AUTUMN ON THE MOORS 189 



from the stomachs and from the insides of the legs — a 

 pretty performance. 



These wagtails mostly disappear with the first frosts 

 of autumn — usually not later than early October — and 

 after that date, one sees very little more of the pied 

 wagtail. But towards the end of that month (October), 

 the beautiful grey wagtails again show up, noticeably 

 abundant. These are arrivals from further north, and 

 some of them linger here quite a long time. Their 

 numbers, however, perceptibly diminish as winter ap- 

 proaches ; though in mild, open seasons, it is not unusual 

 to see one or two of these dainty little creatures about 

 sheltered burn-sides, even in December and January. 

 They are then feeding, apparently, on the eggs or larvae 

 of water-insects, turning over each dead leaf or bit of 

 drifted wrack in search of some food that it may conceal. 



Considering their insect-food and delicacy of form, the 

 seasonal distribution of these two species lies remarkably 

 far northward ; and their range is also restricted. The 

 pied wagtail scarcely reaches so far as Southern Europe, 

 the place which it should occupy in Spain during winter 

 being taken by the white wagtail {M. alba), which latter 

 also goes further north in summer, being the common and 

 familiar wagtail of Norway. 



Curious and quite inexplicable is this diversity in range 

 between two forms so closely allied as scarcely to be 

 differentiable ! No doubt the more enterprising of the 

 two races has found some slight variation in plumage 

 essential to its well-being. 



Altitude and latitude become, in bird-life, equivalents. 

 Thus, while an individual, say a titlark, that has summered 

 on the uplands of Cheviot, may find sufficient seasonal 

 change in a descent to the littoral plains subjacent ; yet 



