Field Vole (Arvicola agrestis), Fig. 18. This small animal, about 5 in. in length, is of a reddish-brown colour above and grey below, and found in woodland glades, grassy plantations, meadows (especially in hilly and moorland districts on "bog," strong marshy land, either grazed or mown for hay), parks, mown or un-grazed orchards, rough grassy parts of pleasure grounds, always where there exists a considerable depth of " bottom grass " or debris of gramineous vegetation. In this soft bottom the field vole makes runs, never burrowing deeply, and cuts the grass between the root and the blade, eating the tender white part just below the ground, and in bad cases so complete is the under-cutting that the whole surface is left with a coating of loose withered herbage readily skimmed off as "hay." Indeed, it is the close, dense, and often mossy bottoms of meadows and pastures, or other land with a thick soil-covering of grass that gives the field vole advantage and protection - and food being abundant, also absence of rodent-devouring animals and bird - for multiplying, and as the females outnumber the males in the proportion of about 75 per cent., and as each female brings forth eight to ten young every six or eight weeks, and the young begin to breed when eight weeks old, the total progeny of one female may in the course of a breeding season from March to late in autumn, amount to thousands, say 10,000. Mild winters and dry spring and summer weather favour their increase, damp weather, heavy rainfall, and frost without snow tend to limit their prolificness.

From the breeding places the field voles move to " fresh fields and pastures new," invading dry hill pastures, heather-clad moorlands, and young plantations, also nurseries, everywhere destroying much, if not all, edible growth, meaning, in hill pastures and moorlands, impoverishment of stock, and in young plantations and nurseries serious devastation. In plantations they bark young trees, biting through ash, beech, hazel, willow, larch and Scots pine of two to five years' growth, while saplings of broad-leaved species are sometimes barked all round at a height of 6 to 10 in. above the soil when several years of age.

The Field Vole.

Fig. 18. - The Field Vole.

Though the field vole is ever present, it is only in certain periods that it assumes the nature of a plague, and these date from 1581, when Holinshed recorded the appearance of mice in the marshes of Danesey Hundred in Essex to such extent as to " sheare and gnaw the grass by the rootes, spoyling and tainting the same with their venimous teeth, in such sort that the cattel which grazed thereon were smitten with a murraine and died thereof; which vermine by policie of man could not be destroyed, till at last there flocked together such a number of owles as all the shire was not able to yield, whereby the marshholders were shortly delivered from the vexation of the said mice." Similar visitations, according to Stowe, Childrey, Lilly, Anstice, Lord Glenbervie, Sir Walter Elliot, etc., occurred in various parts of England and Scotland in 1615, 1648, 1660, 1745, 1813, 1825, 1836, 1864-7, and 1875-6. In 1813-14, the New Forest in Hampshire suffered severely from the depredations of these voles, when the raptorial birds (such as owls, hawks, etc.), weasels, stoats, and many other carnivorous animals are assumed to have been more numerous than in 1876, when a plague of these animals (voles) visited farms on the borders of England and Scotland and committed much havoc, also again during 1891 and 1892.

Red Field Vole (Arvicola Glareolus)

Red Field Vole (Arvicola glareolus), Fig. 19. This little rodent animal is notable for its broad blunt head, short ears almost hidden in fur, short legs and tail, and peculiar reddish brown of its coat. It inhabits woodland glades, hedgebanks (hence the name of bank vole or bank campagnol), meadows, rough grassy parts of parks and pleasure grounds, orchards and other places with a grassy and mossy bottom. Like the field vole, it makes" shallow runs among the grass roots, and feeds largely upon the tender white parts of the grasses. In the thick soil-covering of grass it makes a nest of grass, leaves and moss, breeding twice yearly and producing four to eight at a birth.

The Red Field Vole.

Fig. 19. - The Red Field Vole.

From the general feeding and breeding quarters, the red field vole makes incursions into gardens, causing serious havoc among bulbs, nibbling off ferns and other plants, biting tasty roots such as carrots, and cutting off the berries of strawberries and piling them in heaps before or after extracting the seeds. In nurseries the red field voles attack the terminal buds of young trees, especially Scots pine seedlings and "transplants" of 2 ft. or more height, and there and in plantations of young trees nibble off the bark just above the ground, singling for special attack, larch, pine and aspen, also dogwood and elder, carrying on the destructive work from November to March inclusive. At times they invade plant and fruit houses, and being excellent climbers, mount shelves and nibble off the berries of forced strawberries. But grass and seeds form the chief dietary of red field voles, even in winter when the ground is covered with snow for weeks they work in the grass, shearing off the grassy and mossy soil-covering, so that after the snow has departed the fluff peels off as completely and leaves the soil as bare as similar ground skimmed with a turfing spade.

Like damage is done by the field vole when the ground is covered with snow for a lengthened period.