Tropical biology takes students way out into the field
The screams began before sunrise. And once they started, it was impossible to sleep. In the early morning darkness, the sounds suggested awful things: large beasts, such as dragons, trumpeting in anger. Or perhaps the sounds of war and death.
“The way I describe it is that it sounded like something being killed, or animals killing each other, like in a slow, painful way,” said Samantha Ferguson ’14. “It definitely sounded like death.”
The source of the sound: a troop of aptly named howler monkeys that had taken up residence in a stand of trees sheltering the river station dormitory at La Selva Biological Station. “The first time you hear that sound, every hair on your body stands up,” said Professor of Biology Scott Shumway, who has been visiting the tropics for more than 20 years.
“It’s not like your mother waking you up,” said Francine Camacho ’14. “It’s this screeching and then it hits you: ‘Wow, I’m really sleeping in the rainforest.’”
In point of fact, Camacho and 13 other Wheaton students found themselves waking up in a small dormitory at the La Selva Biological Station, set in the lowland rainforest of northern Costa Rica, just beyond the borders of Braulio Carrillo National Park. They had arrived the day before for the second half of a two-week trip that is the culmination of the course, BIO 318: Tropical Field Biology.
The howler monkeys had arrived at the river station sometime during the night and decided to spend the week in the area. “That does not happen all the time, but tropical rainforests are anything but predictable,” said Associate Professor of Biology Shawn McCafferty, who team-teaches the course and serves as co-leader of the trip with Professor Shumway. “We could have gone an entire trip without seeing a single howler monkey. That would have been surprising, but entirely possible. Instead, they got to see an entire troop camped out in front of them. That was really good.”
The students’ weeklong encounter with the monkeys exemplifies the way in which the course, which also includes a week exploring a tropical reef system off the coast of Belize, serves as a primer on the procedures of field biology as well as its pleasures and pains. In addition, students gain an appreciation for tropical ecosystems and the roles of the flora and fauna to be found there.
The idea for the class stretches all the way back to Professor Shumway’s experiences as an undergraduate in biology and environmental studies working with Tufts University Professor Norton Nickerson.
“I first met Dr. Nick at a visiting day when I was still in high school,” he said. “It was March in Boston, and I’m talking to this guy who’s got a killer suntan and I remember thinking, ‘I can learn something from this guy.’”
Throughout his undergraduate studies, Shumway traveled to Hummingbird Cay in the Bahamas each spring break with his mentor, who brought students to the tropics for three decades. Those experiences shaped Shumway’s career plans and they influenced how he thought about teaching. When Shumway joined the Wheaton faculty in 1991, he arrived with the desire to offer a similar experience for his students. It took nearly 10 years before he led his first trip to the tropics, but it was always a goal.
“For me, the field is the most effective learning environment,” he said. “I can show hundreds of slides of mangrove trees and lecture about their role in the ecosystem, but you’ll remember it a lot better if you’re standing ankle-deep in a mangrove swamp as we talk about it.”
Professor McCafferty brings similar affinity for fieldwork. A molecular biologist, he lived in Latin America for more than a decade, spending much of that time as a researcher at the Smithsonian Tropical Research Institute in Panama. His work involved exploring evolution in the tropics, using modern molecular methods, such as DNA sequencing, to understand the relationships among organisms.
“I’ve been to many, many different countries in Latin America, not just visiting but spending time in those countries,” McCafferty said. “I enjoy bringing students down there and introducing the region to them in a way where they are not just tourists. And they are not tourists: we keep them really, really busy.”
The work begins long before the trip, however. Originally, the entirety of the “Tropical Field Biology” course comprised the two weeks spent in Belize and Costa Rica. The professors distributed readings for the students to study in advance, but there was no time for discussion of the material. So first, they added a half dozen meetings to discuss the readings, before deciding to make it a semester-long course, meeting once each week for three hours.
The topics that the course covers range from the geology and climate of the tropics to the structure and function of coral reefs and rainforests and conservation issues in those environments.
In keeping with the goal of helping undergraduates to develop the habits of scientists, the students read—in addition to Professor of Biology John Kricher’s book A Neotropical Companion—a number of journal articles to familiarize themselves with field research methodologies as well as the structure of primary research reports. The students also lead many of the class discussions, with each individual being responsible for at least one research article.
The course’s emphasis on reading primary literature represents a challenge for the students, many of whom have read just a few journal articles and are unfamiliar with the language and structure of these documents. “It was intense. In a lot of classes, you read from a textbook and then look at a few studies from journals and proceedings,” said Ferguson, an environmental science major. “The field biology class was mostly papers with some textbook readings, so it was flip-flopped.”
The study pays off, students said. “It was really incredibly helpful,” said Patricia Kaishian ’13. “The semester really prepared us very well for what we encountered.”
“I think part of the appreciation students have for the rainforest is that when they are there, it’s not a sea of unidentifiable green,” McCafferty said. “When you enter a rainforest, the diversity is mind-boggling. Our students are able to identify species and see the diversity because of the hard work that they put in beforehand on campus.”
In some ways, however, no amount of reading and discussion can really prepare an individual for the first views of the tropics. “The reality of the trip didn’t hit me until I was on the boat and I saw the island coming up into our view,” Naomi Hodges ’13 said. “I remember thinking, ‘Wow, it’s so beautiful.’”
