Sunday, September 8, 2013 at 8:42AM Branta leucopsis
Mathew records it as a winter visitor which generally arrived at Goodwick Sands about 1st October. Also recorded from Orielton, 1855 and 1877; and from St David's Dec 1893. Seen passing at sea off Skokholm in winter.
R.M.Lockley, G.C.S.Ingram, H.M.Salmon, 1949, The Birds of Pembrokeshire, The West Wales Field Society
Monday, April 8, 2013 at 5:32PM 
The graph shows the total maximum counts each winter for all Pembrokeshire sites in the Wetland Bird Survey.
The black bars represent the Cleddau Estuary complex. The blue bars represent all other sites, both freshwater and saltwater.
There may be higher counts at other times during each winter.
Thursday, December 15, 2011 at 9:56AM Winter visitor and passage migrant. Not recorded in May and June
Mathew (1894) considered the Barnacle Goose to be a winter visitor arriving in October, while Lockley et al. (1949) cite only occasional occurrences, such as birds at Orielton and St David's. This pattern persisted, with up to three noted in 38% of the post Lockley et al. years. Widely kept in collections throughout Britain, and with thriving feral colonies established in several places in southern England, it is likely that most, if not all, of the occasional records refer to birds of feral origin. However, a small passage has been noted in October which is more likely to concern wild birds and it was to this that Lockley et al. were referring when they noted that Barnacle Geese were "seen passing at sea off Skokholm in winter".
A flock of about 50 settled on Ramsey Island in October and November 1968 but it is not known whether they wintered there. A few Barnacle Geese began to winter on Skomer in 1981 and by 1989 this had built up to 130 birds. They have arrived as early as 4 January and in 1989 remained until 13 April. Similar numbers frequented Bittell reservoir, Worcestershire, for a month or so before arrival in Pembrokeshire and although the area of their origin is not known the sighting of a Dutch ringed bird in the Midlands suggests that Siberia is likely. Skomer was blanketed by snow in January 1985 covering the food plants of the geese which moved to nearby Marloes Mere where grass was still exposed. They subsequently used both sites but stayed at Skomer in late March, departing during April. The flock unfortunately did not return after 1989.
Friday, September 16, 2011 at 11:30AM 
Up to three birds were recorded in one 10 Km square during the 1981 – 1984 Winter Atlas.
The National Nature Reserve of Skomer was managed by a Warden from March to October during the Atlas years but not in the winter, when only occasional visits were made. These few visits indicated that up to 39 Barnacle Geese over wintered on the island but this information was not made available to the Winter Atlas, so is not represented on the map.
GHR
http://blx1.bto.org/atlases/BY-atlas.html
Monday, January 10, 2011 at 10:30PM Species account from M Mathew, 1894, "The Birds of Pembrokeshire and its islands"
