In a historic action for conservation of biodiversity, a family of giant otters has been reintroduced in the Gran Parque Iberá in Corrientes, Argentina.
This event, which occurred on June 30, 2025, marks the first reintroduction of a locally extinct mammal in the country, according to Rewilding Argentina.
This reintroduction effort has been the result of hard collaborative work between various administrations, conservation teams, and European zoos.
The reintroduction of these giant otters is a significant step towards the restoration of a crucial wetland, which could help revitalize an ecosystem that was operating below its natural capacity.
Since 1986, a family group of giant otters had not been observed in Argentina, as the species was driven to the brink of local extinction due to hunting and the loss of its natural habitat.
Globally, the Pteronura brasiliensis is listed as “Endangered” on the IUCN Red List due to threats such as water degradation and habitat fragmentation.
The reintroduced family consists of Nima, a female from the Zoo Aquarium of Madrid, Coco, a male from the Givskud Zoo in Denmark, and their two offspring born in November 2024 in Iberá, Pirú and Kyra.
Nima, born in March 2020, is described as a shy otter around humans, which is advantageous for her reintegration into nature, as it minimizes interaction with people and promotes self-sufficiency.
This project is part of the European Endangered Species Program (EEP), coordinated by the European Association of Zoos and Aquaria (EAZA), which manages numerous specimens in Europe to ensure genetic diversity and plan strategic reintroductions.
Reintroduction of giant otters
The Gran Parque Iberá stands out for its 756,000 hectares of protected wetland, offering a safe and prey-rich habitat. It includes the Iberá Provincial Park and the Iberá National Park, created to preserve this invaluable ecosystem.
The giant otters play a vital ecological role as aquatic predators, primarily consuming fish. According to Sebastián Di Martino, director of Conservation of Rewilding Argentina, their presence is essential to restore the balance of the ecosystem.
The reintroduction process was meticulously planned since 2017, incorporating health protocols, transportation techniques, and training in fishing with live fish. The otters went through an adaptation period in pre-release enclosures.
With the support of advanced technology, such as monitoring through harnesses and environmental DNA analysis, scientists can observe and adjust the integration process of the otters into the natural environment, ensuring their survival and well-being.
Rewilding Argentina plans to continue with more releases both in Iberá and in the Chaco, seeking to restore connectivity between populations and ensure the future of this endangered species.
