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 arctica - Black-throated Diver

Range & Status

Holarctic; in Britain and Ireland there are 170 breeding pairs in Scotland and 700 wintering (chiefly western Scotland).

Regional Distribution

Cornwall: a winter and passage migrant in small numbers, with 80,100 on the south coast between January and April (Lock & Robins, 1994). Chief sites are Gerrans Bay and Veryan Bay (these two sites holding up to 70 birds, 5% of British and Irish winter population); four other sites (Mounts Bay, Falmouth Bay, St. Austell Bay and Portwrinkle) hold more than 10 less regularly. It is a scarce visitor to Isles of Scilly.

Habitat & Ecology

Occurs in deep water bays along the south Cornwall coast. Being chiefly an offshore species, the presence of this species is difficult to ascertain unless the sea is very calm.


Inshore fishing (monofilament nets) and oil pollution.

Conservation 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.