Larus fuscus – GWYLAN GEFNDDU LEIAF – Breeding summer visitor, passage migrant, winter visitor
The BTO winter atlas showed that Lesser Black-backed Gulls were present in most 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 46 birds. Over 2,000 were recorded roosting at Llys y fran reservoir during this period.
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.