The lesser black-backed gull is now the second most abundant wintering waterbird in Andalusian wetlands. Many birds are fitted with GPS loggers on their breeding grounds in northern Europe, and using 42 tagged individuals we studied the connectivity network between different sites and habitats in Andalusia. Thirty seven principal sites (nodes) from seven different habitats (ricefields, landfills, natural lakes, reservoirs, fish ponds, coastal marshes and ports) were identified. By analysing nearly 6,000 gull flights, it was found that Doñana ricefields are the most important node in the network, but that 90% of flights are made between a wetland and a landfill. The 37 nodes are split into 10 functional units (modules) in which gulls tend to fly daily and up to 60 km between a wetland roost site, and a landfill feeding site. This network allows to predict how gulls contribute to seed dispersal, wetland eutrophication, and the spread of pathogens such as antibiotic resistant bacteria. informacion[at]ebd.csic.es: Martín-Vélez et al (2019) Functional connectivity network between terrestrial and aquatic habitats by a generalist waterbird, and implications for biovectoring. Science Total Environm 107: 135886 DOI 10.1016/j.scitotenv.2019.135886