Argentina celebrates the return of the giant otter after 40 years

The giant otter (Pteronura brasiliensis) had been absent for more than forty years in the wetlands of Iberá National Park, Argentina. With this, the traditional site carries out a process of reintroduction, a milestone for the conservation of extinct species in the country since 1986.

This reintroduction began in 2017 by the organization Rewilding Argentina, seeking a result relevant not only to zoology, but also to the conservation of global biodiversity.

This animal is a predator with a central role in aquatic ecosystems and a diet based mainly on fish. It can also eat crustaceans, molluscs, reptiles (such as snakes and turtles), small mammals (rodents), and aquatic birds.

With a weight that can reach 33 kilos and a length of up to 1.80 meters, it undergoes a complete reintroduction with the arrival of Nima. A female from the Madrid Zoo, together with Coco, a male brought from Denmark.

The couple and their two children sail along the rivers of Iberá, bringing hope of restoring the lost natural balance to the region.

Argentine wetlands occupy approximately 21% of the country’s territory. They therefore function as “natural sponges”, capable of absorbing and releasing water to help control floods and droughts.

These environments also play a vital role in water purification. Furthermore, the return of the giant otter to the site promises to restore the local ecological balance, but also to revive the tourism sector.

After all, Governor Gustavo Valdés stressed that seeing these animals can attract visitors from different parts of the world and boost the local economy through eco-tourism.

Interest in the observation of endemic species can generate new jobs and opportunities for local communities, especially in the province of Corrientes.

Sebastián Di Martino, of Rewilding Argentina, highlighted that the presence of the giant otter is fundamental to the health of wetlands, as it serves as an indicator of the degree of conservation of these areas.

However, it presents challenges such as constant monitoring of released animals and the need to maintain the environment in conditions that allow their survival.

The giant otter is the largest otter in the world, a semiaquatic and social mustelid, with a long body, strong, flat tail, dense fur and membranes between the toes for swimming.

They live in family groups and have white spots on their necks with unique patterns, which act as “fingerprints”.

It lives in rivers and freshwater lakes, but also moves on land. It is therefore a diurnal animal and lives in family groups led by a breeding pair.

It appears frequently in some important river basins of South America, such as the Amazon River and the Pantanal, both on Brazilian soil.

Gestation lasts approximately 55 to 70 days, with the birth of 1 to 5 puppies that depend on their mother for the first few months.

Therefore, the cubs remain in the family group and learn to hunt from their parents, who help them with their education.

Its scientific name, Pteronura brasiliensis, means “wing with tail”, due to the flat shape of the tail, and also indicates its Brazilian origin.

The species is classified as “endangered” by the IUCN due to illegal hunting, habitat destruction and water contamination, which has led to its extinction in some regions.

It is the loudest otter species, and distinct vocalizations indicating alarm, aggression, and confidence have been documented.

It has no serious natural predators other than humans, although it must compete with other predators, such as the Neotropical otter, jaguar, and several crocodile species, for food resources.

“Ariranha” comes from the Tupi term ari’raña meaning “bruised irara” (eîrara + anha). In Spanish “river wolf” (lobo de río) and water dog (perro de agua) are used occasionally and may have been more common in the accounts of 19th- and early 20th-century Spanish explorers.

Giant otters build burrows, which are holes dug into river banks, usually with several entrances and several chambers inside.

Finally, the species is endemic to South America, present in most countries, including Brazil, Peru, Colombia, Venezuela, Bolivia, Ecuador, Guiana and Paraguay, although it has a history of population reduction.