The descriptive text, below the map, is from the Cornish Red Data Book (2009). The map on this web page depicts the organisms distribution and shows the records made pre-2000 and those made since.
Range & Status
North Atlantic species; in Britain and Ireland 90,000 breeding pairs (chiefly in the north), 20% of world population.
Cornwall: breeds at scattered sites along north and west coast and on south coast east to Nare Head. Some 7-800 birds counted at breeding sites in 1985-87
survey, indicating little change since 1967-70 survey (Smaldon, 1986 and 1988), although numbers in west Cornwall seem to have declined. 537 birds counted on ledges in 2000 survey. Isles of Scilly: some 342 pairs scattered through the islands in 2006. Our populations are amongst the most southerly in the world.
Habitat & Ecology
Breeds in scattered colonies amongst boulders and in crevices on islets and cliffs. Very difficult to assess actual number of pairs as nest sites are mostly hidden. Remains at sea between breeding seasons.
Marine pollution, inshore fishing (monofilament nets), and food shortages.
Monitoring of breeding numbers. Listed (long list) as a globally threatened/declining species (BSGR, 1995).
I.J. Bennallick, S. Board, C.N. French, P.A. Gainey, C. Neil, R. Parslow, A. Spalding and P.E. Tompsett. eds. 2009. Red Data Book for Cornwall and the Isles of Scilly. 2nd Edition.Croceago Press.
The Cornish Red Data Book Project was led by the Cornwall and Isles of Scilly Federation for Biological Recorders (CISFBR). The full text and species accounts (minus the maps) are available on the CISFBR website.