62 THE SENSES OF ANIMALS 



daytime and some at night. Cockchafers (May-bugs and 

 June-bugs) are night-flyers and then Little Owls will hunt 

 them ceaselessly. They are taken in flight and caught in the 

 claws of the owls. I am of the opinion that in spite of the 

 buzzing flight of these beetle pests, Little Owls mostly capture 

 them aided by sight, since I have noticed that on light nights 

 captures will be frequent while on dark nights far fewer 

 cockchafers seem to be taken. My views have also been re- 

 inforced by my experience with a tame Little Owl which 

 I had many years ago, and which I trained to hunt from my 

 fist like a hawk. I tested this Owl in two ways : I would 

 collect some cockchafers from the trees in which they rest 

 during the day and then toss them into the air in good light 

 when the owl seldom missed one. I would also take out the 

 owl on a warm May night, just before dark, when the cock- 

 chafers were beginning their normal flight period. The owl 

 would bob about on my hand, twisting its mobile head this 

 way and that, and then, having seen a cockchafer, would 

 silently launch itself from my hand and take its prey. Its 

 general attitude and method of behaviour both pointed to 

 sight being the sense used. However, I have no doubt that 

 when put to it, Littie Owls can detect the location of prey 

 by hearing as do their relatives. 



Observations on owls at night provide the most interesting 

 results as far as studying the eyes is concerned, though for 

 obvious reasons experiments with captive owls produce the 

 best data. As it is their night vision which is being discussed 

 here, and as it will be obvious that the more activity on the 

 part of the owls the greater the chances of making good 

 observations, the breeding season should be chosen if possible. 

 This is because when there are young to be fed the parent 

 owls can be watched nightly as they bring rats, mice, voles, 

 and other prey to the owlets. When conditions are good for 

 hunting the student will be surprised at the number of food 

 items brought in; these often exceed the amount that one 

 would think necessary for a night's feeding, but surplus 

 corpses will be laid down near the "nest" and if the weather 

 is not too warm these are usually either eaten by the parents 

 or given as a feed early in the evening of the following day. 



Once the breeding place of a pair of owls — Tawny Owls 



