Sula bassana
The colony on Grassholm now (1948) numbers approximately 7,000 pairs. Its history is to be found in various places: in I knew an Island by R.M.Lockley; and in The Breeding, Distribution, History and Population of the North Atlantic Gannet by J.Fisher and H.G.Vevers (Journal of Animal Ecology, 1943, XIX 177-8).
Pembrokeshire Avifauna 