A Serpent's Tail, The Countryman
Despite their positions at the northern and southern tips of the British Isles the island of Unst in Shetland and the Lizard peninsula share many characteristics. Both are certainly beautiful, rugged places with cliffs and moors which vary in mood from bleak and inhospitable to colourful and inviting. One cause of similarity lies underground in the form of their geological make-up but their geographical isolation and differences in climate, due to their relative latitudes, have led both to form their own, unique natural history. In our lifetime we can only glimpse at one stage in the development of these two special sites, but however short the experience it is a privilege nonetheless.
Of the two it is The Lizard which has the more complex geological history. It was formed around 375 million years ago under the ocean when molten rock was forced, at great pressure, through the earth’s crust. As the earth’s plates collided and separated The Lizard became literally welded to the southern tip of England. The geology of The Lizard is not only very complex but also very different from that of the rest of Cornwall to which it became, by chance, attached. The Lizard is a mere youngster when compared to the 600 million year old rocks of Unst but the two share several rock types including slate, schist, gabbro and, crucially, serpentine. Serpentine is a metamorphic rock formed inside the earth’s crust, it occurs at just a handful of sites in the UK and the best two examples are on Unst and The Lizard. Since the underlying rock is fundamental in determining the type of soil, the presence of serpentine, with its high content of magnesium, has been critical in establishing the distinctive flora of the two areas.
One of Unst’s most exceptional botanical areas is at the National Nature Reserve named the Keen of Hamar. Here the serpentine forms a rocky outcrop covered with small angular fragments of stone. The repeated freezing and thawing of the ground has created solifluction stripes, bands of stones sorted by size. Unusual flowers such as Norwegian (or Arctic) sandwort, more commonly found in Scandinavia, and northern rock cress, another arctic flower, thrive in the unusually alkaline conditions created by serpentine. In 1837 a flower found nowhere else in the world, now known as Edmonston’s chickweed, was discovered here by the local naturalist, Thomas Edmonston. The ground is so exposed to the elements that the natural process of succession has not occurred, except on neighbouring land where cattle have added their inimitable enrichment to the earth so management of the site now includes prohibition of grazing stock
Large parts of The Lizard also form a National Nature Reserve, managed by English Nature. Vegetation is significantly more luxuriant than on Shetland but, as on Unst, the impact of serpentine produces a range of plants more typical of chalky soils. In Kynance Cove bloody cranesbill grows in profusion, harebells and dropwort also take advantage of the unusual conditions. The Lizard also boasts a flowering plant found nowhere else in the world; Cornish Heath is a species of heather with such a strong dependence upon the serpentine that it can be used to identify changes in the underlying geology. The milder conditions allow the growth of more invasive species such as gorse so English Nature have introduced the grazing of the coastal fringes by hardy breeds of sheep and ponies. Here the Shetland-connection continues since around thirty Shetland ponies join forces with the cosmopolitan mix of Soay sheep, highland cattle and Exmoor ponies to help keep the vegetation in check. This management has enabled less robust flowering plants to thrive again; one example of this success story is the spring squill, also commonly found on the west coast of Unst, which is now recovering to its former glory.
In 1831 Dr L Edmonston, Laird of the island of Unst, observed the plight of a rare breeding bird on the northern tip of the island, known as Hermaness. At the time there were just three pairs of great skuas nesting on the moorland but through the work of a keeper employed by the Edmonston family the number of pairs increased and in 1907 the RSPB included the area in their ‘watcher scheme’. By 1955 the area was recognised as a nationally important site and was declared a National Nature Reserve; there are currently 650 breeding pairs of bonxies, as they are locally known. There are also significant numbers of other breeding seabirds including puffins, razorbills, guillemots, black guillemots, fulmars, kittiwakes, shags and gannets. Even a lonely black-browed albatross, from the southern hemisphere, spent the best part of thirty years here in the second half of the 20th century.
Though it had long been known as an important site for its flora it wasn’t until 1974 that the first section of The Lizard at Goonhilly was declared a National Nature Reserve, though there are now 2000 hectares which are protected by this status under the management of English Nature. Being significantly closer to humanity than the island of Unst, The Lizard peninsula attracts a good deal more interest from holiday-makers with an estimated quarter of a million visitors per year. But in 2001 some special visitors set the pulses of ornithologists and conservationists racing, the subject of their interest were three choughs. The chough is a bird of great significance to Cornish people, it appears on the Cornish emblem and is very much a part of Cornish history but it had disappeared as a breeding bird from the county in 1952. Speculation as to whether the three visiting choughs might stay long enough to breed was rife but by the beginning of 2002 it was clear that two of the birds were courting. In fact this pair raised three young and hopes are high that they might establish a regular breeding colony here. These choughs range widely in their search for food and it is becoming clear that the managed grazing of the coastal land introduced by conservation groups such as English Nature and the National Trust is vital in producing good quality coastal heath, suitable for the chough. Let us hope that the story of the chough develops in parallel to Unst’s great skua rather than its black-browed albatross!