Aythya ferina
Mathew states: "Not uncommon" as a winter visitor. Recently it has been seen only inside Milford Haven, where it is regular on the upper rached of the Cleddau, and occasionally at Orielton, where a pair remained un 17 May 1934 (H.A.Gilbert).
R.M.Lockley, G.C.S.Ingram, H.M.Salmon, 1949, The Birds of Pembrokeshire, The West Wales Field Society