52 Northern Observations of Inland Birds 



the owl is dependent upon the minutest sounds for 

 guidance, and anyone who has ever flown (or even *' free- 

 wheeled '' down a hill) will reaHze that it would be impos- 

 sible to hear anything at all in the air unless flight were 

 as noiseless as it is possible for it to be. Most people 

 who have watched owls hunting have seen them turn in 

 their flight, swing round some obstacle which must have 

 obstructed their vision, then suddenly pounce — guided, 

 apparently, by some sound so slight that human ears 

 could not have detected it. Such keen hearing — peculiar 

 to rodent-hunting beasts and birds — would be useless 

 in the case of a bird unless supplemented by noiseless 

 flight. 



In 1913 I decided to put this theory to a very sim^ple 

 test. Behind my house was a barn which at that time was 

 infested with rats, so throwing some chicken meal into 

 the centre of the yard, I hid behind a wall at dusk, armed 

 with the Ud of a cardboard box. It was not very long 

 before several rats, young and old, were feeding, at which 

 I waved the cardboard vigorously in the air behind me, 

 creating exactly the sound of wafting wings. The rats 

 took not the least notice ! I repeated the experiment 

 several times, but no matter how loud the delusion they 

 did not heed it. This seemed to me definite proof that 

 silent flight is not essential from the owl's point of view 

 so far as approaching his quarry is concerned, and, 

 therefore, it must exist for the benefit of his own hearing. 



Our four British owls are : the barn owl or screech 

 owl, the brown or tawny owl, which is the gentleman 

 who hoots ; the long-eared owl, and the short-eared owl. 

 The little owl has been introduced, and is, unfortunately, 

 increasing. 



While the barn owl generally screeches, it also occa- 

 sionally hoots, and while the tawny owl generally hoots 

 it also is capable of uttering the most unearthly screech. 



