This is a marine species feeding mainly on small fish, squid and crustaceans, but it will also feed on medusae and offal. It feeds mainly on the wing by pattering and fishing, and will occasionally follow ships and attend trawlers. Breeding starts in May and June, resulting in the formation of colonies on rocky ground on offshore islands and stacks that are largely free of mammalian predators (Carboneras et al. 2014).

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 mainly on the Faroe Islands, but also notably in Ireland and the United Kingdom.

Conservation Actions Underway
The species occurs within 88 existing marine Important Bird Areas (IBAs) across the region. Within the EU it is listed in 130 Special Protection Areas, in the Natura 2000 network. Conservation prospects for Mediterranean population recently improved through provision of nestboxes, which has led to increase in numbers breeding through heightened nesting success, while selective culling of gulls on same Spanish islands led to marked reduction (c. 65%) in number of petrels predated, and to relative increase in their survival and breeding success probabilities of 16% and 23%, respectively (Carboneras et al. 2014). There is active rat eradication and management programme in Britain designed to improve the conservation status of both the present species, H. leucorhous and Manx Shearwater (Puffinus puffinus).

Conservation Actions Proposed
Rats, cats and other invasive mammals should be kept off breeding islands and these species should be removed from islands on which they are present (Tucker and Heath 1994).