16 BIRD-LIFE OF THE BORDERS. 



various portions in turn became adapted to their require- 

 ments. 



Viewed in this light, the great migratory tendency 

 towards the North becomes explicable and comprehensive 

 enough. It simply arises from an innate perennial instinct, 

 which still continues to draw vast numbers of the feathered 

 tribes towards the point which was originally the universal 

 home of all. It is an invariable rule that all birds do breed 

 at the most northerly and coldest points of their annual 

 range. In the Northern Hemisphere, the tendency to move 

 northwards in spring is all but universal ; and, as already 

 pointed out, there are, in many cases, no visible or existing 

 reasons, climatic or otherwise, which make such movement 

 imperative. 



Whatever may be the primary cause of migration, whether, 

 it arises from the old-time instinct I have alluded to or other- 

 wise, it is at least certain that it is a deeply implanted and 

 widely spread impulse throughout the feathered tribes. On 

 referring to the foregoing list it will be seen that as early as 

 February the influx of visitants from southern climes com- 

 mences, and during that month and March the majority of 

 the typical moor-breeding birds have distributed themselves 

 over the hills. The Plovers and Curlew come first, followed 

 by Larks, Wagtails, Gulls, and Redshanks, all these having 

 northerly winter ranges, and hence comparatively short 

 distances to come, are just what one might expect first. 

 The Ring- Ouzel, too, from Southern Europe, follows close 

 behind them. Of the trans-Mediterranean group, the Wheat- 

 ear is the first to arrive, some weeks in advance of the main 

 bodies of warblers, Swallows, Cuckoo, Landrail, and Nightjar. 

 But as though to show how unsafe are any general or 

 dogmatic rules, the Common Sandpiper, which winters in 

 Spain, is one of the latest to arrive ; and the Dunlin, which 

 swarms on our own coast throughout the most severe 

 winters, usually allows the month of April to begin before 

 putting in a tardy appearance on the moors. 



