Great Spotted Woodpeckers are found from the Canaries and northwest Africa, right across Eurasia to Kamchatca and Japan, south in the west to Turkey and northern Iran and in China to northern parts of southeast Asia. It is the most numerous of the ten woodpecker species found in Europe, and the most widespread of the three species found in Britain.
    In Great Britain Bird Atlas 2007-2011 reported a population increase of 408% since 1967, with distribution expanding into previously unoccupied areas, particularly in northern England and Scotland. The causes of this expansion are not fully understood but are thought to possibly include higher winter survival rates following greater availability of food on bird tables, increased availability of feeding and nesting sites in dead elms following the spread of Dutch Elm disease and decreased competition for nesting sites from a declining population of Common Starlings.
    In Wiltshire in the 19th century Great Spotted Woodpeckers were reckoned to be the least common of the three indigenous woodpecker species, although they were widely distributed around the county. By the mid 20th century however their numbers had expanded and easily surpassed the Green Woodpecker as the county's most numerous woodpecker species. The upward trend has continued since: Birds of Wiltshire recorded them in 587 tetrads, with breeding probable or confirmed in 242; WTA2 has them in 723 tetrads with breeding in 301.

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.