Map explanation

This map shows where changes occurred in the breeding season distribution 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.

Gains and improvements

Status

Nos tetrads


Absent to present

68

7%


Present to breeding

44

5%


Absent to breeding

59

6%


No change

Status

Nos tetrads


Present in both

54

6%


Breeding in both

40

4%


Losses and declines

Status

Nos tetrads


Present to absent

114

12%


Breeding to present

50

5%


Breeding to absent

69

8%


Treecreepers are found in temperate and boreal woodland in an area stretching from parts of western Europe (they are absent from much of Iberia, France, Italy and the Low Countries) right across north-central Eurasia to Sakhalin and Japan, south to northeast China and the northern Himalayas, Iran and Turkey.
    In Britain they are absent only from the Northern Isles of Scotland, most of the Outer Hebrides, the highest peaks in mainland Scotland and the English fens. Bird Atlas 2007-2011 recorded a 5% range contraction since the 1968-72 Breeding Atlas, mostly in Cornwall and eastern England. They are very susceptible to cold weather and their numbers drop significantly after harsh winters such as those of 1928/29, 1946/47, 1962/63 and 1978/79, but bounce back quickly when milder weather returns. This causes fluctuations in their abundance from year to year but overall their numbers are stable.
    Treecreepers were reported to be common in Wiltshire in the 19th century and all of the national atlases published in the 20th century reported them as being present in at least 31of Wiltshire's 33 core 10km squares. Birds of Wiltshire recorded them in 371 tetrads, with breeding in 150. WTA2 recorded them in 315 tetrads with breeding in 143.

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: The Breeding and Wintering Birds of Britain and Ireland. BTO Books. 
“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.