i6 



SPRING 



little lonely pools in the woods are colonised by wandering 

 pairs of moorhens right up to mid-summer. It is otherwise 

 with the dippers and grey wagtails of the hill streams, which 

 haunt the same spots in constant numbers from year to year. 

 Each pair has its own chosen nesting-place, never very near 

 another nest of the same kind, though occasionally a pair of 

 each species will share the same bridge girder or mill wall. 

 This exclusion of their own species and tolerance of the 

 other suggests that the dipper and wagtail have separate food 



supplies. Grey wagtails seem unmistakably to be spreading 

 as a building species in parts of the Thames valley, where 

 until lately they were only known as winter visitors. They 

 haunt weirs and sluices, and spray-cooled splashing places 

 most like their favourite haunts on the hill streams. But on 

 their older streams the same spot is peopled by a pair of 

 grey wagtails year after year, and a fresh pair very seldom 

 settles in any other site, for the whole stream is divided out 

 into fishing-beats by the proprietary pairs. It is just the 

 same with the dippers, or water ouzels, or water colleys, as 

 they are called in different parts. Colley is a country word 

 for soot, and a water colley means a water blackbird, just as 

 a colley dog meant originally a black sheep dog, or possibly 

 a dog kept to look after the blackfaced mountain sheep. 



