that mainland buyers are hesitant to buy the lambs because they know they have nothing so good to offer them to keep them growing. The wealth of species of insects, molluscs and other invertebrates on these tertiary basalt islands is much greater than would be found on those of the Torridonian or gneiss formations, even though the basalt does not tend to allow lochans to form. The Glasgow University Expedition to Canna in 1936 published a full report of their extensive finds. Muck and Canna both offer the right kind of cliffs for sea birds, and Canna is also a breeding station for the Manx shearwater.
The island of Eigg (Plate 5) is a big shearwater station, the birds nesting well up towards the Sgurr, 1,280 feet. The Sgurr is the most obvious physical feature of Eigg and by far the island’s most interesting natural phenomenon. It is a geological curiosity which has shed light on the geology of other areas far distant. The late Sir Archibald Geikie solved the riddle which Hugh Miller answered unknowingly at an earlier date. The Sgurr itself is of pitchstone, resting on a thin river bed of conglomerate which contains fossil pieces of driftwood from some far distant time. Beneath this is the tertiary basalt again. The pitchstone shows columnar jointing in places, a character which is still more strongly marked on Oidhsgeir, 18 miles away to WNW. This low islet of pitchstone is considered to be part of the same sheet as the Sgurr of Eigg. There is one other feature of Eigg deriving from its geology which should be mentioned here—the musical sands of Camus Sgiotag, a small bay on the north side of the island. These sands are of partially rounded quartz grains of similar size. If the sand is dry a shrill sound is heard as one walks over it.
To return for a moment to the few acres of Oidhsgeir, an islet which does not reach higher than 38 feet above sea level. Here on the top of the pitchstone columns which are 8 inches or so across the top are found the nests of kittiwakes in the season. There are also great numbers of common and arctic terns and eider ducks. Harvie-Brown, visiting the islet several times in the ’80’s and early ’90’s of last century found teal breeding and was convinced that the pintail duck had nested there also. This phenomenon of a small islet in the open sea gathering to it an immense number of living things for the purpose of their reproduction is one to which we shall return in a later chapter on the oceanic island. The deep-cut channels among the pitchstone columns are also a playground for the Atlantic seal. One channel on the south side runs up into a pool where a boat may lie in perfect safety. Many are the occasions when lobster fishers and venturers in small boats have been glad of the quiet pool of Oidhsgeir. What a strange feeling it is to be lying snug in such a place with the mighty ocean pounding but a few yards away and the spray flying over!
The island of Rum, with its three rock types of gabbro, Torridonian and granite, is for the most part a closed book to naturalists. We may hope this unfortunate period of its history is drawing to a close and that it may yet have a future as a priceless wild-life reserve. There are red deer and wild cats on Rum, there are otters round the shores and on the burns, and such species as badgers and roe deer could be introduced if introductions were thought desirable. Some of the finest kittiwake cliffs in the kingdom are to be seen on Rum, and the Manx shearwater nests in holes high up the 2,600-foot hills. The golden eagle is there still, though the sea eagle disappeared during the second half of the 19th century. Given the chance, we may expect the chough to return to Rum.
Skye may be looked upon as the northern outpost of the Lusitanian zone. It has suffered human depopulation like many another Highland area, but Skye is still one of the most heavily crofted areas of the West. Preservation of game has practically ceased and almost all the hill ground is now crofters’ grazing. Topographically, Skye is magnificent, with its Cuillins and its Quirang, but from the point of view of wild life it is somewhat disappointing. The whole area facing the Minch is faunistically poor, as was pointed out by Harvie-Brown fifty years ago.
The island of Raasay, however, between Skye and the mainland, has a surprisingly rich variety of small birds, doubtless as a result of the woods and the large amount of park-like ground which is of Liassic origin. Personally, I should say that the Lepidoptera of Skye and Raasay would repay close scrutiny, not only from the point of view of numbers of species, but from the areas of distribution. Heslop Harrison and his group have already made fruitful researches in this direction. Raasay, like Mull, has its own sub-species of bank vole (Clethrionomys = Evotymys).
The islands of the Atlantic zone are by far the most interesting part. The mainland coasts are often hidden and tend to lose character. But the country bordering the long sea lochs is of exceptional beauty and contains some habitats—such as the indigenous oak woods—which are almost unique in Scottish natural history. To walk the length of Loch Sunart, ten miles out of the twenty through these oak woods, in the fine weather of June is an aesthetic experience, if only for the sight of the redstarts which are here in great numbers. The scenery of the distance is as beautiful as the redstart among the oaks and hazels near at hand. Perhaps the better way is to travel eastwards from Kilchoan and Ardnamurchan Point where the quality of ocean is apparent as on the islands. Sanna Bay on the northward tip of Ardnamurchan is one of the most beautiful shell-sand bays of the West, but it is rarely visited because of its remoteness. East of Glenborrodale the sense of sea is lost and we are in the woods with the loch below us. The peak of Ben Resipol, 2,777 feet, dominates the landscape and is most shapely when seen from this airt. The traveller can hardly miss seeing Ben Iadain, 1,873 feet, and on the other side of the loch in Morvern. It is a little cap of tertiary basalt perched on the Moine schist, but between the two is a very narrow band of chalk. The sight of this little hill cannot fail to impress one with the immense amount of denudation which must have taken place to remove this molten layer of amorphous volcanic rock from so much of this countryside.
Though the oceanic birds such as kittiwakes and auks are lost as one moves up these long sea lochs, it is surprising how many sea birds are to be found breeding in the season. Arctic terns, eider ducks, herring gulls and mergansers—all are here in numbers. And where there are shallow shores and estuaries there are parties of curlews, oystercatchers and ringed plovers. The hillsides above these long sea lochs are almost devoid of heather. The vegetational complex is one of various species of sedge, a few grasses such as flying bent and mat grass, and bog myrtle and deer’s hair sedge. Heather will appear at the edge of a gulley perhaps where the drainage is good. From a distance the most obvious plant may be bracken—great sheets of it, darker green in summer than the herbage and red in winter.
The ecology of the long sea lochs and their intertidal zones is a subject of great interest for those who have the techniques to follow such studies. The gradual increase in salinity from head to foot of the loch, the diurnal variation caused by the tide, the spasmodic variations caused by spates and droughts, the currents formed, and their effects on the life of the waters, still remain to be worked out in detail. Space will not allow of individual description of all the narrow and long sea lochs from Loch Fyne to Loch Alsh: each one has its similarities and distinctions, and certainly each should be visited by the naturalist who is also keen on good country. Most of these narrow lochs have high hills rising from their shores, which means that their south side loses the sun for four months in late autumn and winter. Loch Hourn is particularly sombre in winter because the hills of Knoydart, which reach to 3,343 feet, seem to tower above the loch. Loch Nevis, on the other hand, is sheltered from the north by these same hills, and the North Morar hills to the south of this wider loch do not rise above 1,480 feet. Inverie, therefore, in its sheltered bay on the north side of Loch Nevis, is one of the kindest places in the West Highlands, despite the high rainfall. Indeed, the West Coast is full of these pockets of kindly shelter allowing luxuriant growth. Many of the policies of the large houses have magnificent specimen trees which have grown within a hundred years or so to a size which would have been impossible in a large part of England.
When these sea lochs narrow at their mouth there is a diurnal tide race of considerable force. That at the Corran Narrows of Loch Linnhe runs at 8 knots at ebb and flow, but that at Connel Ferry on Loch Etive is very much more than this and is quite impassable at half tide. When the tide begins to flow here there is the extraordinary sight of a waterfall in reverse, made by the inrush of sea water.
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