Breeding resident
A common resident since at least Mathew's (1894) time, Great Tits breed throughout Pembrokeshire, being absent only from the bare mountain tops and the offshore islands, with the exception of Caldey. Census work from Dyfed Wildlife Trust reserves suggests that a density of 35 pairs per tetrad would be a reasonably good average across the county, which means the total breeding population is probably about 13,500 pairs.
They are eruptive in some autumns and are found on exposed headlands and reach some of the offshore islands, though in smaller numbers than Blue or Coal Tits.
Fieldwork 1984-88 (based on 478 tetrads)
Red = breeding confirmed = 225
Orange = breeding probable = 114
Yellow = breeding possible = 48
Total tetrads in which registered = 387 (81%)