Reconstructing the historical distribution and local extinction of the giant otter Pteronura brasiliensis in the Atlantic Forest of South America

Quantifying the distribution of an endangered species in space and time is crucial for planning management and conservation actions. The giant otter (Pteronura brasiliensis) is an endangered South American mammal that is considered to be extinct in the Atlantic Forest biome. Historical records of P. brasiliensis were used to reconstruct its original distribution in the Atlantic Forest biome. Based on the historical records and ecological niche models, the original distribution and amount of habitat area lost for the species were estimated. The potential impacts of dams in planning reintroductions for the species were also assessed. Twenty-six records of P. brasiliensis made between 1769 and 1999 were found. Most of the records are concentrated in the Parana River basin. Only six records were based on voucher specimens and photographs. Areas in the southern (Parana state, Brazil) and central (Bahia and Minas Gerais states, Brazil) Atlantic Forest were recovered as highly suitable for the species, even after considering the negative impact of dams. The ecological niche models suggested that P. brasiliensis formerly occupied an area of 909,257 km(2) in the Atlantic Forest. The forested rivers, along the upper Parana basin, in northern Argentina and southern Brazil were the last refugia of the species. Pelt trade was probably a major factor in the species' disappearance, which is evidenced by the fact that Brazilian stakeholders, in Atlantic Forest sites, restricted giant otter hunting as early as 1948. The results show that historical records and ecological niche models can be effectively combined and may guide in-situ conservation actions by identifying potential areas for reintroductions.

Automated summary

This study quantified the distribution of the endangered giant otter in the Atlantic Forest biome using historical records and ecological niche models. The results showed the main distribution area of the species in the Parana River basin, with suitable habitats in the southern and central Atlantic Forest regions despite the potential negative impact of dams.