No change in distribution is evident when the results of the two breeding bird surveys are compared, Blackbirds being found everywhere in the county bar the hill tops and the smallest offshore islands. The 1988-91 National Atlas indicated high to maximum abundance in Pembrokeshire, suggesting a higher density than the UK average, so the estimated 100 pairs per tetrad used with the 1984-88 survey results was probably realistic at 45,000 pairs. Since then the BBS has calculated a 47% increase in Wales over the period 1994 – 2007. Applying this increase to the 2003-07 survey plot suggests the Pembrokeshire breeding population could have reached about 66,000 pairs by 2007.
Graham Rees
Fieldwork 2003-07 (based on 490 tetrads)
Red = breeding confirmed = 317
Orange = breeding probable = 128
Yellow = breeding possible = 10
Total tetrads in which registered = 455 (92.9%)