For most students, the trip not only represents their first encounter with the tropics; for some, it is also their first trip abroad, the professors said. Many of the students in the course had learned of the class in their first year at Wheaton, and they had been waiting and hoping to go.
“I knew as a science major it would be very difficult to go abroad, due to the heavy course load and lab requirements,” said Camacho, a biology major who has spent her summers interning, most recently at the Genome Institute at Washington University in St. Louis. “I knew that this would be the best option for me to go abroad because my summers were already booked with research opportunities.”
The journey to Belize had been long. It began in the early morning hours of January 3 at Logan Airport, with a flight to Miami. From there, the class changed planes to Philip S.W. Goldson International Airport in Belize City, and climbed aboard four small planes to the southern town of Dangriga before boarding the boat to the tiny island of South Water Caye, which is located 14 miles off the coast.
Immediately after arriving, the students pulled on their wetsuits for an introductory swim. “I was really excited,” said Hodges, an environmental science major. “I had never put on a wetsuit before, so that was a struggle. But after I got it on I ran down to the beach—we all did.”
The students shuffled into the clear blue water, picking their way past stingrays that hide in the shallows and swimming over beds of turtle grass before encountering the first small outcroppings of the reef, which has formed in patches around the island. “Suddenly, you are on the reef and there are huge masses of coral, fish swimming everywhere. It was beautiful,” Hodges said.
“The colors underwater were spectacular,” said Molly Horan ’13. “The fish were very vibrant colors, all the different colors of the rainbow. And some of the sponges that were attached to the coral reef were almost like neon colors.”
Those first views of the reef both captivated the students and confirmed what they had already learned during their studies on campus: the Belize reef ecosystem—the world’s second-largest barrier reef and a UNESCO World Heritage site—is in sharp decline due to changing environmental conditions linked to global warming. While areas of the reef continue to be vital, the size of the ecosystem has dwindled, and in some spots, students saw more sand and dead coral than vibrant, healthy reef.
“It’s one of the places with the highest biodiversity in the world, so it’s really sad to see the decline,” said Horan, an anthropology major who is minoring in environmental studies. “I don’t want to downplay what I saw in Belize because it was beautiful, but you could definitely notice the decline. We saw very few bigger fish, which is a change in species composition.”
The class spent the week in Belize studying the reef system. Each day included forays to locations such as “Whale Shoals,” “Twin Cay,” “Tobacco Cut” and “Man-O-War Cay.” In addition to the reef itself, they explored mangrove islands and bird habitats. They also conducted two studies: one, measuring fish diversity along a section of the reef; the second, mapping out a section of the patch reef, identifying the coral and taking a census of the fish.
The schedule was full. With classroom time for discussion and presentations by students interspersed among the dives on the reef, each day began by 7 a.m. and continued with activities until nearly 10 p.m. on many nights.
The second week of the trip, to the rainforest surrounding the La Selva Biological Station in Costa Rica, followed a similar pattern (though each day began earlier, thanks to the howler monkeys).
“A lot of the literature that is published on tropical biology comes from work that has been done at La Selva, so there are a number of scientists there who are doing really neat stuff and who are eager to talk about it,” said Kaishian, a biology major who is interested in sustainable living and agriculture. “I was able to speak with a lot of different people from all over the world, working on things like the biochemistry of a type of butterfly larvae to research on sloths.”
Professor Shumway said the students in this year’s course were particularly adventurous; the entire class made the daylong hike from the La Selva Station to the border of Braulio Carillo National Park. “The corridor created between lowland rainforest of La Selva and the park, which is crowned by the peak of a volcano, is the only remaining undisturbed and protected swath of land linking the highlands and lowlands in all of Central America,” he said. “This connection is important for birds and mammals that migrate seasonally between the two elevations.”
Getting there was not easy. To guard against insects, students trooped along in shin-high rubber boots, long pants and long-sleeve shirts in the hot, humid atmosphere. The terrain grew more challenging, too, the farther down the trail they went. “We got to one place where we had to go down a very steep hill that was muddy and there was no place to put your feet,” Ferguson said. “And when we all got to the bottom, there was no more path, it was just river.”
Despite the hardships, the hike was a highlight of the trip for many of the students in the class. “We had a lot of fun doing that as a group,” said Hodges. “People were slipping and falling where the trail was muddy and steep, but the experience was amazing.”
During the week, the class took several other group trips, including a river tour and a visit to a nearby banana plantation. Students also set off on their own, in pairs, to design and conduct short field research projects that they would present to the class and write up as part of a final paper after the trip was complete.
“We run the course in a way that students get hands-on experience in conducting research through a short project,” Shumway said. “That’s an essential part of the course. It’s what I did when I was an undergraduate.”
Horan and classmate Cole Larson-Whitaker chose to observe green iguanas’ sun-basking behavior to identify the optimal amount of time and temperature at which the lizards spend sunning themselves in treetops each day. To see the iguanas, Horan and Larson-Whitaker staked out an observation post on a suspension bridge near the river station, allowing them to see into treetops.
“One morning I went out with my partner to look at iguanas and we got to hear the howler monkeys,” Horan said. “We were actually up and out before the howler monkeys were awake, which was really cool. Off the bridge, we got to be within a foot of one of the monkeys and her baby, which was really, really spectacular.”
Links for information on each of the locations: