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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

17

2%


Equally abundant

6

1%


Less abundant

37

4%



Not surveyed in both periods

Sand Martins breed throughout most of the Northern Hemisphere, including in every European country except Iceland. The European population winters in sub-Saharan Africa, the British population almost exclusively in West Africa. They are vulnerable to climate variations in their wintering areas and their numbers can crash in years of severe drought in the African Sahel. It can take two years or more for their populations to recover after such a crash. Pairs regularly fledge two broods which helps to speed the rate of recovery.

            In Great Britain they are widespread north of a line drawn from the Wash to the Severn estuary but more sparsely scattered south of that line. Bird Atlas 2007-2011 recorded them in 61% of 10km squares, which represented a 14% reduction in range since the 1968-72 Bird Atlas made up by a 506 fall in the number of occupied 10km squares mostly south of the Wash/Severn dividing line, partly offset by a 212 increase in occupied squares mainly in northwest Scotland.

            In Wiltshire they have been recorded nesting in at least one year since 1949 in 23 different sites, but Birds of Wiltshire recorded breeding in only 13 locations, a total which had fallen to just six (five at the CWP and one at Calne Sand-pits) by the time of the fieldwork for WTA2 between 2007 and 2012. The 2017 Wiltshire Bird Report in Hobby 24 recorded them breeding in just a single CWP site.

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.

 

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