VII. 4 



CHANGE OF HABITS IN ANIMALS INDUCED 

 BY CULTIVATION AND CIVILIZATION 



OF all the effects which the advances of cultivation and 

 civilization have induced upon animals none are more 

 interesting than those little modifications of habit which are 

 clearly acquisitions of comparatively recent date. In these 

 divergences from custom we see at its simplest the elasticity 

 of nature which makes living creatures for the mo'st part 

 bundles of acquired responses, and which ensures that they 

 do not become unresponsive automata. The modifications 

 of habit are of very different degree, from mere adjust- 

 ments of convenience, to changes which seem to have been 

 impressed upon the actual temperahient of the creatures. 



In order to keep in view the more general aspect of the 

 subject, I shall limit my remarks to changes which seem to 

 be real modifications of habit, excluding all freak habits of 

 isolated individuals, and including only such changes as 

 have wide significance or have, as it were, carried with them 

 a large proportion of the members of a species. 



THE HABIT OF SELECTING A DOMICILE 



There is a remarkable constancy of selection exercised 

 by most kinds of animals as regards the nature and even 

 the exact situation of their homes, and this constancy is by 

 no means always dominated by considerations of safety. We 

 do not look for a Rook's nest in a mossy bank, or a Robin's 

 in an "immemorial elm." It is the more striking therefore 

 that in the case of many a creature, the natural choice, en- 

 grained by one knows not how many generations of custom, 

 has given place to a new habit at the touch of civilization. 



Some animals renounce for a new habitat the type of 

 territory in which they originally made their dwelling. The 

 Rabbit, in its native home in the Iberian peninsula, dwelt in 

 rocky places and on dry hill-sides, but introduced to Britain, 



