The giant river otter (Pteronura brasiliensis) has returned to northern Argentina through a structured reintroduction initiative in El Impenetrable National Park, in Chaco Province. The programme has already recorded the presence of a resident pair and the first documented births in the Bermejo River basin after more than a century of local absence, reports
El Maipo, a partner of TV BRICS.
The initiative, implemented in a protected area spanning 128,000 hectares, aims to restore a key aquatic predator to regional ecosystems. The species plays an important ecological role by regulating fish populations and contributing to the balance of freshwater habitats across rivers, lagoons and seasonal water channels. Furthermore, it is the largest otter species in the world, reaching up to 1.8 metres in length, and lives in close-knit family groups.
Reintroduction efforts gained momentum following the arrival of a wild male, Teuco, observed in the Bermejo River area, and the introduction of a female, Yvera, born in Ibera and transferred to Chaco to form a breeding nucleus. Together, they became the foundation of a growing population within the park.
In December 2025, a group of eight giant river otters was introduced to the reserve, joining the existing pair already established in the area. By January 2026, the first three cubs were recorded, with early observations confirming parental care and initial foraging behaviour near the water.
The project is supported by suitable habitat conditions, including the Bermejo River corridor and a system of nine oxbow lakes that provide ideal environments for feeding, shelter and reproduction. Specialists indicate that these ecosystems could potentially support a stable population in the coming years, marking a significant step in long-term conservation efforts.