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
Almost worldwide, but everywhere rather localised, with marked European decline in recent decades; in Britain and Ireland 4000 pairs in 1997 (compared to 12,000 in England and Wales in 1932).
Cornwall: 200-250 pairs estimated (5% of Britain and Ireland total), with greatest densities in mid and east Cornwall (French & Ramsden 2005); considered to have declined, markedly so during the 1980s, but density of population still quite high compared to most of Europe. Isles of Scilly: absent.
Habitat & Ecology
Favours open agricultural land, with tracts of rough field margins and rough grassland. Breeds in hollow trees and old buildings.
Pesticides are known to have been an early cause of decline, but aggravated by tendency towards wetter springs and colder winters in recent decades. The number of road casualties (an estimated 5000 a year in Britain in 1987) and the recent trend to convert disused barns into dwellings, as well as the felling of dead trees and ploughing of rough grassland, have also been suggested as other major factors in the decrease.
Local planning authorities could insist on the provision of nesting spaces and nest-boxes when dealing with barn conversion applications. Areas of rough, unsprayed grassland could be left by stream sides, woodland borders and hedges. Open drinking troughs and tanks should be fitted with a close-fitting plank of wood to prevent accidental drowning. Protected under the Wildlife and Countryside Act 1981. 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.