Natural History in the Highlands and Islands. F. Darling Fraser
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One of the striking things about the Torridonian peaks of the far north-west is their isolation, caused by the vast denudation which has taken place, leaving these few hard cores of sedimentary rock overlying the wilderness of gneiss hillocks and innumerable lochans. The term hard core is here being used metaphorically and not geologically. North of Suilven and Loch Assynt is the massif of Quinag, five conical peaks capped with quartzite, with a fine rampart of cliff and scree on the west side, which is nearly three miles long. The massif is no higher than 2,653 feet, but how much more impressive is it than half a hundred three-thousand-footers in the Central Highlands! South of Suilven there is Cul Mor, 2,786 feet, surrounded on three sides by great precipices; and Stac Polly, 2,009 feet (Plate 4b and Plate 10) the narrow ridge of which is like one of those fairy castles of childhood tales perched on the top of steep slopes. Ben More Coigach rises to over 2,000 feet in under a mile from the sea as the crow flies. The air of this countryside with its lower rainfall is generally much clearer than farther south in the Highlands and adds to that sub-arctic quality which characterizes the area.
Before leaving this far northern corner, the ranges of Foinaven, 2,980 feet, and of Ben More Assynt, 3,273 feet, must be mentioned. The group culminating in Foinaven is without doubt the barest range in Scotland, and composed of that unyielding white rock, the Cambrian quartzite. The northern part is like a giant E, the crossbars being ridges peppered heavily with boulders which form screes again below the shoulders: the hollows of the E are fine corries on the slopes of which the snow bunting has bred. The southern part is a horseshoeshaped ridge of which Ben Arkle, 2,580 feet, is the western rampart. This hill of Cambrian quartzite with its banding of white scree may be viewed to perfection from the highroad on the shores of Loch Stack; but for the greatest glory of this range a six-mile trek must be made to reach the vast horseshoe corrie and Loch an Easain Uaine, the loch of the green falls. It is well to rest here awhile and realize that the pine marten is probably commoner in this neighbourhood than anywhere else in Britain, to remember the snow bunting up in the tumble of boulders and possibly see him feeding on the buds of Saxifraga oppositifolia. The alpine species of plant creep far down these bare hillsides and one wonders what there is here to recompense the deer for the energy used in attempting to graze these slopes. The boreal affinity of this range was further emphasized by the occurrence of alpine butterwort (Pinguicula alpina), which was found nowhere else in Britain but on the high tops of Sutherland and Ross; unfortunately this species may now be quite extinct, as it has not been found since 1900, according to Druce’s Comital Flora. The same authority puts 1794 as the last date on which this plant was found in Skye.
Ben More Assynt itself is a solid quartzite cap with igneous intrusions set upon a mass of Lewisian gneiss. There has been a series of geological overthrusts in the region, in which tumults areas of limestone have come to the surface. This limestone has affected the natural history of the whole region, causing a wealth of crustacean and other aquatic life on the waters affected by the limestone, differences in the temperature of the water of some streams which suddenly rise from the rock, allowing the formation of water-worn caves in which have gathered soil and bones of animals of earlier times. Such organic remains are rare in the Northern Highlands.
The comparatively low ground of all this northern region of the gneiss, so difficult of access and so plentifully strewn with lochs, is also a place where sub-arctic birch scrub (Plate IV) is common and there is a certain amount of hazel. There are large stretches of birch in Inverpolly Forest (Plate 4b) in the vicinity of Loch Sionnascaig, which is one of the most beautiful lochs in the whole Highlands. There are pristine birch-wooded islands in the loch where the grey lag goose bred not so long ago and where the pintail duck has bred recently. There is more birch round Lochinver and below the north face of Quinag, and many a stretch may be found on the hill far from the roads, in places which are almost unknown to the naturalist. Some day we may find the redwing building in these woods, for this bird has been heard singing here from time to time in April, and the redwing is essentially a native of the sub-arctic birch wood.
