BIRDS AND MEN ON ST. KILDA Stac Lee must be one of the most majestic sea rocks in existence.1 It rises out of deep water, and as you sail within a few yards of the black mass it gives you a gasping lift, like a cathedral or a flight of rockets. At one place it even overhangs. Its shape too is magnificent —a great blade of rock, somewhat longer than broad, yet not so thin as to convey any impression of fragility. Hosts of similes poured into my mind. At first I thought of the emerging prong of a sea-god's trident, the crude and gigantic emblem of some northern Poseidon. Then suddenly I had it—it was like one of the great stones at Avebury (those early megaliths to my mind so much more impressive than those of Stonehcnge), magnified some fifty diameters and erected out of sheer bravado in the sea. Its top is bevelled off diagonally, and this sloping plane is white with densely packed gannets; gannet ledges lace the black face obliquely with white, and guillemots and kittiwakes inhabit the lesser projections. Gannets inhabit 21 distinct colonies, from the St. Lawrence to the Bass, from Iceland to southern Ireland. This single colony of Boreray comprises about a fifth of all the gannets in the world. Two separate estimates have given concordant figures—about 17,000 breeding pairs: with the non-breeders, about 40,000 of these enormous and spectacular birds, Stac Lee looks wholly inaccessible. As a matter of fact, it was much more easily and more often climbed by the St. Kildans than Stac an Armin. There is a relatively easy landing, and a ledge leading diagonally upwards. They came there regularly every year to catch the young gannets for their winter provisions. The human biology of St. Kilda is as remarkable as its birds. I should say was, not is, for in 1930 its entire population was evacuated, thus closing a chapter which had been begun before the historic period. Human and avian biology were indeed inextricably inter- woven on St. Kilda. The human population was essentially parasitic on the birds. Fishing was never popular, and its results quite sub- sidiary. It is true that sheep also played a prominent part in the island economy, that there were a few cattle, and that barley, oats, and potatoes were grown; nevertheless, without the birds the human beings could neither have fed themselves nor paid their dues. The total number of inhabitants seems never to have reached 200. It suffered a marked diminution in the early eighteenth century. 1 Professor P. A. Buxton has since told me of Ball's Pyramid, off Lord Howe Island, between Australia and New Zealand. This is 1816 feet in height, but though immensely impressive, is rather a rocky islet than a single rock.