Walking into Marcelo Gordo’s laboratory, you are immediately struck by the extraordinary treasure trove of seeds from the Amazon rainforest. There is an incredible array of colours and sizes—some microscopic, others large and striking. Over the years, Marcelo has built up remarkable knowledge of how these seeds germinate and how their flowers are pollinated through complex interactions involving insects and other forest animals.

While the laboratory itself is fascinating, walking through the tree nursery is equally impressive. A vast diversity of tree species is being cultivated. These trees are grown specifically to support pied tamarins, helping them survive in the fragmented forests in and around the city of Manaus. The pied tamarin is critically endangered, with a very small range that is being rapidly degraded.

In many areas, tamarins are effectively trapped in degraded forest patches. By understanding what they feed on throughout the year, Marcelo can plant key species that provide reliable food sources as the animals move through these landscapes.

This work relies on careful field research. Marcelo and his students follow tamarins and collect faecal samples, which are then analysed to identify the seeds they contain. This allows them to build a detailed picture of the animals’ diet across all seasons.

He went on to establish the Projeto Sauim-de-Coleira (the Pied Tamarin Project), and over the past 27 years has worked with students to rescue and translocate tamarins, as well as to create habitat corridors, build canopy bridges, and restore degraded areas so that the species can persist.

Marcelo now works as a professor of biology at the Federal University of Amazonas in Manaus. Many years ago, when he became aware of the struggles the pied tamarin faced, he started a very small tree nursery on the university grounds, which over the years has grown and grown. He has also gathered a group of incredible people—students and volunteers—who go out at weekends, in their own time, to plant tree saplings in key areas in and around the city. This has been vital to the survival of the pied tamarin in many places, supplying not only food, but with trees planted both sides of dangerous roads, safe places for tamarins to cross overhead.

The plan to replant key trees for the pied tamarin and the people of Manaus is a truly wonderful one, made even better by the fact that Marcelo supports forest communities in collecting the seeds used in the nursery—giving real value to keeping the forest standing.

The nursery has grown, and the work to replant degraded areas has expanded so much that Marcelo has established another nursery on the outskirts of Manaus, where the operation can be scaled up to increase habitat restoration.

The tree nursery itself is an extraordinary place where new things are being learned all the time. Marcelo grows over 100 species that pied tamarins rely on for food. The life histories of these plants are fascinating—some depend on tiny bees to pollinate their flowers, which then go on to produce fertile seeds, while others, such as figs, depend on very specific relationships with small wasps, completing a delicate and intricate ecological cycle.

Many seeds need to pass through the digestive tract of animals to germinate more efficiently; some need light stimuli to germinate and plenty of light to grow, while others take almost a year to germinate and only develop well in shaded areas. In other words, there are species that are important not only for tamarins, but also for the entire process of ecological succession, both in open areas, clearings/gaps and forest edges, as well as within the more preserved forest, and tamarins are very efficient at moving between these environments, carrying seeds from one place to another.

So the work to understand the rainforest’s complex ecology and restore degraded and deforested areas is essential not only to the survival of the pied tamarin, but to the forest itself and all its interconnected species. Marcelo needs all the support he can get.