Sébastien Dalloyau spent his childhood close to the Aiguillon bay, where he developed an early interest in coastal and marine ecosystems. His focus on waterbirds led to a PhD on brent geese at the Chizé research centre. In subsequent years, he worked for the French oceanographic research institute (Ifremer) on benthic seagrass and intertidal habitats. His involvement in ecology allowed him to participate in scientific expeditions to the Taimyr peninsula, sub-Antarctic islands and Kazakhstan. He is currently the national coordinator of the brent goose monitoring network within the Goose Specialist Group (Wetlands International). In parallel, he works as a spatial analyst and expert ecologist for a bird conservation trust. He was recently involved in the French bird atlas and he manages projects on farmland birds, waterbirds and bird programmes in the French overseas territories.