Buzzards, one of the world's most numerous raptor species, breed across temperate Eurasia from Iberia to Japan. In the western part of their range they are essentially sedentary apart from some, mostly local, wandering by non-breeding young adults. Those breeding in East Europe and Asia on the other hand migrate south in winter, in some cases as far as southern Africa.
    In Britain Buzzard numbers have fluctuated greatly over the years. In the 18th century they nested throughout the country, but then over-zealous game preservation practice during the 19th century led to their being persecuted, until by 1915 their range had been cut back to just a narrow broken strip from west Scotland south, patchily, through mid Wales to Devon and Cornwall. At which point the tide turned. Changing agricultural practices, reductions in game-keeping activities in the two world wars and a reduction in hostility to raptors in general gave them the opportunity to build up their numbers and start to spread again. But the process went into reverse again in the 1950s and 1960s following increasing use of organochlorine pesticides and the decimation of the population of rabbits (one of their principal prey items) by myxomatosis. This however proved to be only temporary: Bird Atlas 2007-2011 recorded an increase of more than 100% in range over the whole of the British Isles since the 1968-72 Breeding Atlas, recapturing all the territory they originally occupied.
    In Wiltshire, fluctuations have reflected the national picture. From being nearly extinct in the county in the late 19th and early 20th centuries, with only ocasional records of wanderers, sightings became more regular in the 1920s. Breeding was first recorded in 1934 and by 1936 was becoming common in the county. After the hiatus in the decades immediately following the War (see comments above on the national situation), numbers again began to rise rapidly. Birds of Wiltshire recorded them in 706 tetrads with breeding in 222. WTA2 recorded them in 893 tetrads, breeding in 486.

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.