Fear in Birds. 99 



never seen any bird of prey attempt the pursuit of 

 a swallow. The question then arises, how did this 

 unnecessary fear, so universal in swallows, origi- 

 nate ? Can it be a survival of a far past a time 

 when some wide-ranging small falcon, aerial in 

 habits as the swallow itself, preyed by preference on 

 hirundines only ? 



[NOTE. Herbert Spencer, who accepts Darwin's inference, ex- 

 plains how the fear of man, acquired by experience, becomes instinc- 

 tive in birds, in the following passage : " It is well known that in 

 newly-discovered lands not inhabited by man, birds are so devoid 

 of fear as to allow themselves to be knocked over with sticks ; 

 but that, in the course of generations, they acquire such a dread 

 of man as to fly on his approach : and that this dread is mani- 

 fested by young as well as by old. Now unless this change be 

 ascribed to the killing-off of the least fearful, and the preservation 

 and multiplication of the most fearful which, considering the 

 comparatively small number killed by man, -is an inadequate 

 cause, it must be ascribed to accumulated experience ; and each 

 experience must be held to have a share in producing it. We 

 must conclude that in each bird that escapes with injuries in- 

 flicted by man, or is alarmed by the outcries of other members 

 of the flock (gregarious creatures of any intelligence being neces- 

 sarily more or less sympathetic), there is established an association 

 of ideas between the human aspect and the pains, direct and in- 

 direct, suffered from human agency. And we must further con- 

 clude, that the state of consciousness which compels the bird to 

 take flight, is at first nothing more than an ideal reproduction of 

 those painful impressions which before followed man's approach ; 

 that such ideal reproduction becomes more vivid and more massive 

 as the painful experiences, direct or sympathetic, increase ; and 

 that thus the emotion, in its incipient state, is nothing else than 

 an aggregation of the revived pains before experience. 



" As, in the course of generations, the young birds of this race 

 begin to display a fear of man before yet they have been injured 

 by him, it is an unavoidable inference that the nervous system 

 of the race has been organically modified by these experiences, 

 we have no choice but to conclude, that when a young biid is led 



