Interpretation of the comparative results of the two surveys is difficult. Young conifer plantations occupied during the earlier survey had matured to a state of unsuitability by the latter one. The BBS found an increase, on a UK national basis, of 68% since 1994 and by 24% between 2006 and 2007. This may have been in response to favourable conditions at their African wintering grounds resulting in increased survival.
The 1988-91 National Atlas indicated maximum abundance in Pembrokeshire, so it seems safe to apply the UK wide BBS figure to the county plot. This being so, there were probably 480 – 670 pairs breeding in Pembrokeshire at the end of 2007, compared with an estimated 400 pairs in 1988.
Graham Rees
Fieldwork 2003-07 (based on 490 tetrads)
Red = breeding confirmed = 2
Orange = breeding probable = 83
Yellow = breeding possible = 11
Total tetrads in which registered = 96 (19.6%)