Argentina Updates Red List of Endangered Mammals, Highlighting New Threats and Refining Conservation Efforts

Scientists in Argentina have completed an updated assessment of the country’s mammal species at risk of extinction, revealing new insights into population trends, emerging threats, and the impact of non-native species. The updated national Red List, presented by the Argentine Society for the Study of Mammals (SAREM), evaluates 417 native mammal species – 22 more than the previous assessment in 2019 – and incorporates a new method for measuring the impact of invasive species.

Expanding the Scope of Conservation Assessment

The increase in the number of assessed species reflects both the discovery of previously unrecorded mammals and taxonomic revisions, clarifying the distinct status of species once grouped together. For example, the species commonly known as the pampas cat (Leopardus colocolo) was found to comprise five different species, four of which are present in Argentina. Species previously only observed in neighboring countries, such as the coruro (Spalacopus cyanus), have now been identified within Argentina and included in the assessment. Even re-examined skeletal remains, like those of the long-extinct rat Octomys rosiae, have been reclassified and added to the list.

Shifting Threat Levels and Improved Understanding

The assessment isn’t solely about adding new species; it also involves refining the understanding of existing threats. Threat levels were revised for several species, not always due to population changes, but due to improved data and understanding of their habitats. The kodkod (Leopardus guigna) was downlisted from endangered to vulnerable, although the water opossum (Chironectes minimus) was uplisted from vulnerable to endangered, and the marsh deer (Blastocerus dichotomus) moved from near threatened to vulnerable.

Javier Pereira, general coordinator of the 2025 Categorization of the Mammals of Argentina, emphasized the importance of localized assessments. “A species listed as least concern globally might still face more severe threats in a specific region,” he stated. “Having very good knowledge of biodiversity in each country, each region, each province, is key to making management or conservation decisions.”

Addressing the Impact of Non-Native Species

For the first time, SAREM utilized the environmental impact classification for alien taxa (EICAT) to assess the damage caused by non-native species to Argentina’s biodiversity. Argentina currently has 21 non-native species, including the domestic house cat (Felis catus), red deer (Cervus elaphus), and beaver (Castor canadensis). The Asiatic red-bellied squirrel (Callosciurus erythraeus), for example, has caused both ecological and economic damage by gnawing on infrastructure and impacting native tree populations.

Strengthening Conservation Policy

In 2021, Argentina codified the conservation categories established through the national mammal review, enabling them to inform environmental impact assessments and other policy decisions. This provides a formal basis for legislation aimed at protecting vulnerable mammal populations. The updated Red List provides crucial data for prioritizing conservation efforts and protecting critical biodiversity areas.

“All this knowledge gives us the power to understand many aspects of biodiversity management, and that’s what we always seek to highlight through this work,” Pereira concluded.