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
Palearctic; in Britain and Ireland 1080 breeding pairs (Scotland); 700 in winter.
Cornwall: passage migrant and winter visitor in small numbers to all estuaries; peak numbers occur late August/September when Cornwall total some 120-180 birds; 60-80 remain through the winter (30% of British total). Key passage sites are Camel estuary, Devoran, the Lynher and St. John' s /Millbrook Lakes which hold up to 30 birds at peak passage times; 15-20 (5% of UK total) are regularly reported in winter on the Lynher and Millbrook (both are Nationally significant). Numbers both on passage and in winter on the Lynher and St John' s Lake have declined by 30-50% since 2000, for no obvious reason. Isles of Scilly: up to 10-20 in winter, and 15-20 on passage, chiefly on Tresco.
Habitat & Ecology
Ones and twos feed by tidal channels and upper limits of creeks, gathering for communal roosts (only then can accurate counts be made).
Estuary developments; the main roost site at Lower Anderton, Millbrook (holding 5% of UK winter total) is potentially threatened by planned development of nearby Southdown.
The main estuary sites are SSSI, the Tamar complex is mostly included within an AONB (but St. John' s and Millbrook are excluded); the main Millbrook roost site is also outside the boundary of the SSSI. 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.