The species nests in large colonies on cliffs and offshore islands, but also on the mainland. This strictly marine species wanders mostly over continental shelves, feeding on shoaling pelagic fish such as herring (Clupea harengus), mackerel (Scomber scombrus), sprat (Sprattus sprattus) and sandeels (Ammodytes). Prey is mostly caught by plunge-diving from large heights. It also attends trawlers and will form large congregations where food is plentiful. Breeding is highly seasonal starting between March and April. Young birds will migrate to the extreme south of its range, whereas adults range less extensively but still regularly winter in the Mediterranean (Carboneras et al. 2013).

Although the generation length for both EU and Europe regional assessments were calculated using the same methodology, new information arriving after the EU assessments were undertaken gave rise to an update in the generation lengths. This new information was then used for the Europe level assessments giving rise to a difference between the generation lengths used for the EU and Europe regions.

In Europe, this species breeds principally in the United Kingdom, and also notably in Ireland and Iceland.

Conservation Actions Underway
The species is listed on the African Eurasian Waterbird Agreements. It is covered by the EU Birds Directive as a regularly occurring migratory species. It is currently listed within 34 marine Important Bird Areas. Within the EU it is currently listed within nine Special Protection Areas.

Conservation Actions Proposed
Identification and protection of important sites at sea. Collection of more information on individual movements to assist careful placement of offshore wind farms. On-board monitoring programmes on fishing vessels to determine the number of birds caught across the region, and implementation of bycatch mitigation measures where appropriate.