Chlidonias niger niger
Recorded by Mathew as "seen occasionally" but he gives no dates, and only mentions it as seen as Castlemartin and shot at Fishguard. The only recent records is of an immature bird shot at St Davids, Sept 1904 (Bertram Lloyd)
R.M.Lockley, G.C.S.Ingram, H.M.Salmon, 1949, The Birds of Pembrokeshire, The West Wales Field Society