Inside the Smithsonian’s tropical research island in Panama

In a world that often feels like it has no more mysteries to discover (at least on land), scientists from the Smithsonian Tropical Research Institute (STRI) have recently proven otherwise.

It happened on Barro Colorado Island in Panama, home to a one-of-a-kind rainforest laboratory that’s celebrating its 100th anniversary this year. During a geological expedition, visiting scientists uncovered hundreds of fossilized mangrove wood specimens, perfectly preserved in lava and estimated to be over 22 million years old. In their findings published in March, researchers revealed almost unimaginable details about this long-lost prehistoric forest, where trees grew 130 feet tall and long-extinct animals once thrived. 

Carlos Jaramillo, a Colombian geologist who was involved in the study—and has worked as a staff scientist for the STRI for 19 years — is amazed that a petrified forest had gone unnoticed for so long. “It just tells you how little we know about the tropics,” he told The Post, “even in the most-studied tropical rainforest in the world.”

Discoveries like this are what continue to attract thousands of anthropologists, ecologists, ethologists, evolutionary biologists, paleontologists and physiologists from across the globe to the BCI, as the island is known. They come to live and study in this rainforest haven, home to some1,400 plant species, 500 tree species, and more than 100 types of mammals.

The STRI is the only bureau of the Smithsonian Institution based outside the US, and its work in Panama isn’t confined to the island. They have laboratories near Panama City in the Gamboa Rainforest Reserve —with an amphibian rescue center, insectaries, and an experimental greenhouse that tests tropical plant response to elevated carbon dioxide — and several facilities near the entrance to the Panama Canal. In Panama City’s Natural Metropolitan Park, the STRI uses towering cranes to study forest ecology literally among the treetops. Recent research has also demonstrated that two out of every five of the world’s amphibians are threatened with extinction — and just last year, the Institute lobbied the Panama government to expand the country’s protected marine area by 557%. 

But the BCI remains its biggest draw for scientists. “You eat, breathe, drink science,” ecologist Erin Spear says of her experiences on BCI, where she’s conducted research for almost two decades. “Everyone around you is a scientist and everything you’re doing is science.”

Biologist Sharon Martinson, who spends three months every year at the institute, says visiting the island for the first time “is like stepping into Conrad’s ‘Heart of Darkness,’ ” she tells The Post. “It was sensory overload to fly here from Wyoming and realize this is on the same planet.”

Despite being a wonder of nature, the island itself is man-made. It was formed in 1914, when the Chagres River valley was flooded to create Gatun Lake, the main channel of the Panama Canal. Now surrounded by water, BCI was one of the hilltops that remained, and in April of 1923 it was declared a tropical forest reserve for scientific study. The research station officially opened to scientists on March 29, 1924, with the only cost being the $50 ticket ($913 in 2024 dollars) for the six-day voyage from New York City. The Smithsonian took the reins in 1946, and renamed it the Smithsonian Tropical Research Institute in 1966, making it the institute’s first federally-funded bureau located outside the United States.

The accommodations haven’t changed much since the research station first opened as a sort of “little America” amid the heat and humidity Central America. The only transportation to the island is by boat, and then there’s the 200-plus-step climb from the base of the island to the dormitories and laboratories above. Visitors and residents have access to a cafeteria and research facilities overlooking the lake and Panama Canal, and modest housing units — there’s room for around 50 researchers and staff — that feel like a youth hostel. 

But what the island lacks in luxury it more than makes up for with freedom. Getting access to the island lab involves submitting a research proposal and permit application. If accepted, what a researcher does with his or her time there is pretty much up to them. 

“The staff’s scientists are free to pursue what they want,” says Nancy Knowlton, a coral reef biologist who worked at the STRI for much of the ’80s and ’90s. “Without the need for really large research grants.”

This freedom has resulted in a staggering array of research, with over 13,000 studies published on the Island’s biology ranging from primate behavior to the effects of climate change on tropical ecosystems. 

