CHECK LIST OF 



(8) Microtus pennsylvanicus. 



(Meadow Mouse, Field Vole.) 



Common everywhere and the most destructive animal we have. 



This little animal which by its enormous increase during the last few 

 years has done so much mischief in the Province, is the Short-tailed Field 

 Vole, commonly known as the Meadow Mouse, though it is not really a 

 Mouse at all. It is but rarely found in barns or outbuildings, even in 

 winter, its favorite resorts being low meadows which support a rank vege- 

 tation. When for any reason the low meadows become unable to main- 

 tain the number of voles bred in them, the surplus will move out and 

 spread all over the country, establishing themselves chiefly in the hay and 

 grain fields, where they find favorable conditions during the summer. 

 Food and shelter are everywhere and their natural enemies, which should 

 keep them in check, having all been killed off, these prolific creatures 

 multiply even more rapidly on the cultivated lands than they would in 

 their original habitat. In winter, however, conditions are not so favorable 

 to the Voles in the cultivated districts; the crops having been removed, 

 leaves the fields comparatively bare and devoid of shelter except in the 

 long grass and weed-grown fence lines, and here they take refuge ; an 

 old sunken rail fence being a favorite stronghold and an orchard in which 

 a rank cover crop is left standing forming a perfect paradise for these 

 secretive vermin. Under cover of the decaying vegetation in such places 

 they drive a network of runways in every direction, secure from the obsev- 

 ation of all but the creatures specialized by nature to prey upon them. 



Field Voles are remarkably prolific animals, the females usually pro-- 

 ducing three or four litters a year, but in favorable seasons even more 

 will be produced. During the last few years I have found nests contain- 

 ing young in every month from April to October, both inclusive. The 

 litters generally contain from five to eight young, and indeed I have heard 

 of ten, but so far have never found one as large as that. 



These Voles do not burrow, but construct their nests upon the surface 

 of the ground among rank vegetation or under logs, rails, etc. From 

 these nests their runways are pushed in every direction until they form a 

 perfect network over the land. During the growing season these runs 

 are not easily observed unless specially sought for, but just as the snow is 

 going off in the spring they are readily seen and an idea may then be 

 formed of their numbers. Their food consists of grass, clover, grain (in 

 all stages), fruit and the inner bark or cambium of young trees and 

 bushes, the quantity they devour and spoil being a very heavy tax upon 

 the farm in all seasons, and a particularly serious one when their numbers 

 reach abnormal proportions. 



From 1888 to 1892 part of Scotland was overrun by these Voles, the 

 districts affected being parts of Roxburghshire, Selkirk, Peebles, Lanark 

 and Dumfries. Altogether an area about sixty miles in length and twenty 

 miles in breadth was devastated. In order to ascertain the cause of the 

 outbreak and impossible provide a remedy a Departmental Committee was 