The eastern side of the extreme Northern Highlands is given up to extensive sheep-farming. The hills are of no great height and are of easy slope. The herbage is sweet and good. The largest sheep farms in Great Britain are here, some having upwards of 10,000 ewes. The breed kept is the Cheviot of the distinctive lustrous-woolled Sutherland type. The lambs are sold annually at the great sales at Lairg. No man was more responsible for the development of Cheviot sheep-farming in the North than Sir John Sinclair of Ulbster, in the 1790’s. The influence of sheep-farming on the natural history has been profound and will be given special attention in a later chapter.
This far northern area has been treated at some length, because it is the most remote part of the Highlands and one of which detailed studies in natural history have been rare. It may be recommended as an exhilarating and fruitful field for exploration.
South of Loch Broom, the Torridonian hills are more thickly grouped and reach their highest peaks. Their spiry form and the high corries facing to the east are distinctive. The quality of herbage is generally poor and the terraces formed in the lower reaches of the Torridonian hold up the heavy rainfall so that it is often quite impossible to get about dryshod. How different is the nature of the ground from those smooth dry slopes of glacial sand and gravel which are such a marked feature of the Central Highlands! The differences brought about in the vegetational complex have not been sufficiently stressed by plant ecologists in the past. The ground has not been well walked through and explored as yet.
There are two high hills of the Torridonian which have north-eastern corries quite the most magnificent of their kind and few who have seen them both can decide which is the better. This in itself should show how similar are such groups of hills and the forces which moulded them. I allude to An Teallach of Dundonnell (Plate IIIb and Plate 4a), 3,485 feet, and Beinn Eighe, 3,456 feet, between Kinlochewe and Loch Torridon. Each of these hills has three corries facing NNW. to NE. Coire Mhic Fearchair is the most westerly of the corries of Beinn Eighe, and the Toll Lochan corrie of An Teallach is the easterly one of the range. Some of the buttresses in Coire Mhic Fearchair are exceptionally fine and the corrie makes an almost perfect horseshoe, but for myself I think I prefer the Toll Lochan corrie, for the cliff face at the head of the lochan is of greater depth and of superb architecture, nearly 1,800 feet of it.
Between An Teallach and another corried Torridonian peak, Beinn Dearg Mor, 2,934 feet, is the broad amphitheatre known as Strath na Sheallag, at the head of Loch na Sheallag, from which the Gruinard River runs. This strath is beloved of the deer, and though so remote it draws cattle, sheep and ponies to it from far away. Just as An Teallach has Beinn Dearg Mor as an outlier, so has Beinn Eighe her Beinn Dearg, 2,995 feet, almost a replica of its cousin of Strath na Sheallag. Liathach, 3,456 feet, Beinn Alligin, 3,232 feet, and Slioch, 3,217 feet, these are just three more of these splendid Torridonian peaks—clear of peat from 1,750 feet upwards and often topped with a white cap of quartzite boulders. The sudden change from wet peat-laden terraces to the upper slopes of bare rock, or thin covering of brash and alpine vegetation, results in a sharp snow line in winter which gives these hills a special seasonal beauty. This sudden cessation of the peat immediately allows a different flora, one of plants which can withstand droughts and sudden changes of humidity, and which prefer sweeter conditions than are possible on peat. Here and there among the alpine poa grass and viviparous sheep’s fescue are straggling plants of dwarf juniper, clinging close to the rock. Sea pink and thyme are also to be found on the gravel. Eagle, peregrine falcon and wild cat abound in this country, and as it is all deer forest and not grouse moors of any consequence, the eagle is allowed more sanctuary than it has been given farther south and east.
The glens of the Torridonian area of the North are often well wooded. They have been owned by people with a fair (or perhaps unfair!) measure of worldly riches, who have been able to spend a good deal of money on planting for amenity. Take Dundonnell for example, at the head of Little Loch Broom: the loch side is bare of trees and is given up to crofting townships, but soon after the head of the loch is reached one is into a fine wooded