In France, the population increase of European Herring Gull and Yellow-legged gull (Larus argentatus ; Larus michahellis) in the 20th century on the Atlantic and Mediterranean coast was accompanied by their expansion outside their original site and nesting in the urban areas. This novel situation dated back to the eighties in France leads to conflicts between humans and birds, first with managers of natural areas and shellfish farmers, then with city dwellers who complain about the nests on their roofs. In the 1990s, municipalities set up management systems to control the number of gulls in the city. The present article focuses on understanding how this “gull problem” was constructed in France. It studies how seagull protected by law and appreciated by the inhabitants of the coast has passed to a controlled and regulated bird, considered annoying and invasive by scientists and city dwellers. The aim is to understand the evolution of the seagull representations and analyze how scientists, managers and municipalities seized this dynamic of populations of the bird and these conflicts between humans and birds. The article underlines the importance of developing research on these hybrid communities, composed of humans and non-humans so that people and seagulls can coexist durably on the same territory (Gramaglia, 2010).