An exclusively marine, medium-sized seabird, occupying rocky cliffs along sea coasts and offshore islands in the breeding season (Gaston & Hipfner 2020). A high-arctic species with circumpolar distribution but, in Europe, only found in Iceland, Norway and Russia (Keller et al. 2020). An oceanic migrant with high-latitude populations (Svalbard) undertaking the longest migrations, while those from more S locations (Iceland, N Norway) move less far, or disperse locally. Although its population trend in Europe is unknown (BirdLife International 2021), rapid population declines have been recorded in the N Atlantic (Frederiksen et al. 2019, Gardarsson et al. 2019).