Friday, August 9, 2013 at 7:41AM Phylloscopus sibilatrix
Local summer resident, chiefly in larger woods in eastern half of county, but breeds on west bank of Cleddau (Benton Woods and hear Hook). Only once seen on islands (Skomer, 9 may 1946)
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 6:11PM This summer visitor is the largest and most colourful of the British leaf warblers, its green upperparts contrasting with its bright yellow breast and silky white belly. Seeing the male trembling while it delivers its trilling song is a fulfilling experience. Closed canopy woodland with little understory is the favoured habitat, where the nest is concealed on the ground among rank vegetation.
About a third of the UK population is found in Wales, where ideal habitat of deciduous woodland grazed by sheep has very little understory growth. Those breeding in Pembrokeshire are at the periphery of their distribution and have been found to be less abundant than in the main area. This may in part reflect the fact that the majority of county’s woodlands are not grazed and the understory and shrub layers are too dense for this species.
The UK population was estimated at 17,200 singing males in 1984–85 and the Pembrokeshire total at 250 singing males in 1988. A subsequent steady decline has been detected across northern and western Europe, the UK total being estimated at 9,000 -10,500 by the year 2000. The 2003-07 Pembrokeshire survey found that distribution had decreased by 50% compared with 1984-88, the remaining total being no more than 100 singing males, perhaps fewer.
Graham Rees
Fieldwork 2003-07 (based on 490 tetrads)
Red = breeding confirmed = 3
Orange = breeding probable = 19
Yellow = breeding possible = 3
Total tetrads in which registered = 25 (5.1%)
Sunday, December 25, 2011 at 11:20AM Breeding summer visitor and passage migrant. Not recorded from November to March
Mathew (1894) knew of no definite breeding records for Wood Warbler, and described it as a scarce and very local summer visitor, doubting if it occurred west of the Preseli Mountains, whereas Lockley et al. (1949) recorded it nesting in the east of the county and along the Western Cleddau between Hook and Benton. They also noted it had been recorded just once on the islands, at Skomer on 9 May 1946.
Wood Warblers are still very local breeders, their distribution showing a heavy easterly bias (see map). Their favoured habitat is oak and beech woodland, though in recent years a few pairs have occupied pure sitka and larch plantations. Apparently suitable woodlands exist west of this range, such as St Bride's and Hilton Woods, and males have been known to occupy these areas, singing for a week or more before moving on. They arrive on the breeding grounds between 25 April and early May, but when they depart has not apparently been recorded. On the assumption that most nesting sites were located during the 1984-1988 Breeding Birds Survey, and that singing males are indicative of breeding pairs, the total county population can be fairly accurately assessed at about 250 pairs.
The Wood Warbler is a scarce passage migrant to the mainland coast and offshore islands, one or two being noted in most years. Spring records usually fall between 25 April and 25 May, though one was at Skokholm on 7 April 1977.
One or two autumn passage birds occur between 8 August and 27 September in most years, with one at Strumble Head on 2 October 1983. Autumn birds, although scarce, have occurred with increasing frequency in the last ten years.
Fieldwork 1984-88 (based on 478 tetrads)
Red = breeding confirmed = 7
Orange = breeding probable = 40
Yellow = breeding possible = 4
Total tetrads in which registered = 51 (10.7%)
Sunday, November 13, 2011 at 6:51PM 
Red = breeding confirmed
Orange = breeding probable
Yellow = breeding possible
Sunday, September 26, 2010 at 12:54PM Species account from M Mathew, 1894, "The Birds of Pembrokeshire and its islands"
