The Wiltshire population of this North American species derives from escapes and releases from wildfowl collections. Although these collections were first established in Britain in the late 17th century, Canada Geese were not recorded in Wiltshire until 1867 and even after that there were only sporadic records of small numbers until well into the second half of the 20th century. Breeding was first recorded in the county in 1967 but from then on numbers increased rapidly. They are now common on most Wiltshire rivers, canals and lakes.
    Birds of Wiltshire recorded the presence of the species in 197 tetrads with breeding in 102 of them. There was little overall change in distribution between 1997-2000 and 2007-11 (Bird Atlas 2007- 2011 recorded the species in 196 Wiltshire tetrads), though the number of tetrads in which breeding was recorded increased by 22% to 124.
    There was also a marked increase in the size of flocks: the average size of the maximum recorded flock increased from 369 in 1997-2000 to 468 in 2007-2011 (though the county record remains the 639 recorded at the Cotswold Water Park in 1993). Birds of Wiltshire estimated the total winter population in the county at around 2000.

 

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.