Cornish Biodiversity Network  -  Supporting Wildlife Recording

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Cornish Red Data (2009)

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.

Gavia immer - Great Northern Diver

Range & Status

Nearctic; in Europe breeding only on Iceland. In Britain and Ireland there are 4000

estimated in winter (chiefly Ireland and west Scotland).

Regional Distribution

Cornwall: a winter visitor and passage migrant in small numbers, with peak figures January to March (averages 150 birds). Sites regularly holding more than ten birds include St. Ives Bay, Mount' s Bay, Falmouth Bay, Carrick Roads, Gerrans Bay, Veryan Bay, St. Austell Bay, Looe, Seaton and Portwrinkle. Of particular importance are gatherings of up to 40 birds in March and April about 2kms off Downderry. As a number of these birds seem to be in a flightless stage it could represent an important moult gathering over the shallows of the Sherbeterry Reef. Up to ten scattered in winter in the Isles of Scilly.

Habitat & Ecology

Sheltered rocky bays. It winters chiefly in ones and twos, being less sociable than other divers.


Inshore fishing (monofilament nets) and oil pollution.


Monitoring of winter numbers. Protected under Schedule 1 of Wildlife and Countryside Act 1981 and Annexe 1 of European Union Conservation of Wild Birds Directive. 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.

Cornish Biodiversity Network. 2017.