Natural History in the Highlands and Islands. F. Darling Fraser

years or thereabouts.

      What is most heartening in the woodland situation in the Outer Isles is that the crofters themselves are taking an interest in trees for shelter, and in many a garden you will see a host of willow cuttings bravely shooting forth in summer and making some certain headway against the gales and spray from the Atlantic. Rhododendrons are growing quite well in many places and are at least providing the first cover for something else to grow within their shelter.

      The sands and the machairs of the Hebrides are often referred to in this book: in the Sound of Harris there are several islands which seem little else but shell sand, such as Ensay and Berneray; and there is Vallay of North Uist. But I would not wish to neglect the cliffs which are also important in the natural history of the Outer Isles. The great ocean pounds against them and must be gradually wearing them away, but the rock is the old gneiss and holds remarkably well. Sir Archibald Geikie in his Scenery of Scotland calls to mind the measurement of the pounding effect of waves which was made at the Atlantic rock of Skerryvore before the lighthouse was begun in 1845. The summer average weight of pounding was 611 lbs. per square foot; in the winter months it was 2,086 lbs. per square foot, and in the very heavy south-westerly gale of March 29, 1845, a pressure of 6,083 lbs. per square foot was registered. Even when it is water alone that strikes the rock, the wearing effect is far from negligible, but when other loose rock is moved by the water and pounded against the cliff, even our short lifetimes may be able to notice the denuding effect of wave action. I remember an incident on North Rona which certainly opened my eyes to what a big sea could do. It was in December, 1938, in a period of south-westerly gales which would veer to west and north-west and begin again from south-west before the wind had fallen. They were worst in the nights and I would go out in the mornings to see the magnificence of sea against the low cliffs of the northern peninsula. These cliffs were perhaps forty feet high, but sheer, and going into deep water. The top was irregular with occasional ten-foot gullies a few yards wide in which were some very big boulders eight to ten feet thick, and a lot more of a size just too heavy for a man to lift. When there one morning, a sudden shower caused me to take shelter under one of the big pieces of rock. Peppered scars were visible all over the big boulder above and on the smaller ones lying on the smooth floor of the gully. It was evident that the sea had come green into here and rolled the smaller boulders up and down. But observation was not critical enough to question how these smaller boulders could pepper the big one several feet above. When sheltering there again after another tremendous night, it was obvious that the big boulder was not in the same place as it was the day before. Those pepperings had been caused by its own rollings to and fro in the gully under the impulse of the sea which had filled the gully thirty to forty feet above its normal level. That boulder, probably, had done much to wear the gully itself in the course of thousands of years.

      Some of the cliffs of the Hebridean coasts are impressive and become the crowded haunts of ledge-breeding sea birds. The precipice of Aonaig in Mingulay is 793 feet. The stacks of Arnamull and Lianamull in Mingulay are also very fine. Harvie-Brown thought Lianamull the closest-packed guillemot station he had ever seen. Barra Head or Bernera, the most southerly island of the Hebrides, has some fine cliffs and in front of the lighthouse on the southern face is a gully which takes a terrific updraught of spray in southerly gales and makes the dwelling of the lighthouse suffer a heavy rain of salt water, a rain of sudden torrential showers of a moment’s duration.

      The influence of the sea in times of storm has already been mentioned as a land-making one on the western side of the Hebrides where it throws up sand for biological agencies to work upon. The islands in the Sound of Harris probably change shape through the years, sand being laid down in one place and taken away in another. Pabbay, for example, was the granary of Harris but the sand has encroached over the south-east end and has gone at the west. West again of Vallay, a sandy island of North Uist, the remains of a forest of trees may be discerned at low spring tides. This submerged forest is probably the result of Holocene sinkings, but nevertheless the shell-sand beaches have certainly advanced within historical times. The minister in Harris who was responsible for the account of that parish in the Old Statistical Account of 1794 remarks that certain lands had been lost to the plough within living memory, and that when a sand hill became breached by some agency and was eventually worn away, good loam was sometimes found beneath and even the ruins of houses and churches. Whatever we may have lost in the Holocene sinkings, it may be remarked that the last three thousand years have seen more rising than sinking along Highland coasts.

