Observing-powers of Birds 



those content to live in a fools' paradise. If 

 birds are supremely sharp-sighted, and pay 

 attention to excessively minute detail, the diffi- 

 culty of accounting for the origin of protective 

 mimicry on the natural selection hypothesis 

 becomes all the greater. 



The question whether or not birds are good 

 observers is a most interesting one. Unfor- 

 tunately, hitherto, but little attention has been 

 paid to the subject. The evidence available 

 seems to point to the fact that birds, like savages, 

 have sharp eyes only for certain objects that is 

 to say, for the things they are accustomed to 

 look out for. All observers of nature must have 

 noticed how quick a butcher-bird is to catch sight 

 of a tiny insect upon the ground at a distance of 

 some yards from his perch. 



On the other hand, it is said that when there 

 is snow upon the ground wood pigeons will 

 approach quite close to a man wearing white 

 clothes and a white hat, provided he keep 

 perfectly still. Finn once witnessed in Calcutta a 

 sparrow pick up a very young toad, obviously by 

 mistake, for it dropped it at once with evident 

 distaste. Birds of prey are supposed to have 

 remarkably good eyesight ; yet they can readily 

 be caught by a net stretched out before their 

 quarry. They are not trained to be on the 

 watch for such things as nets, and so do not 

 appear to notice one when erected. 



Q 241 



