Background Réunion Island hosts one of the most unique seabird communities in the world, including two endangered endemic petrels, the Barau's petrel (Pterodroma baraui) and the Mascarene black petrel (Pseudobulweria aterrima). These species are in dire need of emergency conservation measures. They already benefit from national action plans, but the implementation of conservation actions suffers from ecological, technical and financial constraints, resulting in conflicts between nature conservation and socio-economic development. France has the sixth highest proportion of its endemic species threatened at the European level, although these species are mainly located in overseas territories where conservation efforts need to be stepped up to fully implement the EU Biodiversity Strategy by 2020. Objectives The overall objective of the LIFE PETRELS project is to stop the loss of Réunion's biodiversity by saving two endemic petrels from extinction. In order to overcome the technical and financial difficulties that hamper the adoption of appropriate conservation measures, demonstrative and innovative management strategies will be implemented. The aim is develop conservation tools that are adapted to the island’s urban context, in order to involve stakeholders in efforts to reduce threats to seabirds and to undertake conservation actions. Expected results: Reversal of the catastrophic trend of petrel populations in the Réunion National Park; Development of appropriate conservation management techniques, including the identification of breeding colonies and artificial breeding; Enhanced biological knowledge for both endemic petrel species; Control of the spread of invasive species, especially rats and cats, in the remotest areas of the island; Exchange and dissemination of the results to other nature conservation bodies; Consultations with local stakeholders; and Raised awareness of the need to protect these two species.