      The tides in the Sound of Harris have an interesting rhythm of their own, accurately noted by the minister in the Old Statistical Account. The following quotation is from the Admiralty Chart of the Sound of Harris: “It may be generally stated that in Summer, in neap tides, the stream comes from the Atlantic during the whole of the day, and from the Minch during the whole of the night. In Winter this precept is nearly reversed. In Spring tides both of summer and winter the stream sets in from the Atlantic during the greater part of the time the water is rising, but never for more than 5¹/₄ hours, and it flows back into the Atlantic during most of the fall of the tide. Where the water is confined by rocks and islands…the velocity is nearly 5 knots…during springs, and not much less during neaps, whilst in other places it does not exceed a rate of 2 to 2¹/₂ knots.”

      The east side of the Outer Isles is entirely different from the populous and spacious west side. Admittedly, north of Stornoway there are the sandy lands of Gress, Coll, Back and Tolsta, and the Eye Peninsula, supporting many crofts, but south of there the land is peat-laden and comes to abrupt cliffs at the sea’s edge. The bird life is nothing like so interesting as on the western side and on such cliffs as exist there. Long arms of the sea, such as Loch Seaforth and Loch Erisort, Loch Maddy and Loch Eport, run far into the interior; indeed, the last two named almost reach the west coast in Uist. To me this east coast of the Hebrides is uninviting and curiously dead. It is my experience that many of the islands off the West Coast of Scotland are much more interesting on their western sides than on their eastern shores. Raasay is an exception.

      The east side of Harris from East Loch Tarbert to Rodel is well worth a visit to see what man can do in the shape of difficult cultivation. Take for example the township of Manish where the ground rises at a steep slope from the sea. It is in reality a rough face of rock devoid of soil but holding the peat here and there. The lobster fishers of Manish have actually built the soil of their crofts by creating lazy-beds or feannagan with seaweed and peat. By building up these little patches varying from the size of a small dining-table to an irregular strip of several yards long, the inhabitants have overcome the difficulty of drainage. The women carry seaweed up to the lazy-beds each year, all in creels, for the ground could not be reached by ponies. And all cultivation is of necessity done with the spade. Two crops only are grown, potatoes and oats, and the oats are Avena strigosa, which more than one naturalist has thought to be extinct as a cropping oat and only occurring here and there as a weed. The industry of the people of East Harris and their steadfast persistence with a thousand-year-old style of husbandry are remarkable. The potato is the only new thing, being brought to the Outer Isles in 1752. There are many more primitive townships in the Outer Hebrides working lazy-beds, but none in more disadvantageous position than Manish and its neighbours.

      The Outer Isles also have their Atlantic outliers, each little group having its own strong individuality. There is St. Kilda (Plate VIIIa) on the west of the Uists, seventy-four miles out from Lochmaddy via the Sound of Harris; this group of magnificent gabbro architecture has already been mentioned, with the fact that it is the largest gannetry in the British Isles and in the world. It is also the place from which the still growing fulmar population of the British Isles may originally have spread. The islands and their peculiar sub-specific fauna will be described in a later chapter. The Monach Isles are only eight miles west of North Uist, and are likely to follow so many small island groups in becoming uninhabited by man. They are islands of sand caught and built up on reefs of Lewisian gneiss. Another reef to the south of them, Haskeir, has not collected the sand. It is much smaller and uninhabitable but has long been a haunt of the Atlantic seal and was one of the last strongholds before the revival of the species in the present century. The Flannan Isles are twenty-two miles west of Loch Roag, Lewis. They are of gneiss and bounded everywhere by cliffs. The seals feed near them, but of necessity do not breed there because they cannot haul out. The