The southern elephant seal, the largest seal in the world, has its natural habitat on the Patagonian beaches, especially in the Península Valdés (Chubut), where the only breeding colony on the continent is located.
However, since 2024, unusual appearances have been recorded in warmer areas such as the coasts of Buenos Aires, Uruguay, and Brazil, including births of pups in places where they had never been observed before.
Impact of avian flu on the species
The H5N1 avian influenza epidemic that affected Península Valdés in 2023 caused the death of 97% of the pups and an undetermined number of breeding adults. According to a study published in Marine Mammal Science in 2025 by WCS Argentina, CONICET, and the University of California Davis, population recovery could take decades.
The 2024 census revealed a 61% population decrease, leading the species to move from the “Least Concern” category to “Endangered” on the IUCN list.
Appearances and births outside Patagonia
Between September and October 2024, at least six births were recorded on Buenos Aires beaches such as Mar de Ajó, Villa Gesell, Mar del Plata, Mar Chiquita, Miramar, and San Blas, as well as cases in Río Negro and in the state of Santa Catarina (Brazil).
In 2025, the birth of a pup was reported in Piriápolis (Uruguay), the second recorded in that country since 1977, and another within the Quequén River, in the port of Necochea. Individuals shedding skin were also observed on Uruguayan and Brazilian beaches.
Specialists from WCS Argentina point out that these changes in distribution and behavior are atypical and could be related to the avian flu epidemic and factors such as climate change.
How to recognize them
- Adult males: up to 5 meters in length and 4 tons in weight, with a prominent trunk.
- Females: up to 3 meters long and between 500-900 kg.
- Juveniles and pups: present at different times of the year, especially between September and November.
- Skin shedding: a normal process where the old yellowish skin peels off and a new dark gray one appears.
- They move by dragging themselves with their front flippers, unlike sea lions.
Recommendations for protecting them
Human interaction can cause stress and abandonment of pups, as well as harmful energy expenditure for animals that fast during their stay on land. Therefore, it is recommended:
- Stay more than 30 meters away.
- Do not throw objects or try to move them towards the sea.
- Do not approach with dogs or all-terrain vehicles.
- Do not wet them or get between them and the sea.
- Avoid leaving plastic waste or fishing nets, which can cause entanglements.
The appearance of elephant seals on beaches outside their traditional habitat is a phenomenon that reflects the species’ vulnerability following the avian flu epidemic and the possible effects of climate change. Protecting them requires respect, distance, and public awareness, as each individual is key to the recovery of a population that today faces an uncertain future.
