88 BIRD LIFE IN A WESTERN VALLEY 



shelter of the down-stream glens and gorges ; 

 but if he has fixed his summer abode on the lower 

 reaches of the brook, he rarely migrates, for he 

 is sufficiently hardy to endure such changes of 

 temperature as may there occur. Once he has 

 thoroughly explored his chosen haunt, he resists 

 to the utmost of his power every intrusion of 

 strangers of his own species. Ib is, therefore, 

 more than likely that a dipper coming down for 

 the winter from the mountain torrent meets with 

 considerable persecution, and, like an alien gipsy, 

 is passed on under unwelcome escort from place 

 to place till he finds a stretch of water where the 

 rights of proprietorship are not too strictly 

 enforced. 



Almost every wild creature has its own fixed 

 ideas of rights of privilege over a certain district 

 about its home, and in no creature are such ideas 

 more strongly developed than in the dipper. It 

 would be interesting to learn, from the observa- 

 tions of naturalists in various parts where dippers 

 are numerous, what is the extent of river or 

 brook usually " preserved " by a breeding pair 

 of these birds for their own exclusive family 

 requirements. 



As far as I myself have been able to ascertain, 

 dippers almost invariably breed twice a year. 

 The fledglings, directly they are well able to take 

 care of themselves, vanish from the neighbour* 



