We report the predation of a puma Puma concolor by an adult anaconda Eunectes murinus that occurred in south-eastern Brazil. Despite the death of both animals, the incident raises important questions regarding the role they play in their respective niches in the wild.

We report here a natural predation event of an adult female puma by an adult anaconda that occurred in the municipality of Promissão, on the north-western border of São Paulo state, Brazil. The incident was discovered when monitoring an adult female puma through radiotelemetry, as part of a research project on pumas, along the margins of a hydroelectric dam, on the lower Tietê riverbasin. The study is the result of a partnership between the Pró-Carnívoros Institute and the Hydroelectric Power Company AES Tietê, a subsidiary of AES Corp. (SISBIO Licence # 45774-1). The goal of the study is to evaluate the environmental health of the areas under the influence of AES Tietê, using the puma as a conservation tool, through the assessment, evaluation, and monitoring of their population in the study area