Back to Barro Colorado

My hammock on the porch overlooking the island dock

I’ve never liked the rain back home. Especially the odd California rains (if they ever happen…) when it drizzles perpetually, cold moisture clinging to your exposed skin and gray clouds suspended low in the sky for days. Yet as I sit in my hammock on the porch of a lab building on an island in Panama watching droplets pour down, I find the rain captivating. Here, the rain comes as imposing thunderstorms. Distant rumbles of thunder precede the rains, and the howler monkeys begin their chorus of throaty hollering. Then the droplets come, slowly at first, creating little dimples in the murky green canal water surrounding the island. White mist drifts through the canopy of the tallest jungle trees. Suddenly, the clouds split and water comes cascading down, spilling in torrents off leaves and creating tributaries that branch from the rivers intersecting through the island. You can see the front line of the wall of water move across the jungle to the edge of the water. As it moves, the rain changes the texture of the canal water surface from glassy to turbid. The sound of the water falling into the lake mutes all other noise. It’s indeed impressive.

It’s the wet season here in Panama, and I suspect I will have many more rainstorms to look forward to during my 3.5 month stay this summer. I arrived to Barro Colorado Island last week for my very first field season as a PhD student. I’ve been anticipating this trip for months now, even more so once I completed my preliminary exams and coursework at UC Davis. I’ve always loved the field exponentially more than the office. I’m here at BCI studying collective decision-making and social foraging in white-faced capuchin monkeys as a Smithsonian Tropical Research Institute (STRI) fellow.

The STRI lab and office buildings on BCI

Poison-dart frog

BCI is a 16 km² island located directly in the middle of Gatun lake, an artificial body of water created in the early 20^th century when the canal was flooded with water to make way for passing ships. It’s home to one of the Smithsonian research centers, and only scientists and forest guards are resident on the island. Right now, there is a collection of undergraduate interns, field assistants, several graduate students and post docs, a few professors or principal investigators, and forest guards staying on BCI. People here study everything from soil microbes, to lightning strikes, to plant dynamics, animal ecology, insect diversity, and much more. When I arrived, I was given keys to my own little office/lab space and a shared double room (with AC, thank god) in a dormitory located about 100 meters into the forest from the dining hall (although no roommate to be found, yet).

A basilisk lizard

It’s a stunning location; the main buildings sit on the escarpment overlooking the canal waters where you can see gigantic cargo ships trudge through canal zone on their way from one ocean to the other. There’s a little colony of bats that roosts on the lab building walls and a family of poison dart frogs that hop around near my dormitory. The only buildings on the island are the Smithsonian structures and the forest envelops the remainder of the land right up to the canal shoreline. The jungle teems with life, boasting an abundance of plants and animals. I’ve already seen crocodiles, an anteater, coatis, peccaries, many different frogs and toads, bats, monkeys, agoutis, toucans and other birds…

I will spend these next few months tracking and recording the behavior of the capuchins. I’ve already spent 4 days in the forest with monkeys, learning from the two long-term masters students and field assistants for the monkey project, Lucia and Nohely. Lucia has been working with my advisor for many years, and she knows the monkeys and the forest exceptionally well. We wake up in the early morning and set off into the labyrinth of trails dissecting the island. There are 4 monkey groups we follow, 3 of which each have a monkey with a radio telemetry collar. This collar transmits a radio signal, which we can detect using a metal antenna and receiver that we hold high above our heads in the jungle. The receiver will begin to emit a sequence of clicks when we get close to the monkeys. The clicks are louder when the antenna is pointed in the direction of the monkeys and become even louder the closer you get. Almost always, the antenna leads us off the trails, and we must scramble through the dense vegetation to find the monkeys. I usually feel like an elephant in these moments, crashing through the vines and squashing little plants under my rubber boats. 

Capuchin eating Gustavia fruits. These are large, pumpkin-shaped fruits with a green exterior and orange interior. The monkeys usually eat only part of the fruit before discarding the rest. These fruits then come crashing down to the forest floor. I think this might be cause to wear a hard-hat.

While going off trail allows us to be fully immersed in the jungle, it can be utterly disorienting (for me especially…). There are no real landmarks and every new hill and tree resembles the last. Fortunately, we carry a GPS unit with us to both mark the monkeys’ location and guide us. We spend about 7-9 hours a day out in the forest, depending on what time we locate the monkey group in the morning. I come back drenched in sweat and covered in chigger and mosquito bites ready for a cold shower (I already have 105 bites on my body after 4 days in the forest. If this chomping continues, I estimate that I will be bit almost 2,400 times by the end of summer. Please no). Regardless, I could not be more exhilarated to be here. The monkeys are hysterical and the forest is enchanting.

To read more about STRI and BCI, click here:

http://www.stri.si.edu/english/research/facilities/terrestrial/barro_colorado/index.php

Toucan

Anteater

Howler monkey