Sunday, August 4, 2013 at 9:38AM Parus major newtoni
Common resident. Marked westward movement in late autumn when crosses to Skomer and Ramsey, but not Skokholm and Grassholm.
R.M.Lockley, G.C.S.Ingram, H.M.Salmon, 1949, The Birds of Pembrokeshire, The West Wales Field Society
Wednesday, July 4, 2012 at 12:31PM It was estimated that there were 13,500 pairs breeding in the county at the end of the survey of 1984-88, based on an estimated average density of 35 pairs per tetrad. The 1988-91 National Atlas calculated an average density of about 26 pairs per tetrad and their abundance map showed Pembrokeshire holding about average abundance. This suggests the county population was about 10,100 pairs at that time.
The Pembrokeshire survey of 2003-07 showed a 9% increase in distribution and the BBS showed a 34% increase in numbers for Wales. Applying these findings indicates there were about 14,700 pairs breeding in Pembrokeshire at the end of 2007.
As with the Blue Tit, increased winters survival in response to widespread garden feeding will have contributed to the increase in the breeding population.
Graham Rees
Fieldwork 2003-07 (based on 490 tetrads)
Red = breeding confirmed = 260
Orange = breeding probable = 131
Yellow = breeding possible = 30
Total tetrads in which registered = 421 (85.9%)
Monday, December 26, 2011 at 2:28PM 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%)
Friday, November 11, 2011 at 2:57PM 
The BTO winter atlas showed that Great Tits were recorded in most 10km squares during the winters of 1981-82, 1982-82 and 1983-84.
The darker the colour, the higher the relative total count for each 10km square. The darkest blue represents over 38 birds recorded per day.
Graham Rees
Friday, November 11, 2011 at 2:56PM 
Red = breeding confirmed
Orange = breeding probable
Yellow = breeding possible
Sunday, September 26, 2010 at 9:43PM Species account from M Mathew, 1894, "The Birds of Pembrokeshire and its islands"
