nature and has thoughtlessly, perhaps, destroyed the principal natural enemies of 

 these creatures. 



Man himself is almost powerless to stop their ravages to any great extent. 

 The constant exercise of his ingenuity in trapping and so forth results in very little 

 and occupies his time to no purpose. The natural enemies of these animals are 

 gifted with special faculties for their destruction and so are able to cope with them. 

 Chief among the enemies of this class of farm pests are the Hawks, Owls, Shrikes 

 and Crows. These birds are wonderfully provided by nature with the means to 

 fulfill their part in maintaining the correct balance between the small rodents and 

 plant life, and if not destroyed by man would so keep down the numbers of these 

 four-footed thieves that their plundering would be scarcely noticeable. 



Unfortunately all the birds of prey are considered by uninformed people to be 

 chiefly poultry killers and therefore enemies, while the truth is that, with but few 

 exceptions, as is shown further on, our common species are beneficial; and should 

 be protected. 



The incessant destruction of these birds if permitted to continue will sooner 

 or later result in such an increase of mice that they will become a devastating 

 plague, as they have several times in Great Britain and notably in Scotland in the 

 years 1888 to 1892, when parts of Roxburghshire, Selkirk, Peebles, Lanark and 

 Dumfries were over-run by field mice and every growing thing practically destroyed. 

 In order to ascertain the cause of this outbreak, and if possible find a remedy, a 

 committee was appointed by the British Board of Agriculture of which the Earl 

 of Minto, our late Governor-iGeneral. was, I think, chairman. 



Evidence was given before this Committee by about eighty farmers and 

 shepherds and 'by several gamekeepers; their testimony proving conclusively (1) 

 That the effect of the outbreak was to practically destroy all crops. (2) That the 

 cause of the increase in number of the mice was the destruction of hawks, owls, 

 weasels, and other natural enemies of the mice. (3) That remedies are expensive 

 and difficult of application. Poison on small enclosed areas was efficacious, but its 

 application over farms, even if practicable, would be attended with much risk to 

 other forms of life. Traps, while successful in destroying many, are troublesome to 

 make and expensive. 



Cats, though tried on a large scale, were of no service whatever. Large 

 numbers of mice v;ere killed by men and terrier dogs ; systematic work by man and 

 several dogs giving better results than any other method employed, one man witli 

 his dogs having destroyed fifteen thousand in a month. 



The result of this investigation was that the persecution of Hawks and Owls 

 ceased and these birds soon gathered in the district aPPected in sufficient numbers 

 to clear off the mice. 



N'o phenomenon in connection with the plague of field mice in Scotland was 

 more marked than the arrival and continued residence in the affected districts of 

 large numbers of the Short-eared Owl. This bird, which is distributed over every 

 part of the world and used to be quite abundant in Canada, is a regular winter 

 migrant to the British Islands, arriving there in autumn and departing in the 

 ^^pring. Under ordinary circumstances it very rarely nested in Great Britain, but 

 in consequence of the vast multiplication of their chief food, the meadow mice, these 

 Owls not onlv flocked to the spot in great numbers, but as they were undisturbed, 

 nnd in fact protected, they remained and bred freely in the infested district, laying 

 ' too a larger number of eggs for each brood than is usual with them and they also 

 raised more than one brood in the season. The Owls destroyed so manv of the 

 mice in feeding: their voung. that on some of the farms the shepherds stated that the 



