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
W. Palearctic; in Britain and Ireland a former vagrant (with ten records up to 1940)
becoming increasingly frequent as species spread westward across Europe from the Black Sea region, forming tiny satellite colonies within Black-headed Gull colonies, particularly around the southern and eastern shores of the Baltic. First reported nesting in UK in Hampshire in 1968 and now some 15-20 pairs nest within Black-headed Gull colonies in SE England, but nesting is still sporadic. Mixed pairings with Black-headed Gulls are not infrequent \endash two out of 70 birds on St. John' s Lake in late July 2008 were considered to be hybrids.
Cornwall: first record was 1960 (St. Ives) since when numbers increased annually and is reported from all parts of Cornwall in very small numbers. Isles of Scilly: much rarer, although one or two reported annually in recent years.
Habitat & Ecology
Since the mid 1980s increasing numbers arrive from the ' Low countries' (chiefly from Belgium according to their colour rings) from late June through July to undergo post-breeding moult at two key sites \endash St. John' s Lake (peak 35-45 in August) and the Camel (peak 40-50 in September/October); this later peak on the Camel could be St. John' s birds moving on after moult. In 2008 record counts of 70 on St. John' s Lake and 80 on the Camel were made in late July. It is significant that the occasional bird has been found attending breeding colonies of Black-headed Gulls at Colliford and Crowdy indicating potential for future breeding in Cornwall.
Predation at nesting sites, otherwise few.
General monitoring of numbers and keeping a close watch on Black-headed Gull breeding sites.
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.