Every morning, before the river mist lifts from the surface of the Tarapoto Lakes, Eliceo Matapi is already on the water. He cuts the engine two hundred metres from the reed line, listens, and waits. Within minutes, the first grey-pink dorsal fin breaks the surface. Then another. Sometimes six or seven in a single breath cycle.
For visitors on their first Amazon morning, this tends to produce a kind of stunned silence. It is one thing to know intellectually that Inia geoffrensis — the Amazon river dolphin, the boto, the pink river dolphin — exists. It is another to watch one surface three metres from your canoe, exhale slowly, and sink again into water the colour of strong tea.
The encounter looks effortless. But it isn’t accidental. Eliceo has been reading this particular stretch of water since childhood, and what he does in those two hundred metres of silent approach is the product of knowledge built across generations of Matapi river life. This note explains what’s actually happening — biologically, ecologically, and culturally — and why this encounter is available here when it isn’t reliably available almost anywhere else.
The geography that makes Puerto Nariño exceptional
Puerto Nariño sits at the confluence of the Amazon and Loreto Yacu rivers, roughly eighty kilometres upstream from Leticia. Its distinction among Amazon towns is its relationship to the Tarapoto lake system — a network of oxbow lakes, flood plains, and várzea channels that floods and contracts with the river each season.
Tarapoto is not a single lake. It is a series of interconnected water bodies separated by narrow necks, reed islands, and submerged forest that changes character completely between the high-water season (roughly December to May) and the low-water season (roughly July to October). When the Amazon rises, Tarapoto becomes an inland sea. When it falls, the fish concentrate in the remaining pools.
This fish concentration is the key to the dolphins. Inia geoffrensis is a highly opportunistic feeder. Studies across the Amazon basin consistently show that boto density correlates directly with fish density — and fish density in Tarapoto during the low-to-mid water months is among the highest documented anywhere in the Colombian Amazon. The lake system functions as a natural trap: fish that entered the flooded forest during high water are gradually concentrated as the water recedes, and the dolphins follow them in.
Two species, one location
The Tarapoto area hosts both Amazonian dolphin species: Inia geoffrensis (the boto, or pink river dolphin) and Sotalia fluviatilis (the tucuxi, a smaller grey dolphin more closely related to saltwater dolphins). They occupy slightly different niches — the boto works the deeper channels and flooded forest, the tucuxi prefers the open water — but in a good morning on Tarapoto you will often see both.
The boto’s colouration is worth explaining, because it surprises many visitors. Young botos are grey. The pink colouration develops over years and is more pronounced in males. Skin damage, blood vessel proximity to the surface, and repeated abrasion against underwater vegetation are all cited as contributors. The most intensely pink individuals you will see are typically older adult males. Females and juveniles range from pale grey-pink to a dusty rose.
The morning pattern and why it holds
Botos are most active in the two hours after dawn and the hour before dusk. The morning activity window correlates with fish feeding behaviour: many of the small species that boto prey upon (catfish, characins, and small cichlids) are most active at the surface in low light. The dolphins move into shallower water to feed as the fish rise, then retreat to deeper channels during midday.
Near Puerto Nariño, this means the reed line at the edge of Tarapoto — where shallow water meets flooded vegetation — is reliably active from roughly 6:00 to 8:30 in the morning. Eliceo’s protocol is to position the canoe at the edge of the channel before this window opens, engine off, and let the dolphins come to the boat rather than taking the boat to the dolphins. This matters enormously.
“The dolphin decides when it approaches. We never chase. We put ourselves where they already want to be, and we become part of the morning.”
This is not merely a philosophical position. Boto are intelligent, acoustically sensitive animals. They use biosonar to navigate and hunt, and engine noise interferes with that sonar. A motor running near dolphins will push them to distance themselves from the sound source. A quiet canoe, positioned correctly, is not a threat — it becomes part of the environment. This is why the encounters at Puerto Nariño are different in quality from motorboat tours where the driver simply finds the dolphins and motors toward them.
What the Matapi know that the biology books don’t say
The Matapi and Yucuna communities that inhabit the river between Leticia and Puerto Nariño have a relationship with Inia geoffrensis that spans centuries. In Matapi cosmology, the boto occupies a complex position — not simply an animal to be observed, but a being with agency and memory. Eliceo describes boto behaviour in terms that parallel what Western ethology is only beginning to document: individual recognition, territory memory, and what he calls “curiosity about stillness.”
The boto’s reputation for approaching humans — particularly children and young women, according to many Amazon communities — is documented across South American indigenous literature and has entered popular folklore in various forms. What’s relevant here is the behavioural reality behind the myth: botos do display curiosity toward unfamiliar objects at the water surface. They will frequently approach and circle a stationary canoe with apparent interest, especially in locations where they haven’t been harassed.
Tarapoto is one of those locations. The community of Puerto Nariño has maintained informal protections around the lake system for decades, and there is no commercial fishing permitted within the lake boundaries. The dolphins here have had consistent positive or neutral experiences with canoes, and they show it.
Swimming with dolphins
On the Amazon Wildlife Adventure, we offer the option of entering the water at specific sites within Tarapoto during the late morning, after the feeding activity has wound down. Botos have been documented voluntarily approaching swimmers in several locations. Whether this happens on any given morning depends on the animals — it cannot be promised, and we don’t try to orchestrate it.
What we do is put you in the water at the right place and time and keep the group small and quiet. Most groups do experience approaches. Some are extraordinary — a boto circling at arm’s length, close enough to hear it exhale. Others are more distant. The variability is part of what makes it real.
Seasonal patterns and the best window
The peak window for boto encounters at Tarapoto runs from approximately June through October, with July to September considered the most reliable. This coincides with the mid-to-low water period when fish are concentrated in the remaining pools and the dolphins are most active in accessible shallows.
During the high-water months (roughly February to May), the lake system expands dramatically and the dolphins disperse throughout the flooded forest. Encounters are possible but less predictable — you’re working against a much larger search area. December and January also bring rain that can affect water clarity and the early morning light quality that makes these encounters visually memorable.
The river level in the Colombian Amazon typically peaks in April and begins its slow recession through May and June, reaching its lowest point around October before the wet season begins again in November. The sweet spot for combined wildlife activity — not just dolphins, but birds, caiman, manatees, and giant otters — is June through September.
Why group size determines the quality of the experience
We are often asked why our expeditions are capped at six travelers. The dolphin encounter illustrates the reason clearly. A canoe with six people is quiet and sits low in the water. A boat with fourteen has a different acoustic and visual profile entirely. Botos that have had negative experiences with large groups will avoid similar boats in the future — they remember.
Beyond the wildlife itself, a small group means Eliceo can narrate what he’s observing in real time, answer questions, point out behaviour. The morning becomes a lesson rather than a performance. Guests often say they leave the water with a completely different relationship to wild animals — not the passive awe of a zoo encounter, but something more reciprocal and harder to articulate.
That quality is the product of a specific approach built over years of work with these animals and this water. It cannot be replicated by scaling up.
See them with us
Dawn dolphin-watching on the Tarapoto Lakes is part of our Puerto Nariño Explorer and Amazon Wildlife Adventure. Planning your trip? Read Is it safe to travel to the Colombian Amazon?
Ready to experience it yourself?
All expeditions are private, max 6 travelers, and depart from Leticia year-round. WhatsApp Eliceo to check availability and dates.