Abstract

The Arctic Skua Stercorarius parasiticus is one Britain’s rarest breeding seabirds. The entire British population is restricted to Scotland and has declined by 79% between 1986 and 2021. Most research on the skua’s decline has focused on the breeding grounds. However, the species is a long-distance migrant, spending most of the year away from its breeding colonies. To date, potential threats to the species during the non-breeding season have largely been overlooked owing to limited knowledge on its movements and therefore the obstacles birds may face during this time. Here, we detail the migratory routes, staging and wintering areas and migratory strategies of geolocator-tagged, Scottish-breeding Arctic Skuas.