Map explanation

This map shows where changes occurred in the breeding season distribution 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.

Gains and improvements

Status

Nos tetrads


Absent to present

93

10%


Present to breeding

65

7%


Absent to breeding

11

1%


No change

Status

Nos tetrads


Present in both

306

33%


Breeding in both

73

8%


Losses and declines

Status

Nos tetrads


Present to absent

156

17%


Breeding to present

88

10%


Breeding to absent

29

3%


Common Swifts in summer are among the most northerly and most widely distributed of the 90 or so swift species in the world. They breed throughout Europe (except in northern Scotland, Fenno-Scandia and Russia), south to Turkey and Israel, in northwest Africa and across much of central Asia to China. All but a very small proportion migrate to winter in sub-Saharan Africa. The distribution of the European population has remained stable overall since the 1960s though the actual numbers have deceased. The British breeding population is estimated to have declined by 46% between 1996 and 2015.
    In Wiltshire Swifts have been common in summer ever since records began, so much so that 19th and 20th century commentaters made few attempts to produce counts or to estimate variations in population numbers, apart from one comment in 1981 that the modernisation of old buildings had led to losses of nesting sites and consequent reduction in numbers in the larger towns. Fieldwork for Birds of Wiltshire and WTA2 revealed a marked decline in the distribution of the species between 1995-2000 and 2007-2012: Birds of Wiltshire recorded them in 717 Wiltshire tetrads, with breeding in 190 of them; WTA2 in 636 tetrads, with breeding in 149. A concerted effort is now being made by Swift protection groups to preserve traditional nesting sites and provide replacements for lost sites in the form of nest-boxes on existing buildings and specially designed nesting blocks in new builds.


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.