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
Holarctic; in Britain and Ireland there are 30-50 breeding pairs; 120 in winter.
Cornwall: scarce winter visitor and passage migrant, numbers fluctuate but has decreased since 1960s. 10 - 20 birds annually in recent years but regularly only at Carrick Roads (maximum 10 - 15), elsewhere sporadic appearances of 15. A rare visitor, not annual, in the Isles of Scilly.
Habitat & Ecology
Sheltered coastal bays and estuary mouths, chiefly on south Cornish coast; regular also on reservoirs.
Inshore fishing (monofilament nets) and oil pollution. The decline in winter numbers in recent decades has been mirrored by the demise of the Irish breeding population.
Monitoring of winter 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.