more night and survey all of the sites again.  I had practiced capturing frogs so much the prior night, but only caught one that contributed to our dataset.  So I geared up, this time in a full body bug net, and headed back out.  As soon as we got down to the road we could hear the Túngara frogs calling.  Every site was full of them, we caught 58 frogs for the night and I caught almost a quarter of them.  By the end of the second night, I was completely comfortable handling the frogs and would catch them for fun to try to identify their sex or just to watch them swim away after being released.  I even caught a large toad I saw along the road just to further examine it.  Having to catch frogs during my first week in Costa Rica was a great introduction to my OTS program.  It immediately forced me out of my comfort zone and taught me to not be afraid to try new things. I know that catching frogs is the first of many experiences that will push my comfort zone this semester in Costa Rica, and I can’t wait to see what direction I will be pulled next.

Sustainable Conservation in the Highlands of Costa Rica

By Dennis Bolshakov

Costa Rica often shown as an example of how conservation should work: around 25% of the country’s land is protected, and a wide system of national parks and biological research are hallmarks of recent Costa Rican developments (since the 70s). The reality is that conservation has a convoluted past here, with the government often imposing rules without little to no compensation to landowners, and the park system being too expensive for locals to peruse and enjoy, meaning the budget for the parks is small and the visitors to the parks often being foreigners. In fact, “eco-tourism” is a major part of the Costa Rican economy.

When the system of protecting the nation’s lands first started emerging, many people had trouble understanding why protecting the forests was important. The conservation movement was spear-headed by university graduates who understood the importance of the incredible biodiversity found here, while many rural people did not understand why they suddenly could not chop trees down for firewood after generations of doing so. Even though now the literacy rate is around 98% and most people have access to an excellent education, the rigidity of Costa Rican conservation practices leads many people to dislike it, which could be a future reason for un-protecting the reserves. Recently, I heard a very interesting potential approach to conservation: sustainable use of the reserve’s resources can actually provide both protected land and high-quality resources to future generations living near protected forests.

To elaborate, let me first tell you about Cuericí. As part of the OTS Costa Rica Tropical Biology program, I travel to different ecosystems and biological stations to learn about the flora and fauna in the field. Our second station is located in the pre-Montane wet forest near the Cerro de la Muerte mountains in the Cartago Province. When most people think about the tropics, they imagine heat and mosquitos, but this place has neither. At night temperature falls below zero, and during the day I need to wear 3 layers to feel warm. It is an absolutely beautiful place, and I have never felt such a connection to the land as I do here.

The Cuericí biological station is run by Don Carlos Solano, a pioneer of conservation in the area. However, it was never easy to conserve the area. Most of the secondary forest on his grandfather’s land had been converted to pasture land and the primary forest above it was threatened. When he started conserving the land, government help was minimal (around $400 dollars per hectare). To sustain himself and his family he established a trout farm and started bringing in eco-tourists and researchers (like OTS). He planted a forest of alder to restore the top layer and allow the understory to flourish, and native species to rejuvenate. Such active conservation is rare but not unprecedented: to preserve the tropical dry forest in the Guanacaste province, teak trees have been planted, then removed after the native plants had a chance to recolonize.

Sunset over Cuericí. The mountain I took this from was allowed to overgrow with blackberries, which are harvested by the station and used to make juice for the tourists. This field, in addition to the trout farm helps Don Carlos fund his conservation efforts in the nearby mountains.

Don Carlos’ motivation for conservation was so his grandkids could enjoy the forest in the same way he did. However, with current laws, it is not even allowed to use a fallen oak tree. Don Carlos believes that if regulated use were permitted, conservation would not only be more palatable to rural citizens, but also more profitable in the long run. And I agree. I think that before using an ecosystem, there needs to be extensive research about the system to understand its limits, and that use should never even approach these limits. But some foraging and use should be permitted as long as it is well-regulated. That is how it was before widespread deforestation through agriculture, and that is how it should be if we want financially self-sustaining conservation.

