Get to Know Barro Colorado Island, Home to the Smithsonian Tropical Research Institute

Protected by the locks of the Panama Canal, the lush forests of Barro Colorado Island have been luring curious scientists from around the world since its formation. That’s right; one of the planet’s most renowned hotspots for tropical research and conservation is just beyond the concrete walls and commerciality of this famous artificial waterway. In fact, it’s a fortuitous byproduct.

Now home to the Smithsonian Tropical Research Institute’s (STRI) most important live laboratory, Barro Colorado has hosted a mind-boggling range of research projects over the past century—spanning the effects of climate change on forest dynamics to the symbiotic relationship between farmer ants and the fungi they cultivate.

It’s also one of incredibly few places on Earth where visitors have the opportunity to explore the jungle alongside scientists at the forefront of biological discovery, making it a must-see destination for nature lovers.

On three different Costa Rica itineraries offered by National Geographic-Lindblad Expeditions, the National Geographic Quest anchors overnight in Gatun Lake right near the Barro Colorado Nature Monument, giving guests direct access to this verdant paradise. Read on to learn what a rare visit to Barro Colorado Island has in store.

Conservation in the Canal Zone 

As Panama Canal engineers were set to dam the Chagres River, U.S.–based naturalists expressed concerns about such a large-scale disruption. Without the ability to intervene, their next best route was to learn as much as they could.

From 1910 to 1912, the Smithsonian led one of the world’s first major environmental impact studies, surveying, cataloguing, and collecting specimens of the flora and fauna of central Panama’s lowland tropical forests prior to their flooding. 

Already, the Panama Canal watershed’s potential as an ecological enclave for research was imminently apparent and ever since its creation, Barro Colorado has been dedicated to discovery. It’s become both a key source of textbook knowledge about tropical rainforests and an integral training ground for the next generation of scientists.

Though many universities where biologists study are located in the temperate zone, STRI Deputy Director Dr. Oris Sanjur explains, much of the world’s biodiversity—and therefore the most fascinating field work—is in the tropics. 

“I’m actually a product of that training,” says Sanjur. “When I started as an intern about 30 or 35 years ago, Barro Colorado was a place of magic.” She went on to become the first Panamanian and first female director of an institution where women were initially considered “distractions” for male scientists.

Today, she oversees operational support for STRI’s researchers and hopes to serve as a role model for more women, especially Latina women, to lead within the field.

The Most Studied Tropical Forest in the World 

Each year, some 1,400 scientists journey to this unique laboratory to collaborate on monumental, long-term projects or to pursue purely curiosity-driven research like Sabrina Amador, whose lab is researching how the sensitive plant, mimosa pudica, makes the seemingly magical decision to fold in its leaves when touched. 

One of STRI’s landmark studies, the ForestGEO project, monitors the trees of a dedicated 50-hectare plot in the center of Barro Colorado Island. Since 1980, ecologists have conducted a regular census every five years, as a team of researchers and students marks, maps, measures, and identifies every single tree—from the giant trunks of ceiba trees to saplings about the size of your pinky finger. To date, they’ve censused a total of more than 450,000 trees, building a massive database of forest dynamics and a blueprint for 72 similar plots in more than 28 countries.

Barro Colorado—which is named for the red tone of its clay soil—may be manmade, but the environment is far from artificial. The island spans 4,000 acres, nearly six times the size of New York City's Central Park, so it was large enough to maintain the original wildlife and vegetation of the mainland. Aside from sparse laboratory facilities and 25 miles of carefully carved trails, the forest and its 1,400 plant species (and counting!) are free to flourish. 

With more than 100 resident mammal species, you may spot white-nosed coatis, three-toed sloths, and five of Panama’s native monkey species, including white-faced capuchins, howler monkeys, and spider monkeys, which are a sure sign of a healthy environment.

Birdwatchers will delight in seeking some of the island’s 400 bird species. Keep watch for keel-billed toucans, crested guans, slaty-tailed trogons, vibrant turquoise honeycreepers, and rufous motmots, with their crayon-orange heads and intricate tailfeathers. And don't forget the butterflies. Some 500 different species dot the forest with their brightly adorned wings. 

What It’s Like to Visit Barro Colorado Island

Though hundreds of scientific publications offer a window into the splendors of this verdant sanctuary, reading is never quite as impactful as being there. STRI welcomes a limited number of day visitors, who can access the island by boat from Gamboa or via a select few expedition cruise vessels permitted to complete the Canal crossing over 48 hours.

The highlight is a 2.5-hour hike along the same trails used to conduct research with a passionate local naturalist as your guide. With so much abundance to take in and just a few precious hours to do so, Sanjur suggests limiting your senses. 

“I like to close my eyes and listen to the sound of the forest—the chirping of the birds, the howler monkeys howling, the insects, the wind between the trees... You then realize how much noise contamination you get every single day,” she muses. “That sensation, to me, is always so special. You get to connect to who you really are in those moments, and just be amazed by the beauty that surrounds you.”