It was the community that came to Nicolás Schuldt Durán earlier this year, not the other way round. Durán runs Neblina Labs, a conservation technology group, and what he brought to the Siekoya Remolino community in Sucumbíos province was equipment. What the community brought was the map — traditional knowledge of where the small monkeys feed and move, translated into a short list of trees worth wiring for sound.
Three microphones went up. For three days they recorded everything: insects, birds, wind, the accumulated noise of a river-edge forest. When the team went through the audio, no confirmed marmoset call turned up. Durán is not discouraged. The recordings are now training material — the raw substance from which detection models for future surveys are built, species by species, until the software learns what a leoncillo sounds like against everything else.
The economics are the point. Passive acoustic monitoring, Durán says, offers "the best bang for the buck in terms of how many species you can hear for the smallest cost" — cheap enough that a community can run it without an institution standing behind it. Which is precisely the design. Siekopai members are being trained in the technology itself, so the monitoring outlives the project that started it.
Why bother listening for something so small? Because the marmoset is a gum specialist tied to river-edge and seasonally flooded forest, its habitat a thin ribbon along the watercourse rather than a block of trees. It cannot retreat inland. When it vanishes from a stretch of river, the forest there has already been damaged — by logging, by clearing — and the silence is the evidence. The IUCN lists the species as Vulnerable.
There is a darker footnote in the science. When researchers studied pygmy marmosets in northeastern Ecuador in the late 1990s, local people captured animals from two of the study groups. The survivors' vocalisation rates dropped measurably. Under pressure, the monkeys went quiet.
The same community running the microphones also runs camera traps and territorial patrols against illegal hunting and logging in this forest. Sucumbíos has been a working landscape for oil since Texaco arrived in 1964, and the access roads cut for drilling brought settlers and chainsaws behind them. The Siekopai themselves — about 800 people in Ecuador, speakers of Paicoca — descend from families displaced from their northern homeland of Pë'këya during the border war of 1941. In November 2023 a provincial court ordered the state to title them 42,360 hectares of that homeland and to apologise. As of last year, the title had still not been delivered.
So the recording continues. An empty result is still a result, and the next three days of audio will be read against a model that knows a little more than it did.