Crossroad for bird migration: France should improve the conservation of its key-wetland sites used by 6 million waterbirds

Abundance of wild species is generally used to prioritize and evaluate networks of protected areas (PAs). Waterbird abundance information, collected through the International Waterbird Census (IWC), is widely used to identify key sites for migratory waterbirds, which are listed in the Critical Site Network (CSN) database. We reviewed IWC information, as well as national and local surveys of breeding populations, for each significant wetland and each waterbird species in all French territories within the African-Eurasian Migratory Waterbird Agreement range. We used this review to update the French network of critical sites. We then confronted these waterbird data with the corresponding site-specific data provided by the CSN in order to assess its accuracy for French critical sites. In addition, these waterbird data were used to assess the efficiency of the current network of French PAs to encompass these critical sites, with a particular focus on Ramsar wetlands. We updated the French list of critical sites from the outdated 129 sites listed by the CSN to only 97, including 32 sites not previously detected by the CSN. We also showed that only one French critical site out of five benefits from the strongest category of protection over more than three-quarters of its area. Furthermore, almost one critical site out of five has no protection at all over more than half of its area. The French network of critical sites thus lacks adequate protection, including for some of the most important ones in terms of waterbird abundance and diversity. We advocate for a renewed French effort in wetland conservation and support to the CSN tool maintenance.