Map explanation

This map shows where changes occurred in the relative abundance of the species in Wiltshire between 1995-2000 and 2007-2012, as revealed by the fieldwork for Birds of Wiltshire (Wiltshire Ornithological Society 2007) and the shared fieldwork for Bird Atlas 2007-2011 (BTO 2013) and for Wiltshire Tetrad Atlas 2007-2012.

Key

Relative to average

Nos tetrads


More abundant

179

20%


Equally abundant

7

1%


Less abundant

273

30%



Not surveyed in both periods

Sparrowhawks breed in northwest Africa and the Canary Islands, throughout much of Europe and right across Asia (mainly in the northern half) to Kamchatka and Japan. Many northern continental populations move south in winter, some reaching as far south as northeast Africa, Arabia and southeast Asia.
    Migrating Sparrowhawks from Fenno-Scandia and the Low Countries occur on passage along the east and south coasts of Britain. Otherwise Sparrowhawks seen in Britain are sedentary apart from juveniles dispersing once they become independent. In the 1960s their population in Britain was at a low point as a result of poisoning caused by the widespread use of organochlorine pesticides. The phasing out of these chemicals led to a recovery: Bird Atlas 2007-2011 recorded a 29% increase in distribution since the 1968-72 Breeding Atlas. They now breed throughout Britain except in some parts of the northern highlands of Scotland and there is little difference between their summer and winter distributions.
    In Wiltshire Sparrowhawks were recorded in the 19th century as widespread but nowhere numerous. Numbers were kept down as a result of persecution by gamekeepers but it was not until the mid 20th century that they went into serious decline caused by poisoning by organochlorine pesticide residues in the bodies of their prey species. The banning of these pesticides and the classification of Sparrowhawks as a protected species led first to a halt in the decline and then a steady increase in recorded sightings. Survey results indicated a near trebling of the population in the last three decades of the 20th century and stabilisation thereafter: Birds of Wiltshire recorded their presence in 471 tetrads in summer, with breeding in 124. WTA2 recorded them in 457 tetrads, with breeding in 118.
 

References
The following references are used throughout these species accounts, in the abbreviated form given in quotation marks:
“1968-72 Breeding Atlas” – Sharrack, J.T.R. 1976:  The Atlas of Breeding Birds in Britain and Ireland. T. & A. Poyser
1981-84 Winter Atlas” – Lack, P.C. 1986:  The Atlas of Wintering Birds in Britain and Ireland. T. & A. Poyser
“1988-91 Breeding Atlas” – Gibbons, D.W., Reid, J.B. & Chapman, R.A. 1993: The New Atlas of Breeding Birds in Britain and Ireland 1988-91. T. & A. Poyser
Birds of Wiltshire” – Ferguson-Lees, I.J. et al. 2007 : Birds of Wiltshire, published by the tetrad atlas group of the Wiltshire Ornithological Society after mapping fieldwork 1995-2000. Wiltshire Ornithological Society.
“Bird Atlas 2007-2011” – Balmer, D.E., Gillings, S., Caffrey, B.J., Swann, R.L., Downie, I.S. and Fuller, R.J. 2013: Bird Atlas 2007-2011: the Breeding and Wintering Birds of Britain and Ireland
WTA2” – ("Wiltshire Tetrad Atlas 2 ") the present electronic publication, bringing together the Wiltshire data from “Birds of Wiltshire” and “Bird Atlas 2007-11”, together with data from further fieldwork carried out in 2011 and 2012.
"Hobby" - the annual bird report of the Wiltshire Ornithological Society.