Collins New Naturalist Library. L. Matthews Harrison

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СКАЧАТЬ islands. The very similar grey long-eared bat, P. austriacus, slightly larger, greyer, and with broader ears, has only recently been recognised as a separate species. It has been found in the south of Dorset, Hampshire and Sussex, but may prove to be more widely distributed after further study.

      ORDER LAGOMORPHA

      This order contains the rabbits and hares, easily distinguished from rodents by the presence of a second pair of small upper incisor teeth immediately behind the large first pair. There are three British species. Oryctolagus cuniculus, the rabbit, has long been an established member of the fauna although it is not indigenous. It was introduced by man a little before A.D. 1200 from its native Iberian peninsula and north Africa to be raised in confinement for fur and meat; it subsequently escaped, became feral and increased so that it is now found everywhere in the British Isles. The myxomatosis epidemic of the 1950s reduced the population drastically, but numbers have now recovered in many places.

      We have two species of hare, the brown hare, Lepus capensis, and the mountain hare, L. timidus, both considerably larger than the rabbit, and with longer, black-tipped ears and longer legs. Linnaeus named the only hare found in Sweden in his time L. timidus, and a species from South Africa L. capensis, not knowing that the brown hare of Europe differs from the mountain hare, or that its range extends from South Africa to most of Europe and much of Asia – hence the peculiarity that our native brown hare takes its scientific name from the Cape of Good Hope. The brown hare, distinguished by the black upper side of the tail, is found throughout England and Wales, southern and north-eastern Scotland. It is not native to Ireland, but has been introduced into the north, and also into many of the Scotch islands. The mountain hare is smaller, has shorter ears, and the upper side of its tail is not black. After the autumn and winter moult the coat is wholly or partly white, and becomes brown again with the spring moult. The mountain hare is indigenous to the highlands of Scotland and all of Ireland. The Irish mountain hare is considered to be a distinct subspecies slightly larger than the Scotch, and assuming a white coat incompletely or not at all during winter. Mountain hares have been introduced into parts of southern Scotland and some of the islands, the Peak district and north Wales.

      ORDER RODENTIA

      The rodents comprise the rats, mice, squirrels, beavers, porcupines, and cavies. They are mostly small to medium-sized animals, the largest, the Capybara, a huge cavy of South America, reaching a weight of over a hundredweight; few others approach this size. There are about 1,500 species of rodents; Simpson¹³¹ remarks that they are ‘believed to be as abundant individually and in variety as all other mammals put together.’ Fortunately we have only fifteen species living in the British Isles, eight of them introduced; one introduced and one indigenous species are extinct. The incisor teeth of rodents, separated by a long gap from the cheek teeth, are single upper and lower pairs with chisel-like cutting edges and long roots from which growth is continuous so that the loss by wear at the cutting edge is perpetually made good.

       Family Castoridae

      The beaver, Castor fiber, was exterminated in the British Isles about AD 1200, but had been scarce long before. It was abundant in the Fens during prehistoric times.

       Family Sciuridae

      The red squirrel, Sciurus vulgaris, our only indigenous species, is typically an inhabitant of coniferous forests, especially those of our only indigenous pine, Pinus sylvestris, though not confined to them. The fur is reddish brown above, white below, the tail is long and bushy, and in winter tufts of long hair on the ears are conspicuous. The hairs of the tail and ear tufts wear and bleach during spring and summer, leaving the tail almost white and the ear tufts sparse. The numbers of red squirrels have varied widely during the last 300 years, but reached a peak at the turn of the century since when they have declined again. It is now widespread in much of Scotland, Ireland, Wales and northern England, but extinct in most of southern and central England. The causes of the fluctuation in the size of the population are not known.

      The grey squirrel, Sciurus carolinensis, was introduced from North America and irresponsibly released in various places in the last quarter of the nineteenth century and the first of the twentieth. It has spread widely, and is now found in most of England and Wales, central Scotland and central Ireland. It is larger than the red squirrel, and has proportionally larger ears without conspicuous tufts. The fur is grey with yellowish brown streaks on the sides and feet and, in the winter coat, on back and head. The grey squirrel lives in woods of broad-leaved trees as well as of conifers; some town people regard it as an attraction in public parks, but in the country it is so destructive to young trees, fruit, forestry, agriculture and horticulture that it is now illegal to import or to release grey squirrels or keep them in captivity. Legislation, however, came too late to rid us of this pest.

       Family Cricetidae

      There were five species of voles in the British Isles, one probably introduced, and another that was injudiciously introduced but successfully exterminated. The last was the musk rat, Ondatra zibethicus, which escaped from fur farms, to which it had been brought from its native America. It became established in several districts about 1930, but a great official effort of destruction eliminated it seven years later.

      The British voles are small mouse-sized animals with one exception, the water vole, often called the water rat from its larger size. The voles are distinguished from the mice by the rounded or blunt rather than pointed profile of the snout, and the comparatively small ears partly concealed in the fur. The diagnostic character of the different species is given by the pattern of the cheek teeth. Our four species are classified into three genera.

      The bank vole, Clethrionomys glareolus, is recognised by the chestnut red fur of the upper side. It lives mostly in woodland, scrub and hedgerows, under which it makes runways and burrows, but it also habitually climbs among the branches of shrubs and small trees – so much that the late Oliver Hook, the well-known naturalist, nicknamed it ‘Cleth the Climber’, though the wood and yellow-necked mice are at some times and in some places equally or even more arboreal^111a. The bank vole is often a destructive pest in country gardens. It is found all over the mainland of Great Britain, and on many of the islands, but is not indigenous in Ireland where it has recently been introduced, perhaps by some zoological practical joker, and now occupies a large area in the south-west. Four sub-species are recognised, each confined to a separate island – Raasay, Mull, Skomer, and Jersey. All are larger than the mainland race, and that of Skomer is much brighter in colouration.

      The field vole, Microtus agrestis, is of smaller size but has greyish brown fur, smaller ears, and a short tail. It lives mainly in rough grassland and less often among scrub and dense cover; it makes runways and builds its nests under the thick mat of grasses, the stems and leaves of which form the greater part of its food. It is found throughout the mainland of Great Britain and on many of the Hebrides, but not in Ireland, the Isle of Man, Orkney or Shetland.

      The voles of Orkney and Guernsey are slightly larger and darker, and differ from the field vole by a detail in the pattern of the cheek teeth. They are a separate species, M. arvalis, common on the Continent whence they were probably accidentally introduced into the islands long ago.

      Our largest vole, the water vole Arvicola terrestris, about the size of a rat, lives near rivers, ponds and canals, into the banks of which it burrows to make its nest. Although it feeds mainly upon the grass growing near the banks it readily dives into the water and swims well. Its colour is generally brown, but populations of black water voles are present in north Scotland and East Anglia. The water vole is found throughout the mainland of Great Britain but is rare in north-west Scotland, and is absent from most of the islands and from Ireland. The paradox of a water animal having the scientific name ‘terrestris’ is due to the habits of this vole on the Continent, where it is not confined to the neighbourhood of СКАЧАТЬ