Clangula hyemalis – Hwyaden Gynffon-hir – Winter visitor and passage migrant. Not recorded in August and September
The BTO winter atlas showed that Long-tailed Ducks were present in several coastal and estuarine 10km squares during the winters of 1981-82, 1982-82 and 1983-84.
The coloured 10km squares represent 1-2 birds seen in a day.
Graham Rees. Pembrokeshire County Bird Recorder 1981-2007
Data collected by volunteers for the BTO. Lack, P. 1986 Atlas of wintering birds in Britain and Ireland. T & A.D. Poyser.