Welsh Journals

No. of breeding Island Acreage species Caldey and St. Margaret's 611 46 50 Grassholm 22 11 Ramsey 594 23 Skokholm 240 21 Skomer 727 35 Topography and Geology Caldey Island, and the small limestone stack of St. Margaret's which lies off its north-west extremity, are connected by a reef of rocks which are exposed at low tide. The islands are situated in Carmarthen Bay about two miles south of Tenby. Caldey is the property of the Cistercian Community. St. Margaret's is a sanctuary leased by the West Wales Field Society, members of which made many observations in the summers of 1952-54. Caldey is the third largest of the Pembrokeshire islands, and has a circum- ference of some six miles. The northern half is composed of carboniferous limestone, and the southern half of old red sandstone. The junction of these two formations can be seen to advantage at Drinkim Bay. The land slopes gently to the north. Although the island has no really distinctive avifauna, and with the exception of the Cormorants on St. Margaret's, no really large breeding colonies of seabirds, its list of breeding species is nevertheless well in excess of that of any of the other islands. This is due to the fact that Caldey is, and has been for centuries, extensively cultivated, and has a fairly large wood, coniferous plantation, groves of pines and fuchsias, and a good vegetational fringe on the cliff top in many places. Briefly, it can be described as a cultivated plateau (maximum height about 100 feet), with a cliff-top vegetation of hawthorn, gorse, bracken and brambles. The wood, plantation, pines and fuchsias are all in the vicinity of the village and farm, the position of which can be clearly seen on the aerial photograph. The fields are separated by stone walls. There are some sand dunes with marram grass behind Priory Bay on the mainland side of the island. The position of the other bays can be seen on the photograph. The nearness of Caldey to the mainland no doubt contributes towards the long list of breeding species, but the main factor is without doubt the cultivation and prolific vegetation. SYSTEMATIC LIST Great Northern Diver (Gavia immer).-One, probably of this species, flying about! mile offshore on September 15th, 1930. (B.L.) Red-Throated Diver (Gavia stellatus). — An immature bird diving off the south shore, one fishing along the surf line, and at least six more on the Sound between Caldey and Tenby on April 25th, 1930. (B.L.) One, October 22, 1938. (R.M.L.) Frequently seen in the Sound and off the E. coast. (R.M.L.) Storm-Petrel (Hydrobates pelagicus). — Two on St. Margaret's on May 27th, 1902 (Walpole-Bond, 1903). Six seen mile S. of Caldey.