THE ANIMAL VIEW OF CAPTIVITY 251 



the cliff face. Though they could cross the Channel 

 after breakfast and return by mid-day without fatigue, 

 did they choose to do so, they are as much attached 

 to a small area as the birds which haunt our gardens. 

 Another clue to the passive character of animal happi- 

 ness is that given by the behaviour of those creatures 

 which have voluntarily established what is called by 

 naturalists ' commensalism ' with man, living only 

 where he lives, and feeding on what, in a sense, 

 'falls from his table/ Sparrows, starlings, and the 

 half-wild pigeons of London are in the transition 

 state between the freedom of the fields and the 

 confinement of the Zoo, where, by the way, these 

 birds are perhaps tamer and more confident than in 

 any other place. Their life, in its hours and habits, 

 is almost identical with that of the bird inmates of 

 the cages. They eat when they eat, bathe when 

 they bathe, and on cold nights will come and sit in 

 the aviaries of the larger birds which admit their 

 passage through the bars. In no case do they seem 

 anxious for more 'liberty/ It may be doubted if 

 a Zoo sparrow has ever visited Hyde Park, or 

 whether, if the caged birds were given their liberty, 

 they would leave the Gardens. This has in some 

 instances been proved. Some years ago the snow 

 broke in the wire roof of a cage of wild wood- 

 pigeons. These birds remained in the Gardens, and 



