164 THE ZOOLOGIST. 



appreciably affected, although I am informed by one of my corre- 

 spondents that during the leading of his corn last autumn Voles 

 were discovered under nearly every stook, nests were also found, 

 as well as eaten corn ; fears are entertained that the seed-corn 

 may be attacked, especially in lea land, where the Voles can work 

 their way up the furrows. 



There appears to be no increase of the plague at present, 

 indeed some of my correspondents testify to an actual diminution ; 

 all, however, agree that this is not the breeding season ; were such 

 favourable, the prospects for next summer are appalling. Even 

 should the plague be at once exterminated I fear the summer 

 grazing on many farms must be very poor. It has been observed 

 by a correspondent who has given great attention to the subject 

 that " Deep snowstorms, especially in the spring months, un- 

 doubtedly, favour the production of the pest, more than a winter 

 of open fresh weather ; this may be accounted for by the perfect 

 protection the covering of snow affords from the natural enemies 

 of the Vole, and to the vigilance of those enemies being directed 

 elsewhere for food supplies." 



The cause of the plague is almost universally held to be the 

 destruction of the natural enemies of the Voles, — Hawks, Owls, 

 Weasels, &c, — and it has been remarked that, where plantations 

 are present, affording roosting for birds of prey, the districts in 

 their vicinity are less seriously affected. The gentleman above 

 alluded to as having observed the effect of snowstorms, remarks 

 in this connexion : — " During the outbreak of the mice plague in 

 1875, under the large trees in some of the dense woods in Upper 

 Teviotdale, where the Owls roosted during the day, large accumu- 

 lations of the droppings of those birds, consisting of the fur and 

 half-digested skins of the mice, were seen on every hand." Com- 

 plaints are also made of the restrictions regarding moor-burning. 

 I learn that on one farm upon the patches burnt last year and 

 the year before there is not a hole or a Vole to be seen ; it would 

 appear in this case that the vermin had no chance upon the bare 

 ground against their natural enemies. A correspondent, with, I 

 think, sufficient reason, directs attention to the unusual roughness 

 of the pasture in the autumn and winter of 1890, whereby the Voles 

 were afforded obscurity from their enemies and unwonted facilities 

 for breeding. The unusual mildness of the spring of 1891 must 

 also have been very favourable to the protection of the Vole. 



