Anser anser – GWYDD WYLLT – Erratic visitor. Not recorded from July to September
The BTO winter atlas showed that Greylag Geese were present in two 10km squares during the winters of 1981-82, 1982-82 and 1983-84, presumed birds of feral origin.
Data collected by volunteers for the BTO. Lack, P. 1986 Atlas of wintering birds in Britain and Ireland. T & A.D. Poyser.