Trophic ecology and at-sea distribution of tropical seabirds during the breeding season. Use of non-invasive techniques (e.g. fatty acids and stable isotopes) to achieve the diet composition. GPS devices to achieve seabirds' distribution and to identify the at-sea core foraging areas. Fieldwork carried out on a desert islet in Cabo Verde during a few months to monitor the nests, from the start of incubation until the end of breeding season.