Reed Buntings breed all across Eurasia from Iberia to Sakhalin and northern Japan, though rather patchily in southern Europe, Turkey and Iran and in northern Russia. They also occur in Morocco. They are mostly sedentary, except for those breeding in the most northerly parts of their range which move south within the range in winter.
    In Britain they are widespread throughout except in the more barren uplands of Scotland, in the Shetlands and some parts of the Hebrides. They are sedentary apart from some winter movement away from the highest parts of their breeding range, despite which their winter range expanded by 25% between the 1981-84 Winter Atlas and WTA2 partly bolstered by winter migrants from Fenno-Scandia. Their breeding season population increased by 24% between 1995 and 2010, with the increases mostly occurring in eastern and northern Engand and southern Scotland, partly offset by decreases in southeast England.
    In Wiltshire they have been recorded ever since the mid 19th century breeding in small numbers wherever there is water. In winter they were noted forming flocks of up to 200 during the 19th and most of the 20th centuries, though during the last decade of the latter century the highest count was of only 80 in 1995. There were flocks of over 100 in only three winters between 2000 and 2017 - though these included a record 500 on a north Wilts farm on 12 Feb 2012. As for breeding season numbers, Birds of Wiltshire recorded them in 207 tetrads, with breeding in 106; WTA2 recorded them in 212 tetrads, with breeding in 98.                                  

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.