Cory’s shearwaters are the most widespread seabirds in subtropical latitudes of the NE Atlantic. After breeding, they travel to the South Atlantic, some even reaching the Indian Ocean. Their migrations are spectacular and at the breeding sites, partly due to their noisy behaviour, they are widely known by local inhabitants and visitors. Hence, these top marine predators can be used as sentinel organisms of the state of the ocean, because they integrate environmental signals over large spatial and temporal scales, and they can convey relevant information for decision-makers. Results from monitoring of indicator species such as this one can also be better understood by the public, better than complex information about entire ecosystems.

 

The largest world colony of Cory’s shearwaters is the one at the Selvagens Islands (Portugal). Here, regular studies have been carried out since the 1970s by several researchers. After a period without directed research efforts around the turn of the century, our team started a long-term monitoring project in 2004. The monitoring includes a detailed demographic study, plus several behavioural and ecological research projects, including aspects as diverse as the biology of senescence, the foraging ecology and, particularly, different aspects of migratory behaviour. Cory’s shearwater studies are not restricted to the Selvagens and we also do some work at Berlenga (on the Portuguese shelf), Desertas (Madeira) and in the Azores. We also take the opportunity of our long stays on these islands to do research on other seabirds, including several petrel species (particularly with Bulwer’s petrels) and gulls.