Robbers of the Air 



shape of stoats, weasels, hawks and owls in normal 

 numbers, and a succession of mild open winters, short- 

 tailed field voles will occasionally multiply and increase 

 to such an extent that they constitute something in the 

 nature of a plague. The last great visitation of these 

 mischievous rodents occurred in the Lowlands of Scot- 

 land in 1896, when the farmers had hundreds of acres 

 of their grass land temporarily destroyed. Continental 

 short-eared owls discovered this plenitude of their 

 natural food and were not slow to take full advantage 

 of it. When the spring came round instead of flying 

 away home over the North Sea many of them stayed 

 behind to breed. Two hundred nests were found, and 

 if I say that as many more in all probability remained 

 undiscovered I do not think any field naturalist would 

 consider me guilty of an extravagant estimate. 



In order to show how useful these birds were to the 

 agricultural community of that part of the country at 

 the time, it may be mentioned that a gentleman taking 

 a walk over his grounds in Dumfriesshire one morning 

 came upon a short-eared owl incubating a clutch of 

 eggs, and found lying round her no fewer than seventeen 

 dead voles brought along by her mate for her consump- 

 tion. Owing to the plentiful supply of food the birds 

 laid abnormally large clutches of eggs, just as members 

 of the same species do in the Hudson Bay district under 

 similar conditions. 



A peculiarity of the owls, and especially of the 

 species under notice, is that they lay their eggs at con- 

 siderable intervals of time. So much so, in fact, that I 



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