Gelochelidon nilotica – Môr-wennol Ylfinbraff – Vagrant

The Danish and west German breeding population of this tern disperses to the coast before migrating southwards (Cramp 1985) and was probably the origin of single birds seen at Dale Roads on 21 September 1968 (P.J.Morgan) and at Strumble Head on 16 October 1983 (J.W.Donovan, G.H.Rees, and G.J.Walker) and on 30 July 1985 (R.Dobbins). 

Donovan J.W. & Rees G.H, 1994, Birds of Pembrokeshire

CRAMP, S. (ed.) 1977-1993. Handbook of the birds of Europe, the Middle East, and North Africa: the birds of the Western Palearctic. Oxford, Oxford University Press. 7 Vols

More about the Gull-billed Tern in Pembrokeshire