Monday, October 5, 2015

On trout and forest

In the early Cuerici sun, the scales of the three trout shone; purple contrasted with green as trout laid tranquilly on grass. The trout had stopped flapping and looking at them I felt solemn and reverent. I would be fulfilling the pact with nature that all meat-eaters are supposed to fulfill: to take a life to sustain his own.  For too long I had avoided this obligation, enjoying the bountiful nutrients of meat without facing the burden of killing. Now a sense of purpose coursed through me as I vowed to end the trout’s life quickly, and promised to not waste its sacrifice. I will not take this sacrifice for granted.
At the Cuerici Biological Station, part owner/manager Don Carlos and his family live simply. Trout farming and his position as manager of the station form the majority of his income. Don Carlos and his ownership group keep the majority of the forest around the station intact as part of their conservation and education effort.  When they bought the land twenty-four years ago as a group of nature-loving friends, they had a vision: to spread their appreciation for the Costa Rican forest.  The station hosts student groups throughout the year, and Don Carlos takes every group on hikes through the montane oak forest of Cuerici. He would point out the transition in flora as the elevation increases, explain the medicinal properties of different plants, and tell of the picky quetzals that only eat fruits in perfect shape. Then he might point out the centuries-old oak trees that are irresistible temptations to every logger because of their minimal branching and great height.

In forest Don Carlos and his family see not resources to be exploited or jungle blocking city and agriculture expansion; they see a fragile cradle of biodiversity to be lived in harmony with. They voluntarily sacrificed the chance at an affluent lifestyle for a simple one to conserve the forest. Yet, not everyone could be (and definitely should not be) expected to make the same kind of sacrifice and that is one of the issues facing Costa Rica today.  Should individual landowners be expected to assist in conservation or should the government do it all?  Should the government be allowed to relocate citizens from their home in the name of conservation?  And how involved should locals be in conservation? These are some of the questions and there are no easy answers.

For Don Carlos, one of the answers is trout farming.  The trout provide a source of income and is also a hobby.  After twenty-some years of tinkering, Don Carlos has perfected his trout farming technique. Thousands of trout are raised organically, generation after generation, allowing Don Carlos to sell adult fish as food and young fish as progeny for other farms. 


The trout was pan fried for lunch. After savoring every bite I can safely say it was the best meal I had in Costa Rica. It is a privilege, not a right, to be able to have meat. To me the same can be said of the forest.  The need to treasure the sacrifice of the trout and the need to treasure the forest is the same.  We are not given these resources, it is not a natural-born right that we are forever entitled to.  We do not own the life of the trout nor do we own the forest. It is a privilege; it is a contract and we have to uphold our end of the bargain.

Saturday, October 3, 2015

Color my world

It’s one thing to read about something in from a textbook, and another to see it unfold before your very eyes. Indeed, the past month spent in Costa Rica can be summarized as a first-hand journey of exploring the encyclopedia of life.
Step into the forest and perhaps what strikes you immediately is a tapestry of various hues and shades of green. Yet, if one takes a closer look, a wide spectrum of different colors begins to emerge beyond the sea of green – a dot of red here, a line of yellow there, a flash of blue in the distance. Nature has an interesting way of playing with colors, especially so in the rain forest. For some organisms, it is part of a fashion show, attracting attention from potential mates, pollinators and dispersers. For others, it becomes part of their camouflage, allowing them to blend seamlessly with the background, evading the watchful eyes of predators. Yet for a group of somewhat eccentric creatures, evolution has enabled them to use coloration as a warning signal, a beacon that says – don’t try to mess with me or you’ll be in for a bad time.
            A classic example of warning coloration or aposematism is the Poison Dart Frog. Fortunately for us, two species of dart frogs call La Selva home – the Strawberry Poison Dart Frog (Oophaga pumilio), and the Green and Black Poison Dart Frog (Denbrobates auratus). Intrigued by these beautiful amphibians, two of my course mates (Jeanne & Mackenzie) and I were interested to know how aposematic coloration, and to a larger extent novel phenotypes and coloration, may affect predation on and consequently establishment of an organism in a community. With a constraint on time, we decided to work with a simpler model that employed similar anti-predatory techniques and settled on Lepidopteran larvae. Following predation experiment protocols in scientific literature, we manufactured 600 model caterpillars of three different designs, stepped out of the comforts of our air-conditioned computer room into the warm and humid forest, and exposed them to the predators of La Selva. 24 hours later, we collected the models and analyzed impressions left on them to identify the predators. After hours of looking for bite marks, and recording predation rates of the different designs, we were surprised to find similar predation rates across the different designs, contrary to our hypothesis. This confounded us until a discussion with faculty highlighted that we did not account for how different the designs were in terms of conspicuousness. After making this correction, we finally saw evidences of predators avoiding novel and aposematic prey – a biological phenomenon learned in books transpiring right before our very eyes.  

Field experience under the belt, interesting results collected, and watching one of nature’s secrets unfold, I can’t think of a better way to wrap up our time in La Selva. I am definitely looking forward to the remainder of the semester that lies ahead.
Donovan Loh
Duke University