EODENTIA (voles). 471 



belly. This vole lives in colonies, preferring low-lying pastiires, 

 where it burrows into the ground. This species is most prolific, 

 having often four litters in the year, each consisting of eight 

 to ten young. Field Voles are frequently most destructive in 

 pasture-land, also destroying the bark of trees. 



The Water-Vole or Water-Rat {A. anqyhibius) lives along the 

 banks of streams and in damp meadows, tunnelling branched 

 passages into the soil. It is blackish-brown on the back, with 

 a greyish-brown belly, and is often very destructive to grass- 

 land and corn and " clamped " roots. This vole takes the eggs 

 of poultry, and damages the banks of rivers, canals, and dykes 

 often to an alarming extent. 



The Bank Vole (A. glareolus), a brownish-red species with 

 pure white breast, belly, and feet, occurs chiefly in forest tracks. 

 Unlike the field-vole, the tail is very long, there being twenty- 

 three caudal vertebrae ; and the ears are also longer than those 

 of the field-vole, coming above the fur. It is from three and a 

 half to four inches long, the tail being an inch and three-quarters. 

 A. glareolus may be found in sheltered hedge-banks and ivy-clad 

 tree-stumps, and amongst the exposed roots of trees in banks. 



Plagues of Voles. — In 1891 there was a great plague of field- 

 voles (A. agrestis) in South Scotland. In Eoxburgh and Dum- 

 fries alone over 90,000 acres were more or less afi'ected. They 

 first increased in 1890, overran the boggy and rough land, 

 and then spread everywhere, damaging grass, heather, and 

 trees, and carrying ruin before them. What had preceded this 

 plague? Constant war with trap and gun upon the game- 

 keepers' so-called "vermin. " The Scottish farmers had to 

 suffer for the ignorance of the gamekeepers, who had killed off 

 the natural enemies of the voles — namely, the hawks, owls, 

 crows, weasels, polecats, &c. — which even in game preservation 

 do more good than harm, as we have seen in the fatal "grouse 

 disease.'' 



A still more serious outbreak of voles {A. ai-wdis) occurred in 

 Thessaly in 1892, which threatened to destroy the whole corn 