“There are very few other locations worldwide . . . where we have 100 years of data to help us understand how forests change, how nutrient cycles work, and how populations of animals change through time,” Joshua Tewksbury, the institute’s current director, tells The Post.

While the intent has always been noble, the STRI’s history hasn’t always been a welcoming scientific melting pot. David Fairchild, an American botanist and one of the first scientists to call the island home in the 1920s, fought to keep women away from Barro Colorado. “Let us keep a place where real research men can find quiet, keen intellectual stimulation, freedom from any outside distraction,” he wrote. It wasn’t until after World War II that female scientists and administrators were finally invited to the island. Despite being located in Panama, English was also the STRI’s predominant language well into the 21st century — only changing in the years following the Canal’s shift to Panamanian rule back in 1999.

More recently, 16 female scientists shared stories of sexual misconduct from their male colleagues at the STRI, according to a 2021 BuzzFeed report. Within a year, the institute launched a full investigation, with director Tewksbury posting a detailed summary of the STRI’s commitment to institutional reform.

The STRI has persevered, likely because it offers a unique scientific experience. Here, it isn’t necessary to bring samples back to a laboratory. Because the island, six square miles (Manhattan is 22 square miles by comparison), is the laboratory.

Martinson, the director of the Listening Lab at Colorado State University, travels to the STRI to track the mating songs of male katydids. “It’s really, really hard to find a katydid,” says Martinson, who would venture through the thick tropical forest at 11 p.m. and 4 a.m., when katydids are most active. “They’ve had millions of years to get really good at hiding. But on a good night on BCI, we’d find hundreds of them.”

Martinson also plays banjo professionally — she’s recorded several albums with her band the Littlest Birds — and she sometimes brings her banjo to the island, playing along with the sounds of the rainforest. “I think it’s important to keep both the science side of the brain and the creative arts side of the brain equally in tune,” she says.

It’s a sentiment shared by anthropologist Clarence Carpenter, who did groundbreaking studies of howler monkey behavior on the Barro Colorado Island in the 1960s, and described the BCI as a place “mixed with both poetry and science.”

Martinson and Carpenter weren’t the only eccentrics drawn to the institute. Rodolfo Flores, a Panamanian botanist and STRI intern, discovered 10 new species of plants on the island over the last decade, four of which he’s had tattooed for prosperity on his body. It’s a quirk that’s landed him in a Panama jail at least once, when authorities confused him for a gang member. “Tattoos in Panama are still a taboo and the police can easily arrest you under that pretext,” he explains.

The rich biodiversity on Barro Colorado Island may be what attracts researchers, but it’s people like Flores and Martinson that make it such a fascinating place to live and work. And not just because of their idiosyncrasies. 

“You go to dinner and all you talk about is science,” says Spear, whose research focuses on tree disease and mortality. Once, while dining with fellow scientists at the BCI cafeteria, she mentioned that she had no idea how to grow fungi in petri dishes. “Can you teach me how to do it?” she asked the group. Several of them volunteered.

The focus on collaboration is one of the main things that keeps Martinson coming back. “It’s rare in science to have people from disparate areas coming together, living together, working together,” she says. “And with that comes the higher likelihood that something really creative and different is going to be figured out.”

The relationships formed on Barro Colorado Island — including a handful of marriages — have often been as significant as (and beneficial to) the research itself, so much that one of the biggest events of the STRI centennial is the upcoming alumni reunion, scheduled for this June. 

In the end, the secret to why the STRI hasn’t just survived but thrived over the last century goes beyond its bountiful biodiversity and reputation as the greatest rainforest laboratory in the world. Although regular folks can visit the island with a bit of advanced planning, It’s the scientists who’ve fostered a community on this island.

“I think everybody here is super passionate about science,” says Spear. “They’re all curiosity-driven, which sounds kind of simplistic but it’s true. All of us want to make a positive change in the world.”