Larus marinus
In Mathew's day there were only a few pairs resident on the islands, and he only mentions the Bishop's Rock and St Margaret's. It has now greatly increased, and is found on all the islands, and along the whole coast, breeding. At least 150 pairs Skomer and Middleholm in 1946.
R.M.Lockley, G.C.S.Ingram, H.M.Salmon, 1949, The Birds of Pembrokeshire, The West Wales Field Society