Saxicola torqata hibernans
Common resident on all rough furze commons and escarpments, moving towards coast in cold weather. Sometimes breeds on the islands, to which it is a regular winter visitor. Numbers much reduced in hard weather and almost wiped out by snow and frost early in 1947.
R.M.Lockley, G.C.S.Ingram, H.M.Salmon, 1949, The Birds of Pembrokeshire, The West Wales Field Society