20 THE FIELD VOLE 



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 



FIG. 1 8. THE FIELD VOLE. 



and pastures new," invading dry hill pastures, heather-clad moor- 

 lands, and young plantations, also nurseries, everywhere destroy- 

 ing 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. 



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, 



