By Barbara Gonzalez, PiLA Fellow, Osa Conservation, Costa Rica on
5:30 a.m.
I climb the canopy tower with four other friends, and the forest greets us from thirty meters up. The trees breathe around us, mist glitters on leaves, and a few shy drops of rain tap our heads. As the sun peeks over the horizon, distant howler monkeys answer it, and a chorus of birds announces the day. We spend an hour birding from the top of the tower, logging what we see into eBird: scarlet macaws, white-shouldered tanagers, chestnut-backed antbirds, mealy amazons, and more. Then, as we head for breakfast, a warm plate of rice and beans fuels us for what becomes a long, packed, beautiful day: BioBlitz Day 2025 at Osa Conservation on the Osa Peninsula in Costa Rica.
If you haven’t heard of a BioBlitz, it’s precisely what it sounds like: an intense, time-filled survey day when scientists, volunteers, and community members work together to find and identify as many species as possible in a place, usually in 24 hours. For me, this was a perfect snapshot of the many projects and people who are part of Osa Conservation, the non-profit organization I joined for 6 months.
8:00 a.m.
After breakfast, we head to the Piro River with Socorro, a parataxonomist whose energy and local knowledge are contagious and incredibly inspiring. We collect aquatic macroinvertebrates with nets and trays, the kind of tiny organisms you’d miss if you weren’t looking. Socorro was named a rainforest hero a few years ago; her devotion to teaching her community about aquatic life and river health is why so many of us know what to look for. We use the local version of the BMWP (Biological Monitoring Working Party) index to assess water quality: identifying sensitive groups such as Trichoptera and Plecoptera indicates that the river is doing well. Finding multiple representatives of these taxa felt like a small victory and pointed to the overall health of the Piro River!
10:30 a.m.
By late morning, I join the restoration crew. Their eyes are trained to spot native trees, seedlings, and tiny seeds nestled in leaf litter; everything goes into iNaturalist - a powerful citizen science platform. We find frogs, toads, and the occasional “walking tree,” with its majestic stilt-like roots. Walking with this incredible team, I learned that restoration is as much about people and local knowledge as it is about protecting and preserving native plant species.
Back at the lab after lunch, we identify the macroinvertebrates we collected. Each specimen is a clue, a score that helps map the river’s health. Finding more sensitive taxa confirmed what we suspected. The Piro River is worth protecting, and the data gives us the language to prioritize it.
03:00 p.m.
In the afternoon, Paulina, a bat biologist, guides us on a walk to the famous “bat tree.” The tree is enormous. A giant Ajo tree (Caryocar costaricense) with a cavity at its base that serves as shelter for wildlife and, for a moment, for us. Five of us crawl inside, safety goggles, masks, and headlamps on, and we listen in awe. Paulina explains how tree cavities are microhabitats. Safe, temperature-regulated spaces perfect for roosting, raising young, and hiding from predators. That silence inside the trunk felt like a physical lesson in why habitat structures matter. We counted and identified bats, many of them vampire bats, and left with a new fondness and respect for these often-misunderstood and underappreciated mammals.
07:00 p.m.
After dinner, the night shift begins: frog monitoring with Erick, Osa’s herpetologist. Erick can spot a tiny, translucent glass frog in the dark and identify it instantly by its call. That night, we found glass frogs and red-eyed tree frogs along with their eggs - tiny pearl-like beads suspended from leaves, one of the most astonishing sights I’ve encountered. Nearby, a paca (tepezcuintle) sheltered quietly in the riverbank. It was the perfect end to a packed and memorable day.
Not every day at Osa looked like the bioblitz (most didn’t), but that day distilled everything I loved about my fellowship: collaboration, curiosity, and hands-on science with our community. As a Princeton in Latin America fellow focused on vertical stratification, I spent many hours at the 30 m canopy tower collecting data, but days like the bioblitz reminded me why that vertical perspective matters. The forest is not just horizontal space; it’s a multilayered world, with different communities living at different heights and microclimates. The canopy, understory, and forest floor each tell a different part of the conservation story.
A few takeaways from the BioBlitz day and my six months at Osa:
Citizen science works. Recording species on platforms like iNaturalist and eBird creates data that communities and conservationists can use to protect places. What we document, we can defend and study further.
Conservation needs community. Training and listening to local leaders, parataxonomists, and rangers creates long-term stewardship. Everyone has a role in conservation: scientists, students, community members, children, and curious fellows like me can all contribute their granito de arena (contribute their bit).
Look up more often. Studying forests vertically revealed communities I’d never have noticed from the ground. The canopy tower wasn’t just a research tool; it was a reminder that biodiversity is layered and complex.
I arrived in Costa Rica unable to name half the birds, plants, or insects I now can better recognize. You don’t have to be an expert to start. Apps like Merlin, iNaturalist, and simple field guides, plus a willingness to ask questions, let anyone join in, contribute, and learn something new. So if you’re near a green space, I’d encourage you to try a mini-bioblitz with friends. Pick a morning, bring a notebook and a phone, look closely, and record what you find. The world gets richer and more fascinating when we notice it, and when we count it, we give it a better chance to stay.
My time at Osa taught me that conservation is equal parts data and relationships. The field skills, the lab hours, the nights in the river: they all tied back to people who care deeply for this magical place. From a 5:30 a.m. sunrise in the canopy to midnight walking along the Piro River, the BioBlitz day captured why I am so deeply grateful to have been there: for the learning, the friendships, and the chance to add a small but meaningful bit to a much bigger effort.