Mammals in the British Isles. L. Harrison Matthews
Читать онлайн книгу.
to the waters off the coast and to the sea shore from which they come a short way onto land only in remote undisturbed islands. They are, however, animals of particular interest to zoologists, and of unusual endearment to the public in general. Two species live and breed on British coasts; five others are merely accidental vagrants from northern seas, and thus form no regular part of our fauna.
Family Phocidae
The common seal, Phoca vitulina, and the grey seal, Halichoerus grypus, are not easy to tell apart when in the water, unless very close to the viewer. The coat colour of both species varies greatly; the basic pattern is of dark spots on a grey background, the spots tending to be smaller in the common seal, but no two individuals are exactly alike. Bull common seals reach a length of two metres overall, cows about 20 cm less, whereas bull grey seals reach three metres but the cows some 45 cm to 60 cm less. The snout of the common seal is comparatively short, giving the head a rounded appearance and a ‘dished’ profile; in the grey seal it is long and high, giving a convex profile to the head. Both species can be found on many parts of our coasts, but concentrate in special places to form breeding colonies. The common seal is least likely to be met with on the southern and western coasts of England and Wales; it breeds at several places on the east coast, especially in the Wash, in Orkney and Shetland, on the west of Scotland and the islands, and the east of northern Ireland. On the east coast of England the main breeding colony of the grey seal is at the Farne islands; in Scotland it abounds in Orkney and Shetland and many islands of the west. There are also breeding colonies on the coasts of Wales, Cornwall, and much of Ireland. The common seal prefers shallow waters with sand and mudbanks and is often found in estuaries, whereas the grey seal lives in deeper waters off rocky coasts. Both species come ashore to give birth, the young of the grey seal remaining on or above the beach for about their first three weeks, but those of the common seal, born on sand or mudbanks covered at high tide, swim with their mothers from the first.
ORDER PERISSODACTYLA
Family Equidae
Wild horses have been extinct in the British Isles for about 10,000 years, but half-wild breeds derived from introduced domestic horses exist in several districts of extensive unenclosed land.
ORDER ARTIODACTYLA
Family Suidae
The wild boar, Sus scrofa, has been extinct in Great Britain for some 300 years. Although its domesticated descendants have played an important part in the rural economy of Ireland it was never indigenous there.
Family Cervidae
Stags of the largest of our two native species of deer, the red deer Cervus elaphus, stand up to about four feet at the withers, hinds about six inches less. The coat colour varies greatly; in general it is red-brown in summer, grey-brown in winter, with a white patch on the rump. Calves at birth are reddish-brown with white spots, but lose the spots at their first moult at the age of about two months. Horns, now generally called antlers, a term originally meaning the branches or tines, are carried only by stags. They are dropped from the pedicles, from which they grow on the forehead, in spring or summer, whereupon new ones at once start growing and are complete by the autumn. The red deer, formerly present throughout the British Isles, remains as a truly wild animal only in Scotland, the Lake district, on Exmoor and the Quantock Hills, and in south-west Ireland; elsewhere feral deer, often derived from escaped park animals, are present in many places. In Scotland the deer are animals of the hill, but in lowland England they are more generally inhabitants of woodland where they reach greater size and the stags bear larger antlers.
The sika deer, C. nippon, smaller than the red deer but similar in build, was introduced from the Far East in the second half of the nineteenth century, and feral populations have become established in a number of places in the British Isles. The coat is red with light spots in summer, darker and unspotted in winter; the rump patch and tail are white except for a narrow black line on the latter. The antlers of the stags are smaller and have fewer tines than those of the red deer, and lack a bez tine between the brow and trez tines. Sika deer inhabit woodlands from which they come out to graze from dusk to dawn. They hybridize freely with red deer where the ranges of the two species overlap.
The fallow deer, Dama dama, is another introduced species, but has been adopted into our fauna for a much longer time – probably almost a thousand years. It has for long been a favourite ornament in parks from which it has escaped so that feral populations are widespread in England, Wales and Ireland, and are found in some parts of Scotland; those in Epping and the New Forests probably represent the early stock. Bucks stand about three feet high at the withers, does a few inches less; the antlers of the bucks are usually handsomely palmated. The colour varies greatly but is light with spots in summer, much darker and generally without spots in the winter. The border of the white rump patch is black, as is the upper surface of the tail.
The roe deer, Capreolus capreolus, is a true native of Great Britain but not of Ireland. It is plentiful in Scotland and northern England, but has been introduced into southern England, and into East Anglia where it was exterminated some two hundred years ago. It is a small deer, barely two feet six inches at the withers, with no visible tail. The colour is tawny red, the muzzle black and the chin white; in the darker brown winter coat two white patches appear on the throat. The antlers of the buck are short spikes each with one forwardly directed tine at the base and a backwardly directed one at the top. Roe live in woodlands, which they leave to browse on bushes at dawn and dusk.
Two other small species of introduced deer are at large in parts of England, descended from animals that escaped from captivity during the present century. The muntjac, Muntiacus reevesi, is widespread through much of south, central and eastern England, and is still increasing its range. It is not more than eighteen inches high at the withers; the coat is deep chestnut in colour, lighter below. The antlers are short spikes carried on long hair-covered pedicles prolonged forward as ribs on the face. Muntjac live in dense cover where they are more easily heard than seen, for they utter a short sharp bark repeated many times when disturbed. The Chinese water deer, Hydropotes inermis, is slightly larger, reddish to greyish brown, and with large ears; the bucks do not have antlers but long upper canine teeth that project from the mouth as tusks nearly three inches in length. Water deer live among long dense herbage on which they graze – they are less widespread than the muntjac, being feral but numerous in parts of Bedfordshire, Northamptonshire, Buckinghamshire, and Huntingdonshire.
Family Bovidae
Cattle, sheep and goats do not exist in the wild in the British Isles. Wild cattle, from which domestic cattle are descended, have been extinct in Great Britain for some three thousand years – the ‘wild’ white cattle preserved in several parks are derived from domestic animals. A primitive breed of sheep, the Soay breed, has long been present on the island of the St. Kilda group to which it gives its name meaning ‘Sheep island’; it is derived from domestic stock. The ‘wild’ goats that are feral on mountains or islands in various parts of the British Isles are derived from domestic animals, for the species has never been indigenous. The domestic sheep, however, has played an important part in shaping the ecological background of the British fauna, much of our so-called man-made landscape being in fact a sheep-moulded landscape.
In the chapters that follow we consider the biology of this mammalian fauna, enquire into its origin and present distribution, and investigate the way of life of its various members, and how it shares the approximately 75 million acres of its homeland with over fifty million human beings.
THE small number of mammalian species now living in the British Isles is sometimes spoken of as an impoverished fauna. This is not strictly correct; it is a small fauna compared with those of some other lands, but of the forty-six indigenous species only five have been exterminated in historic times, whereas fourteen that are not indigenous have been introduced and now permanently enrich