The species is marine and pelagic usually keeping well away from land, except at colonies (Carboneras et al. 2014). It breeds on barren offshore islands, occupying cliffs, caves and boulder fields; sometimes inland on rocky slopes, up to 435 m above sea-level (Thibault et al. 1997). Birds return to colonies in February and breeding starts April (Carboneras et al. 2014). It is colonial, nesting in burrows, rock crevices, natural hollows or cracks, sometimes in caves up to c. 20 m deep (Carboneras et al. 2014). Clutch size a single egg (Thibault et al. 1997). It feeds mainly on fish, squid, crustaceans, other zooplankton and offal at least during the breeding season (Brooke 2004). The species is migratory, generally departing the breeding grounds in mid to late October (Carboneras et al. 2014). It is known to winter mainly in the Canary Current (Navarro et al. 2009). Mediterranean birds exit into the Atlantic, where they move rapidly south, but also uncommon to rare off eastern North America (mainly May-October) (Howell 2012), and some birds occasionally range northwards in the north-east Atlantic, to British Isles (Fisher and Flood, 2010) and Sweden (Erterius 2005), with other accidental records from Czech Republic, Austria, Switzerland and Ukraine (Thibault et al. 1997).

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 largely in Italy and Greece, and also notably in Spain and Malta.

Conservation Actions Underway
EU Birds Directive Annex I. Bern Convention Appendix II. In most areas human exploitation has ceased or is only occasional and some breeding islands have been declared reserves. Feasibility of eradicating Rattus rattus from Italian islands with breeding seabirds has been evaluated, but would apparently be of much greater benefit to Puffinus yelkouan than the present species, while an intensive rat-control programme was successfully initiated at two subcolonies on Chafarinas Is (Spain) in 1999-2004 (Carboneras et al. 2014). In addition, censuses, monitoring, creation of protected areas and studies of the species's biology and ecology have all taken place. At colonies mammal control, provision of artificial nest sites and management to reduce disturbance have also been implemented (Anselme & Durand 2012).

Conservation Actions Proposed
Rat control programmes appear to deliver only a small increase in the population growth rate whereas change in adult survival has a much larger impact. Therefore increasing adult survival is of greater importance and rat eradication programmes can only be used to 'buy' time (Igual et al. 2009). Further research and monitoring is required and the continuation of measures to reduce disturbance. Actions to reduce the impact of L. michahellis where appropriate should be implemented. An international network with the aim to prioritize conservation actions and monitoring programmes should be developed. Mortality in longline fishing should be monitored and measures such as setting longlines only at certain times of the day to reduce the accidental catch should be followed (Belda and Sanchez 2001).