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 one million pairs in 1960s, but population crashed by 75% in 1968-69; at least 85-270,000 pairs in 1995. Decrease attributed to desertification of principal wintering areas in Sahel zone of West Africa.
Cornwall: summer visitor, breeding in very small colonies. Some 45 colonies supporting 250 pairs throughout Cornwall are detailed in Penhallurick (1978), but several of these were by then no longer in use. Numbers reached their lowest ebb in the mid 1980s, since when there has been a slight upward turn. In 1993 there were some 80-100 pairs nesting at six very scattered sites, the largest of which held at least 40 pairs. Isles of Scilly: one - three pairs nested 1969 and 1970.
Habitat & Ecology
Breeds in small colonies in holes in sand-pits and river banks, in Cornwall even in suitable cliff faces.
Human disturbance at nesting colonies i.e. working quarries.
Some sites are 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.