An interesting example where such conservation is being done is the use of cattle at the Palo Verde National Park tropical dry forest to eliminate invasive species. Before it was made a national park, the area was mostly pasture land for cattle, and the dry forest was extremely fragmented and often chopped down to make room for more pasture (at one point, the government even subsidized deforestation!). After it became a protected land, the forest started recovering, but two species started choking out others in their respective environments: an African species of grass that is extremely resilient towards fire outcompeted native grasses, and cattails took over the adjacent wetland. After many failed attempts and much consternation, a controversial strategy was implemented: local ranchers were permitted to let their cattle roam on certain day in certain areas, and because the two species were so dominant, they were the primary food of the cows. Now, the African grass is mostly defeated, but the cattails remain a problem. Another way the researchers fight the cattail is using special tractors to mull it into the water in such a way it cannot regrow. I think that using the cattle is an excellent strategy because it is a win-win-win situation for the locals, the researchers, and ultimately the protected area. In addition, the fees the ranchers pay to use the land helps fund conservation. And I think that similar, regulated use of public protected areas should be implemented everywhere.

The Wetlands at Palo Verde National Park: observe how at the right, near the biological station the wetland is more green and open, while farther to the east (left) cattails (the brown patches) choke the landscape all the way to the horizon.

Theory and Practice

By Mikayla Kifer

Science is an amazing, beautiful mix of ideas on the page and observations in real life. People make their livings by studying the relationship between the two, and the quest to understand truth is realized by comparing what we see and what we think we know. As young students, we learn all the “laws” of the world. But as we start to experiment and read journal articles, we discover that the world isn’t as fully understood and stable as we thought. This is, or should be, the greatest joy of science—we should be filled with an insatiable need to understand the world around us and uncover truths that are hidden.

            The relationship between theory and practice has become abundantly clear to me this semester. Part of the reason I wanted to study tropical biology in Costa Rica was because I felt that I had been learning a lot of theory in college, but not the nitty-gritty details that reveal how it all fits together. I had a strong desire to be in the field and learn the specifics of the theories that didn’t make complete sense without their fundamental real-life components.

            Since I’ve been here, I’ve been learning that it’s all much more messy than that. Relationships that make sense according to theories, don’t always make sense in practice. It’s often not clear why animals behave the way they do. Studying plant taxonomy has taught me that there are always exceptions to the rule. Science is supposed to explain the world around us, but it needs a whole lot of tweaking along the way. Contrary to what it might seem, this experience hasn’t made me doubt the validity of scientific evidence, though I retain a healthy amount of skepticism. Rather, it’s given me more faith in the scientific process by demonstrating the immense complexity of the world around us and the care that goes into understanding it.

            Science is rarely about finding evidence in order to posit huge theories; it seems to me that it’s more about finding small truths, being certain about them, and using them to support big ideas. This small process seems much more exciting to me. It’s great that research has implications for big concepts and applied knowledge, but well-done studies are exciting because they are truth within the small scope that they're focusing on. Everyone has a different reason for doing scientific research; this one is mine and I think it gets at the fundamental reason of why we do science in the first place.

            Because the relationship between theory and practice is so complex, it's a real challenge to represent scientific findings and their significance accurately. Communicating what science is is one of the most difficult tasks of a scientist, but also the most essential. Understanding truth is not useful if you can’t share it. Unfortunately, there seems to be a fundamental disconnect between scientific truth and the public’s understanding of it. I believe this stems from nonscientists misunderstanding what science can do and what it can't do. Scientific research can indicate that there is a highly likelihood that anthropogenic climate change is happening. Scientific research cannot predict with 100% accuracy the effects of these changes and should not be discredited when it cannot do so.

            I’ve thought about this a lot and I don’t have a solution, but I think it would be a good start to begin to integrate scientific theory into everyday life. The scientific method is derived from basic logic (induction and deduction) and thus it is not overly complicated to understand. Asking nonscientists to have a basic understanding of the scientific method would help them have a greater understanding of the limits of scientific evidence. If this were the case, we would be better able to focus on the whole point of science—finding truth—and that truth would be more readily communicated and therefore more appreciated.

            It is my hope that one day everyone will be able to appreciate the complexity of scientific understanding, especially as it relates to small truths that fit into our big theories in interesting and unexpected ways. For now, I’m excited to continue exploring this relationship myself by learning with both my hands and my mind.