Saturday, August 10, 2013 at 8:19AM Sylvia atricapilla atricapilla
Fairly common summer resident in suitable tangled copses even in the west. Appears on the islands with last species in late April and early May; rarely in autumn.
R.M.Lockley, G.C.S.Ingram, H.M.Salmon, 1949, The Birds of Pembrokeshire, The West Wales Field Society
Friday, June 29, 2012 at 6:06PM A predominantly grey warbler, the male with a distinctive black cap, the female’s cap ginger, the Blackcap inhabits the cover of trees and scrub, where it nests. It is found in all bar the barest parts of the county. Its melodic, fluty, song draws attention to its presence but it can be difficult to locate. Most Blackcaps are summer visitors to Pembrokeshire.
A variety of monitoring schemes have concluded that Blackcaps have been consistently increasing since at least the 1970’s. Despite much conjecture, no convincing explanation has been suggested as to why this has been so. The 2003-07 county survey found that there had been a 17% increase in distribution compared with that found in 1984-88. The BBS has calculated an increase of 87% in Wales between 1994 and 2007. Applying these increases locally suggests approaching 13,000 pairs were breeding in Pembrokeshire at the end of 2007, compared to 7,000 pairs estimated in 1988.
Graham Rees
Fieldwork 2003-07 (based on 490 tetrads)
Red = breeding confirmed = 71
Orange = breeding probable = 317
Yellow = breeding possible = 9
Total tetrads in which registered = 397 (81%)
Sunday, December 25, 2011 at 11:04AM Breeding summer visitor, passage migrant and winter visitor
Mathew (1894) classified the Blackcap as a summer visitor that was far from common, with a few pairs in the north-east of the county, also noting that it was "stated to be common in the extreme south". Lockley etal. (1949) regarded it as a "fairly common" summer resident which appeared on the islands on spring migration but rarely in autumn.
Today they breed throughout Pembrokeshire and appear to be equally common in all parts of the county. An average density of 20 pairs per tetrad, based on singing birds, suggests that the total breeding population is about 7,000 pairs. They arrive at the breeding grounds throughout April and early May, whereas migrants pass through the islands from 26 March to mid-June, most of them in April. Autumn passage has been noted from 23 July to 30 November with a distinct peak in October.
Blackcaps regularly winter here, though the birds involved are not neccessarily part of the local breeding stock. Wintering birds obscure the validity of early and late passage dates, but, as they do not normally winter on Skokholm and Skomer, island data has been used to delineate migration periods.
Fieldwork 1984-88 (based on 478 tetrads)
Red = breeding confirmed = 86
Orange = breeding probable = 248
Yellow = breeding possible = 5
Total tetrads in which registered = 339 (70.9%)
Thursday, November 10, 2011 at 10:12PM 
Red = breeding confirmed
Orange = breeding probable
Yellow = breeding possible
Friday, September 16, 2011 at 11:40AM 
The BTO winter atlas showed that Blackcaps were present in almost 40% of 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 3 birds recorded per day.
Blackcaps visiting bird feeders has aided detection.
Graham Rees
Sunday, September 26, 2010 at 12:45PM Species account from M Mathew, 1894, "The Birds of Pembrokeshire and its islands"
