Gavia stellata
Divers (also known as loons in the US) nest in the north of the Palaearctic zone, in Siberia, Iceland and North America. During the breeding season, these aquatic birds fish in the calm waters of lakes, either on the surface or by diving. In winter, divers frequent coastal waters in small groups, particularly in sheltered Breton bays and in the northern Bay of Biscay. The red-throated diver is the most common species on our coasts, coming mostly from Fennoscandinavia, Scotland and Iceland. Several hundreds o thousands of individuals are also seen every year migrating to southern Europe. Divers are regularly the victims of entanglement in drift nets and pollution, for example by oil spills. Several studies have shown that divers can be greatly displaced by the installation of offshore wind turbines, which can restrict their distribution and reduce access to areas that are favourable for feeding.
The divers are captured at sea from a boat on their wintering areas and fitted with OT20-D GPS devices weighing around 22g and including a pressure sensor to record the duration and depth of dives as well as their geographical positions and flight altitude. This data will provide a better understanding of the distribution and feeding areas of divers on our coasts in winter, as well as their migratory movements at sea.