LLANDDWYN 5 



Having wintered probably in Africa, the Redstart 

 returns to us in spring by way of the south and east 

 coasts of England, distributes itself throughout 

 England and Wales, avoiding to a large extent the 

 south-western counties of the former and thinning out 

 as it spreads northward, whilst only a very small num- 

 ber pass over into Ireland. Whether the island of 

 Anglesey, like the south-western counties of England, 

 be a " thin patch " in the distribution of this bird, or 

 its rarity there results from a lack of suitable nesting 

 places, I will not attempt to decide further than by 

 stating that the island of Anglesey, once called 

 Ynys Dywyll the Dark Isle, because of the shadow 

 of its abundant growth of trees, was by the cupidity 

 or stupidity of our forefathers denuded of such 

 growth, so as now to be in a large measure a great 

 rolling heath, with no notable collection of trees, save 

 such as line portions of the shores of the Menai 

 Straits or the slopes that overlook them. Here the 

 Redstart finds suitable asylum, and three pairs, all with 

 young out in the trees, were seen by us at this time. 



The occurrence here of two cases of limited 

 distribution, the one of the land-confined Mole, the 

 other of the sea-crossing Redstart, challenges some 

 sort of explanation. 



In the case of the Mole, though geological evidence 

 renders it sufficiently clear that the land passage 

 from England into Ireland was at one time con- 

 tinuous, the fact that there exists no record of the 

 Mole in Ireland testifies to its further westward 

 progress having been barred by the influx of the sea, 

 filling up the subsiding interspace and effectually 

 separating the two countries. 



